const assert = require('assert') const EventEmitter = require('events') const createMetamaskProvider = require('web3-provider-engine/zero.js') const SubproviderFromProvider = require('web3-provider-engine/subproviders/provider.js') const createInfuraProvider = require('eth-json-rpc-infura/src/createProvider') const ObservableStore = require('obs-store') const ComposedStore = require('obs-store/lib/composed') const extend = require('xtend') const EthQuery = require('eth-query') const createEventEmitterProxy = require('../../lib/events-proxy.js') const log = require('loglevel') const { ROPSTEN, RINKEBY, KOVAN, MAINNET, LOCALHOST, } = require('./enums') const LOCALHOST_RPC_URL = 'http://localhost:8545' const INFURA_PROVIDER_TYPES = [ROPSTEN, RINKEBY, KOVAN, MAINNET] const env = process.env.METAMASK_ENV const METAMASK_DEBUG = process.env.METAMASK_DEBUG const testMode = (METAMASK_DEBUG || env === 'test') const defaultProviderConfig = { type: testMode ? RINKEBY : MAINNET, } module.exports = class NetworkController extends EventEmitter { constructor (opts = {}) { super() // parse options const providerConfig = opts.provider || defaultProviderConfig // create stores this.providerStore = new ObservableStore(providerConfig) this.networkStore = new ObservableStore('loading') this.store = new ComposedStore({ provider: this.providerStore, network: this.networkStore }) // create event emitter proxy this._proxy = createEventEmitterProxy() this.on('networkDidChange', this.lookupNetwork) } initializeProvider (_providerParams) { this._baseProviderParams = _providerParams const { type, rpcTarget } = this.providerStore.getState() this._configureProvider({ type, rpcTarget }) this._proxy.on('block', this._logBlock.bind(this)) this._proxy.on('error', this.verifyNetwork.bind(this)) this.ethQuery = new EthQuery(this._proxy) this.lookupNetwork() return this._proxy } verifyNetwork () { // Check network when restoring connectivity: if (this.isNetworkLoading()) this.lookupNetwork() } getNetworkState () { return this.networkStore.getState() } setNetworkState (network) { return this.networkStore.putState(network) } isNetworkLoading () { return this.getNetworkState() === 'loading' } lookupNetwork () { // Prevent firing when provider is not defined. if (!this.ethQuery || !this.ethQuery.sendAsync) { return log.warn('NetworkController - lookupNetwork aborted due to missing ethQuery') } this.ethQuery.sendAsync({ method: 'net_version' }, (err, network) => { if (err) return this.setNetworkState('loading') log.info('web3.getNetwork returned ' + network) this.setNetworkState(network) }) } setRpcTarget (rpcTarget) { const providerConfig = { type: 'rpc', rpcTarget, } this.providerStore.updateState(providerConfig) this._switchNetwork(providerConfig) } async setProviderType (type) { assert.notEqual(type, 'rpc', `NetworkController - cannot call "setProviderType" with type 'rpc'. use "setRpcTarget"`) assert(INFURA_PROVIDER_TYPES.includes(type) || type === LOCALHOST, `NetworkController - Unknown rpc type "${type}"`) const providerConfig = { type } this.providerStore.updateState(providerConfig) this._switchNetwork(providerConfig) } getProviderConfig () { return this.providerStore.getState() } // // Private // _switchNetwork (opts) { this.setNetworkState('loading') this._configureProvider(opts) this.emit('networkDidChange') } _configureProvider (opts) { const { type, rpcTarget } = opts // infura type-based endpoints const isInfura = INFURA_PROVIDER_TYPES.includes(type) if (isInfura) { this._configureInfuraProvider(opts) // other type-based rpc endpoints } else if (type === LOCALHOST) { this._configureStandardProvider({ rpcUrl: LOCALHOST_RPC_URL }) // url-based rpc endpoints } else if (type === 'rpc'){ this._configureStandardProvider({ rpcUrl: rpcTarget }) } else { throw new Error(`NetworkController - _configureProvider - unknown type "${type}"`) } } _configureInfuraProvider ({ type }) { log.info('_configureInfuraProvider', type) const infuraProvider = createInfuraProvider({ network: type }) const infuraSubprovider = new SubproviderFromProvider(infuraProvider) const providerParams = extend(this._baseProviderParams, { engineParams: { pollingInterval: 8000, blockTrackerProvider: infuraProvider, }, dataSubprovider: infuraSubprovider, }) const provider = createMetamaskProvider(providerParams) this._setProvider(provider) } _configureStandardProvider ({ rpcUrl }) { const providerParams = extend(this._baseProviderParams, { rpcUrl, engineParams: { pollingInterval: 8000, }, }) const provider = createMetamaskProvider(providerParams) this._setProvider(provider) } _setProvider (provider) { // collect old block tracker events const oldProvider = this._provider let blockTrackerHandlers if (oldProvider) { // capture old block handlers blockTrackerHandlers = oldProvider._blockTracker.proxyEventHandlers // tear down oldProvider.removeAllListeners() oldProvider.stop() } // override block tracler provider._blockTracker = createEventEmitterProxy(provider._blockTracker, blockTrackerHandlers) // set as new provider this._provider = provider this._proxy.setTarget(provider) } _logBlock (block) { log.info(`BLOCK CHANGED: #${block.number.toString('hex')} 0x${block.hash.toString('hex')}`) this.verifyNetwork() } }