<?php
// Requête : http://serveur/pticlic.php?action=getparties&nb=2&mode=normal&user=foo&passwd=bar

$do_initdb = false;
$email_admin = '';              // Adresse e-mail Administrateur.

$SQL_DBNAME = (dirname(__FILE__) . "/db");

function mDie($err,$msg)
{
	echo "{ error:".json_encode("".$err).", msg:".json_encode("".$msg)."}";
	exit;
}

if (!$db = new SQlite3($SQL_DBNAME))
	mDie(1,"Erreur lors de l'ouverture de la base de données SQLite3");


/** Initialise la base de données avec un nom d'utilisateur et un mot de passe
*/
function initdb()
{
	global $db;

	$db->exec("insert into user(login, mail, hash_passwd, score) values('foo', 'foo@isp.com', '".md5('bar')."', 0);");
}

if ($do_initdb) 
	initdb();

if(!isset($_GET['action']) || !isset($_GET['user']) || !isset($_GET['passwd']))
	mDie(2,"La requête est incomplète");

// Login
$action = $_GET['action'];
$user = SQLite3::escapeString($_GET['user']);
$hash_passwd = md5($_GET['passwd']);

if ($hash_passwd !== $db->querySingle("SELECT hash_passwd FROM user WHERE login='$user';"))
	mDie(3,"Utilisateur non enregistré ou mauvais mot de passe");


/** Selectionne aléatoirement un noeud.
*/
function random_node()
{
	global $db;

	return $db->querySingle("select eid from node where eid = (abs(random()) % (select max(eid) from node))+1 or eid = (select max(eid) from node where eid > 0) order by eid limit 1;");
}


// TODO : Yoann : peut-être faire une classe create_game avec les fonctions ci-dessous comme méthodes ?

/**
* @param cloudSize : Taille du nuage.
* @param centerEid : Identifiant du mot central.
* @param r1 Type de la relation 1.
* @param r2 Type de la relation 2.
*/
function cg_build_result_sets($cloudSize, $centerEid, $r1, $r2)
{
	global $db;

	// 'w' => weight (poids), 'd' => difficulté, 's' => select
	// Le select doit ranvoyer trois colonnes :
	//   eid => l'eid du mot à mettre dans le nuage,
	//   r1 => la probabilité pour que le mot soit dans r1, entre -1 et 1 (négatif = ne devrait pas y être, positif = devrait y être à coup sûr, 0 = on sait pas).
	// TODO : comment mettre un poids sur random, sachant qu'il ne peut / devrait pas être dans ces select, mais plutôt un appel à random_node() ?
	$typer1r2 = "type in ($r1, $r2)";
	$sources = array(
		// Voisins 1 saut du bon type (= relations déjà existantes)
		array('w'=>40, 'd'=>1, 's'=>"select end as eid, type = $r1 as r1, type = $r2 as r2, 0 as r0, 0 as trash from relation where start = $centerEid and $typer1r2 order by random();"),
		// Voisins 1 saut via r_associated (0), donc qu'on voudrait spécifier si possible.
		array('w'=>40, 'd'=>2, 's'=>"select end as eid, 0.25 as r1, 0.25 as r2, 0.5 as r0, 0 as trash from relation where start = $centerEid and type = 0 order by random();"),
		// Voisins 1 saut via les autres relations
		// TODO ! certains de ces select pourraient renvoyer des mots de types systèmes (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001), il faut les éliminer.
		array('w'=>20, 'd'=>3, 's'=>"select end as eid, 0.1 as r1, 0.1 as r2, 0.8 as r0, 0 as trash from relation where start = $centerEid and type not in (0, $r1, $r2) order by random();"),
		// Voisins 2 sauts, avec un mix de R1 et R2 pour les liens. Par ex [ A -R1-> B -R2-> C ] ou bien [ A -R2-> B -R2-> C ]
		// Version optimisée de : "select end as eid from relation where $typer1r2 and start in oneHopWithType order by random();"
		array('w'=>30, 'd'=>3, 's'=>"select B.end as eid, ((A.type = $r1) + (B.type = $r1)) / 3 as r1, ((A.type = $r2) + (B.type = $r2)) / 3 as r2, 1/6 as r0, 1/6 as trash from relation as A, relation as B where A.start = $centerEid and A.$typer1r2 and B.start = A.end and B.$typer1r2 order by random();"),
		// Voisins 1 saut r1/r2 + 1 saut synonyme
		// Version optimisée de : "select end as eid from relation where start in oneHopWithType and type = 5 order by random();"
		array('w'=>20, 'd'=>5, 's'=>"select B.end as eid, (A.type = $r1) * 0.75 as r1, (A.type = $r2) * 0.75 as r2, 0.25 as r0, 0 as trash from relation as A, relation as B where A.start = $centerEid and A.$typer1r2 and B.start = A.end and B.type = 5 order by random();"),
		// Version optimisée de : "select end as eid from relation where start in (select end from relation where start = $centerEid and type = 5) and $typer1r2 order by random();"
		array('w'=>20, 'd'=>6, 's'=>"select B.end as eid, (B.type = $r1) * 0.75 as r1, (B.type = $r2) * 0.75 as r2, 0.25 as r0, 0 as trash from relation as A, relation as B where A.start = $centerEid and A.type = 5 and B.start = A.end and B.$typer1r2 order by random();"),
		// Voisins 2 sauts (tous)
		array('w'=>10, 'd'=>7, 's'=>"select end as eid, 0.1 as r1, 0.1 as r2, 0.3 as r0, 0.5 as trash from relation where start in (select end from relation where start = $centerEid) order by random();"),
		// Centre pointe vers X, M pointe vers X aussi, on prend M.
		// Version optimisée de : "select start as eid from relation where end in (select end from relation where start = $centerEid) and type not in (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001) order by random();"
		// Ce n'est toujours pas ça… : "select eid from (select B.start as eid from relation as A, relation as B where A.type not in (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001) and A.start = $centerEid and B.type not in (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001) and B.end = A.end limit 1) order by random();"
		// Tordu, mais ça marche \o/ . En fait il faut empêcher l'optimiseur de ramener le random avant le limit (et l'optimiseur est malin… :)
		array('w'=>10, 'd'=>8, 's'=>"select x as eid, 0.1 as r1, 0.1 as r2, 0.2 as r0, 0.6 as trash from (select x from (select X.eid + Y.dumb as x from (select B.start as eid from relation as A, relation as B where A.type not in (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001) and A.start = 74860 and B.type not in (4, 12, 36, 18, 29, 45, 46, 47, 48, 1000, 1001) and B.end = A.end limit $cloudSize) as X, (select 0 as dumb) as Y)) order by random();"),
		'rand' => array('w'=>5, 'd'=>10, 's'=>false) // random. Le r1 et r2 de random sont juste en-dessous
	);

	$sumWeights = 0;
	
	foreach ($sources as $k => $x)
	{
		$sumWeights += $x['w'];
		$sources[$k]['rsPos'] = 0;
		$sources[$k]['rsSize'] = 0;
		
		if ($x['s'] !== false)
		{
			$sources[$k]['resultSet'] = array();
			$res = $db->query($x['s']);
			$i = 0;
			
			while ($i < 10 && $sources[$k]['resultSet'][] = $res->fetchArray())
			{
				$i++;
				$sources[$k]['rsSize']++;
			}
		} 
		else
		{
			$sources[$k]['resultSet'] = array();
			
			for ($i = 0; $i < 10; $i++)
			{
				$sources[$k]['resultSet'][] = array('eid'=>random_node(), 'r1'=>0, 'r2'=>0, 'r0'=>0, 'trash'=>1);
				$sources[$k]['rsSize']++;
			}
		}
	}

	return array($sources, $sumWeights);
}


/**
* @return array : Tableau avec la relation 1 et la relation 2.
*/
function cg_choose_relations()
{
	$relations = array(5, 7, 9, 10, /* Pas d'icônes pour celles-ci. */ 13, 14, 22);
	$r1 = rand(0,count($relations)-1);
	$r2 = rand(0,count($relations)-2);

	if ($r2 >= $r1)
		$r2++;

	$r1 = $relations[$r1];
	$r2 = $relations[$r2];

	return array($r1, $r2);
}

/**
* @param cloudSize : Taille du nuage.
* @param sources Les sources.
* @param sumWeights La somme des poids.
* @return array : Tableau avec comme premier élément le nuage et comme second élément le total de difficulté.
*/
function cg_build_cloud($cloudSize, $sources, $sumWeights)
{
	// On boucle tant qu'il n'y a pas eu au moins 2 sources épuisées
	$cloud = array();
	$nbFailed = 0;
	$i = 0;
	$totalDifficulty = 0;
	
	while ($i < $cloudSize && $nbFailed < 5*$cloudSize)
	{
		// On choisit une source aléatoire en tennant compte des poids.
		$rands = rand(1,$sumWeights);
		$sumw = 0;
		$src = $sources['rand'];
		$srck = null;

		// Sélection d'une source aléatoire
		foreach ($sources as $k => $x)
		{
			$sumw += $x['w'];
			
			if ($rands < $sumw)
			{
				$src = $x;
				$srck = $k;
				break;
			}
		}
		
		// Vérification si on est à la fin du ResultSet de cette source.
		if ($src['rsPos'] >= $src['rsSize'])
		{
			$nbFailed++;

			if ($srck !== null)
			{
				$sumWeights -= $src['w'];
				unset($sources[$srck]);
			}

			continue;
		}
		
		// On récupère un résultat de cette source.
		// TODO : vérifier que $src['rsPos']++ fait ce que l'on veut
		$res = $src['resultSet'][$src['rsPos']++];

		// TODO (FAIT) : vérifier si $res['eid'] est présent dans un des $cloud[*]['eid'], car la condition qui suit est fausse.
		foreach ($c in $cloud) {
			if ($c['eid'] == $res['eid']) {
				$nbFailed++;
				continue;
			}
		}

		// position dans le nuage, difficulté, eid, probaR1, probaR2
		$totalDifficulty += $src['d'];
		$cloud[$i] = array('pos'=>$i++, 'd'=>$src['d'], 'eid'=>$res['eid'], 'probaR1'=>$res['r1'], 'probaR2'=>$res['r2'], 'probaR0'=>$res['r0'], 'probaTrash'=>$res['trash']);
	}

	$res = $sources['rand']['resultSet'][0];
	
	while ($i < $cloudSize)
	{
		$totalDifficulty += $sources['rand']['d'];
		$cloud[$i] = array('pos'=>$i++, 'd'=>$sources['rand']['d'], 'eid'=>random_node(), 'probaR1'=>$res['r1'], 'probaR2'=>$res['r2'], 'probaR0'=>$res['r0'], 'probaTrash'=>$res['trash']);
	}

	return array($cloud, $totalDifficulty);
}


/**
* @param centerEid : Identifiant du mot central.
* @param cloud : Le nuage.
* @param r1 : Le type de la relation 1.
* @param r2 : Le type de la relation 2.
* @param totalDifficulty : La difficulté totale.
*/
function cg_insert($centerEid, $cloud, $r1, $r2, $totalDifficulty)
{
	global $db;

	// Insère dans la base une partie avec le mot central $centerEid, le nuage $cloud et les relations $r1 et $r2
	$db->exec("begin transaction;");
	$db->exec("INSERT INTO game(gid, eid_central_word, relation_1, relation_2, difficulty)
		   VALUES (null, $centerEid, $r1, $r2, $totalDifficulty);");
	$gid = $db->lastInsertRowID();

	$db->exec("INSERT INTO played_game(pgid, gid, login, played)
		   VALUES (null, $gid, null, 1);");
	$pgid = $db->lastInsertRowID();

	foreach ($cloud as $c)
	{
		$db->exec("INSERT INTO game_cloud(gid, num, difficulty, eid_word, totalWeight, probaR1, probaR2, probaR0, probaTrash)
			   VALUES ($gid, ".$c['pos'].", ".$c['d'].", ".$c['eid'].", 2, ".$c['probaR1'].", ".$c['probaR2'].", ".$c['probaR0'].", ".$c['probaTrash'].");");
		
		$db->exec("INSERT INTO played_game_cloud(pgid, gid, type, num, relation, weight, score)
			   VALUES ($pgid, $gid, 0, ".$c['pos'].", $r1, ".$c['probaR1'].", 0);");

		$db->exec("INSERT INTO played_game_cloud(pgid, gid, type, num, relation, weight, score)
			   VALUES ($pgid, $gid, 0, ".$c['pos'].", $r1, ".$c['probaR1'].", 0);");
	}

	$db->exec("commit;");
}


/** Génère une partie pour une certaine taille de nuage.
* @param cloudSize : Taille du nuage.
*/
function create_game($cloudSize)
{
	global $db;

	// select random node
	$centerEid = random_node();

	$r1 = cg_choose_relations(); $r2 = $r1[1]; $r1 = $r1[0];
	$sources = cg_build_result_sets($cloudSize, $centerEid, $r1, $r2); $sumWeights = $sources[1]; $sources = $sources[0];
	$cloud = cg_build_cloud($cloudSize, $sources, $sumWeights); $totalDifficulty = $cloud[1]; $cloud = $cloud[0];
	cg_insert($centerEid, $cloud, $r1, $r2, $totalDifficulty);
}


/** Retourne un identifiant de partie aléatoire de la liste de parties jouables
* @return gid : Identifiant de partie.
*/
function random_game()
{
	global $db;

	return $db->querySingle("select gid from game where gid = (abs(random()) % (select max(gid) from game))+1 or gid = (select max(gid) from game where gid > 0) order by gid limit 1;");
}


/** Formate une partie en JSON en l'imprimant.
* @param game_id : L'identifiant d'une partie.
*/
function game2json($game_id)
{
	global $db, $user;
	
	// TODO : planter si la requête suivante échoue pour quelque raison que ce soit.
	$db->exec("INSERT INTO played_game(pgid, gid, login, played) VALUES (null, $game_id, '$user', 0);");
	$pgid = $db->lastInsertRowID();
	
	// TODO Yoann : faire des tests d'erreur pour ces select ?
	$game = $db->query("select gid, (select name from node where eid = eid_central_word) as name_central_word, eid_central_word, relation_1, relation_2 from game where gid = ".$game_id.";");
	$game = $game->fetchArray();
	
	echo '{"gid":'.$game_id.',"pgid":'.$pgid.',"cat1":'.$game['relation_1'].',"cat2":'.$game['relation_2'].',"cat3":0,"cat4":-1,';
	echo '"center":{"id":'.$game['eid_central_word'].',"name":'.json_encode(''.$game['name_central_word']).'},';
	echo '"cloudsize":10,"cloud":['; // TODO ! compter dynamiquement.
	
	$res = $db->query("select eid_word,(select name from node where eid=eid_word) as name_word from game_cloud where gid = ".$game_id.";");
	$notfirst = false;
	
	while ($x = $res->fetchArray())
	{
		if ($notfirst) 
			echo ",";
		else
			$notfirst=true;

		echo '{"id":'.$x['eid_word'].',"name":'.json_encode("".$x['name_word']).'}';
	}

	echo "]}";
}


/** Création d'une partie.
*/
function createGame()
{
	if(!isset($_GET['nb']) || !isset($_GET['mode']))
		mDie(2,"La requête est incomplète");

	$nbParties = intval($_GET['nb']);

	for ($i = 0; $i < $nbParties; $i++)
		create_game(10);
}


/** Récupération d'une partie.
*/
function getGame()
{
	if(!isset($_GET['nb']) || !isset($_GET['mode']))
		mDie(2,"La requête est incomplète");

	$nbGames = intval($_GET['nb']);
	
	echo "[";

	for ($i=0; $i < $nbGames; $i)
	{
		game2json(random_game());

		if ((++$i) < $nbGames)
			echo ",";
	}
	
	echo "]";
}


/** Insertion des données d'une partie.
*/
function setGame()
{
	global $db, $user;

	if (!isset($_GET['pgid']) || !isset($_GET['gid']))
		mDie(2,"La requête est incomplète");
	
	$pgid = intval($_GET['pgid']);
	$gid = intval($_GET['gid']);
		
	if ('t' !== $db->querySingle("SELECT 't' FROM played_game WHERE pgid = $pgid and $gid = $gid and played = 0 and login = '$user';"))
		mDie(4,"Cette partie n'est associée à votre nom d'utilisateur, ou bien vous l'avez déjà jouée.");
		
	$userReputation = $db->querySingle("SELECT score FROM user WHERE login='$user';");
	$userReputation = ($userReputation > 0) ? log($userReputation) : 0;
		
	$db->exec("begin transaction;");
	$db->exec("update played_game set played = 1 where pgid = $pgid;");

	$r0 = 0;
	$trash = -1;
	$r1 = $db->querySingle("SELECT relation_1, relation_2 FROM game WHERE gid = $gid;", true);
	$r2 = $r1['relation_2'];
	$r1 = $r1['relation_1'];
	$res = $db->query("SELECT num, difficulty, totalWeight, probaR1, probaR2, probaR0, probaTrash FROM game_cloud WHERE gid = $gid;");
	
	while ($row = $res->fetchArray())
	{
		$num = $row['num'];
		if (!isset($_GET[$num])) {
			mDie(5,"Pas de réponse pour le mot $num de cette partie.");
		}
		$relanswer = intval($_GET[$num]);

		switch ($relanswer) 
		{
			case $r1:    $answer = 0; $probaRx = "probaR1"; break;
			case $r2:    $answer = 1; $probaRx = "probaR2"; break;
			case $r0:    $answer = 2; $probaRx = "probaR0"; break;
			case $trash: $answer = 3; $probaRx = "probaTrash"; break;
			default: mDie(5, "Réponse invalide pour le mot $num.");
		}
			
		$probas = array($row['probaR1']/$row['totalWeight'], $row['probaR2']/$row['totalWeight'], $row['probaR0']/$row['totalWeight'], $row['probaTrash']/$row['totalWeight']);
		// Calcul du score. Score = proba[réponse de l'utilisateur]*coeff1 - proba[autres reponses]*coeff2
		// score = - proba[autres reponses]*coeff2
		$score = -0.7 * (($probas[0] + $probas[1] + $probas[2] + $probas[3]) - $probas[$answer]);
		// ici, -0.7 <= score <= 0
		// score = proba[réponse de l'utilisateur]*coeff1 - proba[autres reponses]*coeff2
		$score += ($row['difficulty']/5) * $probas[$answer];
		// ici, -0.7 <= score <= 2
		// Adapter le score en fonction de la réputation de l'utilisateur (quand il est jeune, augmenter le score pour le motiver).
		$score += min(2 - max(0, ($userReputation / 4) - 1), 2);
		// ici, -0.7 <= score <= 4

		$db->exec("insert into played_game_cloud(pgid, gid, type, num, relation, weight, score) values($pgid, $gid, 1, $num, $r1, ".$userReputation.", ".$score.");");
		$db->exec("update game_cloud set $probaRx = $probaRx + ".max($userReputation,1)." where gid = $gid;");
		$db->exec("update game_cloud set totalWeight = totalWeight + ".max($userReputation,1)." where gid = $gid;");
		$db->exec("update user set score = score + ".$score." where login = '$user';");
	}

	$db->exec("commit;");
	// On renvoie une nouvelle partie pour garder le client toujours bien alimenté.
	game2json(random_game());
}

/** La fonction principale.
* @param action : Un identifiant d'action.
*/
function main($action)
{	
	// Sinon tout est bon on effectu l'opération correspondant à la commande passée.
	// TODO : en production, utiliser : header("Content-Type: application/json; charset=utf-8");
	header("Content-Type: text/plain; charset=utf-8");
	
	if  ($action == 2)				// "Create partie"
		// Requête POST : http://serveur/pticlic.php?action=2&nb=2&mode=normal&user=foo&passwd=bar
		createGame();
	else if($action == 0)				// "Get partie"
		// Requête POST : http://serveur/pticlic.php?action=0&nb=2&mode=normal&user=foo&passwd=bar
		getGame();
	else if($action == 1)				// "Set partie"
		// Requête POST : http://serveur/pticlic.php?action=1&mode=normal&user=foo&passwd=bar&gid=1234&pgid=12357&0=0&1=-1&2=22&3=13&9=-1
		setGame();
	else
		mDie(2,"Commande inconnue");
}

main($action);

?>