path: root/cmd/utils/jeth.go

// Copyright 2015 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum 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 go-ethereum 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 go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package utils

import (
    "encoding/json"
    "fmt"
    "time"

    "github.com/ethereum/go-ethereum/jsre"
    "github.com/ethereum/go-ethereum/rpc"

    "github.com/robertkrimen/otto"
)

type Jeth struct {
    re     *jsre.JSRE
    client rpc.Client
}

// NewJeth create a new backend for the JSRE console
func NewJeth(re *jsre.JSRE, client rpc.Client) *Jeth {
    return &Jeth{re, client}
}

// err returns an error object for the given error code and message.
func (self *Jeth) err(call otto.FunctionCall, code int, msg string, id interface{}) (response otto.Value) {
    m := rpc.JSONErrResponse{
        Version: "2.0",
        Id:      id,
        Error: rpc.JSONError{
            Code:    code,
            Message: msg,
        },
    }

    errObj, _ := json.Marshal(m.Error)
    errRes, _ := json.Marshal(m)

    call.Otto.Run("ret_error = " + string(errObj))
    res, _ := call.Otto.Run("ret_response = " + string(errRes))

    return res
}

// UnlockAccount asks the user for the password and than executes the jeth.UnlockAccount callback in the jsre.
// It will need the public address for the account to unlock as first argument.
// The second argument is an optional string with the password. If not given the user is prompted for the password.
// The third argument is an optional integer which specifies for how long the account will be unlocked (in seconds).
func (self *Jeth) UnlockAccount(call otto.FunctionCall) (response otto.Value) {
    var account, passwd otto.Value
    duration := otto.NullValue()

    if !call.Argument(0).IsString() {
        fmt.Println("first argument must be the account to unlock")
        return otto.FalseValue()
    }

    account = call.Argument(0)

    // if password is not given or as null value -> ask user for password
    if call.Argument(1).IsUndefined() || call.Argument(1).IsNull() {
        fmt.Printf("Unlock account %s\n", account)
        if input, err := Stdin.PasswordPrompt("Passphrase: "); err != nil {
            return otto.FalseValue()
            passwd, _ = otto.ToValue(input)
        } else {
            throwJSExeception(err.Error())
        }
    } else {
        if !call.Argument(1).IsString() {
            throwJSExeception("password must be a string")
        }
        passwd = call.Argument(1)
    }

    // third argument is the duration how long the account must be unlocked.
    // verify that its a number.
    if call.Argument(2).IsDefined() && !call.Argument(2).IsNull() {
        if !call.Argument(2).IsNumber() {
            throwJSExeception("unlock duration must be a number")
        }
        duration = call.Argument(2)
    }

    // jeth.unlockAccount will send the request to the backend.
    if val, err := call.Otto.Call("jeth.unlockAccount", nil, account, passwd, duration); err == nil {
        return val
    } else {
        throwJSExeception(err.Error())
    }

    return otto.FalseValue()
}

// NewAccount asks the user for the password and than executes the jeth.newAccount callback in the jsre
func (self *Jeth) NewAccount(call otto.FunctionCall) (response otto.Value) {
    var passwd string
    if len(call.ArgumentList) == 0 {
        var err error
        passwd, err = Stdin.PasswordPrompt("Passphrase: ")
        if err != nil {
            return otto.FalseValue()
        }
        passwd2, err := Stdin.PasswordPrompt("Repeat passphrase: ")
        if err != nil {
            return otto.FalseValue()
        }

        if passwd != passwd2 {
            fmt.Println("Passphrases don't match")
            return otto.FalseValue()
        }
    } else if len(call.ArgumentList) == 1 && call.Argument(0).IsString() {
        passwd, _ = call.Argument(0).ToString()
    } else {
        fmt.Println("expected 0 or 1 string argument")
        return otto.FalseValue()
    }

    if ret, err := call.Otto.Call("jeth.newAccount", nil, passwd); err == nil {
        return ret
    } else {
        fmt.Printf("%v\n", err)
        return otto.FalseValue()
    }

    return otto.FalseValue()
}

// Send will serialize the first argument, send it to the node and returns the response.
func (self *Jeth) Send(call otto.FunctionCall) (response otto.Value) {
    // verify we got a batch request (array) or a single request (object)
    ro := call.Argument(0).Object()
    if ro == nil || (ro.Class() != "Array" && ro.Class() != "Object") {
        throwJSExeception("Internal Error: request must be an object or array")
    }

    // convert otto vm arguments to go values by JSON serialising and parsing.
    data, err := call.Otto.Call("JSON.stringify", nil, ro)
    if err != nil {
        throwJSExeception(err.Error())
    }

    jsonreq, _ := data.ToString()

    // parse arguments to JSON rpc requests, either to an array (batch) or to a single request.
    var reqs []rpc.JSONRequest
    batch := true
    if err = json.Unmarshal([]byte(jsonreq), &reqs); err != nil {
        // single request?
        reqs = make([]rpc.JSONRequest, 1)
        if err = json.Unmarshal([]byte(jsonreq), &reqs[0]); err != nil {
            throwJSExeception("invalid request")
        }
        batch = false
    }

    call.Otto.Set("response_len", len(reqs))
    call.Otto.Run("var ret_response = new Array(response_len);")

    for i, req := range reqs {
        if err := self.client.Send(&req); err != nil {
            return self.err(call, -32603, err.Error(), req.Id)
        }

        result := make(map[string]interface{})
        if err = self.client.Recv(&result); err != nil {
            return self.err(call, -32603, err.Error(), req.Id)
        }

        id, _ := result["id"]
        jsonver, _ := result["jsonrpc"]

        call.Otto.Set("ret_id", id)
        call.Otto.Set("ret_jsonrpc", jsonver)
        call.Otto.Set("response_idx", i)

        // call was successful
        if res, ok := result["result"]; ok {
            payload, _ := json.Marshal(res)
            call.Otto.Set("ret_result", string(payload))
            response, err = call.Otto.Run(`
                ret_response[response_idx] = { jsonrpc: ret_jsonrpc, id: ret_id, result: JSON.parse(ret_result) };
            `)
            continue
        }

        // request returned an error
        if res, ok := result["error"]; ok {
            payload, _ := json.Marshal(res)
            call.Otto.Set("ret_result", string(payload))
            response, err = call.Otto.Run(`
                ret_response[response_idx] = { jsonrpc: ret_jsonrpc, id: ret_id, error: JSON.parse(ret_result) };
            `)
            continue
        }

        return self.err(call, -32603, fmt.Sprintf("Invalid response"), new(int64))
    }

    if !batch {
        call.Otto.Run("ret_response = ret_response[0];")
    }

    // if a callback was given execute it.
    if call.Argument(1).IsObject() {
        call.Otto.Set("callback", call.Argument(1))
        call.Otto.Run(`
        if (Object.prototype.toString.call(callback) == '[object Function]') {
            callback(null, ret_response);
        }
        `)
    }

    return
}

// throwJSExeception panics on an otto value, the Otto VM will then throw msg as a javascript error.
func throwJSExeception(msg interface{}) otto.Value {
    p, _ := otto.ToValue(msg)
    panic(p)
    return p
}

// Sleep will halt the console for arg[0] seconds.
func (self *Jeth) Sleep(call otto.FunctionCall) (response otto.Value) {
    if len(call.ArgumentList) >= 1 {
        if call.Argument(0).IsNumber() {
            sleep, _ := call.Argument(0).ToInteger()
            time.Sleep(time.Duration(sleep) * time.Second)
            return otto.TrueValue()
        }
    }
    return throwJSExeception("usage: sleep(<sleep in seconds>)")
}

// SleepBlocks will wait for a specified number of new blocks or max for a
// given of seconds. sleepBlocks(nBlocks[, maxSleep]).
func (self *Jeth) SleepBlocks(call otto.FunctionCall) (response otto.Value) {
    nBlocks := int64(0)
    maxSleep := int64(9999999999999999) // indefinitely

    nArgs := len(call.ArgumentList)

    if nArgs == 0 {
        throwJSExeception("usage: sleepBlocks(<n blocks>[, max sleep in seconds])")
    }

    if nArgs >= 1 {
        if call.Argument(0).IsNumber() {
            nBlocks, _ = call.Argument(0).ToInteger()
        } else {
            throwJSExeception("expected number as first argument")
        }
    }

    if nArgs >= 2 {
        if call.Argument(1).IsNumber() {
            maxSleep, _ = call.Argument(1).ToInteger()
        } else {
            throwJSExeception("expected number as second argument")
        }
    }

    // go through the console, this will allow web3 to call the appropriate
    // callbacks if a delayed response or notification is received.
    currentBlockNr := func() int64 {
        result, err := call.Otto.Run("eth.blockNumber")
        if err != nil {
            throwJSExeception(err.Error())
        }
        blockNr, err := result.ToInteger()
        if err != nil {
            throwJSExeception(err.Error())
        }
        return blockNr
    }

    targetBlockNr := currentBlockNr() + nBlocks
    deadline := time.Now().Add(time.Duration(maxSleep) * time.Second)

    for time.Now().Before(deadline) {
        if currentBlockNr() >= targetBlockNr {
            return otto.TrueValue()
        }
        time.Sleep(time.Second)
    }

    return otto.FalseValue()
}