/*jshint esversion: 6 */
let chokidar = require('chokidar');

let fs = require('../core/fs.js');

// TODO: this should be receiving the config object not re-reading the
// embark.json file
class Watch {
  constructor(options) {
    this.logger = options.logger;
    this.events = options.events;
  }

  start() {
    let self = this;
    // TODO: should come from the config object instead of reading the file
    // directly
    let embarkConfig = fs.readJSONSync("embark.json");

    this.watchAssets(embarkConfig, function () {
      self.logger.trace('ready to watch asset changes');
    });

    this.watchContracts(embarkConfig, function () {
      self.logger.trace('ready to watch contract changes');
    });

    this.watchConfigs(function () {
      self.logger.trace('ready to watch config changes');
    });

    this.logger.info("ready to watch file changes");
  }

  watchAssets(embarkConfig, callback) {
    let self = this;
    let appConfig = embarkConfig.app;
    let filesToWatch = [];

    for (let targetFile in appConfig) {
      filesToWatch.push(appConfig[targetFile]);
    }

    this.watchFiles(
      filesToWatch,
      function (eventName, path) {
        self.logger.info(`${eventName}: ${path}`);
        self.events.emit('file-' + eventName, 'asset', path);
        self.events.emit('file-event', 'asset', path);
      },
      function () {
        callback();
      }
    );
  }

  watchContracts(embarkConfig, callback) {
    let self = this;
    this.watchFiles(
      [embarkConfig.contracts],
      function (eventName, path) {
        self.logger.info(`${eventName}: ${path}`);
        self.events.emit('file-' + eventName, 'contract', path);
        self.events.emit('file-event', 'contract', path);
      },
      function () {
        callback();
      }
    );
  }

  watchConfigs(callback) {
    let self = this;
    this.watchFiles(
      "config/**/contracts.json",
      function (eventName, path) {
        self.logger.info(`${eventName}: ${path}`);
        self.events.emit('file-' + eventName, 'config', path);
        self.events.emit('file-event', 'config', path);
      },
      function () {
        callback();
      }
    );
  }

  watchFiles(files, changeCallback, doneCallback) {
    this.logger.trace('watchFiles');
    this.logger.trace(files);

    let configWatcher = chokidar.watch(files, {
      ignored: /[\/\\]\./, persistent: true, ignoreInitial: true, followSymlinks: true
    });

    configWatcher
      .on('add', path => changeCallback('add', path))
      .on('change', path => changeCallback('change', path))
      .on('unlink', path => changeCallback('remove', path))
      .on('ready', doneCallback);
  }

}

module.exports = Watch;