const assert = require('assert') const EventEmitter = require('events') const ObservableStore = require('obs-store') const ComposedStore = require('obs-store/lib/composed') const EthQuery = require('eth-query') const JsonRpcEngine = require('json-rpc-engine') const providerFromEngine = require('eth-json-rpc-middleware/providerFromEngine') const log = require('loglevel') const createMetamaskMiddleware = require('./createMetamaskMiddleware') const createInfuraClient = require('./createInfuraClient') const createJsonRpcClient = require('./createJsonRpcClient') const createLocalhostClient = require('./createLocalhostClient') const { createSwappableProxy, createEventEmitterProxy } = require('swappable-obj-proxy') const { ROPSTEN, RINKEBY, KOVAN, MAINNET, LOCALHOST, } = require('./enums') 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 }) this.on('networkDidChange', this.lookupNetwork) // provider and block tracker this._provider = null this._blockTracker = null // provider and block tracker proxies - because the network changes this._providerProxy = null this._blockTrackerProxy = null } initializeProvider (providerParams) { this._baseProviderParams = providerParams const { type, rpcTarget } = this.providerStore.getState() this._configureProvider({ type, rpcTarget }) this.lookupNetwork() } // return the proxies so the references will always be good getProviderAndBlockTracker () { const provider = this._providerProxy const blockTracker = this._blockTrackerProxy return { provider, blockTracker } } 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._provider) { return log.warn('NetworkController - lookupNetwork aborted due to missing provider') } const ethQuery = new EthQuery(this._provider) 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.providerConfig = 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 "${type}"`) const providerConfig = { type } this.providerConfig = providerConfig } resetConnection () { this.providerConfig = this.getProviderConfig() } set providerConfig (providerConfig) { this.providerStore.updateState(providerConfig) this._switchNetwork(providerConfig) } getProviderConfig () { return this.providerStore.getState() } // // Private // _switchNetwork (opts) { this.setNetworkState('loading') this._configureProvider(opts) this.emit('networkDidChange') } _configureProvider (opts) { const { type, rpcTarget } = opts // infura type-based endpoints const isInfura = INFURA_PROVIDER_TYPES.includes(type) if (isInfura) { this._configureInfuraProvider(opts) // other type-based rpc endpoints } else if (type === LOCALHOST) { this._configureLocalhostProvider() // url-based rpc endpoints } else if (type === 'rpc') { this._configureStandardProvider({ rpcUrl: rpcTarget }) } else { throw new Error(`NetworkController - _configureProvider - unknown type "${type}"`) } } _configureInfuraProvider ({ type }) { log.info('NetworkController - configureInfuraProvider', type) const networkClient = createInfuraClient({ network: type }) this._setNetworkClient(networkClient) } _configureLocalhostProvider () { log.info('NetworkController - configureLocalhostProvider') const networkClient = createLocalhostClient() this._setNetworkClient(networkClient) } _configureStandardProvider ({ rpcUrl }) { log.info('NetworkController - configureStandardProvider', rpcUrl) const networkClient = createJsonRpcClient({ rpcUrl }) this._setNetworkClient(networkClient) } _setNetworkClient ({ networkMiddleware, blockTracker }) { const metamaskMiddleware = createMetamaskMiddleware(this._baseProviderParams) const engine = new JsonRpcEngine() engine.push(metamaskMiddleware) engine.push(networkMiddleware) const provider = providerFromEngine(engine) this._setProviderAndBlockTracker({ provider, blockTracker }) } _setProviderAndBlockTracker ({ provider, blockTracker }) { // update or intialize proxies if (this._providerProxy) { this._providerProxy.setTarget(provider) } else { this._providerProxy = createSwappableProxy(provider) } if (this._blockTrackerProxy) { this._blockTrackerProxy.setTarget(blockTracker) } else { this._blockTrackerProxy = createEventEmitterProxy(blockTracker, { eventFilter: 'skipInternal' }) } // set new provider and blockTracker this._provider = provider this._blockTracker = blockTracker } _logBlock (block) { log.info(`BLOCK CHANGED: #${block.number.toString('hex')} 0x${block.hash.toString('hex')}`) this.verifyNetwork() } }