/**
 *  Copyright 2016 Ludovic Pouzenc <ludovic@pouzenc.fr>
 * 
 *  CHD OpenWRT is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  CHD OpenWRT is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 * 
 *  You should have received a copy of the GNU General Public License
 *  along with CHD OpenWRT.  If not, see <http://www.gnu.org/licenses/>.
**/

/*
document.onreadystatechange = function () {
	console.log("document.onreadystatechange");
};

document.onunload = function () {
	console.log("document.onunload");
	for(var i=0; i<1000000000; i++) {}
};*/

document.addEventListener("DOMContentLoaded", function() {
	console.log("DOMContentLoaded");

	// HTML5 form validation
	var supports_input_validity = function() { var i = document.createElement("input"); return "setCustomValidity" in i; }

	if(supports_input_validity()) {
		var pwd1Input = document.getElementById("field_pwd1");
		var pwd2Input = document.getElementById("field_pwd2");
		var key1Input = document.getElementById("field_key1");
		var key2Input = document.getElementById("field_key2");

		pwd2Input.addEventListener("keyup", function() {
			this.setCustomValidity(
				(this.value!=pwd1Input.value)?pwd2Input.title:""
			)}, false);

		key2Input.addEventListener("keyup", function() {
			this.setCustomValidity(
				(this.value!=key1Input.value)?key2Input.title:""
			)}, false);
	}

	/* Range slider value update
	var txpower = document.getElementById("field_txpower");
	var txpowerText = document.getElementById("field_txpower_text");
	txpower.addEventListener("change", function(e) {
			txpowerText.value=txpower.value + " dB";
		}, true);
	*/
	var btn_gen = document.getElementById("btn_gen");
	btn_gen.value="Téléchager le fichier de mise à jour";

	// Additionnal form validation (on submit)
	var checkForm = function(e) {

		if (this.pwd1.value != this.pwd2.value) {
			this.pwd1.focus();
			e.preventDefault();
			return;
		}
		if (this.key1.value != this.key2.value) {
			this.key1.focus();
			e.preventDefault();
			return;
		}
		// Safari needs this one too
		if (!e.target.checkValidity()) {
			e.preventDefault();
			return;
		}
		// Form will pass, disable the form button to prevent multiple clicks
		var btn_gen = document.getElementById("btn_gen");
		btn_gen.value="Patientez puis sauvez le fichier";
		btn_gen.disabled=true;
		btn_gen.style.color="gray";
	};
	var form_main = document.getElementById("form_main");
	form_main.addEventListener("submit", checkForm, true);

	// Guess of current LAN gateway
	var field_ip4lan = document.getElementById("field_ip4lan");
	getIPs(function(ip){
		console.log(ip);
		var res = ip.match(/^192\.168\.\d+/);
		if ( res ) {
			// Dumb guess of gateway IP
			field_ip4lan.value = res + ".1";
		}
	});

}, false);


window.addEventListener('unload', function(event) {
	console.log('unload');

	// Revert submit button to inital state if history.go(-1) was used
	var btn_gen = document.getElementById("btn_gen");
	btn_gen.value="Télécharger le fichier de mise à jour";
	btn_gen.disabled=false;
	btn_gen.style.color="black";

});


// LAN IPs detection
function getIPs(callback){
	var ip_dups = {};

	//compatibility for firefox and chrome
	var RTCPeerConnection = window.RTCPeerConnection
		|| window.mozRTCPeerConnection
		|| window.webkitRTCPeerConnection;
	var useWebKit = !!window.webkitRTCPeerConnection;

	if(!RTCPeerConnection){
		return; // The following code pops JS errors on Safari
	}

	//bypass naive webrtc blocking using an iframe
	if(!RTCPeerConnection){
		//NOTE: you need to have an iframe in the page right above the script tag
		//
		//<iframe id="iframe" sandbox="allow-same-origin" style="display: none"></iframe>
		//<script>...getIPs called in here...
		//
		var win = iframe.contentWindow;
		RTCPeerConnection = win.RTCPeerConnection
			|| win.mozRTCPeerConnection
			|| win.webkitRTCPeerConnection;
		useWebKit = !!win.webkitRTCPeerConnection;
	}

	//minimal requirements for data connection
	var mediaConstraints = {
optional: [{RtpDataChannels: true}]
	};

	//firefox already has a default stun server in about:config
	//    media.peerconnection.default_iceservers =
	//    [{"url": "stun:stun.services.mozilla.com"}]
	var servers = undefined;

	//add same stun server for chrome
	if(useWebKit)
		servers = {iceServers: [{urls: "stun:stun.services.mozilla.com"}]};

	//construct a new RTCPeerConnection
	var pc = new RTCPeerConnection(servers, mediaConstraints);

	function handleCandidate(candidate){
		//match just the IP address
		var ip_regex = /([0-9]{1,3}(\.[0-9]{1,3}){3})/
			var ip_addr = ip_regex.exec(candidate)[1];

		//remove duplicates
		if(ip_dups[ip_addr] === undefined)
			callback(ip_addr);

		ip_dups[ip_addr] = true;
	}

	//listen for candidate events
	pc.onicecandidate = function(ice){

		//skip non-candidate events
		if(ice.candidate)
			handleCandidate(ice.candidate.candidate);
	};

	//create a bogus data channel
	pc.createDataChannel("");

	//create an offer sdp
	pc.createOffer(function(result){

			//trigger the stun server request
			pc.setLocalDescription(result, function(){}, function(){});

			}, function(){});

	//wait for a while to let everything done
	setTimeout(function(){
			//read candidate info from local description
			var lines = pc.localDescription.sdp.split('\n');

			lines.forEach(function(line){
				if(line.indexOf('a=candidate:') === 0)
				handleCandidate(line);
				});
			}, 1000);
}