const db = global.db;
const { EventEmitter } = require('events');
const log = require("./logger");

log.info("Starting event watcher...");

const emitter = new EventEmitter();

var lastEventIndex = 0;

async function getLastEventIndex() {
	const result = await db.query('SELECT EventIndex FROM Events ORDER BY EventIndex DESC LIMIT 1');
	if (result && result.length > 0) {
		lastEventIndex = result[0].EventIndex;
		log.info(`Last event index: ${lastEventIndex}`);
	}
}

getLastEventIndex();

async function fetchEvents() {
	try {
		const events = await db.query('SELECT * FROM Events WHERE EventIndex > ? ORDER BY EventIndex ASC', [lastEventIndex]);
		if (events && events.length > 0) {
			log.debug(`Fetched ${events.length} new event(s)`);
			events.forEach(event => {
				emitter.emit('event', event);
				lastEventIndex = event.EventIndex;
				log.debug(`Processed event index: ${lastEventIndex}; ${JSON.stringify(event)}`);
			});
		}
	} catch (err) {
		log.error(`Error fetching events: ${err}`);
	}
	setTimeout(fetchEvents, 1000);
}

fetchEvents();

module.exports = emitter;