const express = require('express');
const dgram = require('dgram');
const oscParser = require('./osc-parser');
const bodyParser = require('body-parser');
const { Bundle, Client } = require('node-osc');
const path = require('path');
const config = require('../frontend/assets/config.json');

const app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({extended:true}));
app.use(express.static('./frontend/assets'));

app.get('/', function (req, res) {
	res.sendFile('./frontend/index.html', {
		root: path.resolve(__dirname + '/..')
	});
});

const httpServer = require('http').Server(app);

/* --------
 * RECEIVER
 * --------
 */

const receiverIo = require('socket.io')(httpServer, {
	transports: ['websocket']
});

const onSocketListening = function() {
	const address = receiverUdpSocket.address();
	console.log('Serveur TUIO en écoute sur : ' + address.address + ':' + address.port);
};

const onSocketConnection = function(socket) {
	receiverUdpSocket.on('message', function(msg) {
		socket.emit('osc', oscParser.decode(msg));
	});
};

const receiverUdpSocket = dgram.createSocket('udp4');
receiverUdpSocket.on('listening', onSocketListening);
receiverUdpSocket.bind(config.app.oscUdpPort, '127.0.0.1');

app.get('/receiver/json', function (req, res) {
	res.status(200).send();
});

receiverIo.sockets.on('connection', (socket) =>{
	console.log(`Connecté au client ${socket.id}`);

	const dgramCallback = function (buf) {
		if (config.app.debugLog.backend.receiver.oscDatagram) {
			console.log(oscParser.decode(buf));
		}
		socket.emit('osc', oscParser.decode(buf));
	};

	// forward UDP packets via socket.io
	receiverUdpSocket.on('message', dgramCallback);

	// prevent memory leak on disconnect
	socket.on('disconnect', function (socket) {
		receiverUdpSocket.removeListener('message', dgramCallback);
	});
});

/* -------
 * EMITTER
 * -------
 */

const emitterOscClient = new Client('127.0.0.1', config.app.oscUdpPort);
let alive = [];
let fseq;

let objTriangle = [] ;

function getHypotenuse(touch1, touch2) {
	const x = Math.abs(touch1.x - touch2.x);
	const y = Math.abs(touch1.y - touch2.y);
	return Math.sqrt(Math.pow(x, 2) + Math.pow(y, 2));
}

function getTop(dotTrio) {
	const dist01 = getHypotenuse(dotTrio[0], dotTrio[1]);
	const dist02 = getHypotenuse(dotTrio[0], dotTrio[2]);
	const dist12 = getHypotenuse(dotTrio[1], dotTrio[2]);

	const diff01m02 = Math.abs(dist01 - dist02);
	const diff01m12 = Math.abs(dist01 - dist12);
	const diff02m12 = Math.abs(dist02 - dist12);

	if (diff01m02 < diff02m12 && diff01m02 < diff01m12) {
		return 0;
	}
	else if (diff01m12 < diff01m02 && diff01m12 < diff02m12) {
		return 1;
	}
	else if (diff02m12 < diff01m02 && diff02m12 < diff01m12) {
		return 2;
	}
}

function getAngleApex(dotTrio, topIndex) {
	let dotA;
	let dotB;
	let dotC;
	dotB = dotTrio[topIndex];
	if (topIndex == 0) {
		dotA = dotTrio[1];
		dotC = dotTrio[2];
	}
	else if (topIndex == 1) {
		dotA = dotTrio[0];
		dotC = dotTrio[2];
	}
	else if (topIndex == 2) {
		dotA = dotTrio[0];
		dotC = dotTrio[1];
	}

	const AB = [dotB.x - dotA.x, dotB.y - dotA.y];
	const CB = [dotB.x - dotC.x, dotB.y - dotC.y];

	const dotProd = (AB[0] * CB[0] + AB[1] * CB[1]);
	const crossProd = (AB[0] * CB[1] - AB[1] * CB[0]);

	const alpha = Math.atan2(crossProd, dotProd);
	//return alpha ;
	return Math.floor(alpha * 180. / Math.PI + 0.5) ;
}

function getOrientation(dotTrio, topIndex) {
	let dotA;
	let dotB;
	let dotC;
	dotB = dotTrio[topIndex];
	if (topIndex == 0) {
		dotA = dotTrio[1];
		dotC = dotTrio[2];
	}
	else if (topIndex == 1) {
		dotA = dotTrio[0];
		dotC = dotTrio[2];
	}
	else if (topIndex == 2) {
		dotA = dotTrio[0];
		dotC = dotTrio[1];
	}

	const middlePt = [(dotA.x + dotC.x) / 2, (dotA.y + dotC.y) / 2 ] ;
	let diff = [dotB.x - middlePt[0], dotB.y - middlePt[1]] ;
	const length = Math.sqrt(Math.pow(diff[0], 2) + Math.pow(diff[1], 2) ) ;
	//normalize diff
	diff = [diff[0] / length, diff[1] / length];
	const rad = Math.atan2(diff[0], diff[1]) ;
 	return Math.floor(-1 * rad * 180 / Math.PI)  ;
	 //return length ;
}

let currentOscBundle = null;
let hasPending = false;
let waiting = false;

const sendBundle = () => {
	if (hasPending) {
		emitterOscClient.send(currentOscBundle, () => {
			hasPending = false;
		});
	}
	setTimeout(() => {
		sendBundle();
	}, config.app.timerRefresh);
};
sendBundle();

app.post('/emitter/json', function (req, res) {
	if (config.app.debug && config.app.debugLog.backend.emitter.httpRequest) {
		console.log('## Emitter POST request ##');
	}
	let oscBundle;
	if (req.body.event === 'touchend') {
		fseq = fseq ? fseq + 1 : 1;

		const aliveMessage = [ '/tuio/2Dcur', 'alive' ].concat(alive);
		currentOscBundle = new Bundle(
			[ '/tuio/2Dcur', 'source', `tangibles${req.body.section.toString()}@127.0.0.1` ],
			aliveMessage,
			[ '/tuio/2Dcur', 'fseq', fseq ],
			[
				'/tuio/2Dcur',
				'del',
				req.body.changedTouches[0].identifier
			]
		);
		emitterOscClient.send(currentOscBundle, () => {
			const index = alive.indexOf(req.body.changedTouches[0].identifier);
			alive.splice(index, 1);
			if (alive.length === 0) {
				currentOscBundle = new Bundle(
					[ '/tuio/2Dcur', 'source', `tangibles${req.body.section.toString()}@127.0.0.1` ],
					[ '/tuio/2Dcur', 'alive' ],
					[ '/tuio/2Dcur', 'fseq', fseq ]
				);
				emitterOscClient.send(currentOscBundle, () => {
					res.status(200).send();
					fseq = 0;
					hasPending = false;
				});
			} else {
				res.status(200).send();
			}
		});
	} else {
		if (req.body.changedTouches && req.body.changedTouches.length && req.body.changedTouches.length > 0) {
			fseq = fseq ? fseq + 1 : 1;
			const touches = Object.keys(req.body.changedTouches);
			const aliveMessage = [ '/tuio/2Dcur', 'alive' ].concat(alive);
			touches.forEach(touch => {
				const id = req.body.changedTouches[touch].identifier;
				if (!alive.includes(id)) {
					alive.push(id);
					aliveMessage.push(id);
				}
			});

			/* Listage de tous les points */
			const dots = [];
			touches.forEach(function(touch) {
				dots.push({
					id: req.body.changedTouches[touch].identifier,
					x: req.body.changedTouches[touch].clientX,
					y: req.body.changedTouches[touch].clientY
				});
			});
			if (config.app.debug && config.app.debugLog.backend.emitter.dots) {
				console.log('-- dots --', dots);
			}

			/* Listage des segments */
			const segments = [];
			if (dots.length > 2) {
				for (var i = 0; i < dots.length; i++) {
					for (var j = 0; j < dots.length; j++) {
						if (j !== i) {
							/* on vérifie que le segment n'est pas déjà listé */
							const alreadyExists = segments.find(segment => {
								return segment.identifiers.includes(i) && segment.identifiers.includes(j);
							});
							/* on calcule la taille du segment (l'hypoténuse) */
							var hyp = getHypotenuse(dots[i], dots[j]);
							/* on garde uniquement les segments inférieurs à 750px (valeur par défaut)
							 * cette valeur est la variable de configuration "maxDistanceBetweenPoints" */
							if (!alreadyExists && hyp <= config.app.maxDistanceBetweenPoints) {
								segments.push({
									identifiers: [i, j],
									x1: dots[i].x,
									x2: dots[j].x,
									y1: dots[i].y,
									y2: dots[j].y,
									hyp
								});
							}
						}
					}
				}
			}
			if (config.app.debug && config.app.debugLog.backend.emitter.segments) {
				console.log('-- segments --', segments);
			}

			/* Listage des triangles */
			const triangles = [];
			/* on boucle sur les segments */
			segments.forEach((segment) => {
				const dot1 = segment.identifiers[0];
				const dot2 = segment.identifiers[1];
				/* on vérifie que le triangle n'est pas déjà listé */
				const alreadyExists = triangles.find(triangle => {
					return triangle.includes(dot1) && triangle.includes(dot2);
				});
				if (!alreadyExists) {
					/* on cherche les segments qui contiennent un des 2 points du segment actuel
					 * ex: si le segment actuel est AB, on cherche un segment contenant A (pour AC) et un autre contenant B (pour BC) */
					const found1 = segments.findIndex(seg => {
						return (seg.identifiers.includes(dot1) && !seg.identifiers.includes(dot2));
					});
					const found2 = segments.findIndex(seg => {
						return (seg.identifiers.includes(dot2) && !seg.identifiers.includes(dot1));
					});
					/* si on trouve bien les 2 segments (AC et BC), on peut créer un triangle */
					if (found1 !== -1 && found2 !== -1) {
						/* on devine quel est le 3ème point du triangle par rapport au segment actuel (le point C par rapport au segment AB) */
						const dot3 = segments[found1].identifiers.find(identifier => {
							return identifier !== dot1 && identifier !== dot2;
						});
						triangles.push([dot1, dot2, dot3]);
					}
				}
			});
			if (config.app.debug && config.app.debugLog.backend.emitter.triangles) {
				console.log('-- triangles --', triangles);
			}

			/* objet pour stocker les informations des triangles identifiés (points, centre, apexAngle, orientation, indice apex, width, height) */

			objTriangle = {} ;

			/* Définition de l'apex, de la position du centre et de l'orientation */
			triangles.forEach(triangle => {
				objTriangle.dots = [];
				objTriangle.dots[0] = dots[triangle[0]];
				objTriangle.dots[1] = dots[triangle[1]];
				objTriangle.dots[2] = dots[triangle[2]];

				objTriangle.apex = getTop(objTriangle.dots);
				objTriangle.center = [
					(objTriangle.dots[0].x+objTriangle.dots[1].x+objTriangle.dots[2].x)/3 ,
					(objTriangle.dots[0].y+objTriangle.dots[1].y+objTriangle.dots[2].y)/3
				];

				objTriangle.angleApex = getAngleApex(objTriangle.dots, objTriangle.apex) ;
				objTriangle.orientation = getOrientation(objTriangle.dots, objTriangle.apex) ;

				if (req.body.debug) {
					console.log('-- apex --', objTriangle.apex);
					console.log('centerPos : ' + objTriangle.center + ' orientation : ' + objTriangle.orientation);
				}
			});


			//plante vite
			// if (objTriangle.dots != undefined){
			// 	let oscBundleObj ;
			// 	oscBundleObj = new Bundle(
			// 		[ '/tuio/2Dobj', 'source', `tangibles${req.body.section.toString()}@127.0.0.1` ],
			// 		[ '/tuio/2Dobj', 'alive', 1 ],
			// 		[
			// 			'/tuio/2Dobj',
			// 			'set',
			// 			1,
			// 			1,
			// 			objTriangle.center[0],
			// 			objTriangle.center[1],
			// 			objTriangle.orientation,
			// 			0.0,
			// 			0.0,
			// 			0.0,
			// 			0.0,
			// 			0.0
			// 		],
			// 		[ '/tuio/2Dobj', 'fseq', fseq ]
			// 	);
			// 	// 	// objTriangle.forEach(triangleIndex => {
			// 	// 	// 	oscBundle.append(
			// 	// 	// 		[
			// 	// 	// 			'/tuio/2Dobj',
			// 	// 	// 			'set',
			// 	// 	// 			triangleIndex,
			// 	// 	// 			triangleIndex,
			// 	// 	// 			objTriangle[triangleIndex].center[0],
			// 	// 	// 			objTriangle[triangleIndex].center[1],
			// 	// 	// 			objTriangle[triangleIndex].orientation,
			// 	// 	// 			0.0,
			// 	// 	// 			0.0,
			// 	// 	// 			0.0,
			// 	// 	// 			0.0,
			// 	// 	// 			0.0
			// 	// 	// 		]
			// 	// 	// 	);
			// 	// 	// });
			// 	console.log(oscBundleObj);
			// 	emitterOscClient.send(oscBundleObj, () => {
			// 		res.status(200).send();
			// 	});
			// }


			// oscBundle = new Bundle(
			// 	[ '/tuio/2Dcur', 'source', `tangibles${req.body.section.toString()}@127.0.0.1` ],
			// 	aliveMessage,
			// 	[ '/tuio/2Dcur', 'fseq', fseq ]
			// );
			// touches.forEach(touch => {
			// 	oscBundle.append(
			// 		[
			// 			'/tuio/2Dcur',
			// 			'set',
			// 			req.body.changedTouches[touch].identifier,
			// 			req.body.changedTouches[touch].clientX / req.body.screenW,
			// 			req.body.changedTouches[touch].clientY / req.body.screenH,
			// 			0.0,
			// 			0.0
			// 		]
			// 	);
			// });
			currentOscBundle = new Bundle ;
			currentOscBundle.append([ '/tuio/2Dobj', 'alive', 1 ]);
			if (objTriangle.dots != undefined) {
				currentOscBundle.append([
					'/tuio/2Dobj',
					'set',
					1,
					1,
					//objTriangle.center[0],
					//objTriangle.center[1],
					objTriangle.center[0] / req.body.screenW,
					objTriangle.center[1] / req.body.screenH,
					objTriangle.orientation,
					0.0,
					0.0,
					0.0,
					0.0,
					0.0
				]);
			}

			currentOscBundle.append(['/tuio/2Dobj', 'fseq', fseq]);
			hasPending = true;
			res.status(200).send();
		} else {
			res.status(400).send();
		}
	}
});

httpServer.listen(config.app.httpPort, function () {
	console.log(`Votre app est disponible sur http://localhost:${config.app.httpPort} !`)
});