const configJSON = require('../config.json');
const logger = require('./logger.js');
const Watcher = require('./watcher.js');

const watchers = [];

function initialize() {
    return new Promise(function (resolve, reject) {
        if (configJSON == undefined || configJSON.watchers == undefined || configJSON.watchers.length == 0) {
            reject('no watchers in \'config.json\' defined');
        }
        var tmp = []
        for (var index = 0; index < configJSON.watchers.length; index++) {
            tmp.push(new Watcher(configJSON.watchers[index], watcherCallback));
        }
        Promise.all(tmp.map(check))
            .then(resolve)
            .catch(reject);
    });
}
function check(watcher) {
    return new Promise((resolve, reject) => {
        if (watcher == undefined) {
            reject();
        }
        watcher.check()
            .then(() => {
                watchers.push(watcher)
                logger.debug('added watcher \'' + watcher.device + '\' to internal map');
            })
            .then(resolve)
            .catch(reject);
    });
}

function start() {
    return new Promise((resolve, reject) => {
        logger.info('starting ' + watchers.length + ' watcher(s)...');
        var promises = [];
        for (var index = 0; index < watchers.length; index++) {
            promises.push(watchers[index].start());
        }
        Promise.all(promises)
            .then(resolve)
            .catch(reject);
    });
}

function stop() {
    return new Promise((resolve, reject) => {
        logger.info('stopping ' + watchers.length + ' watcher(s)...');
        var promises = [];
        for (var index = 0; index < watchers.length; index++) {
            promises.push(watchers[index].stop());
        }
        Promise.all(promises)
            .then(resolve)
            .catch(reject);
    });
}

function watcherCallback(watcher) {
    watchers.splice(watchers.findIndex((foundWatcher) => foundWatcher.device == watcher), 1);
    logger.debug('removed watcher \'' + watcher + '\' from internal map');
}

module.exports = {
    initialize,
    start,
    stop
}