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

const watchers = [];

async function initialize(config) {
    if (config === undefined) {
        throw new Error('could not initialize watchers, no config defined');
    }
    if (config.length === 0) {
        throw new Error('no watchers defined');
    }
    for (var index = 0; index < config.length; index++) {
        var watcher = new Watcher(config[index], watcherCallback);
        await watcher.check();
        watchers.push(watcher);
        logger.debug('added watcher \'' + watcher.device + '\' to internal map');
    }
}

async function start() {
    logger.info('starting ' + watchers.length + ' watcher(s)...');
    for (var index = 0; index < watchers.length; index++) {
        await watchers[index].start();
    }
}

async function stop() {
    logger.info('stopping ' + watchers.length + ' watcher(s)...');
    for (var index = 0; index < watchers.length; index++) {
        await watchers[index].stop();
    }
}

async function watcherCallback(watcher) {
    if (watcher.restart) {
        await watcher.start();
        return;
    }
    watchers.splice(watchers.findIndex((foundWatcher) => foundWatcher.device === watcher), 1);
    logger.debug('removed watcher \'' + watcher.device + '\' from internal map');
    if (watchers.length === 0) {
        logger.warn('no watchers are active any longer');
    }
}

module.exports = {
    initialize,
    start,
    stop
}