/*
 * Spreed WebRTC.
 * Copyright (C) 2013-2015 struktur AG
 *
 * This file is part of Spreed WebRTC.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

"use strict";

// Android detection hack - probably put this someplace else.
var webrtcDetectedAndroid = ((window.navigator || {}).userAgent).match(/android (\d+)/i) !== null;

define([
	'jquery',
	'underscore',
	'mediastream/peercall',
	'mediastream/peerconference',
	'mediastream/peerxfer',
	'mediastream/peerscreenshare',
	'mediastream/usermedia',
	'mediastream/utils',
	'mediastream/tokens',
	'webrtc.adapter'],

function($, _, PeerCall, PeerConference, PeerXfer, PeerScreenshare, UserMedia, utils, tokens) {

	if (webrtcDetectedAndroid) {
		console.log("This seems to be Android");
	}

	var roomTypeConference = "Conference";

	var InternalPC = function(call) {
		this.currentcall = call;
		this.isinternal = true;
	};

	InternalPC.prototype.close = function() {
		this.currentcall.e.triggerHandler("connectionStateChange", ["closed", this.currentcall]);
	};

	InternalPC.prototype.addStream = function() {
	};

	InternalPC.prototype.removeStream = function() {
	};

	InternalPC.prototype.negotiationNeeded = function() {
	};

	var InternalCall = function(webrtc) {
		this.id = null;
		this.webrtc = webrtc;
		this.e = $({});
		this.isinternal = true;
		this.pc = new InternalPC(this);

		this.mediaConstraints = $.extend(true, {}, this.webrtc.settings.mediaConstraints);
	};

	InternalCall.prototype.setInitiate = function(initiate) {
	};

	InternalCall.prototype.createPeerConnection = function(success_cb, error_cb) {
		success_cb(this.pc);
	};

	InternalCall.prototype.close = function() {
		this.pc.close();
		this.e.triggerHandler("closed", [this]);
	};

	var WebRTC = function(api) {

		this.api = api;

		this.e = $({});

		this.conference = new PeerConference(this);
		this.currentroom = null;
		this.msgQueues = {};
		this.usermediaReady = false;
		this.pendingMediaCalls = [];

		this.usermedia = null;
		this.audioMute = false;
		this.videoMute = false;

		// Settings.are cloned into peer call on call creation.
		this.settings = {
			mediaConstraints: {
				audio: true,
				video: {
					optional: [],
					mandatory: {
						maxWidth: 640,
						maxHeight: 480
					}
				}
			},
			pcConfig: {
				iceServers: [{
					url: 'stun:' + 'stun.l.google.com:19302'
				}]
			},
			pcConstraints: {
				mandatory: {},
				optional: []
			},
			screensharing: {
				mediaConstraints: {
					audio: false,
					video: {
						optional: [],
						mandatory: {}
					}
				}
			},
			// sdpParams values need to be strings.
			sdpParams: {
				//audioSendBitrate: ,
				audioSendCodec: "opus/48000",
				//audioRecvBitrate: ,
				//audioRecvCodec: ,
				//opusMaxPbr: ,
				opusStereo: "true",
				//videoSendBitrate: ,
				//videoSendInitialBitrate: ,
				videoSendCodec: "VP8/90000"
				//videoRecvBitrate: ,
				//videoRecvCodec
			},
			// Set up audio and video regardless of what devices are present.
			offerOptions: {
				offerToReceiveAudio: true,
				offerToReceiveVideo: true
			},
			renegotiation: true
		};

		this.screensharingSettings = {

		};

		this.api.e.bind("received.offer received.candidate received.answer received.bye received.conference", _.bind(this.processReceived, this));
		this.api.e.bind("received.room", _.bind(this.receivedRoom, this));
	};

	WebRTC.prototype.receivedRoom = function(event, room) {
		if (this.isConferenceRoom()) {
			// Switching from a conference room closes all current connections.
			_.defer(_.bind(function() {
				this.doHangup();
			}, this));
		}
		console.log("Joined room", room, this.api.id);
		this.currentroom = room;
		_.defer(_.bind(function() {
			this.maybeStartLocalVideo();
		}, this), 100);
	};

	WebRTC.prototype.isConferenceRoom = function() {
		return this.currentroom && this.currentroom.Type === roomTypeConference;
	};

	WebRTC.prototype.maybeStartLocalVideo = function() {
		if (!this.isConferenceRoom()) {
			return;
		}

		console.log("Start local video");
		var call = new InternalCall(this);
		this._doCallUserMedia(call);
	};

	WebRTC.prototype.stopLocalVideo = function() {
		if (this.usermedia) {
			this.usermedia.stop();
		}
	};

	WebRTC.prototype.processReceived = function(event, to, data, type, to2, from) {

		//console.log(">>>>>>>>>>>>", type, from, data, to, to2);

		if (data && data._token) {
			// Internal token request.
			var token = data._token;
			var id = data._id;
			delete data._token;
			delete data._id;
			// TODO(longsleep): Check if that really needs to be in another file.
			tokens.processReceivedMessage(this, token, id, to, data, type, to2, from);
			return;
		}

		this.processReceivedMessage(to, data, type, to2, from);
	};

	WebRTC.prototype.findTargetCall = function(id) {
		return this.conference.getCall(id);
	};

	WebRTC.prototype.callForEachCall = function(fn) {
		var calls = this.conference.getCalls();
		if (!calls.length) {
			return 0;
		}
		_.map(calls, fn);
		return calls.length;
	};

	WebRTC.prototype._getMessageQueue = function(id, create) {
		var queue = this.msgQueues[id] || null;
		if (queue === null && create) {
			queue = this.msgQueues[id] = [];
		}
		return queue;
	};

	WebRTC.prototype.pushBackMessage = function(id, message) {
		this._getMessageQueue(id, true).push(message);
	};

	WebRTC.prototype.pushFrontMessage = function(id, message) {
		this._getMessageQueue(id, true).unshift(message);
	};

	WebRTC.prototype.popFrontMessage = function(id) {
		var queue = this._getMessageQueue(id);
		if (!queue) {
			return null;
		}
		var message = queue.shift();
		if (!queue.length) {
			delete this.msgQueues[id];
		}
		return message;
	};

	WebRTC.prototype._processOffer = function(to, data, type, to2, from) {
		console.log("Offer process.");
		var call = this.conference.getCall(from);
		if (call) {
			// Remote peer is trying to renegotiate media.
			if (!this.settings.renegotiation && call.peerconnection && call.peerconnection.hasRemoteDescription()) {
				// Call replace support without renegotiation.
				this.doHangup("unsupported", from);
				console.error("Processing new offers is not implemented without renegotiation.");
				return;
			}

			call.setRemoteDescription(new window.RTCSessionDescription(data), _.bind(function(sessionDescription, currentcall) {
				this.e.triggerHandler("peercall", [currentcall]);
				currentcall.createAnswer(_.bind(function(sessionDescription, currentcall) {
					console.log("Sending answer", sessionDescription, currentcall.id);
					this.api.sendAnswer(currentcall.id, sessionDescription);
				}, this));
			}, this));
			return;
		}

		var autoaccept = false;
		if (data._conference) {
			if (this.conference.id !== data._conference) {
				console.warn("Received Offer for unknown conference -> busy.", from);
				this.api.sendBye(from, "busy");
				this.e.triggerHandler("busy", [from, to2, to]);
				return;
			}

			console.log("Received conference Offer -> auto.", from, data._conference);
			// Clean own internal data before feeding into browser.
			delete data._conference;
			autoaccept = true;
		} else if (this.conference.hasCalls()) {
			// TODO(fancycode): support joining callers to currently active conference.
			console.warn("Received Offer while already in a call -> busy.", from);
			this.api.sendBye(from, "busy");
			this.e.triggerHandler("busy", [from, to2, to]);
			return;
		}

		call = this.createCall(from, this.api.id, from);
		if (!this.conference.addIncoming(from, call)) {
			console.warn("Already got a call, not processing Offer", from, autoaccept);
			return;
		}

		this.pushFrontMessage(from, [to, data, type, to2, from]);
		if (autoaccept) {
			if (!this.doAccept(call, true)) {
				this.popFrontMessage(from);
			}
			return;
		}

		// Delegate next steps to UI.
		this.e.triggerHandler("offer", [from, to2, to]);
	};

	WebRTC.prototype._processCandidate = function(to, data, type, to2, from) {
		var call = this.conference.getCall(from);
		if (!call) {
			console.warn("Received Candidate for unknown id -> ignore.", from);
			return;
		}

		var candidate = new window.RTCIceCandidate({
			sdpMLineIndex: data.sdpMLineIndex,
			sdpMid: data.sdpMid,
			candidate: data.candidate
		});
		call.addIceCandidate(candidate);
		//console.log("Got candidate", data.sdpMid, data.sdpMLineIndex, data.candidate);
	};

	WebRTC.prototype._processAnswer = function(to, data, type, to2, from) {
		var call = this.conference.getCall(from);
		if (!call) {
			console.warn("Received Answer from unknown id -> ignore", from);
			return;
		}

		console.log("Answer process.");
		this.conference.setCallActive(call.id);
		// TODO(longsleep): In case of negotiation this could switch offer and answer
		// and result in a offer sdp sent as answer data. We need to handle this.
		call.setRemoteDescription(new window.RTCSessionDescription(data), function() {
			// Received remote description as answer.
			console.log("Received answer after we sent offer", data);
		});
	};

	WebRTC.prototype._processBye = function(to, data, type, to2, from) {
		console.log("Bye process.");
		this.doHangup("receivedbye", from);
		// Delegate bye to UI.
		this.e.triggerHandler("bye", [data.Reason, from, to, to2]);
	};

	WebRTC.prototype._processConference = function(to, data, type, to2, from) {
		var ids = this.conference.getCallIds();
		if (!ids.length && !this.isConferenceRoom()) {
			console.warn("Received Conference for unknown call -> ignore.", to, data);
			return;
		} else if (ids.length == 1) {
			// Peer-to-peer call will be upgraded to conference.
			if (data.indexOf(ids[0]) === -1) {
				console.warn("Received Conference for unknown call -> ignore.", to, data);
				return;
			}
			this.conference.id = to;
		} else if (this.conference.id && this.conference.id !== to) {
			console.warn("Received Conference for wrong id -> ignore.", to, this.conference);
			return;
		}

		if (!this.conference.id) {
			if (!this.isConferenceRoom()) {
				console.warn("Received initial Conference for non-conference room -> ignore.", to, this.conference);
				return;
			}
			this.conference.id = to;
			console.log("Setting received conference id", to);
		}

		console.log("Applying conference update", data);
		var myid = this.api.id;
		_.each(data, _.bind(function(id) {
			var res = myid < id ? -1 : myid > id ? 1 : 0;
			console.log("Considering conference peers to call", res, id);
			if (res === -1) {
				this.doCall(id, true);
			}
		}, this));
		this.e.triggerHandler("peerconference", [this.conference]);
	};

	WebRTC.prototype.processReceivedMessage = function(to, data, type, to2, from) {
		switch (type) {
			case "Offer":
				this._processOffer(to, data, type, to2, from);
				break;
			case "Candidate":
				this._processCandidate(to, data, type, to2, from);
				break;
			case "Answer":
				this._processAnswer(to, data, type, to2, from);
				break;
			case "Bye":
				this._processBye(to, data, type, to2, from);
				break;
			case "Conference":
				this._processConference(to, data, type, to2, from);
				break;
			default:
				console.log("Unhandled message type", type, data);
				break;
		}
	};

	WebRTC.prototype.testMediaAccess = function(cb) {

		var success = function(stream) {
			console.info("testMediaAccess success");
			cb(true);
		};
		var failed = function() {
			console.info("testMediaAccess failed");
			cb(false);
		};
		UserMedia.testGetUserMedia(success, failed);

	};

	WebRTC.prototype.createCall = function(id, from, to) {
		var call = new PeerCall(this, id, from, to);
		call.e.on("connectionStateChange", _.bind(function(event, iceConnectionState, currentcall) {
			this.onConnectionStateChange(iceConnectionState, currentcall);
		}, this));
		call.e.on("remoteStreamAdded", _.bind(function(event, stream, currentcall) {
			this.onRemoteStreamAdded(stream, currentcall);
		}, this));
		call.e.on("remoteStreamRemoved", _.bind(function(event, stream, currentcall) {
			this.onRemoteStreamRemoved(stream, currentcall);
		}, this));
		call.e.on("error", _.bind(function(event, error_id, message) {
			if (!error_id) {
				error_id = "failed_peerconnection";
			}
			this.e.triggerHandler("error", [message, error_id]);
			_.defer(_.bind(this.doHangup, this), "error", id); // Hangup on error is good yes??
		}, this));
		call.e.on("closed", _.bind(function() {
			this.conference.removeCall(id);
		}, this));
		return call;
	};

	WebRTC.prototype.doUserMedia = function(call) {

		if (this.usermedia) {
			// We should not create a new UserMedia object while the current one
			// is still being used.
			console.error("UserMedia already created, check caller");
		}

		// Create default media (audio/video).
		var usermedia = new UserMedia({
			renegotiation: this.settings.renegotiation,
			audioMute: this.audioMute,
			videoMute: this.videoMute
		});
		usermedia.e.on("mediasuccess mediaerror", _.bind(function(event, um) {
			this.e.triggerHandler("usermedia", [um]);
			this.usermediaReady = true;
			// Start always, no matter what.
			while (this.pendingMediaCalls.length > 0) {
				var c = this.pendingMediaCalls.shift();
				this.maybeStart(um, c);
			}
		}, this));
		usermedia.e.on("mediachanged", _.bind(function(event, um) {
			// Propagate media change events.
			this.e.triggerHandler("usermedia", [um]);
		}, this));
		usermedia.e.on("stopped", _.bind(function(event, um) {
			if (um === this.usermedia) {
				this.e.triggerHandler("usermedia", [null]);
				this.usermediaReady = false;
				this.usermedia = null;
				this.maybeStartLocalVideo();
			}
		}, this));
		this.e.one("stop", function() {
			usermedia.stop();
		});
		this.usermedia = usermedia;
		this.e.triggerHandler("usermedia", [usermedia]);
		this.pendingMediaCalls.push(call);

		return usermedia.doGetUserMedia(call);

	};

	WebRTC.prototype._doCallUserMedia = function(call) {
		if (this.usermedia) {
			if (!this.usermediaReady) {
				this.pendingMediaCalls.push(call);
			} else {
				this.maybeStart(this.usermedia, call);
			}
			return true;
		}

		var ok = this.doUserMedia(call);
		if (ok) {
			this.e.triggerHandler("waitforusermedia", [call]);
			return true;
		}

		this.e.triggerHandler("error", ["Failed to access camera/microphone.", "failed_getusermedia"]);
		if (call.id) {
			this.doHangup("usermedia", call.id);
		}
		return false;
	};

	WebRTC.prototype._doAutoStartCall = function(call) {
		if (!this.usermedia) {
			return false;
		}

		if (!this.usermediaReady) {
			// getUserMedia is still pending, defer starting of call.
			this.pendingMediaCalls.push(call);
		} else {
			this.maybeStart(this.usermedia, call, true);
		}
		return true;
	};

	WebRTC.prototype.doCall = function(id, autocall) {
		var call = this.createCall(id, null, id);
		call.setInitiate(true);
		var count = this.conference.getCallsCount();
		if (!this.conference.addOutgoing(id, call)) {
			console.log("Already has a call with", id);
			return;
		}
		this.e.triggerHandler("peercall", [call]);
		if (!autocall) {
			this.e.triggerHandler("connecting", [call]);
		}
		if ((autocall && count > 0) || this.isConferenceRoom()) {
			call.e.on("sessiondescription", _.bind(function(event, sessionDescription) {
				var cid = this.conference.getOrCreateId();
				console.log("Injected conference id into sessionDescription", cid);
				sessionDescription._conference = cid;
			}, this));
		}
		if (count > 0) {
			if (count === 1) {
				// Notify UI that it's a conference now.
				this.e.triggerHandler("peerconference", [this.conference]);
			}
			if (this._doAutoStartCall(call)) {
				return;
			}
		}

		if (!this._doCallUserMedia(call)) {
			return;
		}
	};

	WebRTC.prototype.doAccept = function(call, autoanswer) {
		if (typeof call === "string") {
			var id = call;
			call = this.conference.getCall(id);
			if (!call) {
				console.warn("Trying to accept unknown call.", id);
				return false;
			}
		}

		this.conference.setCallActive(call.id);
		if (autoanswer && this._doAutoStartCall(call)) {
			return true;
		}

		return this._doCallUserMedia(call);
	};

	WebRTC.prototype.doXfer = function(id, token, options) {

		var registeredToken = tokens.get(token);
		if (!registeredToken) {
			console.warn("Cannot start xfer for unknown token", token);
			return;
		}

		// Create new xfer object.
		var xfer = new PeerXfer(this, null, token, id);
		var opts = $.extend({
			created: function() {},
			connected: function() {},
			error: function() {},
			closed: function() {}
		}, options);

		// Store as handler on the token object.
		registeredToken.addHandler(xfer, id);

		// Bind ICE connection state events.
		xfer.e.on("connectionStateChange", _.bind(function(event, iceConnectionState, currentxfer) {
			console.log("Xfer state changed", iceConnectionState);
			switch (iceConnectionState) {
				case "completed":
				case "connected":
					// Do nothing here, we wait for dataReady.
					break;
				case "disconnected":
					opts.error(currentxfer);
					break;
				case "closed":
					opts.closed(currentxfer);
					break;
			}
		}, this));

		// Bind data channel ready event.
		xfer.e.on("dataReady", _.bind(function(event, currentxfer) {
			opts.connected(currentxfer);
		}, this));

		// Trigger initial event.
		opts.created(xfer);

		// Connect.
		xfer.setInitiate(true);
		xfer.createPeerConnection(_.bind(function(pc) {
			xfer.e.on("negotiationNeeded", _.bind(function(event, currentxfer) {
				this.sendOfferWhenNegotiationNeeded(currentxfer, id);
			}, this));
			_.defer(pc.negotiationNeeded);
		}, this));

	};

	WebRTC.prototype.doScreenshare = function(options) {

		var usermedia = new UserMedia({
			noAudio: true
		});
		var ok = usermedia.doGetUserMedia(null, PeerScreenshare.getCaptureMediaConstraints(this, options));
		if (ok) {
			this.e.one("done", function() {
				usermedia.stop();
			});
			return usermedia;
		} else {
			return null;
		}

	};

	WebRTC.prototype.doSubscribeScreenshare = function(id, token, options) {

		var registeredToken = tokens.get(token);
		if (!registeredToken) {
			console.warn("Cannot subscribe screen share for unknown token", token);
			return;
		}

		var peerscreenshare = new PeerScreenshare(this, null, token, id);
		var opts = $.extend({
			created: function() {},
			connected: function() {},
			error: function() {},
			closed: function() {}
		}, options);

		this.e.one("done", function() {
			peerscreenshare.close();
		});

		// Store as handler on the token object.
		registeredToken.addHandler(peerscreenshare, id);

		// Bind ICE connection state events.
		peerscreenshare.e.on("connectionStateChange", _.bind(function(event, iceConnectionState, currentscreenshare) {
			console.log("Screen share state changed", iceConnectionState);
			switch (iceConnectionState) {
				case "completed":
				case "connected":
					opts.connected(currentscreenshare);
					break;
				case "disconnected":
					opts.error(currentscreenshare);
					break;
				case "closed":
					opts.closed(currentscreenshare);
					break;
			}
		}, this));

		// Trigger initial event.
		opts.created(peerscreenshare);

		// Connect.
		peerscreenshare.setInitiate(true); //XXX(longsleep): This creates a data channel which is not needed.
		peerscreenshare.createPeerConnection(_.bind(function(pc) {
			peerscreenshare.e.on("negotiationNeeded", _.bind(function(event, currentscreenshare) {
				this.sendOfferWhenNegotiationNeeded(currentscreenshare, id);
			}, this));
			_.defer(pc.negotiationNeeded);
		}, this));

	};

	WebRTC.prototype.stop = function() {

		this.conference.close();
		this.e.triggerHandler("peerconference", [null]);
		this.e.triggerHandler("peercall", [null]);
		this.e.triggerHandler("stop");
		this.msgQueues = {};

	}

	WebRTC.prototype.doHangup = function(reason, id) {

		if (!id) {
			console.log("Closing all calls")
			_.each(this.conference.getCallIds(), _.bind(function(callid) {
				this.doHangup(reason, callid);
			}, this));
			this.stop();
			return true;
		}

		console.log("Hanging up.", id);
		var call = this.conference.removeCall(id);
		if (!call) {
			console.warn("Tried to hangup unknown call.", reason, id);
			return false;
		}
		call.close();
		if (reason !== "receivedbye") {
			this.api.sendBye(id, reason);
		}
		var calls = this.conference.getCalls();
		if (!calls.length) {
			// Last peer disconnected, perform cleanup.
			this.e.triggerHandler("peercall", [null]);
			_.defer(_.bind(function() {
				this.e.triggerHandler("done", [reason]);
			}, this));
			this.stop();
		} else if (calls.length === 1) {
			this.e.triggerHandler("peerconference", [null]);
			this.e.triggerHandler("peercall", [calls[0]]);
		}
		return true;
	}

	WebRTC.prototype.maybeStart = function(usermedia, call, autocall) {

		//console.log("maybeStart", call);
		if (call.peerconnection) {
			console.log("Already started", call);
			return;
		}

		if (!autocall) {
			if (!call.isinternal) {
				this.e.triggerHandler("connecting", [call]);
			} else if (!this.conference.hasCalls()) {
				// Signal UI that media access has been granted.
				this.e.triggerHandler("done");
			}
		}
		console.log('Creating PeerConnection.', call);
		call.createPeerConnection(_.bind(function(peerconnection) {
			// Success call.
			usermedia.addToPeerConnection(peerconnection);
			if (!call.initiate) {
				this.processPendingMessages(call.id);
			}
			call.e.on("negotiationNeeded", _.bind(function(event, call) {
				this.sendOfferWhenNegotiationNeeded(call);
			}, this));
		}, this), _.bind(function() {
			// Error call.
			this.e.triggerHandler("error", ["Failed to create peer connection. See log for details."]);
			if (call.id) {
				this.doHangup("failed", call.id);
			}
		}, this));

	};

	WebRTC.prototype.processPendingMessages = function(id) {
		do {
			var message = this.popFrontMessage(id);
			if (!message) {
				break;
			}
			this.processReceivedMessage.apply(this, message);
		} while (true);
	};

	WebRTC.prototype.sendOfferWhenNegotiationNeeded = function(currentcall, to) {

		// TODO(longsleep): Check if the check for stable is really required.
		if (currentcall.peerconnection.pc.signalingState === "stable") {
			if (!to) {
				to = currentcall.id;
			}
			currentcall.createOffer(_.bind(function(sessionDescription, currentcall) {
				console.log("Sending offer with sessionDescription", sessionDescription, to, currentcall);
				// TODO(longsleep): Support sending this through data channel too if we have one.
				this.api.sendOffer(to, sessionDescription);
			}, this));
		}

	};

	WebRTC.prototype.onConnectionStateChange = function(iceConnectionState, currentcall) {
		// Defer this to allow native event handlers to complete before running more stuff.
		_.defer(_.bind(function() {
			this.e.triggerHandler('statechange', [iceConnectionState, currentcall]);
		}, this));
	};

	WebRTC.prototype.onRemoteStreamAdded = function(stream, currentcall) {
		this.e.triggerHandler("streamadded", [stream, currentcall]);
	};

	WebRTC.prototype.onRemoteStreamRemoved = function(stream, currentcall) {
		this.e.triggerHandler("streamremoved", [stream, currentcall]);
	};

	WebRTC.prototype.setVideoMute = function(mute) {

		// Force boolean.
		this.videoMute = !! mute;
		if (this.usermedia) {
			this.usermedia.applyVideoMute(this.videoMute);
		}

	};

	WebRTC.prototype.setAudioMute = function(mute) {

		// Force boolean.
		this.audioMute = !! mute;
		if (this.usermedia) {
			this.usermedia.applyAudioMute(this.audioMute);
		}

	};

	return WebRTC;

});