import { Sequelize } from 'sequelize';
import config from 'lib/Config';
import { Log } from 'lib/Log';

type SequelDBClientState = {
	connection?: Sequelize;
	connecting?: Promise<void>;
	connected: boolean;
};

const log = Log.child({
	module: 'DB',
});

if (!config.postgresql.database) throw new Error('No database specified to connect to. Aborting...');

const state: SequelDBClientState = {
	connection: undefined,
	connecting: undefined,
	get connected() {
		return this.connection !== undefined;
	},
};

export const client = new Sequelize(config.postgresql.database, config.postgresql.user, config.postgresql.pass, {
	host: config.postgresql.host,
	port: config.postgresql.port,
	dialect: 'postgres',
	logging: log.trace.bind(log),
});

export const connect = (): Promise<void> =>
	new Promise((resolve, reject) => {
		if (state.connected) {
			resolve();
			return;
		}

		if (!state.connecting) {
			state.connecting = new Promise((iresolve, ireject) => {
				client.authenticate().then(iresolve).catch(ireject);
			});
		}

		state.connecting.then(resolve).catch(reject);
	});

export const disconnect = () => {
	if (state.connection) {
		return state.connection
			.close()
			.then(() => {
				state.connected = false;
				log.debug('Closed connection...');
			})
			.catch((err) => {
				log.error('Failed to close connection', err);
			});
	}
};

/** Create the initial connection */
connect().catch((err) => {
	log.error('Failed to establish connection', err);
	throw new Error('Failed to establish connection');
});

// eslint-disable-next-line @typescript-eslint/no-misused-promises
process.on('SIGINT', disconnect);
// eslint-disable-next-line @typescript-eslint/no-misused-promises
process.on('SIGTERM', disconnect);