'use strict';

let logger = require('../Utils/Logger')('NIS');
let nem = require('nem-sdk').default;

/**
 * Listener for all blockchain and website events
 */
class Blockchain
{
    constructor() {
        this.isConnected = false;
        this.hostname = null;
        this.endpoint = null;
        this.wallet = null;
        this._onConfirmed = null;
        this._onBlock = null;

        let KeyPair = nem.crypto.keyPair.create(process.env.APP_PRIVATE_KEY);
        this.netId = process.env.NEM_NETWORK === 'testnet'
            ? nem.model.network.data.testnet.id
            : nem.model.network.data.mainnet.id;
        this.wallet = nem.model.address.toAddress(KeyPair.publicKey.toString(), this.netId);
        logger.info('Configured bot for wallet: ' + this.wallet);
    }

    start(host) {
        logger.info('Starting bot on host: ' + host);
        this.setHostname(host);
        this.connect(this.getConnector());
    }

    getConnector() {
        this.endpoint = nem.model.objects.create("endpoint")('http://'+this.hostname, nem.model.nodes.defaultPort);
        let endpointWs = nem.model.objects.create("endpoint")('http://'+this.hostname, 7778);
        return nem.com.websockets.connector.create(endpointWs, this.wallet);
    }

    setHostname(hostname) {
        this.hostname = hostname;
    }

    onBlock(callback) {
        this._onBlock = callback;
    }

    onConfirmed(callback) {
        this._onConfirmed = callback;
    }

    connect(connector) {
        if (!this.hostname || !this.wallet) {
            logger.info('Cannot connect: invalid settings!');
            this.isConnected = false;
            return false;
        }

        return connector.connect().then(() => {
            logger.info('Connected to: '+ connector.endpoint.host);
            this.isConnected = true;
            if (this._onBlock !== null) {
                logger.info('Subscribing for new blocks...');
                nem.com.websockets.subscribe.chain.blocks(connector, (res) => {
                    this._onBlock(res);
                });
            }
            if (this._onConfirmed !== null) {
                logger.info('Subscribing for new transactions...');
                connector.stompClient.send('');
                nem.com.websockets.subscribe.account.transactions.confirmed(connector, (res) => {
                    this._onConfirmed(res);
                }, this.wallet);
            }
            nem.com.websockets.subscribe.errors(connector, function(res){
                logger.error(res);
            });
        }, (err) => {
            logger.error('An error occured: ' + JSON.stringify(err));
            this.reconnect();
        });
    }

    reconnect() {
        this.isConnected = false;
        if (!this.hostname || !this.wallet) {
            logger.info('Cannot reconnect: invalid settings!');
            return false;
        }
        logger.info('Reconnecting to: '+ this.hostname);
        this.connect(this.getConnector());
    }
}

module.exports = new Blockchain();