/**
 * Server module
 *
 * @module server
 */

/**
 * The server file
 *
 * @class Server
 */

"use strict";

var app = require("http").createServer(handler)
  , io = require("socket.io").listen(app)
  , fs = require("fs")
  , sqlite3 = require("sqlite3").verbose()
  , db = "timenets.db";

app.listen(8080);

/**
 * Open the database
 *
 * @method openDb
 * @return opened database
 */
function openDb() {
	return new sqlite3.Database(db, sqlite3.OPEN_READWRITE, function() {
		console.log("Database opened");
	});
}

/**
 * Node.js/Socket.io webserver callback, serves files
 *
 * @method handler
 */
function handler (req, res) {
	var url = req.url;
	if (url === "/") {
		url = "/index.html";
	}	

	fs.readFile(__dirname + url,
	function (err, data) {
		if (err) {
			res.writeHead(500);
			return res.end("Error loading " + url);
		}

		res.writeHead(200);
		res.write(data);
		res.end();
	});
}

/**
 * Called when a client connection is established
 *
 * @event connection
 * @param socket
 */
io.sockets.on("connection", function (socket) {
	var timenets = [];
	var db;
	console.log("New connection");
	
	// send list of available timenets
	if (timenets.length === 0) {
		console.log("sending timenets list");
		db = openDb();
		db.serialize(function (err) {
			db.each("select * from timenets", function(err, row) {
				timenets.push({id: row.id, name: row.name});
			});
		});
		db.close(function (err) {
			socket.emit("timenet_list", {timenets: timenets});
		});
	}
	
	/**
	 * Called when a client requests timenet data
	 *
	 * @event get_data
	 * @param data contains the timenet id that is requested
	 */
	socket.on("get_data", function (data) {
		var id = data.id;
		var persons = [];
		var relationships = [];
		var annotations = [];
		
		console.log("Received request for timenet " + id);
		db = openDb();
		
		db.serialize(function() {
			db.each("select * from person where timenets_id = $id;", { $id: id }, function(err, row) {
				if (err) {
					console.log("Error reading from DB!");
				}
				
				/**
				 * A single person. Also used in client
				 *
				 * @class Person
				 * @for Server
				 */
				persons[row.id] = {
					id: row.id,
					name: row.name,
					sex: row.sex,
					dateOfBirth: new Date(row.date_of_birth),
					dateOfDeath: new Date(row.date_of_death),
					doi: 0,
					childRelationships: [],
					conjugalRelationships: [],
					annotations: []
				};
			});

			db.each("select * from annotations where timenets_id = $id;", { $id: id }, function(err, row) {
				if (err) {
					console.log("Error reading from DB!");
				}
				
				/**
				 * Annotation. Also used in client
				 *
				 * @class Annotation
				 * @for Server
				 */
				annotations[row.id] = {
					id: row.id,
					personId: row.person_id,
					date: new Date(row.annotation_date),
					title: row.title,
					text: row.text,
				};
			});

			db.each("select * from relationship where timenets_id = $id;", { $id: id }, function(err, row) {
				if (err) {
					console.log("Error reading from DB!");
				}
				
				var startDate;
				var endDate;
				if (row.relationship_type === 2) { // child
					startDate = new Date(persons[row.person1_id].dateOfBirth);
					endDate = new Date(persons[row.person1_id].dateOfDeath);
				} else {
					startDate = new Date(row.relationship_start_date);
					endDate = new Date(row.relationship_end_date);
				}
				
				/**
				 * Relationship. Also used in client
				 *
				 * @class Relationship
				 * @for Server
				 */
				relationships[row.id] = {
					person1Id: row.person1_id,
					person2Id: row.person2_id,
					type: row.relationship_type,
					startDate: startDate,
					endDate: endDate
				};
			});
		});
		
		/**
		 * Close the database and send data to the client afterwards
		 *
		 * @method db.close
		 * @for Server
		 */
		db.close(function (err) {
			if (!err) {
				// assign relationships to persons
				persons.forEach(function (p) {
					if (p === null) { 
						return; 
					}
					relationships.forEach(function (rel, i) {
						if (rel === null) {
							return;
						}
						if (rel.person1Id === p.id || rel.person2Id === p.id) {
							if (rel.type === 1) {
								p.conjugalRelationships.push(i);
							} else if (rel.type === 2) {
								p.childRelationships.push(i);
							}
						}
					});
					annotations.forEach(function(anno,i){
						if (anno === null) {
							return;
						}
						if(anno.personId === p.id){
							p.annotations.push(i);
						}
						
					});
					
					
				});
				
				console.log("Sending data");
				// send the data to the client
				socket.emit("db_data", {persons: persons, relationships: relationships, annotations: annotations});
			}
		});
		
	});
});