path: root/core/vm/oracle_contracts.go

// Copyright 2018 The dexon-consensus Authors
// This file is part of the dexon-consensus library.
//
// The dexon-consensus library is free software: you can redistribute it
// and/or modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation, either version 3 of the License,
// or (at your option) any later version.
//
// The dexon-consensus library is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
// General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the dexon-consensus library. If not, see
// <http://www.gnu.org/licenses/>.

package vm

import (
    "bytes"
    "encoding/binary"
    "errors"
    "fmt"
    "math"
    "math/big"
    "sort"
    "sync/atomic"

    "github.com/tangerine-network/go-tangerine/accounts/abi"
    "github.com/tangerine-network/go-tangerine/common"
    "github.com/tangerine-network/go-tangerine/core/state"
    "github.com/tangerine-network/go-tangerine/core/types"
    "github.com/tangerine-network/go-tangerine/crypto"
    "github.com/tangerine-network/go-tangerine/params"
    "github.com/tangerine-network/go-tangerine/rlp"

    coreCommon "github.com/tangerine-network/tangerine-consensus/common"
    dexCore "github.com/tangerine-network/tangerine-consensus/core"
    coreCrypto "github.com/tangerine-network/tangerine-consensus/core/crypto"
    coreUtils "github.com/tangerine-network/tangerine-consensus/core/utils"

    "github.com/tangerine-network/tangerine-consensus/core/crypto/ecdsa"
    coreTypes "github.com/tangerine-network/tangerine-consensus/core/types"
    dkgTypes "github.com/tangerine-network/tangerine-consensus/core/types/dkg"
)

type Bytes32 [32]byte

type FineType uint64

const (
    FineTypeFailStop = iota
    FineTypeFailStopDKG
    FineTypeInvalidDKG
    FineTypeForkVote
    FineTypeForkBlock
)

const GovernanceActionGasCost = 200000

// Storage position enums.
const (
    roundHeightLoc = iota
    totalSupplyLoc
    totalStakedLoc
    nodesLoc
    nodesOffsetByAddressLoc
    nodesOffsetByNodeKeyAddressLoc
    lastProposedHeightLoc
    crsRoundLoc
    crsLoc
    dkgRoundLoc
    dkgResetCountLoc
    dkgMasterPublicKeysLoc
    dkgMasterPublicKeyOffsetLoc
    dkgComplaintsLoc
    dkgComplaintsProposedLoc
    dkgReadyLoc
    dkgReadysCountLoc
    dkgFinalizedLoc
    dkgFinalizedsCountLoc
    dkgSuccessLoc
    dkgSuccessesCountLoc
    ownerLoc
    minStakeLoc
    lockupPeriodLoc
    miningVelocityLoc
    nextHalvingSupplyLoc
    lastHalvedAmountLoc
    minGasPriceLoc
    blockGasLimitLoc
    lambdaBALoc
    lambdaDKGLoc
    notarySetSizeLoc
    notaryParamAlphaLoc
    notaryParamBetaLoc
    roundLengthLoc
    minBlockIntervalLoc
    fineValuesLoc
    finedRecordsLoc
)

func publicKeyToNodeKeyAddress(pkBytes []byte) (common.Address, error) {
    pk, err := crypto.UnmarshalPubkey(pkBytes)
    if err != nil {
        return common.Address{}, err
    }
    return crypto.PubkeyToAddress(*pk), nil
}

func getDKGMasterPublicKeyID(mpk *dkgTypes.MasterPublicKey) Bytes32 {
    return Bytes32(mpk.ProposerID.Hash)
}

func getDKGComplaintID(comp *dkgTypes.Complaint) Bytes32 {
    return Bytes32(crypto.Keccak256Hash(
        comp.ProposerID.Hash[:],
        comp.PrivateShare.ProposerID.Hash[:],
        []byte(fmt.Sprintf("%v", comp.IsNack()))))
}

func IdToAddress(id coreTypes.NodeID) common.Address {
    return common.BytesToAddress(id.Hash[12:])
}

// State manipulation helper fro the governance contract.
type GovernanceState struct {
    StateDB StateDB
}

func (s *GovernanceState) getState(loc common.Hash) common.Hash {
    return s.StateDB.GetState(GovernanceContractAddress, loc)
}

func (s *GovernanceState) setState(loc common.Hash, val common.Hash) {
    s.StateDB.SetState(GovernanceContractAddress, loc, val)
}

func (s *GovernanceState) getStateBigInt(loc *big.Int) *big.Int {
    res := s.StateDB.GetState(GovernanceContractAddress, common.BigToHash(loc))
    return new(big.Int).SetBytes(res.Bytes())
}

func (s *GovernanceState) setStateBigInt(loc *big.Int, val *big.Int) {
    s.setState(common.BigToHash(loc), common.BigToHash(val))
}

func (s *GovernanceState) getSlotLoc(loc *big.Int) *big.Int {
    return new(big.Int).SetBytes(crypto.Keccak256(common.BigToHash(loc).Bytes()))
}

func (s *GovernanceState) getMapLoc(pos *big.Int, key []byte) *big.Int {
    return new(big.Int).SetBytes(crypto.Keccak256(key, common.BigToHash(pos).Bytes()))
}

func (s *GovernanceState) readBytes(loc *big.Int) []byte {
    // Length of the dynamic array (bytes).
    rawLength := s.getStateBigInt(loc)
    lengthByte := new(big.Int).Mod(rawLength, big.NewInt(256))

    // Bytes length <= 31, lengthByte % 2 == 0
    // return the high 31 bytes.
    if new(big.Int).Mod(lengthByte, big.NewInt(2)).Cmp(big.NewInt(0)) == 0 {
        length := new(big.Int).Div(lengthByte, big.NewInt(2)).Uint64()
        return rawLength.Bytes()[:length]
    }

    // Actual length = (rawLength - 1) / 2
    length := new(big.Int).Div(new(big.Int).Sub(rawLength, big.NewInt(1)), big.NewInt(2)).Uint64()

    // Data address.
    dataLoc := s.getSlotLoc(loc)

    // Read continuously for length bytes.
    carry := int64(0)
    if length%32 > 0 {
        carry = 1
    }
    chunks := int64(length/32) + carry
    var data []byte
    for i := int64(0); i < chunks; i++ {
        loc = new(big.Int).Add(dataLoc, big.NewInt(i))
        data = append(data, s.getState(common.BigToHash(loc)).Bytes()...)
    }
    data = data[:length]
    return data
}

func (s *GovernanceState) writeBytes(loc *big.Int, data []byte) {
    length := int64(len(data))

    if length == 0 {
        s.setState(common.BigToHash(loc), common.Hash{})
        return
    }

    // Short bytes (length <= 31).
    if length < 32 {
        data2 := append([]byte(nil), data...)
        // Right pad with zeros
        for len(data2) < 31 {
            data2 = append(data2, byte(0))
        }
        data2 = append(data2, byte(length*2))
        s.setState(common.BigToHash(loc), common.BytesToHash(data2))
        return
    }

    // Write 2 * length + 1.
    storedLength := new(big.Int).Add(new(big.Int).Mul(
        big.NewInt(length), big.NewInt(2)), big.NewInt(1))
    s.setStateBigInt(loc, storedLength)
    // Write data chunck.
    dataLoc := s.getSlotLoc(loc)
    carry := int64(0)
    if length%32 > 0 {
        carry = 1
    }
    chunks := length/32 + carry
    for i := int64(0); i < chunks; i++ {
        loc = new(big.Int).Add(dataLoc, big.NewInt(i))
        maxLoc := (i + 1) * 32
        if maxLoc > length {
            maxLoc = length
        }
        data2 := data[i*32 : maxLoc]
        // Right pad with zeros.
        for len(data2) < 32 {
            data2 = append(data2, byte(0))
        }
        s.setState(common.BigToHash(loc), common.BytesToHash(data2))
    }
}

func (s *GovernanceState) eraseBytes(loc *big.Int) {
    // Length of the dynamic array (bytes).
    rawLength := s.getStateBigInt(loc)
    lengthByte := new(big.Int).Mod(rawLength, big.NewInt(256))

    // Bytes length <= 31, lengthByte % 2 == 0
    // return the high 31 bytes.
    if new(big.Int).Mod(lengthByte, big.NewInt(2)).Cmp(big.NewInt(0)) == 0 {
        s.setStateBigInt(loc, big.NewInt(0))
        return
    }

    // Actual length = (rawLength - 1) / 2
    length := new(big.Int).Div(new(big.Int).Sub(
        rawLength, big.NewInt(1)), big.NewInt(2)).Uint64()

    // Fill 0.
    s.writeBytes(loc, make([]byte, length))

    // Clear slot.
    s.setStateBigInt(loc, big.NewInt(0))
}

func (s *GovernanceState) read1DByteArray(loc *big.Int) [][]byte {
    arrayLength := s.getStateBigInt(loc)
    dataLoc := s.getSlotLoc(loc)

    data := [][]byte{}
    for i := int64(0); i < int64(arrayLength.Uint64()); i++ {
        elementLoc := new(big.Int).Add(dataLoc, big.NewInt(i))
        data = append(data, s.readBytes(elementLoc))
    }
    return data
}

func (s *GovernanceState) appendTo1DByteArray(loc *big.Int, data []byte) {
    // Increase length by 1.
    arrayLength := s.getStateBigInt(loc)
    s.setStateBigInt(loc, new(big.Int).Add(arrayLength, big.NewInt(1)))

    // Write element.
    dataLoc := s.getSlotLoc(loc)
    elementLoc := new(big.Int).Add(dataLoc, arrayLength)
    s.writeBytes(elementLoc, data)
}

func (s *GovernanceState) erase1DByteArray(loc *big.Int) {
    arrayLength := s.getStateBigInt(loc)
    dataLoc := s.getSlotLoc(loc)

    for i := int64(0); i < int64(arrayLength.Uint64()); i++ {
        elementLoc := new(big.Int).Add(dataLoc, big.NewInt(i))
        s.eraseBytes(elementLoc)
    }
    s.setStateBigInt(loc, big.NewInt(0))
}

// uint256[] public roundHeight;
func (s *GovernanceState) RoundHeight(round *big.Int) *big.Int {
    baseLoc := s.getSlotLoc(big.NewInt(roundHeightLoc))
    loc := new(big.Int).Add(baseLoc, round)
    return s.getStateBigInt(loc)
}
func (s *GovernanceState) PushRoundHeight(height *big.Int) {
    // Increase length by 1.
    length := s.getStateBigInt(big.NewInt(roundHeightLoc))
    s.setStateBigInt(big.NewInt(roundHeightLoc), new(big.Int).Add(length, big.NewInt(1)))

    baseLoc := s.getSlotLoc(big.NewInt(roundHeightLoc))
    loc := new(big.Int).Add(baseLoc, length)

    s.setStateBigInt(loc, height)
}

// uint256 public totalSupply;
func (s *GovernanceState) TotalSupply() *big.Int {
    return s.getStateBigInt(big.NewInt(totalSupplyLoc))
}
func (s *GovernanceState) IncTotalSupply(amount *big.Int) {
    s.setStateBigInt(big.NewInt(totalSupplyLoc), new(big.Int).Add(s.TotalSupply(), amount))
}
func (s *GovernanceState) DecTotalSupply(amount *big.Int) {
    s.setStateBigInt(big.NewInt(totalSupplyLoc), new(big.Int).Sub(s.TotalSupply(), amount))
}

// uint256 public totalStaked;
func (s *GovernanceState) TotalStaked() *big.Int {
    return s.getStateBigInt(big.NewInt(totalStakedLoc))
}
func (s *GovernanceState) IncTotalStaked(amount *big.Int) {
    s.setStateBigInt(big.NewInt(totalStakedLoc), new(big.Int).Add(s.TotalStaked(), amount))
}
func (s *GovernanceState) DecTotalStaked(amount *big.Int) {
    s.setStateBigInt(big.NewInt(totalStakedLoc), new(big.Int).Sub(s.TotalStaked(), amount))
}

// struct Node {
//     address owner;
//     bytes publicKey;
//     uint256 staked;
//     uint256 fined;
//     string name;
//     string email;
//     string location;
//     string url;
//     uint256 unstaked;
//     uint256 unstakedAt;
//     uint256 lastProposedHeight;
// }
//
// Node[] nodes;

type nodeInfo struct {
    Owner      common.Address
    PublicKey  []byte
    Staked     *big.Int
    Fined      *big.Int
    Name       string
    Email      string
    Location   string
    Url        string
    Unstaked   *big.Int
    UnstakedAt *big.Int
}

const nodeStructSize = 10

func (s *GovernanceState) LenNodes() *big.Int {
    return s.getStateBigInt(big.NewInt(nodesLoc))
}
func (s *GovernanceState) Node(index *big.Int) *nodeInfo {
    node := new(nodeInfo)

    arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
    elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
        new(big.Int).Mul(index, big.NewInt(nodeStructSize)))

    // Owner.
    loc := elementBaseLoc
    node.Owner = common.BytesToAddress(s.getState(common.BigToHash(elementBaseLoc)).Bytes())

    // PublicKey.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
    node.PublicKey = s.readBytes(loc)

    // Staked.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(2))
    node.Staked = s.getStateBigInt(loc)

    // Fined.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(3))
    node.Fined = s.getStateBigInt(loc)

    // Name.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(4))
    node.Name = string(s.readBytes(loc))

    // Email.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(5))
    node.Email = string(s.readBytes(loc))

    // Location.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(6))
    node.Location = string(s.readBytes(loc))

    // Url.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(7))
    node.Url = string(s.readBytes(loc))

    // Unstaked.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(8))
    node.Unstaked = s.getStateBigInt(loc)

    // UnstakedAt.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(9))
    node.UnstakedAt = s.getStateBigInt(loc)

    return node
}
func (s *GovernanceState) PushNode(n *nodeInfo) {
    // Increase length by 1.
    arrayLength := s.LenNodes()
    s.setStateBigInt(big.NewInt(nodesLoc), new(big.Int).Add(arrayLength, big.NewInt(1)))

    s.UpdateNode(arrayLength, n)
}
func (s *GovernanceState) UpdateNode(index *big.Int, n *nodeInfo) {
    arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
    elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
        new(big.Int).Mul(index, big.NewInt(nodeStructSize)))

    // Owner.
    loc := elementBaseLoc
    s.setState(common.BigToHash(loc), n.Owner.Hash())

    // PublicKey.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(1))
    s.writeBytes(loc, n.PublicKey)

    // Staked.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(2))
    s.setStateBigInt(loc, n.Staked)

    // Fined.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(3))
    s.setStateBigInt(loc, n.Fined)

    // Name.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(4))
    s.writeBytes(loc, []byte(n.Name))

    // Email.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(5))
    s.writeBytes(loc, []byte(n.Email))

    // Location.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(6))
    s.writeBytes(loc, []byte(n.Location))

    // Url.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(7))
    s.writeBytes(loc, []byte(n.Url))

    // Unstaked.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(8))
    s.setStateBigInt(loc, n.Unstaked)

    // UnstakedAt.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(9))
    s.setStateBigInt(loc, n.UnstakedAt)

    // Update set size.
    s.CalNotarySetSize()
}
func (s *GovernanceState) EraseNode(index *big.Int) {
    s.UpdateNode(index, &nodeInfo{
        Staked:     big.NewInt(0),
        Fined:      big.NewInt(0),
        Unstaked:   big.NewInt(0),
        UnstakedAt: big.NewInt(0),
    })
}
func (s *GovernanceState) PopLastNode() {
    // Decrease length by 1.
    arrayLength := s.LenNodes()
    newArrayLength := new(big.Int).Sub(arrayLength, big.NewInt(1))
    s.setStateBigInt(big.NewInt(nodesLoc), newArrayLength)

    s.EraseNode(newArrayLength)
}
func (s *GovernanceState) UpdateNodeInfo(index *big.Int, n *nodeInfo) {
    arrayBaseLoc := s.getSlotLoc(big.NewInt(nodesLoc))
    elementBaseLoc := new(big.Int).Add(arrayBaseLoc,
        new(big.Int).Mul(index, big.NewInt(nodeStructSize)))

    // Name.
    loc := new(big.Int).Add(elementBaseLoc, big.NewInt(4))
    s.eraseBytes(loc)
    s.writeBytes(loc, []byte(n.Name))

    // Email.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(5))
    s.eraseBytes(loc)
    s.writeBytes(loc, []byte(n.Email))

    // Location.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(6))
    s.eraseBytes(loc)
    s.writeBytes(loc, []byte(n.Location))

    // Url.
    loc = new(big.Int).Add(elementBaseLoc, big.NewInt(7))
    s.eraseBytes(loc)
    s.writeBytes(loc, []byte(n.Url))
}

func (s *GovernanceState) Nodes() []*nodeInfo {
    var nodes []*nodeInfo
    for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
        nodes = append(nodes, s.Node(big.NewInt(i)))
    }
    return nodes
}
func (s *GovernanceState) QualifiedNodes() []*nodeInfo {
    var nodes []*nodeInfo
    for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
        node := s.Node(big.NewInt(i))
        // Node with unpaid fine is consider unqualified.
        if node.Fined.Cmp(big.NewInt(0)) > 0 {
            continue
        }
        if node.Staked.Cmp(s.MinStake()) >= 0 {
            nodes = append(nodes, node)
        }
    }
    return nodes
}
func (s *GovernanceState) FinedNodes() []*nodeInfo {
    var nodes []*nodeInfo
    for i := int64(0); i < int64(s.LenNodes().Uint64()); i++ {
        node := s.Node(big.NewInt(i))
        if node.Fined.Cmp(big.NewInt(0)) > 0 {
            nodes = append(nodes, node)
        }
    }
    return nodes
}

// mapping(address => uint256) public nodesOffsetByAddress;
func (s *GovernanceState) NodesOffsetByAddress(addr common.Address) *big.Int {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByAddressLoc), addr.Bytes())
    return new(big.Int).Sub(s.getStateBigInt(loc), big.NewInt(1))
}
func (s *GovernanceState) PutNodesOffsetByAddress(addr common.Address, offset *big.Int) {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByAddressLoc), addr.Bytes())
    s.setStateBigInt(loc, new(big.Int).Add(offset, big.NewInt(1)))
}
func (s *GovernanceState) DeleteNodesOffsetByAddress(addr common.Address) {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByAddressLoc), addr.Bytes())
    s.setStateBigInt(loc, big.NewInt(0))
}

// mapping(address => uint256) public nodesOffsetByNodeKeyAddress;
func (s *GovernanceState) NodesOffsetByNodeKeyAddress(addr common.Address) *big.Int {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByNodeKeyAddressLoc), addr.Bytes())
    return new(big.Int).Sub(s.getStateBigInt(loc), big.NewInt(1))
}
func (s *GovernanceState) PutNodesOffsetByNodeKeyAddress(addr common.Address, offset *big.Int) {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByNodeKeyAddressLoc), addr.Bytes())
    s.setStateBigInt(loc, new(big.Int).Add(offset, big.NewInt(1)))
}
func (s *GovernanceState) DeleteNodesOffsetByNodeKeyAddress(addr common.Address) {
    loc := s.getMapLoc(big.NewInt(nodesOffsetByNodeKeyAddressLoc), addr.Bytes())
    s.setStateBigInt(loc, big.NewInt(0))
}

func (s *GovernanceState) PutNodeOffsets(n *nodeInfo, offset *big.Int) {
    address, err := publicKeyToNodeKeyAddress(n.PublicKey)
    if err != nil {
        panic(err)
    }
    s.PutNodesOffsetByNodeKeyAddress(address, offset)
    s.PutNodesOffsetByAddress(n.Owner, offset)
}
func (s *GovernanceState) DeleteNodeOffsets(n *nodeInfo) {
    address, err := publicKeyToNodeKeyAddress(n.PublicKey)
    if err != nil {
        panic(err)
    }
    s.DeleteNodesOffsetByNodeKeyAddress(address)
    s.DeleteNodesOffsetByAddress(n.Owner)
}

func (s *GovernanceState) GetNodeByID(id coreTypes.NodeID) (*nodeInfo, error) {
    offset := s.NodesOffsetByNodeKeyAddress(IdToAddress(id))
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errors.New("node not found")
    }
    node := s.Node(offset)
    return node, nil
}

// mapping(address => uint256) public lastProposedHeight;
func (s *GovernanceState) LastProposedHeight(addr common.Address) *big.Int {
    loc := s.getMapLoc(big.NewInt(lastProposedHeightLoc), addr.Bytes())
    return s.getStateBigInt(loc)
}
func (s *GovernanceState) PutLastProposedHeight(addr common.Address, height *big.Int) {
    loc := s.getMapLoc(big.NewInt(lastProposedHeightLoc), addr.Bytes())
    s.setStateBigInt(loc, height)
}

// uint256 public crsRound;
func (s *GovernanceState) CRSRound() *big.Int {
    return s.getStateBigInt(big.NewInt(crsRoundLoc))
}
func (s *GovernanceState) SetCRSRound(round *big.Int) {
    s.setStateBigInt(big.NewInt(crsRoundLoc), round)
}

// bytes32 public crs;
func (s *GovernanceState) CRS() common.Hash {
    return s.getState(common.BigToHash(big.NewInt(crsLoc)))
}
func (s *GovernanceState) SetCRS(crs common.Hash) {
    s.setState(common.BigToHash(big.NewInt(crsLoc)), crs)
}

// uint256 public dkgRound;
func (s *GovernanceState) DKGRound() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgRoundLoc))
}
func (s *GovernanceState) SetDKGRound(round *big.Int) {
    s.setStateBigInt(big.NewInt(dkgRoundLoc), round)
}

// uint256[] public dkgResetCount;
func (s *GovernanceState) DKGResetCount(round *big.Int) *big.Int {
    arrayBaseLoc := s.getSlotLoc(big.NewInt(dkgResetCountLoc))
    return s.getStateBigInt(new(big.Int).Add(arrayBaseLoc, round))
}
func (s *GovernanceState) IncDKGResetCount(round *big.Int) {
    loc := new(big.Int).Add(s.getSlotLoc(big.NewInt(dkgResetCountLoc)), round)
    count := s.getStateBigInt(loc)
    s.setStateBigInt(loc, new(big.Int).Add(count, big.NewInt(1)))
}

// bytes[] public dkgMasterPublicKeys;
func (s *GovernanceState) LenDKGMasterPublicKeys() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgMasterPublicKeysLoc))
}
func (s *GovernanceState) DKGMasterPublicKey(offset *big.Int) []byte {
    loc := big.NewInt(dkgMasterPublicKeysLoc)
    dataLoc := s.getSlotLoc(loc)
    elementLoc := new(big.Int).Add(dataLoc, offset)
    return s.readBytes(elementLoc)
}
func (s *GovernanceState) DKGMasterPublicKeyItem(offset *big.Int) *dkgTypes.MasterPublicKey {
    element := s.DKGMasterPublicKey(offset)
    x := new(dkgTypes.MasterPublicKey)
    if err := rlp.DecodeBytes(element, x); err != nil {
        panic(err)
    }
    return x
}
func (s *GovernanceState) DKGMasterPublicKeys() [][]byte {
    return s.read1DByteArray(big.NewInt(dkgMasterPublicKeysLoc))
}
func (s *GovernanceState) PushDKGMasterPublicKey(mpk []byte) {
    s.appendTo1DByteArray(big.NewInt(dkgMasterPublicKeysLoc), mpk)
}
func (s *GovernanceState) DKGMasterPublicKeyItems() []*dkgTypes.MasterPublicKey {
    // Prepare DKGMasterPublicKeys.
    var dkgMasterPKs []*dkgTypes.MasterPublicKey
    for _, mpk := range s.DKGMasterPublicKeys() {
        x := new(dkgTypes.MasterPublicKey)
        if err := rlp.DecodeBytes(mpk, x); err != nil {
            panic(err)
        }
        dkgMasterPKs = append(dkgMasterPKs, x)
    }
    return dkgMasterPKs
}
func (s *GovernanceState) ClearDKGMasterPublicKeys() {
    s.erase1DByteArray(big.NewInt(dkgMasterPublicKeysLoc))
}

// mapping(bytes32 => uint256) public dkgMasterPublicKeyOffset;
func (s *GovernanceState) DKGMasterPublicKeyOffset(id Bytes32) *big.Int {
    loc := s.getMapLoc(big.NewInt(dkgMasterPublicKeyOffsetLoc), id[:])
    return new(big.Int).Sub(s.getStateBigInt(loc), big.NewInt(1))
}
func (s *GovernanceState) PutDKGMasterPublicKeyOffset(id Bytes32, offset *big.Int) {
    loc := s.getMapLoc(big.NewInt(dkgMasterPublicKeyOffsetLoc), id[:])
    s.setStateBigInt(loc, new(big.Int).Add(offset, big.NewInt(1)))
}
func (s *GovernanceState) ClearDKGMasterPublicKeyOffset() {
    for _, mpk := range s.DKGMasterPublicKeyItems() {
        s.PutDKGMasterPublicKeyOffset(getDKGMasterPublicKeyID(mpk), big.NewInt(-1))
    }
}

// bytes[] public dkgComplaints;
func (s *GovernanceState) LenDKGComplaints() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgComplaintsLoc))
}
func (s *GovernanceState) DKGComplaint(offset *big.Int) []byte {
    loc := big.NewInt(dkgComplaintsLoc)
    dataLoc := s.getSlotLoc(loc)
    elementLoc := new(big.Int).Add(dataLoc, offset)
    return s.readBytes(elementLoc)
}
func (s *GovernanceState) DKGComplaints() [][]byte {
    return s.read1DByteArray(big.NewInt(dkgComplaintsLoc))
}
func (s *GovernanceState) PushDKGComplaint(complaint []byte) {
    s.appendTo1DByteArray(big.NewInt(dkgComplaintsLoc), complaint)
}
func (s *GovernanceState) ClearDKGComplaints() {
    s.erase1DByteArray(big.NewInt(dkgComplaintsLoc))
}
func (s *GovernanceState) DKGComplaintItems() []*dkgTypes.Complaint {
    var dkgComplaints []*dkgTypes.Complaint
    for _, pk := range s.DKGComplaints() {
        x := new(dkgTypes.Complaint)
        if err := rlp.DecodeBytes(pk, x); err != nil {
            panic(err)
        }
        dkgComplaints = append(dkgComplaints, x)
    }
    return dkgComplaints
}

// mapping(bytes32 => bool) public dkgComplaintsProposed;
func (s *GovernanceState) DKGComplaintProposed(id Bytes32) bool {
    loc := s.getMapLoc(big.NewInt(dkgComplaintsProposedLoc), id[:])
    return s.getStateBigInt(loc).Cmp(big.NewInt(0)) > 0
}
func (s *GovernanceState) PutDKGComplaintProposed(id Bytes32, status bool) {
    loc := s.getMapLoc(big.NewInt(dkgComplaintsProposedLoc), id[:])
    val := big.NewInt(0)
    if status {
        val = big.NewInt(1)
    }
    s.setStateBigInt(loc, val)
}
func (s *GovernanceState) ClearDKGComplaintProposed() {
    for _, comp := range s.DKGComplaintItems() {
        s.PutDKGComplaintProposed(getDKGComplaintID(comp), false)
    }
}

// mapping(address => bool) public dkgMPKReadys;
func (s *GovernanceState) DKGMPKReady(addr common.Address) bool {
    mapLoc := s.getMapLoc(big.NewInt(dkgReadyLoc), addr.Bytes())
    return s.getStateBigInt(mapLoc).Cmp(big.NewInt(0)) != 0
}
func (s *GovernanceState) PutDKGMPKReady(addr common.Address, ready bool) {
    mapLoc := s.getMapLoc(big.NewInt(dkgReadyLoc), addr.Bytes())
    res := big.NewInt(0)
    if ready {
        res = big.NewInt(1)
    }
    s.setStateBigInt(mapLoc, res)
}
func (s *GovernanceState) ClearDKGMPKReadys(notarySet map[coreTypes.NodeID]struct{}) {
    for id := range notarySet {
        s.PutDKGMPKReady(IdToAddress(id), false)
    }
}

// uint256 public dkgMPKReadysCount;
func (s *GovernanceState) DKGMPKReadysCount() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgReadysCountLoc))
}
func (s *GovernanceState) IncDKGMPKReadysCount() {
    s.setStateBigInt(big.NewInt(dkgReadysCountLoc),
        new(big.Int).Add(s.getStateBigInt(big.NewInt(dkgReadysCountLoc)), big.NewInt(1)))
}
func (s *GovernanceState) ResetDKGMPKReadysCount() {
    s.setStateBigInt(big.NewInt(dkgReadysCountLoc), big.NewInt(0))
}

// mapping(address => bool) public dkgFinalizeds;
func (s *GovernanceState) DKGFinalized(addr common.Address) bool {
    mapLoc := s.getMapLoc(big.NewInt(dkgFinalizedLoc), addr.Bytes())
    return s.getStateBigInt(mapLoc).Cmp(big.NewInt(0)) != 0
}
func (s *GovernanceState) PutDKGFinalized(addr common.Address, finalized bool) {
    mapLoc := s.getMapLoc(big.NewInt(dkgFinalizedLoc), addr.Bytes())
    res := big.NewInt(0)
    if finalized {
        res = big.NewInt(1)
    }
    s.setStateBigInt(mapLoc, res)
}
func (s *GovernanceState) ClearDKGFinalizeds(dkgSet map[coreTypes.NodeID]struct{}) {
    for id := range dkgSet {
        s.PutDKGFinalized(IdToAddress(id), false)
    }
}

// uint256 public dkgFinalizedsCount;
func (s *GovernanceState) DKGFinalizedsCount() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgFinalizedsCountLoc))
}
func (s *GovernanceState) IncDKGFinalizedsCount() {
    s.setStateBigInt(big.NewInt(dkgFinalizedsCountLoc),
        new(big.Int).Add(s.getStateBigInt(big.NewInt(dkgFinalizedsCountLoc)), big.NewInt(1)))
}
func (s *GovernanceState) ResetDKGFinalizedsCount() {
    s.setStateBigInt(big.NewInt(dkgFinalizedsCountLoc), big.NewInt(0))
}

// mapping(address => bool) public dkgSuccesses;
func (s *GovernanceState) DKGSuccess(addr common.Address) bool {
    mapLoc := s.getMapLoc(big.NewInt(dkgSuccessLoc), addr.Bytes())
    return s.getStateBigInt(mapLoc).Cmp(big.NewInt(0)) != 0
}
func (s *GovernanceState) PutDKGSuccess(addr common.Address, success bool) {
    mapLoc := s.getMapLoc(big.NewInt(dkgSuccessLoc), addr.Bytes())
    res := big.NewInt(0)
    if success {
        res = big.NewInt(1)
    }
    s.setStateBigInt(mapLoc, res)
}
func (s *GovernanceState) ClearDKGSuccesses(dkgSet map[coreTypes.NodeID]struct{}) {
    for id := range dkgSet {
        s.PutDKGSuccess(IdToAddress(id), false)
    }
}

// uint256 public dkgSuccessesCount;
func (s *GovernanceState) DKGSuccessesCount() *big.Int {
    return s.getStateBigInt(big.NewInt(dkgSuccessesCountLoc))
}
func (s *GovernanceState) IncDKGSuccessesCount() {
    s.setStateBigInt(big.NewInt(dkgSuccessesCountLoc),
        new(big.Int).Add(s.getStateBigInt(big.NewInt(dkgSuccessesCountLoc)), big.NewInt(1)))
}
func (s *GovernanceState) ResetDKGSuccessesCount() {
    s.setStateBigInt(big.NewInt(dkgSuccessesCountLoc), big.NewInt(0))
}

// address public owner;
func (s *GovernanceState) Owner() common.Address {
    val := s.getState(common.BigToHash(big.NewInt(ownerLoc)))
    return common.BytesToAddress(val.Bytes())
}
func (s *GovernanceState) SetOwner(newOwner common.Address) {
    s.setState(common.BigToHash(big.NewInt(ownerLoc)), newOwner.Hash())
}

// uint256 public minStake;
func (s *GovernanceState) MinStake() *big.Int {
    return s.getStateBigInt(big.NewInt(minStakeLoc))
}

// uint256 public lockupPeriod;
func (s *GovernanceState) LockupPeriod() *big.Int {
    return s.getStateBigInt(big.NewInt(lockupPeriodLoc))
}

// uint256 public miningVelocity;
func (s *GovernanceState) MiningVelocity() *big.Int {
    return s.getStateBigInt(big.NewInt(miningVelocityLoc))
}
func (s *GovernanceState) HalfMiningVelocity() {
    s.setStateBigInt(big.NewInt(miningVelocityLoc),
        new(big.Int).Div(s.MiningVelocity(), big.NewInt(2)))
}

// uint256 public nextHalvingSupply;
func (s *GovernanceState) NextHalvingSupply() *big.Int {
    return s.getStateBigInt(big.NewInt(nextHalvingSupplyLoc))
}
func (s *GovernanceState) IncNextHalvingSupply(amount *big.Int) {
    s.setStateBigInt(big.NewInt(nextHalvingSupplyLoc),
        new(big.Int).Add(s.NextHalvingSupply(), amount))
}

// uint256 public lastHalvedAmount;
func (s *GovernanceState) LastHalvedAmount() *big.Int {
    return s.getStateBigInt(big.NewInt(lastHalvedAmountLoc))
}
func (s *GovernanceState) HalfLastHalvedAmount() {
    s.setStateBigInt(big.NewInt(lastHalvedAmountLoc),
        new(big.Int).Div(s.LastHalvedAmount(), big.NewInt(2)))
}
func (s *GovernanceState) MiningHalved() {
    s.HalfMiningVelocity()
    s.HalfLastHalvedAmount()
    s.IncNextHalvingSupply(s.LastHalvedAmount())
}

// uint256 public minGasPrice;
func (s *GovernanceState) MinGasPrice() *big.Int {
    return s.getStateBigInt(big.NewInt(minGasPriceLoc))
}

// uint256 public blockGasLimit;
func (s *GovernanceState) BlockGasLimit() *big.Int {
    return s.getStateBigInt(big.NewInt(blockGasLimitLoc))
}
func (s *GovernanceState) SetBlockGasLimit(reward *big.Int) {
    s.setStateBigInt(big.NewInt(blockGasLimitLoc), reward)
}

// uint256 public lambdaBA;
func (s *GovernanceState) LambdaBA() *big.Int {
    return s.getStateBigInt(big.NewInt(lambdaBALoc))
}

// uint256 public lambdaDKG;
func (s *GovernanceState) LambdaDKG() *big.Int {
    return s.getStateBigInt(big.NewInt(lambdaDKGLoc))
}

// uint256 public notarySetSize;
func (s *GovernanceState) NotarySetSize() *big.Int {
    return s.getStateBigInt(big.NewInt(notarySetSizeLoc))
}
func (s *GovernanceState) CalNotarySetSize() {
    nodeSetSize := float64(len(s.QualifiedNodes()))
    setSize := math.Ceil((nodeSetSize*0.6-1)/3)*3 + 1

    if nodeSetSize >= 80 {
        alpha := float64(s.NotaryParamAlpha().Uint64()) / decimalMultiplier
        beta := float64(s.NotaryParamBeta().Uint64()) / decimalMultiplier
        setSize = math.Ceil(alpha*math.Log(nodeSetSize) - beta)
    }
    s.setStateBigInt(big.NewInt(notarySetSizeLoc), big.NewInt(int64(setSize)))
}

// uint256 public notaryParamAlpha;
func (s *GovernanceState) NotaryParamAlpha() *big.Int {
    return s.getStateBigInt(big.NewInt(notaryParamAlphaLoc))
}

// uint256 public notaryParamBeta;
func (s *GovernanceState) NotaryParamBeta() *big.Int {
    return s.getStateBigInt(big.NewInt(notaryParamBetaLoc))
}

// uint256 public roundLength;
func (s *GovernanceState) RoundLength() *big.Int {
    return s.getStateBigInt(big.NewInt(roundLengthLoc))
}

// uint256 public minBlockInterval;
func (s *GovernanceState) MinBlockInterval() *big.Int {
    return s.getStateBigInt(big.NewInt(minBlockIntervalLoc))
}

// uint256[] public fineValues;
func (s *GovernanceState) FineValue(index *big.Int) *big.Int {
    arrayBaseLoc := s.getSlotLoc(big.NewInt(fineValuesLoc))
    return s.getStateBigInt(new(big.Int).Add(arrayBaseLoc, index))
}
func (s *GovernanceState) FineValues() []*big.Int {
    len := s.getStateBigInt(big.NewInt(fineValuesLoc))
    result := make([]*big.Int, len.Uint64())
    for i := 0; i < int(len.Uint64()); i++ {
        result[i] = s.FineValue(big.NewInt(int64(i)))
    }
    return result
}
func (s *GovernanceState) SetFineValues(values []*big.Int) {
    s.setStateBigInt(big.NewInt(fineValuesLoc), big.NewInt(int64(len(values))))

    arrayBaseLoc := s.getSlotLoc(big.NewInt(fineValuesLoc))
    for i, v := range values {
        s.setStateBigInt(new(big.Int).Add(arrayBaseLoc, big.NewInt(int64(i))), v)
    }
}

// mapping(bytes32 => bool) public fineRdecords;
func (s *GovernanceState) FineRecords(recordHash Bytes32) bool {
    loc := s.getMapLoc(big.NewInt(finedRecordsLoc), recordHash[:])
    return s.getStateBigInt(loc).Cmp(big.NewInt(0)) > 0
}
func (s *GovernanceState) SetFineRecords(recordHash Bytes32, status bool) {
    loc := s.getMapLoc(big.NewInt(finedRecordsLoc), recordHash[:])
    value := int64(0)
    if status {
        value = int64(1)
    }
    s.setStateBigInt(loc, big.NewInt(value))
}

// Initialize initializes governance contract state.
func (s *GovernanceState) Initialize(config *params.DexconConfig, totalSupply *big.Int) {
    if config.NextHalvingSupply.Cmp(totalSupply) <= 0 {
        panic(fmt.Sprintf("invalid genesis found, totalSupply: %s, nextHavlingSupply: %s",
            totalSupply, config.NextHalvingSupply))
    }

    // Genesis CRS.
    crs := crypto.Keccak256Hash([]byte(config.GenesisCRSText))
    s.SetCRS(crs)

    // Round 0 height.
    s.PushRoundHeight(big.NewInt(0))

    // Owner.
    s.SetOwner(config.Owner)

    // Governance configuration.
    s.UpdateConfiguration(config)

    // Set totalSupply.
    s.IncTotalSupply(totalSupply)

    // Set DKGRound.
    s.SetDKGRound(big.NewInt(int64(dexCore.DKGDelayRound)))
}

// Register is a helper function for creating genesis state.
func (s *GovernanceState) Register(
    addr common.Address, publicKey []byte,
    name, email, location, url string, staked *big.Int) {
    offset := s.LenNodes()
    node := &nodeInfo{
        Owner:      addr,
        PublicKey:  publicKey,
        Staked:     staked,
        Fined:      big.NewInt(0),
        Name:       name,
        Email:      email,
        Location:   location,
        Url:        url,
        Unstaked:   big.NewInt(0),
        UnstakedAt: big.NewInt(0),
    }
    s.PushNode(node)
    s.PutNodeOffsets(node, offset)

    if staked.Cmp(big.NewInt(0)) == 0 {
        return
    }

    // Add to network total staked.
    s.IncTotalStaked(staked)
}

func (s *GovernanceState) Disqualify(n *nodeInfo) error {
    nodeAddr, err := publicKeyToNodeKeyAddress(n.PublicKey)
    if err != nil {
        return err
    }

    // Node might already been unstaked in the latest state.
    offset := s.NodesOffsetByNodeKeyAddress(nodeAddr)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return errors.New("node does not exist")
    }

    // Set fined value.
    node := s.Node(offset)
    amount := s.FineValue(big.NewInt(FineTypeFailStop))
    node.Fined = new(big.Int).Add(node.Fined, amount)
    s.UpdateNode(offset, node)

    return nil
}

const decimalMultiplier = 100000000.0

// Configuration returns the current configuration.
func (s *GovernanceState) Configuration() *params.DexconConfig {
    return &params.DexconConfig{
        MinStake:          s.getStateBigInt(big.NewInt(minStakeLoc)),
        LockupPeriod:      s.getStateBigInt(big.NewInt(lockupPeriodLoc)).Uint64(),
        MiningVelocity:    float32(s.getStateBigInt(big.NewInt(miningVelocityLoc)).Uint64()) / decimalMultiplier,
        NextHalvingSupply: s.getStateBigInt(big.NewInt(nextHalvingSupplyLoc)),
        LastHalvedAmount:  s.getStateBigInt(big.NewInt(lastHalvedAmountLoc)),
        MinGasPrice:       s.getStateBigInt(big.NewInt(minGasPriceLoc)),
        BlockGasLimit:     s.getStateBigInt(big.NewInt(blockGasLimitLoc)).Uint64(),
        LambdaBA:          s.getStateBigInt(big.NewInt(lambdaBALoc)).Uint64(),
        LambdaDKG:         s.getStateBigInt(big.NewInt(lambdaDKGLoc)).Uint64(),
        NotaryParamAlpha:  float32(s.getStateBigInt(big.NewInt(notaryParamAlphaLoc)).Uint64()) / decimalMultiplier,
        NotaryParamBeta:   float32(s.getStateBigInt(big.NewInt(notaryParamBetaLoc)).Uint64()) / decimalMultiplier,
        RoundLength:       s.getStateBigInt(big.NewInt(roundLengthLoc)).Uint64(),
        MinBlockInterval:  s.getStateBigInt(big.NewInt(minBlockIntervalLoc)).Uint64(),
        FineValues:        s.FineValues(),
    }
}

// UpdateConfiguration updates system configuration.
func (s *GovernanceState) UpdateConfiguration(cfg *params.DexconConfig) {
    s.setStateBigInt(big.NewInt(minStakeLoc), cfg.MinStake)
    s.setStateBigInt(big.NewInt(lockupPeriodLoc), big.NewInt(int64(cfg.LockupPeriod)))
    s.setStateBigInt(big.NewInt(miningVelocityLoc), big.NewInt(int64(cfg.MiningVelocity*decimalMultiplier)))
    s.setStateBigInt(big.NewInt(nextHalvingSupplyLoc), cfg.NextHalvingSupply)
    s.setStateBigInt(big.NewInt(lastHalvedAmountLoc), cfg.LastHalvedAmount)
    s.setStateBigInt(big.NewInt(minGasPriceLoc), cfg.MinGasPrice)
    s.setStateBigInt(big.NewInt(blockGasLimitLoc), big.NewInt(int64(cfg.BlockGasLimit)))
    s.setStateBigInt(big.NewInt(lambdaBALoc), big.NewInt(int64(cfg.LambdaBA)))
    s.setStateBigInt(big.NewInt(lambdaDKGLoc), big.NewInt(int64(cfg.LambdaDKG)))
    s.setStateBigInt(big.NewInt(notaryParamAlphaLoc), big.NewInt(int64(cfg.NotaryParamAlpha*decimalMultiplier)))
    s.setStateBigInt(big.NewInt(notaryParamBetaLoc), big.NewInt(int64(cfg.NotaryParamBeta*decimalMultiplier)))
    s.setStateBigInt(big.NewInt(roundLengthLoc), big.NewInt(int64(cfg.RoundLength)))
    s.setStateBigInt(big.NewInt(minBlockIntervalLoc), big.NewInt(int64(cfg.MinBlockInterval)))
    s.SetFineValues(cfg.FineValues)

    // Calculate set size.
    s.CalNotarySetSize()
}

type rawConfigStruct struct {
    MinStake         *big.Int
    LockupPeriod     *big.Int
    BlockGasLimit    *big.Int
    MinGasPrice      *big.Int
    LambdaBA         *big.Int
    LambdaDKG        *big.Int
    NotaryParamAlpha *big.Int
    NotaryParamBeta  *big.Int
    RoundLength      *big.Int
    MinBlockInterval *big.Int
    FineValues       []*big.Int
}

// UpdateConfigurationRaw updates system configuration.
func (s *GovernanceState) UpdateConfigurationRaw(cfg *rawConfigStruct) {
    s.setStateBigInt(big.NewInt(minStakeLoc), cfg.MinStake)
    s.setStateBigInt(big.NewInt(lockupPeriodLoc), cfg.LockupPeriod)
    s.setStateBigInt(big.NewInt(minGasPriceLoc), cfg.MinGasPrice)
    s.setStateBigInt(big.NewInt(blockGasLimitLoc), cfg.BlockGasLimit)
    s.setStateBigInt(big.NewInt(lambdaBALoc), cfg.LambdaBA)
    s.setStateBigInt(big.NewInt(lambdaDKGLoc), cfg.LambdaDKG)
    s.setStateBigInt(big.NewInt(notaryParamAlphaLoc), cfg.NotaryParamAlpha)
    s.setStateBigInt(big.NewInt(notaryParamBetaLoc), cfg.NotaryParamBeta)
    s.setStateBigInt(big.NewInt(roundLengthLoc), cfg.RoundLength)
    s.setStateBigInt(big.NewInt(minBlockIntervalLoc), cfg.MinBlockInterval)
    s.SetFineValues(cfg.FineValues)

    // Calculate set size.
    s.CalNotarySetSize()
}

// event ConfigurationChanged();
func (s *GovernanceState) emitConfigurationChangedEvent() {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["ConfigurationChanged"].Id()},
        Data:    []byte{},
    })
}

// event CRSProposed(uint256 indexed Round, bytes32 CRS);
func (s *GovernanceState) emitCRSProposed(round *big.Int, crs common.Hash) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["CRSProposed"].Id(), common.BigToHash(round)},
        Data:    crs.Bytes(),
    })
}

// event NodeOwnershipTransfered(address indexed NodeAddress, address indexed NewOwnerAddress);
func (s *GovernanceState) emitNodeOwnershipTransfered(nodeAddr, newNodeAddr common.Address) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics: []common.Hash{GovernanceABI.Events["NodeOwnershipTransfered"].Id(),
            nodeAddr.Hash(), newNodeAddr.Hash()},
        Data: []byte{},
    })
}

// event NodePublicKeyReplaced(address indexed NodeAddress, bytes PublicKey);
func (s *GovernanceState) emitNodePublicKeyReplaced(nodeAddr common.Address, pk []byte) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["NodePublicKeyReplaced"].Id(), nodeAddr.Hash()},
        Data:    pk,
    })
}

// event Staked(address indexed NodeAddress, uint256 Amount);
func (s *GovernanceState) emitStaked(nodeAddr common.Address, amount *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["Staked"].Id(), nodeAddr.Hash()},
        Data:    common.BigToHash(amount).Bytes(),
    })
}

// event Unstaked(address indexed NodeAddress, uint256 Amount);
func (s *GovernanceState) emitUnstaked(nodeAddr common.Address, amount *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["Unstaked"].Id(), nodeAddr.Hash()},
        Data:    common.BigToHash(amount).Bytes(),
    })
}

// event Withdrawn(address indexed NodeAddress, uint256 Amount);
func (s *GovernanceState) emitWithdrawn(nodeAddr common.Address, amount *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["Withdrawn"].Id(), nodeAddr.Hash()},
        Data:    common.BigToHash(amount).Bytes(),
    })
}

// event NodeAdded(address indexed NodeAddress);
func (s *GovernanceState) emitNodeAdded(nodeAddr common.Address) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["NodeAdded"].Id(), nodeAddr.Hash()},
        Data:    []byte{},
    })
}

// event NodeRemoved(address indexed NodeAddress);
func (s *GovernanceState) emitNodeRemoved(nodeAddr common.Address) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["NodeRemoved"].Id(), nodeAddr.Hash()},
        Data:    []byte{},
    })
}

// event Reported(address indexed NodeAddress, uint256 Type, bytes Arg1, bytes Arg2);
func (s *GovernanceState) emitReported(nodeAddr common.Address, reportType *big.Int, arg1, arg2 []byte) {

    t1, err := abi.NewType("uint256", nil)
    if err != nil {
        panic(err)
    }
    t2, err := abi.NewType("bytes", nil)
    if err != nil {
        panic(err)
    }

    arg := abi.Arguments{
        abi.Argument{
            Name:    "ReportType",
            Type:    t1,
            Indexed: false,
        },
        abi.Argument{
            Name:    "Arg1",
            Type:    t2,
            Indexed: false,
        },
        abi.Argument{
            Name:    "Arg2",
            Type:    t2,
            Indexed: false,
        },
    }

    data, err := arg.Pack(reportType, arg1, arg2)
    if err != nil {
        panic(err)
    }
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["Reported"].Id(), nodeAddr.Hash()},
        Data:    data,
    })
}

// event Fined(address indexed NodeAddress, uint256 Amount);
func (s *GovernanceState) emitFined(nodeAddr common.Address, amount *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["Fined"].Id(), nodeAddr.Hash()},
        Data:    common.BigToHash(amount).Bytes(),
    })
}

// event FinePaid(address indexed NodeAddress, uint256 Amount);
func (s *GovernanceState) emitFinePaid(nodeAddr common.Address, amount *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["FinePaid"].Id(), nodeAddr.Hash()},
        Data:    common.BigToHash(amount).Bytes(),
    })
}

// event DKGReset(uint256 indexed Round, uint256 BlockHeight);
func (s *GovernanceState) emitDKGReset(round *big.Int, blockHeight *big.Int) {
    s.StateDB.AddLog(&types.Log{
        Address: GovernanceContractAddress,
        Topics:  []common.Hash{GovernanceABI.Events["DKGReset"].Id(), common.BigToHash(round)},
        Data:    common.BigToHash(blockHeight).Bytes(),
    })
}

type coreDKGUtil interface {
    NewGroupPublicKey(*GovernanceState, *big.Int, int) (tsigVerifierIntf, error)
}
type tsigVerifierIntf interface {
    VerifySignature(coreCommon.Hash, coreCrypto.Signature) bool
}

// defaultCoreDKGUtil implements coreDKGUtil.
type defaultCoreDKGUtil struct {
    gpk atomic.Value
}

func (c *defaultCoreDKGUtil) NewGroupPublicKey(
    state *GovernanceState, round *big.Int, threshold int) (tsigVerifierIntf, error) {
    var gpk *dkgTypes.GroupPublicKey
    var err error

    v := c.gpk.Load()
    if v != nil {
        gpk = v.(*dkgTypes.GroupPublicKey)
        if gpk.Round == round.Uint64() {
            return gpk, nil
        }
    }

    mpks := state.DKGMasterPublicKeyItems()
    comps := state.DKGComplaintItems()
    gpk, err = dkgTypes.NewGroupPublicKey(round.Uint64(), mpks, comps, threshold)
    if err != nil {
        return nil, err
    }
    c.gpk.Store(gpk)
    return gpk, nil
}

// GovernanceContract represents the governance contract of DEXCON.
type GovernanceContract struct {
    evm         *EVM
    state       GovernanceState
    contract    *Contract
    coreDKGUtil coreDKGUtil
    util        GovUtil
}

func (g *GovernanceContract) StateAt(height uint64) (*state.StateDB, error) {
    return g.evm.StateAtNumber(height)
}

func (g *GovernanceContract) GetHeadGovState() (*GovernanceState, error) {
    return &g.state, nil
}

func (g *GovernanceContract) Address() common.Address {
    return GovernanceContractAddress
}

func (g *GovernanceContract) transfer(from, to common.Address, amount *big.Int) bool {
    // TODO(w): add this to debug trace so it shows up as internal transaction.
    if g.evm.CanTransfer(g.evm.StateDB, from, amount) {
        g.evm.Transfer(g.evm.StateDB, from, to, amount)
        return true
    }
    return false
}

func (g *GovernanceContract) useGas(gas uint64) ([]byte, error) {
    if !g.contract.UseGas(gas) {
        return nil, ErrOutOfGas
    }
    return nil, nil
}

func (g *GovernanceContract) configNotarySetSize(round *big.Int) *big.Int {
    s, err := g.util.GetConfigState(round.Uint64())
    if err != nil {
        return big.NewInt(0)
    }
    return s.NotarySetSize()
}

func (g *GovernanceContract) getNotarySet(round *big.Int) map[coreTypes.NodeID]struct{} {
    crs := g.util.CRS(round.Uint64())
    if crs == (common.Hash{}) {
        return map[coreTypes.NodeID]struct{}{}
    }

    target := coreTypes.NewNotarySetTarget(coreCommon.Hash(crs))
    ns := coreTypes.NewNodeSet()

    state, err := g.util.GetConfigState(round.Uint64())
    if err != nil {
        return map[coreTypes.NodeID]struct{}{}
    }
    for _, x := range state.QualifiedNodes() {
        mpk, err := ecdsa.NewPublicKeyFromByteSlice(x.PublicKey)
        if err != nil {
            panic(err)
        }
        ns.Add(coreTypes.NewNodeID(mpk))
    }
    return ns.GetSubSet(int(g.configNotarySetSize(round).Uint64()), target)
}

func (g *GovernanceContract) inNotarySet(round *big.Int, nodeID coreTypes.NodeID) bool {
    dkgSet := g.getNotarySet(round)
    _, ok := dkgSet[nodeID]
    return ok
}

func (g *GovernanceContract) clearDKG() {
    dkgSet := g.getNotarySet(g.state.DKGRound())
    g.state.ClearDKGMasterPublicKeyOffset()
    g.state.ClearDKGMasterPublicKeys()
    g.state.ClearDKGComplaintProposed()
    g.state.ClearDKGComplaints()
    g.state.ClearDKGMPKReadys(dkgSet)
    g.state.ResetDKGMPKReadysCount()
    g.state.ClearDKGFinalizeds(dkgSet)
    g.state.ResetDKGFinalizedsCount()
    g.state.ClearDKGSuccesses(dkgSet)
    g.state.ResetDKGSuccessesCount()
}

func (g *GovernanceContract) fineFailStopDKG(threshold int) {
    fineNode := make(map[coreTypes.NodeID]struct{})
    dkgSet := g.getNotarySet(g.state.DKGRound())
    for id := range dkgSet {
        offset := g.state.DKGMasterPublicKeyOffset(Bytes32(id.Hash))
        if offset.Cmp(big.NewInt(0)) >= 0 {
            continue
        }
        fineNode[id] = struct{}{}
    }
    complaintsByID := map[coreTypes.NodeID]map[coreTypes.NodeID]struct{}{}
    for _, complaint := range g.state.DKGComplaints() {
        comp := new(dkgTypes.Complaint)
        if err := rlp.DecodeBytes(complaint, comp); err != nil {
            panic(err)
        }

        if comp.IsNack() {
            if _, exist := complaintsByID[comp.PrivateShare.ProposerID]; !exist {
                complaintsByID[comp.PrivateShare.ProposerID] =
                    make(map[coreTypes.NodeID]struct{})
            }
            complaintsByID[comp.PrivateShare.ProposerID][comp.ProposerID] = struct{}{}
        }
    }
    for id, complaints := range complaintsByID {
        if len(complaints) >= threshold {
            fineNode[id] = struct{}{}
        }
    }
    nodes := make(coreTypes.NodeIDs, 0, len(fineNode))
    for id := range fineNode {
        nodes = append(nodes, id)
    }
    sort.Sort(nodes)
    for _, id := range nodes {
        offset := g.state.NodesOffsetByNodeKeyAddress(IdToAddress(id))
        // Node might have been unstaked.
        if offset.Cmp(big.NewInt(0)) < 0 {
            continue
        }

        node := g.state.Node(offset)
        amount := g.state.FineValue(big.NewInt(FineTypeFailStopDKG))
        node.Fined = new(big.Int).Add(node.Fined, amount)
        g.state.UpdateNode(offset, node)
        g.state.emitFined(node.Owner, amount)
    }
}

func (g *GovernanceContract) addDKGComplaint(comp []byte) ([]byte, error) {
    caller := g.contract.Caller()
    offset := g.state.NodesOffsetByNodeKeyAddress(caller)

    // Can not add complaint if caller does not exists.
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    // Finalized caller is not allowed to propose complaint.
    if g.state.DKGFinalized(caller) {
        return nil, errExecutionReverted
    }

    // Calculate 2f + 1
    threshold := 2*g.configNotarySetSize(g.evm.Round).Uint64()/3 + 1

    // If 2f + 1 of DKG set is finalized, one can not propose complaint anymore.
    if g.state.DKGFinalizedsCount().Uint64() >= threshold {
        return nil, errExecutionReverted
    }

    var dkgComplaint dkgTypes.Complaint
    if err := rlp.DecodeBytes(comp, &dkgComplaint); err != nil {
        return nil, errExecutionReverted
    }

    if g.state.DKGComplaintProposed(getDKGComplaintID(&dkgComplaint)) {
        return nil, errExecutionReverted
    }
    round := big.NewInt(int64(dkgComplaint.Round))
    if round.Uint64() != g.evm.Round.Uint64()+1 {
        return nil, errExecutionReverted
    }

    if dkgComplaint.Reset != g.state.DKGResetCount(round).Uint64() {
        return nil, errExecutionReverted
    }

    // DKGComplaint must belongs to someone in DKG set.
    if !g.inNotarySet(round, dkgComplaint.ProposerID) {
        return nil, errExecutionReverted
    }

    verified, _ := coreUtils.VerifyDKGComplaintSignature(&dkgComplaint)
    if !verified {
        return nil, errExecutionReverted
    }

    mpkOffset := g.state.DKGMasterPublicKeyOffset(Bytes32(dkgComplaint.PrivateShare.ProposerID.Hash))
    mpk := g.state.DKGMasterPublicKeyItem(mpkOffset)

    // Verify DKG complaint is correct.
    ok, err := coreUtils.VerifyDKGComplaint(&dkgComplaint, mpk)
    if !ok || err != nil {
        return nil, errExecutionReverted
    }

    // Fine the attacker.
    need, err := coreUtils.NeedPenaltyDKGPrivateShare(&dkgComplaint, mpk)
    if err != nil {
        return nil, errExecutionReverted
    }
    if need {
        node, err := g.state.GetNodeByID(dkgComplaint.PrivateShare.ProposerID)
        if err != nil {
            return nil, errExecutionReverted
        }
        fineValue := g.state.FineValue(big.NewInt(FineTypeInvalidDKG))
        if err := g.fine(node.Owner, fineValue, comp, nil); err != nil {
            return nil, errExecutionReverted
        }
    }

    g.state.PushDKGComplaint(comp)
    g.state.PutDKGComplaintProposed(getDKGComplaintID(&dkgComplaint), true)

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) addDKGMasterPublicKey(mpk []byte) ([]byte, error) {
    var dkgMasterPK dkgTypes.MasterPublicKey
    if err := rlp.DecodeBytes(mpk, &dkgMasterPK); err != nil {
        return nil, errExecutionReverted
    }
    round := big.NewInt(int64(dkgMasterPK.Round))
    if round.Uint64() != g.evm.Round.Uint64()+1 {
        return nil, errExecutionReverted
    }

    if g.state.DKGRound().Cmp(g.evm.Round) == 0 {
        // Clear DKG states for next round.
        g.clearDKG()
        g.state.SetDKGRound(round)
    }

    mpkOffset := g.state.DKGMasterPublicKeyOffset(getDKGMasterPublicKeyID(&dkgMasterPK))
    if mpkOffset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    caller := g.contract.Caller()
    offset := g.state.NodesOffsetByNodeKeyAddress(caller)

    // Can not add dkg mpk if not staked.
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    // MPKReady caller is not allowed to propose mpk.
    if g.state.DKGMPKReady(caller) {
        return nil, errExecutionReverted
    }

    // Calculate 2f + 1
    threshold := 2*g.configNotarySetSize(g.evm.Round).Uint64()/3 + 1

    // If 2f + 1 of DKG set is mpk ready, one can not propose mpk anymore.
    if g.state.DKGMPKReadysCount().Uint64() >= threshold {
        return nil, errExecutionReverted
    }

    if dkgMasterPK.Reset != g.state.DKGResetCount(round).Uint64() {
        return nil, errExecutionReverted
    }

    // DKGMasterPublicKey must belongs to someone in DKG set.
    if !g.inNotarySet(round, dkgMasterPK.ProposerID) {
        return nil, errExecutionReverted
    }

    verified, _ := coreUtils.VerifyDKGMasterPublicKeySignature(&dkgMasterPK)
    if !verified {
        return nil, errExecutionReverted
    }

    mpkOffset = g.state.LenDKGMasterPublicKeys()
    g.state.PushDKGMasterPublicKey(mpk)
    g.state.PutDKGMasterPublicKeyOffset(getDKGMasterPublicKeyID(&dkgMasterPK), mpkOffset)

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) addDKGMPKReady(ready []byte) ([]byte, error) {
    caller := g.contract.Caller()

    var dkgReady dkgTypes.MPKReady
    if err := rlp.DecodeBytes(ready, &dkgReady); err != nil {
        return nil, errExecutionReverted
    }
    round := big.NewInt(int64(dkgReady.Round))
    if round.Uint64() != g.evm.Round.Uint64()+1 {
        return nil, errExecutionReverted
    }

    if dkgReady.Reset != g.state.DKGResetCount(round).Uint64() {
        return nil, errExecutionReverted
    }

    // DKGFInalize must belongs to someone in DKG set.
    if !g.inNotarySet(round, dkgReady.ProposerID) {
        return nil, errExecutionReverted
    }

    verified, _ := coreUtils.VerifyDKGMPKReadySignature(&dkgReady)
    if !verified {
        return nil, errExecutionReverted
    }

    if !g.state.DKGMPKReady(caller) {
        g.state.PutDKGMPKReady(caller, true)
        g.state.IncDKGMPKReadysCount()
    }

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) addDKGFinalize(finalize []byte) ([]byte, error) {
    caller := g.contract.Caller()

    var dkgFinalize dkgTypes.Finalize
    if err := rlp.DecodeBytes(finalize, &dkgFinalize); err != nil {
        return nil, errExecutionReverted
    }
    round := big.NewInt(int64(dkgFinalize.Round))
    if round.Uint64() != g.evm.Round.Uint64()+1 {
        return nil, errExecutionReverted
    }

    if dkgFinalize.Reset != g.state.DKGResetCount(round).Uint64() {
        return nil, errExecutionReverted
    }

    // DKGFInalize must belongs to someone in DKG set.
    if !g.inNotarySet(round, dkgFinalize.ProposerID) {
        return nil, errExecutionReverted
    }

    verified, _ := coreUtils.VerifyDKGFinalizeSignature(&dkgFinalize)
    if !verified {
        return nil, errExecutionReverted
    }

    if !g.state.DKGFinalized(caller) {
        g.state.PutDKGFinalized(caller, true)
        g.state.IncDKGFinalizedsCount()
    }

    threshold := 2*g.configNotarySetSize(g.evm.Round).Uint64()/3 + 1

    if g.state.DKGFinalizedsCount().Uint64() == threshold {
        tsigThreshold := coreUtils.GetDKGThreshold(&coreTypes.Config{
            NotarySetSize: uint32(g.configNotarySetSize(g.evm.Round).Uint64())})
        g.fineFailStopDKG(tsigThreshold)
    }

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) addDKGSuccess(success []byte) ([]byte, error) {
    caller := g.contract.Caller()

    var dkgSuccess dkgTypes.Success
    if err := rlp.DecodeBytes(success, &dkgSuccess); err != nil {
        return nil, errExecutionReverted
    }
    round := big.NewInt(int64(dkgSuccess.Round))
    if round.Uint64() != g.evm.Round.Uint64()+1 {
        return nil, errExecutionReverted
    }

    if dkgSuccess.Reset != g.state.DKGResetCount(round).Uint64() {
        return nil, errExecutionReverted
    }

    // DKGFInalize must belongs to someone in DKG set.
    if !g.inNotarySet(round, dkgSuccess.ProposerID) {
        return nil, errExecutionReverted
    }

    verified, _ := coreUtils.VerifyDKGSuccessSignature(&dkgSuccess)
    if !verified {
        return nil, errExecutionReverted
    }

    if !g.state.DKGSuccess(caller) {
        g.state.PutDKGSuccess(caller, true)
        g.state.IncDKGSuccessesCount()
    }

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) updateConfiguration(cfg *rawConfigStruct) ([]byte, error) {
    // Only owner can update configuration.
    if g.contract.Caller() != g.state.Owner() {
        return nil, errExecutionReverted
    }

    // Sanity checks.
    if cfg.MinStake.Cmp(big.NewInt(0)) <= 0 ||
        cfg.LockupPeriod.Cmp(big.NewInt(0)) <= 0 ||
        cfg.BlockGasLimit.Cmp(big.NewInt(0)) <= 0 ||
        cfg.MinGasPrice.Cmp(big.NewInt(0)) <= 0 ||
        cfg.LambdaBA.Cmp(big.NewInt(0)) <= 0 ||
        cfg.LambdaDKG.Cmp(big.NewInt(0)) <= 0 ||
        cfg.RoundLength.Cmp(big.NewInt(0)) <= 0 ||
        cfg.MinBlockInterval.Cmp(big.NewInt(0)) <= 0 {
        return nil, errExecutionReverted
    }

    g.state.UpdateConfigurationRaw(cfg)
    g.state.emitConfigurationChangedEvent()

    return nil, nil
}

func (g *GovernanceContract) register(
    publicKey []byte, name, email, location, url string) ([]byte, error) {

    // Reject invalid inputs.
    if len(name) >= 64 || len(email) >= 128 || len(location) >= 64 || len(url) >= 128 {
        return nil, errExecutionReverted
    }

    caller := g.contract.Caller()
    value := g.contract.Value()
    offset := g.state.NodesOffsetByAddress(caller)

    // Can not register if already registered.
    if offset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    nodeKeyAddr, err := publicKeyToNodeKeyAddress(publicKey)
    if err != nil {
        return nil, errExecutionReverted
    }

    offset = g.state.NodesOffsetByNodeKeyAddress(nodeKeyAddr)

    // Can not register if node key is duplicate.
    if offset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    offset = g.state.LenNodes()
    node := &nodeInfo{
        Owner:      caller,
        PublicKey:  publicKey,
        Staked:     value,
        Fined:      big.NewInt(0),
        Name:       name,
        Email:      email,
        Location:   location,
        Url:        url,
        Unstaked:   big.NewInt(0),
        UnstakedAt: big.NewInt(0),
    }
    g.state.PushNode(node)
    g.state.PutNodeOffsets(node, offset)
    g.state.emitNodeAdded(caller)

    if value.Cmp(big.NewInt(0)) > 0 {
        g.state.IncTotalStaked(value)
        g.state.emitStaked(caller, value)
    }
    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) stake() ([]byte, error) {
    caller := g.contract.Caller()
    value := g.contract.Value()

    if big.NewInt(0).Cmp(value) == 0 {
        return nil, errExecutionReverted
    }

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)
    if node.Fined.Cmp(big.NewInt(0)) > 0 {
        return nil, errExecutionReverted
    }

    node.Staked = new(big.Int).Add(node.Staked, value)
    g.state.UpdateNode(offset, node)

    g.state.IncTotalStaked(value)
    g.state.emitStaked(caller, value)

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) unstake(amount *big.Int) ([]byte, error) {
    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)

    // Can not unstake if there are unpaied fine.
    if node.Fined.Cmp(big.NewInt(0)) > 0 {
        return nil, errExecutionReverted
    }

    // Can not unstake if there are unwithdrawn stake.
    if node.Unstaked.Cmp(big.NewInt(0)) > 0 {
        return nil, errExecutionReverted
    }
    if node.Staked.Cmp(amount) < 0 {
        return nil, errExecutionReverted
    }

    node.Staked = new(big.Int).Sub(node.Staked, amount)
    node.Unstaked = amount
    node.UnstakedAt = g.evm.Time
    g.state.UpdateNode(offset, node)

    g.state.DecTotalStaked(amount)
    g.state.emitUnstaked(caller, amount)

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) updateNodeInfo(
    name, email, location, url string) ([]byte, error) {

    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    // Reject invalid inputs.
    if len(name) >= 64 || len(email) >= 128 || len(location) >= 64 || len(url) >= 128 {
        return nil, errExecutionReverted
    }

    g.state.UpdateNodeInfo(offset, &nodeInfo{
        Name:     name,
        Email:    email,
        Location: location,
        Url:      url,
    })

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) withdraw() ([]byte, error) {
    if !g.withdrawable() {
        return nil, errExecutionReverted
    }
    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)

    amount := node.Unstaked
    node.Unstaked = big.NewInt(0)
    node.UnstakedAt = big.NewInt(0)
    g.state.UpdateNode(offset, node)

    if node.Staked.Cmp(big.NewInt(0)) == 0 {
        length := g.state.LenNodes()
        lastIndex := new(big.Int).Sub(length, big.NewInt(1))

        // Delete the node.
        if offset.Cmp(lastIndex) != 0 {
            lastNode := g.state.Node(lastIndex)
            g.state.UpdateNode(offset, lastNode)
            g.state.PutNodeOffsets(lastNode, offset)
        }
        g.state.DeleteNodeOffsets(node)
        g.state.PopLastNode()
        g.state.emitNodeRemoved(caller)
    }

    // Return the staked fund.
    if !g.transfer(GovernanceContractAddress, node.Owner, amount) {
        return nil, errExecutionReverted
    }
    g.state.emitWithdrawn(caller, amount)

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) withdrawable() bool {
    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return false
    }

    node := g.state.Node(offset)

    // Can not withdraw if there are unpaied fine.
    if node.Fined.Cmp(big.NewInt(0)) > 0 {
        return false
    }

    // Can not withdraw if there are no pending withdrawal.
    if node.Unstaked.Cmp(big.NewInt(0)) == 0 {
        return false
    }

    unlockTime := new(big.Int).Add(node.UnstakedAt, g.state.LockupPeriod())
    return g.evm.Time.Cmp(unlockTime) > 0
}

func (g *GovernanceContract) payFine(nodeAddr common.Address) ([]byte, error) {
    nodeOffset := g.state.NodesOffsetByAddress(nodeAddr)
    if nodeOffset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(nodeOffset)
    if node.Fined.Cmp(big.NewInt(0)) <= 0 || node.Fined.Cmp(g.contract.Value()) < 0 {
        return nil, errExecutionReverted
    }

    node.Fined = new(big.Int).Sub(node.Fined, g.contract.Value())
    g.state.UpdateNode(nodeOffset, node)

    // Pay the fine to governance owner.
    if !g.transfer(GovernanceContractAddress, g.state.Owner(), g.contract.Value()) {
        return nil, errExecutionReverted
    }

    g.state.emitFinePaid(nodeAddr, g.contract.Value())

    return g.useGas(GovernanceActionGasCost)
}

func (g *GovernanceContract) proposeCRS(nextRound *big.Int, signedCRS []byte) ([]byte, error) {
    if nextRound.Uint64() != g.evm.Round.Uint64()+1 ||
        g.state.CRSRound().Uint64() == nextRound.Uint64() {
        return nil, errExecutionReverted
    }

    prevCRS := g.state.CRS()

    // CRS(n) = hash(CRS(n-1)) if n <= core.DKGRoundDelay
    if g.evm.Round.Uint64() == dexCore.DKGDelayRound {
        for i := uint64(0); i < dexCore.DKGDelayRound; i++ {
            prevCRS = crypto.Keccak256Hash(prevCRS[:])
        }
    }

    threshold := coreUtils.GetDKGThreshold(&coreTypes.Config{
        NotarySetSize: uint32(g.state.NotarySetSize().Uint64())})
    dkgGPK, err := g.coreDKGUtil.NewGroupPublicKey(&g.state, nextRound, threshold)
    if err != nil {
        return nil, errExecutionReverted
    }
    signature := coreCrypto.Signature{
        Type:      "bls",
        Signature: signedCRS,
    }
    if !dkgGPK.VerifySignature(coreCommon.Hash(prevCRS), signature) {
        return nil, errExecutionReverted
    }

    // Save new CRS into state and increase round.
    crs := crypto.Keccak256Hash(signedCRS)

    g.state.SetCRS(crs)
    g.state.SetCRSRound(nextRound)
    g.state.emitCRSProposed(nextRound, crs)

    return g.useGas(GovernanceActionGasCost)
}

type sortBytes [][]byte

func (s sortBytes) Less(i, j int) bool {
    return bytes.Compare(s[i], s[j]) < 0
}

func (s sortBytes) Swap(i, j int) {
    s[i], s[j] = s[j], s[i]
}

func (s sortBytes) Len() int {
    return len(s)
}

func (g *GovernanceContract) fine(nodeAddr common.Address, amount *big.Int, payloads ...[]byte) error {
    sort.Sort(sortBytes(payloads))

    hash := Bytes32(crypto.Keccak256Hash(payloads...))
    if g.state.FineRecords(hash) {
        return errors.New("already fined")
    }
    g.state.SetFineRecords(hash, true)

    nodeOffset := g.state.NodesOffsetByAddress(nodeAddr)
    if nodeOffset.Cmp(big.NewInt(0)) < 0 {
        return errExecutionReverted
    }

    // Set fined value.
    node := g.state.Node(nodeOffset)
    node.Fined = new(big.Int).Add(node.Fined, amount)
    g.state.UpdateNode(nodeOffset, node)

    g.state.emitFined(nodeAddr, amount)

    return nil
}

func (g *GovernanceContract) report(reportType *big.Int, arg1, arg2 []byte) ([]byte, error) {
    typeEnum := FineType(reportType.Uint64())
    var reportedNodeID coreTypes.NodeID

    switch typeEnum {
    case FineTypeForkVote:
        vote1 := new(coreTypes.Vote)
        if err := rlp.DecodeBytes(arg1, vote1); err != nil {
            return nil, errExecutionReverted
        }
        vote2 := new(coreTypes.Vote)
        if err := rlp.DecodeBytes(arg2, vote2); err != nil {
            return nil, errExecutionReverted
        }
        need, err := coreUtils.NeedPenaltyForkVote(vote1, vote2)
        if !need || err != nil {
            return nil, errExecutionReverted
        }
        reportedNodeID = vote1.ProposerID
    case FineTypeForkBlock:
        block1 := new(coreTypes.Block)
        if err := rlp.DecodeBytes(arg1, block1); err != nil {
            return nil, errExecutionReverted
        }
        block2 := new(coreTypes.Block)
        if err := rlp.DecodeBytes(arg2, block2); err != nil {
            return nil, errExecutionReverted
        }
        need, err := coreUtils.NeedPenaltyForkBlock(block1, block2)
        if !need || err != nil {
            return nil, errExecutionReverted
        }
        reportedNodeID = block1.ProposerID
    default:
        return nil, errExecutionReverted
    }

    node, err := g.state.GetNodeByID(reportedNodeID)
    if err != nil {
        return nil, errExecutionReverted
    }

    g.state.emitReported(node.Owner, reportType, arg1, arg2)

    fineValue := g.state.FineValue(reportType)
    if err := g.fine(node.Owner, fineValue, arg1, arg2); err != nil {
        return nil, errExecutionReverted
    }
    return nil, nil
}

func (g *GovernanceContract) resetDKG(newSignedCRS []byte) ([]byte, error) {
    round := g.evm.Round
    nextRound := new(big.Int).Add(round, big.NewInt(1))

    // If no one call addDKGMasterPublicKey, DKG of previous round will not be
    // cleared.
    if g.state.DKGRound().Cmp(round) == 0 {
        // Clear DKG states for next round.
        g.clearDKG()
        g.state.SetDKGRound(nextRound)
    }

    resetCount := g.state.DKGResetCount(nextRound)

    // Just restart DEXON if failed at round 0.
    if round.Cmp(big.NewInt(0)) == 0 {
        return nil, errExecutionReverted
    }

    // Extend the the current round.
    // target = (85 + 100 * DKGResetCount)%
    target := new(big.Int).Add(
        big.NewInt(85),
        new(big.Int).Mul(big.NewInt(100), resetCount))

    roundHeight := g.state.RoundHeight(round)
    gs, err := g.util.GetConfigState(round.Uint64())
    if err != nil {
        return nil, err
    }
    config := gs.Configuration()

    targetBlockNum := new(big.Int).SetUint64(config.RoundLength)
    targetBlockNum.Mul(targetBlockNum, target)
    targetBlockNum.Quo(targetBlockNum, big.NewInt(100))
    targetBlockNum.Add(targetBlockNum, roundHeight)

    // Check if current block over 85%of current round.
    blockHeight := g.evm.Context.BlockNumber
    if blockHeight.Cmp(targetBlockNum) < 0 {
        return nil, errExecutionReverted
    }

    tsigThreshold := coreUtils.GetDKGThreshold(&coreTypes.Config{
        NotarySetSize: uint32(g.configNotarySetSize(nextRound).Uint64())})
    // Check if next DKG has not enough of success.
    if g.state.DKGSuccessesCount().Uint64() >=
        uint64(coreUtils.GetDKGValidThreshold(&coreTypes.Config{
            NotarySetSize: uint32(g.configNotarySetSize(nextRound).Uint64()),
        })) {
        // Check if next DKG did not success.
        // Calculate 2f + 1
        threshold := 2*g.configNotarySetSize(nextRound).Uint64()/3 + 1

        // If 2f + 1 of DKG set is finalized, check if DKG succeeded.
        if g.state.DKGFinalizedsCount().Uint64() >= threshold {
            gpk, err := g.coreDKGUtil.NewGroupPublicKey(&g.state, nextRound, tsigThreshold)
            if gpk, ok := gpk.(*dkgTypes.GroupPublicKey); ok {
                if len(gpk.QualifyNodeIDs) < coreUtils.GetDKGValidThreshold(&coreTypes.Config{
                    NotarySetSize: uint32(g.configNotarySetSize(nextRound).Uint64())}) {
                    err = dkgTypes.ErrNotReachThreshold
                }
            }

            // DKG success.
            if err == nil {
                return nil, errExecutionReverted
            }
            switch err {
            case dkgTypes.ErrNotReachThreshold, dkgTypes.ErrInvalidThreshold:
            default:
                return nil, errExecutionReverted
            }
        }
    }

    // Fine fail stop DKGs.
    g.fineFailStopDKG(tsigThreshold)

    // Update CRS.
    state, err := g.util.GetStateAtRound(round.Uint64())
    if err != nil {
        return nil, errExecutionReverted
    }
    prevCRS := state.CRS()

    // CRS(n) = hash(CRS(n-1)) if n <= core.DKGRoundDelay
    if round.Uint64() == dexCore.DKGDelayRound {
        for i := uint64(0); i < dexCore.DKGDelayRound; i++ {
            prevCRS = crypto.Keccak256Hash(prevCRS[:])
        }
    }

    for i := uint64(0); i < resetCount.Uint64()+1; i++ {
        prevCRS = crypto.Keccak256Hash(prevCRS[:])
    }

    dkgGPK, err := g.coreDKGUtil.NewGroupPublicKey(state, round,
        coreUtils.GetDKGThreshold(&coreTypes.Config{
            NotarySetSize: uint32(g.configNotarySetSize(round).Uint64())}))
    if err != nil {
        return nil, errExecutionReverted
    }
    signature := coreCrypto.Signature{
        Type:      "bls",
        Signature: newSignedCRS,
    }
    if !dkgGPK.VerifySignature(coreCommon.Hash(prevCRS), signature) {
        return nil, errExecutionReverted
    }

    // Clear DKG states for next round.
    g.clearDKG()
    g.state.SetDKGRound(nextRound)

    // Save new CRS into state and increase round.
    newCRS := crypto.Keccak256(newSignedCRS)
    crs := common.BytesToHash(newCRS)

    g.state.SetCRS(crs)
    g.state.SetCRSRound(nextRound)
    g.state.emitCRSProposed(nextRound, crs)

    // Increase reset count.
    g.state.IncDKGResetCount(nextRound)
    g.state.emitDKGReset(round, blockHeight)

    return nil, nil
}

// Run executes governance contract.
func (g *GovernanceContract) Run(evm *EVM, input []byte, contract *Contract) (ret []byte, err error) {
    if len(input) < 4 {
        return nil, errExecutionReverted
    }

    // Initialize contract state.
    g.evm = evm
    g.state = GovernanceState{evm.StateDB}
    g.contract = contract
    g.util = GovUtil{g}

    // Parse input.
    method, exists := GovernanceABI.Sig2Method[string(input[:4])]
    if !exists {
        return nil, errExecutionReverted
    }

    arguments := input[4:]

    // Dispatch method call.
    switch method.Name {
    case "addDKGComplaint":
        var Complaint []byte
        if err := method.Inputs.Unpack(&Complaint, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.addDKGComplaint(Complaint)
    case "addDKGMasterPublicKey":
        var PublicKey []byte
        if err := method.Inputs.Unpack(&PublicKey, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.addDKGMasterPublicKey(PublicKey)
    case "addDKGMPKReady":
        var MPKReady []byte
        if err := method.Inputs.Unpack(&MPKReady, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.addDKGMPKReady(MPKReady)
    case "addDKGFinalize":
        var Finalize []byte
        if err := method.Inputs.Unpack(&Finalize, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.addDKGFinalize(Finalize)
    case "addDKGSuccess":
        var Success []byte
        if err := method.Inputs.Unpack(&Success, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.addDKGSuccess(Success)
    case "nodesLength":
        res, err := method.Outputs.Pack(g.state.LenNodes())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "payFine":
        address := common.Address{}
        if err := method.Inputs.Unpack(&address, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.payFine(address)
    case "proposeCRS":
        args := struct {
            Round     *big.Int
            SignedCRS []byte
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.proposeCRS(args.Round, args.SignedCRS)
    case "report":
        args := struct {
            Type *big.Int
            Arg1 []byte
            Arg2 []byte
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.report(args.Type, args.Arg1, args.Arg2)
    case "resetDKG":
        args := struct {
            NewSignedCRS []byte
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.resetDKG(args.NewSignedCRS)
    case "register":
        args := struct {
            PublicKey []byte
            Name      string
            Email     string
            Location  string
            Url       string
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.register(args.PublicKey, args.Name, args.Email, args.Location, args.Url)
    case "stake":
        return g.stake()
    case "transferOwnership":
        var newOwner common.Address
        if err := method.Inputs.Unpack(&newOwner, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.transferOwnership(newOwner)
    case "transferNodeOwnership":
        var newOwner common.Address
        if err := method.Inputs.Unpack(&newOwner, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.transferNodeOwnership(newOwner)
    case "transferNodeOwnershipByFoundation":
        args := struct {
            OldOwner common.Address
            NewOwner common.Address
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.transferNodeOwnershipByFoundation(args.OldOwner, args.NewOwner)
    case "unstake":
        amount := new(big.Int)
        if err := method.Inputs.Unpack(&amount, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.unstake(amount)
    case "updateConfiguration":
        var cfg rawConfigStruct
        if err := method.Inputs.Unpack(&cfg, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.updateConfiguration(&cfg)
    case "updateNodeInfo":
        args := struct {
            Name     string
            Email    string
            Location string
            Url      string
        }{}
        if err := method.Inputs.Unpack(&args, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.updateNodeInfo(args.Name, args.Email, args.Location, args.Url)
    case "withdraw":
        return g.withdraw()
    case "withdrawable":
        res, err := method.Outputs.Pack(g.withdrawable())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil

    // --------------------------------
    // Solidity auto generated methods.
    // --------------------------------

    case "blockGasLimit":
        res, err := method.Outputs.Pack(g.state.BlockGasLimit())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "crs":
        res, err := method.Outputs.Pack(g.state.CRS())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "crsRound":
        res, err := method.Outputs.Pack(g.state.CRSRound())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgComplaints":
        offset := new(big.Int)
        if err := method.Inputs.Unpack(&offset, arguments); err != nil {
            return nil, errExecutionReverted
        }
        complaint := g.state.DKGComplaint(offset)
        res, err := method.Outputs.Pack(complaint)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgComplaintsProposed":
        id := Bytes32{}
        if err := method.Inputs.Unpack(&id, arguments); err != nil {
            return nil, errExecutionReverted
        }
        proposed := g.state.DKGComplaintProposed(id)
        res, err := method.Outputs.Pack(proposed)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgFinalizeds":
        addr := common.Address{}
        if err := method.Inputs.Unpack(&addr, arguments); err != nil {
            return nil, errExecutionReverted
        }
        finalized := g.state.DKGFinalized(addr)
        res, err := method.Outputs.Pack(finalized)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgFinalizedsCount":
        count := g.state.DKGFinalizedsCount()
        res, err := method.Outputs.Pack(count)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgSuccesses":
        addr := common.Address{}
        if err := method.Inputs.Unpack(&addr, arguments); err != nil {
            return nil, errExecutionReverted
        }
        finalized := g.state.DKGSuccess(addr)
        res, err := method.Outputs.Pack(finalized)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgSuccessesCount":
        count := g.state.DKGSuccessesCount()
        res, err := method.Outputs.Pack(count)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgMasterPublicKeys":
        offset := new(big.Int)
        if err := method.Inputs.Unpack(&offset, arguments); err != nil {
            return nil, errExecutionReverted
        }
        mpk := g.state.DKGMasterPublicKey(offset)
        res, err := method.Outputs.Pack(mpk)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgMasterPublicKeyOffset":
        id := Bytes32{}
        if err := method.Inputs.Unpack(&id, arguments); err != nil {
            return nil, errExecutionReverted
        }
        offset := g.state.DKGMasterPublicKeyOffset(id)
        res, err := method.Outputs.Pack(offset)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgMPKReadys":
        addr := common.Address{}
        if err := method.Inputs.Unpack(&addr, arguments); err != nil {
            return nil, errExecutionReverted
        }
        ready := g.state.DKGMPKReady(addr)
        res, err := method.Outputs.Pack(ready)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgMPKReadysCount":
        count := g.state.DKGMPKReadysCount()
        res, err := method.Outputs.Pack(count)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgResetCount":
        round := new(big.Int)
        if err := method.Inputs.Unpack(&round, arguments); err != nil {
            return nil, errExecutionReverted
        }
        res, err := method.Outputs.Pack(g.state.DKGResetCount(round))
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "dkgRound":
        res, err := method.Outputs.Pack(g.state.DKGRound())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "finedRecords":
        record := Bytes32{}
        if err := method.Inputs.Unpack(&record, arguments); err != nil {
            return nil, errExecutionReverted
        }
        value := g.state.FineRecords(record)
        res, err := method.Outputs.Pack(value)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "fineValues":
        index := new(big.Int)
        if err := method.Inputs.Unpack(&index, arguments); err != nil {
            return nil, errExecutionReverted
        }
        value := g.state.FineValue(index)
        res, err := method.Outputs.Pack(value)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "lambdaBA":
        res, err := method.Outputs.Pack(g.state.LambdaBA())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "lambdaDKG":
        res, err := method.Outputs.Pack(g.state.LambdaDKG())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "lastHalvedAmount":
        res, err := method.Outputs.Pack(g.state.LastHalvedAmount())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "lastProposedHeight":
        address := common.Address{}
        if err := method.Inputs.Unpack(&address, arguments); err != nil {
            return nil, errExecutionReverted
        }
        res, err := method.Outputs.Pack(g.state.LastProposedHeight(address))
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "lockupPeriod":
        res, err := method.Outputs.Pack(g.state.LockupPeriod())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "minBlockInterval":
        res, err := method.Outputs.Pack(g.state.MinBlockInterval())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "minGasPrice":
        res, err := method.Outputs.Pack(g.state.MinGasPrice())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "miningVelocity":
        res, err := method.Outputs.Pack(g.state.MiningVelocity())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "minStake":
        res, err := method.Outputs.Pack(g.state.MinStake())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "nextHalvingSupply":
        res, err := method.Outputs.Pack(g.state.NextHalvingSupply())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "nodes":
        index := new(big.Int)
        if err := method.Inputs.Unpack(&index, arguments); err != nil {
            return nil, errExecutionReverted
        }
        info := g.state.Node(index)
        res, err := method.Outputs.Pack(
            info.Owner, info.PublicKey, info.Staked, info.Fined,
            info.Name, info.Email, info.Location, info.Url,
            info.Unstaked, info.UnstakedAt)
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "nodesOffsetByAddress":
        address := common.Address{}
        if err := method.Inputs.Unpack(&address, arguments); err != nil {
            return nil, errExecutionReverted
        }
        res, err := method.Outputs.Pack(g.state.NodesOffsetByAddress(address))
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "nodesOffsetByNodeKeyAddress":
        address := common.Address{}
        if err := method.Inputs.Unpack(&address, arguments); err != nil {
            return nil, errExecutionReverted
        }
        res, err := method.Outputs.Pack(g.state.NodesOffsetByNodeKeyAddress(address))
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "notarySetSize":
        res, err := method.Outputs.Pack(g.state.NotarySetSize())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "notaryParamAlpha":
        res, err := method.Outputs.Pack(g.state.NotaryParamAlpha())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "notaryParamBeta":
        res, err := method.Outputs.Pack(g.state.NotaryParamBeta())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "owner":
        res, err := method.Outputs.Pack(g.state.Owner())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "replaceNodePublicKey":
        var pk []byte
        if err := method.Inputs.Unpack(&pk, arguments); err != nil {
            return nil, errExecutionReverted
        }
        return g.replaceNodePublicKey(pk)
    case "roundHeight":
        round := new(big.Int)
        if err := method.Inputs.Unpack(&round, arguments); err != nil {
            return nil, errExecutionReverted
        }
        res, err := method.Outputs.Pack(g.state.RoundHeight(round))
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "roundLength":
        res, err := method.Outputs.Pack(g.state.RoundLength())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "totalStaked":
        res, err := method.Outputs.Pack(g.state.TotalStaked())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    case "totalSupply":
        res, err := method.Outputs.Pack(g.state.TotalSupply())
        if err != nil {
            return nil, errExecutionReverted
        }
        return res, nil
    }
    return nil, errExecutionReverted
}

func (g *GovernanceContract) transferOwnership(newOwner common.Address) ([]byte, error) {
    // Only owner can update configuration.
    if g.contract.Caller() != g.state.Owner() {
        return nil, errExecutionReverted
    }
    if newOwner == (common.Address{}) {
        return nil, errExecutionReverted
    }
    g.state.SetOwner(newOwner)
    return nil, nil
}

func (g *GovernanceContract) transferNodeOwnership(newOwner common.Address) ([]byte, error) {
    if newOwner == (common.Address{}) {
        return nil, errExecutionReverted
    }
    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    newOffset := g.state.NodesOffsetByAddress(newOwner)
    if newOffset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)
    g.state.DeleteNodeOffsets(node)

    node.Owner = newOwner
    g.state.PutNodeOffsets(node, offset)
    g.state.UpdateNode(offset, node)

    g.state.emitNodeOwnershipTransfered(caller, newOwner)

    return nil, nil
}

func (g *GovernanceContract) transferNodeOwnershipByFoundation(oldOwner, newOwner common.Address) ([]byte, error) {
    // Only owner can update configuration.
    if g.contract.Caller() != g.state.Owner() {
        return nil, errExecutionReverted
    }

    if newOwner == (common.Address{}) {
        return nil, errExecutionReverted
    }

    offset := g.state.NodesOffsetByAddress(oldOwner)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    newOffset := g.state.NodesOffsetByAddress(newOwner)
    if newOffset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)
    g.state.DeleteNodeOffsets(node)

    node.Owner = newOwner
    g.state.PutNodeOffsets(node, offset)
    g.state.UpdateNode(offset, node)

    g.state.emitNodeOwnershipTransfered(oldOwner, newOwner)

    return nil, nil
}

func (g *GovernanceContract) replaceNodePublicKey(newPublicKey []byte) ([]byte, error) {
    caller := g.contract.Caller()

    offset := g.state.NodesOffsetByAddress(caller)
    if offset.Cmp(big.NewInt(0)) < 0 {
        return nil, errExecutionReverted
    }

    newNodeKeyAddr, err := publicKeyToNodeKeyAddress(newPublicKey)
    if err != nil {
        return nil, errExecutionReverted
    }

    newNodeKeyOffset := g.state.NodesOffsetByNodeKeyAddress(newNodeKeyAddr)
    if newNodeKeyOffset.Cmp(big.NewInt(0)) >= 0 {
        return nil, errExecutionReverted
    }

    node := g.state.Node(offset)

    g.state.DeleteNodeOffsets(node)

    node.PublicKey = newPublicKey
    g.state.PutNodeOffsets(node, offset)
    g.state.UpdateNode(offset, node)

    g.state.emitNodePublicKeyReplaced(caller, newPublicKey)

    return nil, nil
}

func PackProposeCRS(round uint64, signedCRS []byte) ([]byte, error) {
    method := GovernanceABI.Name2Method["proposeCRS"]
    res, err := method.Inputs.Pack(big.NewInt(int64(round)), signedCRS)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackAddDKGMasterPublicKey(mpk *dkgTypes.MasterPublicKey) ([]byte, error) {
    method := GovernanceABI.Name2Method["addDKGMasterPublicKey"]
    encoded, err := rlp.EncodeToBytes(mpk)
    if err != nil {
        return nil, err
    }
    res, err := method.Inputs.Pack(encoded)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackAddDKGMPKReady(ready *dkgTypes.MPKReady) ([]byte, error) {
    method := GovernanceABI.Name2Method["addDKGMPKReady"]
    encoded, err := rlp.EncodeToBytes(ready)
    if err != nil {
        return nil, err
    }
    res, err := method.Inputs.Pack(encoded)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackAddDKGComplaint(complaint *dkgTypes.Complaint) ([]byte, error) {
    method := GovernanceABI.Name2Method["addDKGComplaint"]
    encoded, err := rlp.EncodeToBytes(complaint)
    if err != nil {
        return nil, err
    }

    res, err := method.Inputs.Pack(encoded)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackAddDKGFinalize(final *dkgTypes.Finalize) ([]byte, error) {
    method := GovernanceABI.Name2Method["addDKGFinalize"]
    encoded, err := rlp.EncodeToBytes(final)
    if err != nil {
        return nil, err
    }

    res, err := method.Inputs.Pack(encoded)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackAddDKGSuccess(final *dkgTypes.Success) ([]byte, error) {
    method := GovernanceABI.Name2Method["addDKGSuccess"]
    encoded, err := rlp.EncodeToBytes(final)
    if err != nil {
        return nil, err
    }

    res, err := method.Inputs.Pack(encoded)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackReportForkVote(vote1, vote2 *coreTypes.Vote) ([]byte, error) {
    method := GovernanceABI.Name2Method["report"]

    vote1Bytes, err := rlp.EncodeToBytes(vote1)
    if err != nil {
        return nil, err
    }

    vote2Bytes, err := rlp.EncodeToBytes(vote2)
    if err != nil {
        return nil, err
    }

    res, err := method.Inputs.Pack(big.NewInt(FineTypeForkVote), vote1Bytes, vote2Bytes)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackReportForkBlock(block1, block2 *coreTypes.Block) ([]byte, error) {
    method := GovernanceABI.Name2Method["report"]

    block1Bytes, err := rlp.EncodeToBytes(block1)
    if err != nil {
        return nil, err
    }

    block2Bytes, err := rlp.EncodeToBytes(block2)
    if err != nil {
        return nil, err
    }

    res, err := method.Inputs.Pack(big.NewInt(FineTypeForkBlock), block1Bytes, block2Bytes)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

func PackResetDKG(newSignedCRS []byte) ([]byte, error) {
    method := GovernanceABI.Name2Method["resetDKG"]
    res, err := method.Inputs.Pack(newSignedCRS)
    if err != nil {
        return nil, err
    }
    data := append(method.Id(), res...)
    return data, nil
}

// RandomContract provides access to on chain randomness.
type RandomContract struct {
    evm      *EVM
    contract *Contract
}

func (*RandomContract) Run(evm *EVM, input []byte,
    contract *Contract) (ret []byte, err error) {
    nonce := evm.StateDB.GetNonce(evm.Origin)

    cost := params.RandGas
    if !contract.UseGas(cost) {
        return nil, ErrOutOfGas
    }

    binaryOriginNonce := make([]byte, binary.MaxVarintLen64)
    binary.PutUvarint(binaryOriginNonce, nonce)

    binaryUsedIndex := make([]byte, binary.MaxVarintLen64)
    binary.PutUvarint(binaryUsedIndex, evm.RandCallIndex)

    evm.RandCallIndex += 1

    ret = crypto.Keccak256(
        evm.Randomness,
        evm.Origin.Bytes(),
        binaryOriginNonce,
        binaryUsedIndex)
    return
}