/**
* @license Apache-2.0
*
* Copyright (c) 2019 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*    http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/

'use strict';

var httpServer = require( '@stdlib/net/http-server' );
var passThrough = require( '@stdlib/streams/node/transform' );
var REPL = require( './../../lib' );

// Define server options:
var sopts = {
	'port': 7331,
	'maxport': 9999,
	'hostname': 'localhost'
};

// Create a function for creating an HTTP server:
var createServer = httpServer( sopts, onRequest );

// Start the HTTP server:
createServer( done );

function done( error, server ) {
	var addr;
	if ( error ) {
		throw error;
	}
	// Log the server address so we know on what port we are listening:
	addr = server.address();
	console.log( 'Address: %s:%d', addr.address, addr.port );
}

function onRequest( req, res ) {
	var istream;
	var ostream;
	var ropts;
	var repl;

	res.setHeader( 'content-type', 'multipart/octet-stream' );

	// Define "pass through" transform streams for handling request and response data:
	istream = passThrough();
	ostream = passThrough();

	// Setup the data flow:
	req.pipe( istream );
	ostream.pipe( res );

	// Define the REPL options, resetting the welcome message and prompts so that we only stream the evaluated results:
	ropts = {
		'input': istream,
		'output': ostream,
		'global': true,
		'welcome': '',
		'inputPrompt': '',
		'outputPrompt': '',
		'padding': 0
	};

	// Create a new REPL instance:
	repl = new REPL( ropts );

	// Listen for when the REPL has "drained" its command queue:
	repl.once( 'drain', onDrain );

	function onDrain() {
		// Once the REPL drains, we've finished executing commands, so we can end the response and close the REPL:
		res.end();
		repl.close();
	}
}