"use strict";

const cluster = require( "cluster" );
const cl = global.botanLoader;
const Dragonfly = global.Dragonfly;

const domain = require('domain');
const http = require( "http" );

class Serving
{
	constructor( server, handler, req, res )
	{
		this.server = server;
		this.handler = handler;
		this.req = req;
		this.res = res;

		var _self = this;

		var _rejection = ( e, p ) => _self.tryExitGracefully( e );
		var _uncaught = e => _self.tryExitGracefully( e );

		process
			.once( "unhandledRejection", _rejection  )
			.once( "uncaughtException", _uncaught )
		;

		res._rejection = _rejection;
		res._uncaught = _uncaught;

		var d = domain.create();
		d.addListener( 'error', ( e ) => _self.tryExitGracefully( e ) );
		d.add( req );
		d.add( res );
		d.run( () => _self.handler( req, res ) );
	}

	tryExitGracefully( e )
	{
		Dragonfly.Error( e.stack || e );

		try
		{
			var killtimer = setTimeout( () => process.exit(1), 3000 );
			killtimer.unref();

			this.server.close();

			// Message is hardcoded to prevent further exceptions occured
			// This function must be bug-free
			this.res.statusCode = 500;
			this.res.setHeader( 'Content-Type', 'text/plain' );
			this.res.end( e.message || e );
		}
		catch( ex )
		{
			Dragonfly.Error( ex.stack );
		}
		finally
		{
			cluster.worker.disconnect();
		}
	}
}

module.exports = function( handler, port )
{
	if( cluster.isMaster )
	{
		Dragonfly.Debug( "Not Listening on master" );
		return;
	}

	var server = null;

	server = http.createServer(
		function( req, res )
		{
			res._hrtime = process.hrtime.bigint();
			new Serving( server, handler, req, res );
		}
	);

	server.listen( port );
	Dragonfly.Info( "Listening on: " + port, Dragonfly.Visibility.VISIBLE );
	return server;
};