import { createServer, type AddressInfo } from 'node:net';
import pgPromise from 'pg-promise';
import type {
	IExecuteFunctions,
	ICredentialTestFunctions,
	ILoadOptionsFunctions,
	ITriggerFunctions,
} from 'n8n-workflow';

import { formatPrivateKey } from '@utils/utilities';
import type {
	ConnectionsData,
	PgpConnectionParameters,
	PostgresNodeCredentials,
	PostgresNodeOptions,
} from '../helpers/interfaces';
import { LOCALHOST } from '@utils/constants';

const getPostgresConfig = (
	credentials: PostgresNodeCredentials,
	options: PostgresNodeOptions = {},
) => {
	const dbConfig: PgpConnectionParameters = {
		host: credentials.host,
		port: credentials.port,
		database: credentials.database,
		user: credentials.user,
		password: credentials.password,
		keepAlive: true,
	};

	if (options.connectionTimeout) {
		dbConfig.connectionTimeoutMillis = options.connectionTimeout * 1000;
	}

	if (options.delayClosingIdleConnection) {
		dbConfig.keepAliveInitialDelayMillis = options.delayClosingIdleConnection * 1000;
	}

	if (credentials.allowUnauthorizedCerts === true) {
		dbConfig.ssl = {
			rejectUnauthorized: false,
		};
	} else {
		dbConfig.ssl = !['disable', undefined].includes(credentials.ssl as string | undefined);
		// @ts-ignore these typings need to be updated
		dbConfig.sslmode = credentials.ssl || 'disable';
	}

	return dbConfig;
};

export async function configurePostgres(
	this: IExecuteFunctions | ICredentialTestFunctions | ILoadOptionsFunctions | ITriggerFunctions,
	credentials: PostgresNodeCredentials,
	options: PostgresNodeOptions = {},
): Promise<ConnectionsData> {
	const pgp = pgPromise({
		// prevent spam in console "WARNING: Creating a duplicate database object for the same connection."
		// duplicate connections created when auto loading parameters, they are closed immediately after, but several could be open at the same time
		noWarnings: true,
	});

	if (typeof options.nodeVersion === 'number' && options.nodeVersion >= 2.1) {
		// Always return dates as ISO strings
		[pgp.pg.types.builtins.TIMESTAMP, pgp.pg.types.builtins.TIMESTAMPTZ].forEach((type) => {
			pgp.pg.types.setTypeParser(type, (value: string) => {
				return new Date(value).toISOString();
			});
		});
	}

	if (options.largeNumbersOutput === 'numbers') {
		pgp.pg.types.setTypeParser(20, (value: string) => {
			return parseInt(value, 10);
		});
		pgp.pg.types.setTypeParser(1700, (value: string) => {
			return parseFloat(value);
		});
	}

	const dbConfig = getPostgresConfig(credentials, options);

	if (!credentials.sshTunnel) {
		const db = pgp(dbConfig);
		return { db, pgp };
	} else {
		if (credentials.sshAuthenticateWith === 'privateKey' && credentials.privateKey) {
			credentials.privateKey = formatPrivateKey(credentials.privateKey);
		}
		const sshClient = await this.helpers.getSSHClient(credentials);

		// Create a TCP proxy listening on a random available port
		const proxy = createServer();
		const proxyPort = await new Promise<number>((resolve) => {
			proxy.listen(0, LOCALHOST, () => {
				resolve((proxy.address() as AddressInfo).port);
			});
		});

		const close = () => {
			proxy.close();
			sshClient.off('end', close);
			sshClient.off('error', close);
		};
		sshClient.on('end', close);
		sshClient.on('error', close);

		await new Promise<void>((resolve, reject) => {
			proxy.on('error', (err) => reject(err));
			proxy.on('connection', (localSocket) => {
				sshClient.forwardOut(
					LOCALHOST,
					localSocket.remotePort!,
					credentials.host,
					credentials.port,
					(err, clientChannel) => {
						if (err) {
							proxy.close();
							localSocket.destroy();
						} else {
							localSocket.pipe(clientChannel);
							clientChannel.pipe(localSocket);
						}
					},
				);
			});
			resolve();
		}).catch((err) => {
			proxy.close();

			let message = err.message;
			let description = err.description;

			if (err.message.includes('ECONNREFUSED')) {
				message = 'Connection refused';
				try {
					description = err.message.split('ECONNREFUSED ')[1].trim();
				} catch (e) {}
			}

			if (err.message.includes('ENOTFOUND')) {
				message = 'Host not found';
				try {
					description = err.message.split('ENOTFOUND ')[1].trim();
				} catch (e) {}
			}

			if (err.message.includes('ETIMEDOUT')) {
				message = 'Connection timed out';
				try {
					description = err.message.split('ETIMEDOUT ')[1].trim();
				} catch (e) {}
			}

			err.message = message;
			err.description = description;
			throw err;
		});

		const db = pgp({
			...dbConfig,
			port: proxyPort,
			host: LOCALHOST,
		});
		return { db, pgp };
	}
}