1 files changed, 184 insertions, 0 deletions
diff --git a/ethchain/block_chain.go b/ethchain/block_chain.go
new file mode 100644
index 000000000..56bc43a8e
--- /dev/null
+++ b/ethchain/block_chain.go
@@ -0,0 +1,184 @@
+package ethchain
+
+import (
+	"bytes"
+	"github.com/ethereum/eth-go/ethutil"
+	"log"
+	"math"
+	"math/big"
+)
+
+type BlockChain struct {
+	// The famous, the fabulous Mister GENESIIIIIIS (block)
+	genesisBlock *Block
+	// Last known total difficulty
+	TD *big.Int
+
+	LastBlockNumber uint64
+
+	CurrentBlock  *Block
+	LastBlockHash []byte
+}
+
+func NewBlockChain() *BlockChain {
+	bc := &BlockChain{}
+	bc.genesisBlock = NewBlockFromData(ethutil.Encode(Genesis))
+
+	bc.setLastBlock()
+
+	return bc
+}
+
+func (bc *BlockChain) Genesis() *Block {
+	return bc.genesisBlock
+}
+
+func (bc *BlockChain) NewBlock(coinbase []byte, txs []*Transaction) *Block {
+	var root interface{}
+	var lastBlockTime int64
+	hash := ZeroHash256
+
+	if bc.CurrentBlock != nil {
+		root = bc.CurrentBlock.State().Root
+		hash = bc.LastBlockHash
+		lastBlockTime = bc.CurrentBlock.Time
+	}
+
+	block := CreateBlock(
+		root,
+		hash,
+		coinbase,
+		ethutil.BigPow(2, 32),
+		nil,
+		"",
+		txs)
+
+	if bc.CurrentBlock != nil {
+		var mul *big.Int
+		if block.Time < lastBlockTime+42 {
+			mul = big.NewInt(1)
+		} else {
+			mul = big.NewInt(-1)
+		}
+
+		diff := new(big.Int)
+		diff.Add(diff, bc.CurrentBlock.Difficulty)
+		diff.Div(diff, big.NewInt(1024))
+		diff.Mul(diff, mul)
+		diff.Add(diff, bc.CurrentBlock.Difficulty)
+		block.Difficulty = diff
+	}
+
+	return block
+}
+
+func (bc *BlockChain) HasBlock(hash []byte) bool {
+	data, _ := ethutil.Config.Db.Get(hash)
+	return len(data) != 0
+}
+
+func (bc *BlockChain) GenesisBlock() *Block {
+	return bc.genesisBlock
+}
+
+// Get chain return blocks from hash up to max in RLP format
+func (bc *BlockChain) GetChainFromHash(hash []byte, max uint64) []interface{} {
+	var chain []interface{}
+	// Get the current hash to start with
+	currentHash := bc.CurrentBlock.Hash()
+	// Get the last number on the block chain
+	lastNumber := bc.BlockInfo(bc.CurrentBlock).Number
+	// Get the parents number
+	parentNumber := bc.BlockInfoByHash(hash).Number
+	// Get the min amount. We might not have max amount of blocks
+	count := uint64(math.Min(float64(lastNumber-parentNumber), float64(max)))
+	startNumber := parentNumber + count
+
+	num := lastNumber
+	for ; num > startNumber; currentHash = bc.GetBlock(currentHash).PrevHash {
+		num--
+	}
+	for i := uint64(0); bytes.Compare(currentHash, hash) != 0 && num >= parentNumber && i < count; i++ {
+		// Get the block of the chain
+		block := bc.GetBlock(currentHash)
+		currentHash = block.PrevHash
+
+		chain = append(chain, block.RlpValue().Value)
+		//chain = append([]interface{}{block.RlpValue().Value}, chain...)
+
+		num--
+	}
+
+	return chain
+}
+
+func (bc *BlockChain) setLastBlock() {
+	data, _ := ethutil.Config.Db.Get([]byte("LastBlock"))
+	if len(data) != 0 {
+		block := NewBlockFromBytes(data)
+		info := bc.BlockInfo(block)
+		bc.CurrentBlock = block
+		bc.LastBlockHash = block.Hash()
+		bc.LastBlockNumber = info.Number
+
+		log.Printf("[CHAIN] Last known block height #%d\n", bc.LastBlockNumber)
+	}
+
+	// Set the last know difficulty (might be 0x0 as initial value, Genesis)
+	bc.TD = ethutil.BigD(ethutil.Config.Db.LastKnownTD())
+}
+
+func (bc *BlockChain) SetTotalDifficulty(td *big.Int) {
+	ethutil.Config.Db.Put([]byte("LastKnownTotalDifficulty"), td.Bytes())
+	bc.TD = td
+}
+
+// Add a block to the chain and record addition information
+func (bc *BlockChain) Add(block *Block) {
+	bc.writeBlockInfo(block)
+
+	// Prepare the genesis block
+	bc.CurrentBlock = block
+	bc.LastBlockHash = block.Hash()
+
+	ethutil.Config.Db.Put(block.Hash(), block.RlpEncode())
+}
+
+func (bc *BlockChain) GetBlock(hash []byte) *Block {
+	data, _ := ethutil.Config.Db.Get(hash)
+
+	return NewBlockFromData(data)
+}
+
+func (bc *BlockChain) BlockInfoByHash(hash []byte) BlockInfo {
+	bi := BlockInfo{}
+	data, _ := ethutil.Config.Db.Get(append(hash, []byte("Info")...))
+	bi.RlpDecode(data)
+
+	return bi
+}
+
+func (bc *BlockChain) BlockInfo(block *Block) BlockInfo {
+	bi := BlockInfo{}
+	data, _ := ethutil.Config.Db.Get(append(block.Hash(), []byte("Info")...))
+	bi.RlpDecode(data)
+
+	return bi
+}
+
+// Unexported method for writing extra non-essential block info to the db
+func (bc *BlockChain) writeBlockInfo(block *Block) {
+	bc.LastBlockNumber++
+	bi := BlockInfo{Number: bc.LastBlockNumber, Hash: block.Hash(), Parent: block.PrevHash}
+
+	// For now we use the block hash with the words "info" appended as key
+	ethutil.Config.Db.Put(append(block.Hash(), []byte("Info")...), bi.RlpEncode())
+}
+
+func (bc *BlockChain) Stop() {
+	if bc.CurrentBlock != nil {
+		ethutil.Config.Db.Put([]byte("LastBlock"), bc.CurrentBlock.RlpEncode())
+
+		log.Println("[CHAIN] Stopped")
+	}
+}