const EventEmitter = require('events') const async = require('async') const extend = require('xtend') const Semaphore = require('semaphore') const ObservableStore = require('obs-store') const ethUtil = require('ethereumjs-util') const BN = require('ethereumjs-util').BN const TxProviderUtil = require('./lib/tx-utils') const createId = require('./lib/random-id') module.exports = class TransactionManager extends EventEmitter { constructor (opts) { super() this.store = new ObservableStore(extend({ transactions: [], }, opts.initState)) this.memStore = new ObservableStore({}) this.networkStore = opts.networkStore || new ObservableStore({}) this.preferencesStore = opts.preferencesStore || new ObservableStore({}) this.txHistoryLimit = opts.txHistoryLimit this.provider = opts.provider this.blockTracker = opts.blockTracker this.txProviderUtils = new TxProviderUtil(this.provider) this.blockTracker.on('block', this.checkForTxInBlock.bind(this)) this.signEthTx = opts.signTransaction this.nonceLock = Semaphore(1) // memstore is computed from a few different stores this._updateMemstore() this.store.subscribe(() => this._updateMemstore() ) this.networkStore.subscribe(() => this._updateMemstore() ) this.preferencesStore.subscribe(() => this._updateMemstore() ) } getState () { return this.memStore.getState() } getNetwork () { return this.networkStore.getState().network } getSelectedAddress () { return this.preferencesStore.getState().selectedAddress } // Returns the tx list getTxList () { let network = this.getNetwork() let fullTxList = this.getFullTxList() return fullTxList.filter(txMeta => txMeta.metamaskNetworkId === network) } // Returns the number of txs for the current network. getTxCount () { return this.getTxList().length } // Returns the full tx list across all networks getFullTxList () { return this.store.getState().transactions } // Adds a tx to the txlist addTx (txMeta) { let txCount = this.getTxCount() let network = this.getNetwork() let fullTxList = this.getFullTxList() let txHistoryLimit = this.txHistoryLimit // checks if the length of the tx history is // longer then desired persistence limit // and then if it is removes only confirmed // or rejected tx's. // not tx's that are pending or unapproved if (txCount > txHistoryLimit - 1) { var index = fullTxList.findIndex((metaTx) => ((metaTx.status === 'confirmed' || metaTx.status === 'rejected') && network === txMeta.metamaskNetworkId)) fullTxList.splice(index, 1) } fullTxList.push(txMeta) this._saveTxList(fullTxList) this.once(`${txMeta.id}:signed`, function (txId) { this.removeAllListeners(`${txMeta.id}:rejected`) }) this.once(`${txMeta.id}:rejected`, function (txId) { this.removeAllListeners(`${txMeta.id}:signed`) }) this.emit('updateBadge') this.emit(`${txMeta.id}:unapproved`, txMeta) } // gets tx by Id and returns it getTx (txId, cb) { var txList = this.getTxList() var txMeta = txList.find(txData => txData.id === txId) return cb ? cb(txMeta) : txMeta } // updateTx (txMeta) { var txId = txMeta.id var txList = this.getFullTxList() var index = txList.findIndex(txData => txData.id === txId) txList[index] = txMeta this._saveTxList(txList) this.emit('update') } get unapprovedTxCount () { return Object.keys(this.getUnapprovedTxList()).length } get pendingTxCount () { return this.getTxsByMetaData('status', 'signed').length } addUnapprovedTransaction (txParams, done) { let txMeta async.waterfall([ // validate (cb) => this.txProviderUtils.validateTxParams(txParams, cb), // prepare txMeta (cb) => { // create txMeta obj with parameters and meta data let time = (new Date()).getTime() let txId = createId() txParams.metamaskId = txId txParams.metamaskNetworkId = this.getNetwork() txMeta = { id: txId, time: time, status: 'unapproved', metamaskNetworkId: this.getNetwork(), txParams: txParams, } // calculate metadata for tx this.txProviderUtils.analyzeGasUsage(txMeta, cb) }, // save txMeta (cb) => { this.addTx(txMeta) this.setMaxTxCostAndFee(txMeta) cb(null, txMeta) }, ], done) } setMaxTxCostAndFee (txMeta) { var txParams = txMeta.txParams var gasCost = new BN(ethUtil.stripHexPrefix(txParams.gas || txMeta.estimatedGas), 16) var gasPrice = new BN(ethUtil.stripHexPrefix(txParams.gasPrice || '0x4a817c800'), 16) var txFee = gasCost.mul(gasPrice) var txValue = new BN(ethUtil.stripHexPrefix(txParams.value || '0x0'), 16) var maxCost = txValue.add(txFee) txMeta.txFee = txFee txMeta.txValue = txValue txMeta.maxCost = maxCost txMeta.gasPrice = gasPrice this.updateTx(txMeta) } getUnapprovedTxList () { var txList = this.getTxList() return txList.filter((txMeta) => txMeta.status === 'unapproved') .reduce((result, tx) => { result[tx.id] = tx return result }, {}) } approveTransaction (txId, cb = warn) { const self = this // approve self.setTxStatusApproved(txId) // only allow one tx at a time for atomic nonce usage self.nonceLock.take(() => { // begin signature process async.waterfall([ (cb) => self.fillInTxParams(txId, cb), (cb) => self.signTransaction(txId, cb), (rawTx, cb) => self.publishTransaction(txId, rawTx, cb), ], (err) => { self.nonceLock.leave() if (err) { this.setTxStatusFailed(txId, { errCode: err.errCode || err, message: err.message || 'Transaction failed during approval', }) return cb(err) } cb() }) }) } cancelTransaction (txId, cb = warn) { this.setTxStatusRejected(txId) cb() } fillInTxParams (txId, cb) { let txMeta = this.getTx(txId) this.txProviderUtils.fillInTxParams(txMeta.txParams, (err) => { if (err) return cb(err) this.updateTx(txMeta) cb() }) } signTransaction (txId, cb) { let txMeta = this.getTx(txId) let txParams = txMeta.txParams let fromAddress = txParams.from let ethTx = this.txProviderUtils.buildEthTxFromParams(txParams) this.signEthTx(ethTx, fromAddress).then(() => { this.setTxStatusSigned(txMeta.id) cb(null, ethUtil.bufferToHex(ethTx.serialize())) }).catch((err) => { cb(err) }) } publishTransaction (txId, rawTx, cb) { this.txProviderUtils.publishTransaction(rawTx, (err, txHash) => { if (err) return cb(err) this.setTxHash(txId, txHash) this.setTxStatusSubmitted(txId) cb() }) } // receives a txHash records the tx as signed setTxHash (txId, txHash) { // Add the tx hash to the persisted meta-tx object let txMeta = this.getTx(txId) txMeta.hash = txHash this.updateTx(txMeta) } /* Takes an object of fields to search for eg: var thingsToLookFor = { to: '0x0..', from: '0x0..', status: 'signed', } and returns a list of tx with all options matching this is for things like filtering a the tx list for only tx's from 1 account or for filltering for all txs from one account and that have been 'confirmed' */ getFilteredTxList (opts) { var filteredTxList Object.keys(opts).forEach((key) => { filteredTxList = this.getTxsByMetaData(key, opts[key], filteredTxList) }) return filteredTxList } getTxsByMetaData (key, value, txList = this.getTxList()) { return txList.filter((txMeta) => { if (txMeta.txParams[key]) { return txMeta.txParams[key] === value } else { return txMeta[key] === value } }) } // STATUS METHODS // get::set status // should return the status of the tx. getTxStatus (txId) { const txMeta = this.getTx(txId) return txMeta.status } // should update the status of the tx to 'rejected'. setTxStatusRejected (txId) { this._setTxStatus(txId, 'rejected') } // should update the status of the tx to 'approved'. setTxStatusApproved (txId) { this._setTxStatus(txId, 'approved') } // should update the status of the tx to 'signed'. setTxStatusSigned (txId) { this._setTxStatus(txId, 'signed') } // should update the status of the tx to 'submitted'. setTxStatusSubmitted (txId) { this._setTxStatus(txId, 'submitted') } // should update the status of the tx to 'confirmed'. setTxStatusConfirmed (txId) { this._setTxStatus(txId, 'confirmed') } setTxStatusFailed (txId, reason) { let txMeta = this.getTx(txId) txMeta.err = reason this.updateTx(txMeta) this._setTxStatus(txId, 'failed') } // merges txParams obj onto txData.txParams // use extend to ensure that all fields are filled updateTxParams (txId, txParams) { var txMeta = this.getTx(txId) txMeta.txParams = extend(txMeta.txParams, txParams) this.updateTx(txMeta) } // checks if a signed tx is in a block and // if included sets the tx status as 'confirmed' checkForTxInBlock () { var signedTxList = this.getFilteredTxList({status: 'submitted'}) if (!signedTxList.length) return signedTxList.forEach((txMeta) => { var txHash = txMeta.hash var txId = txMeta.id if (!txHash) { let errReason = { errCode: 'No hash was provided', message: 'We had an error while submitting this transaction, please try again.', } return this.setTxStatusFailed(txId, errReason) } this.txProviderUtils.query.getTransactionByHash(txHash, (err, txParams) => { if (err || !txParams) { if (!txParams) return txMeta.err = { isWarning: true, errorCode: err, message: 'There was a problem loading this transaction.', } this.updateTx(txMeta) return console.error(err) } if (txParams.blockNumber) { this.setTxStatusConfirmed(txId) } }) }) } // PRIVATE METHODS // Should find the tx in the tx list and // update it. // should set the status in txData // - `'unapproved'` the user has not responded // - `'rejected'` the user has responded no! // - `'approved'` the user has approved the tx // - `'signed'` the tx is signed // - `'submitted'` the tx is sent to a server // - `'confirmed'` the tx has been included in a block. _setTxStatus (txId, status) { var txMeta = this.getTx(txId) txMeta.status = status this.emit(`${txMeta.id}:${status}`, txId) if (status === 'submitted' || status === 'rejected') { this.emit(`${txMeta.id}:finished`, txMeta) } this.updateTx(txMeta) this.emit('updateBadge') } // Saves the new/updated txList. // Function is intended only for internal use _saveTxList (transactions) { this.store.updateState({ transactions }) } _updateMemstore () { const unapprovedTxs = this.getUnapprovedTxList() const selectedAddressTxList = this.getFilteredTxList({ from: this.getSelectedAddress(), metamaskNetworkId: this.getNetwork(), }) this.memStore.updateState({ unapprovedTxs, selectedAddressTxList }) } } const warn = () => console.warn('warn was used no cb provided')