const fs = require('fs');
const path = require('path');
const Queue = require('better-queue');
const chokidar = require('chokidar');

const paths = require('../data/paths.json'); // get our paths
const settings = require('../data/settings.json'); // get the settings

const { log } = require('./utils');
const file = require('./file');
const db = require('./db');

const queue = new Queue(async (input, cb) => {
  cb = cb || function(){};
  let result = true; //await file.process(input); // process the queue
  cb(null, result);
}, settings.queue);


queue.on('task_started', (taskId, result, stats) => {
  console.log('task_started',taskId);
});
queue.on('task_progress', (taskId, completed, total)  => {
  console.log('task_progress',taskId);
});
queue.on('task_finish', (taskId, result, stats)  => {
  console.log('task_finish',taskId);
  // log the activity
  // taskId = 1, result: 3, stats = { elapsed: <time taken> }
});
queue.on('task_failed', (taskId, err) => {
  console.log('task_failed',taskId);
  // get the file from the task
  //if (settings.queue.deleteOnFail) file.remove();
});

const cancel = async (taskId) => {
  queue.cancel(taskId);
};

const pause = async () => {
  queue.pause();
};

const resume = async () => {
  queue.resume();
};

const stats = async () => {
  return queue.getStats();
};

// initialize watches and db then start the watcher
const watch = () => {

  const dirs = Object.keys(paths); // get a list of the paths from the keys
  const defaults = settings.defaults; // load tje defaults
  const opts = settings.watcher; // setup watcher options
  let watches = []; // array of things to watch

  opts.ignored = new RegExp(opts.ignored); // convert the ignored into a reqex

  // loop the dirs
  for (let d in dirs) {
    let dir = dirs[d]; // pointer
    let options = Object.assign({}, defaults, paths[dir]); // baseline the options
    let database = db.connect(dir); // connect to the database
    database.defaults({ files: [] }).write();   // init the database
    // loop the exts to watch
    for (let e in options.exts) {
      let ext = options.exts[e]; // alias the ext
      watches.push(`${dir}/**/*.${ext}`); // push the watch
    }
  }

  // init our watcher
  const watcher = chokidar.watch(watches, opts);
  log(`Watching:\n${JSON.stringify(watches,null,2)}\n`,false);

  watcher
    .on('add', async f => {
      queue.push(f); // when a file is added ... push the file onto the queue to be processed
    })
    .on('change', f => {
      log(` -> "${f}" [changed] (${new Date()})\n`,false); // when a file changes ...
    })
    .on('unlink', async f => {
      log(` -> "${f}" [removed] (${new Date()})\n`,false); // when a file is removed ...
      //file.cleanup(dirs, f);
    })
    .on('error', error => {
      log(` -> Error ${new Date()}: ${error.message || error}\n`, false);
    });
};

module.exports = {
  cancel,
  pause,
  queue,
  resume,
  stats,
  watch
};