<?php
/*
* Tic Tac Toe gnieark's IA
* For programming challenge https://github.com/jeannedhack/programmingChallenges
* Gnieark 2015 
* licensed under the Do What the Fuck You Want to Public License http://www.wtfpl.net/
*/
function scoreCases($grid,$myChar,$hisChar,$profondeur=0){
	//lister les cases vides de la grille
	foreach($grid as $key => $case){
        $tempGrid=$grid;
        $tempGrid[$key]=$myChar;
        if($case==""){ //on ne "score que les cases qui sont libres
            //tester si je gagne en jouant là
            if(isGridWin($tempGrid)){
		if(fmod($profondeur,2)==0){
		 $scores[$key]=10-$profondeur;	
           	}else{
		 $scores[$key]=$profondeur-10;
		}	
	    }elseif(nbFreeCases($tempGrid)==0){
		$scores[$key]=0;
	    }else{
		//trouver le plus grand score dans l'array plus profond	en valeur absolue
		$scores[$key]=0;
		$scoresDeeper=scoreCases($tempGrid,$hisChar,$myChar,$profondeur+1);
		foreach($scoresDeeper as $scD){
			if(abs($scD)>abs($scores[$key])){
			 $scores[$key]=$scD;
			}
		}
	    }
	}
	}
	//print_r($scores);print_r($grid);echo "------------"; 	
     return $scores;
}
function nbFreeCases($grille){
	$nb=0;
    foreach($grille as $case){
        if ($case==""){
            $nb++;
        }
    }
    return $nb;
}
function isGridWin($grille){
  if(
            (($grille['0-0']==$grille['0-1'])&&($grille['0-1']==$grille['0-2'])&&($grille['0-2']!==""))
        OR  (($grille['1-0']==$grille['1-1'])&&($grille['1-1']==$grille['1-2'])&&($grille['1-2']!==""))
        OR  (($grille['2-0']==$grille['2-1'])&&($grille['2-1']==$grille['2-2'])&&($grille['2-2']!==""))
        OR  (($grille['0-0']==$grille['1-0'])&&($grille['1-0']==$grille['2-0'])&&($grille['2-0']!==""))
        OR  (($grille['0-1']==$grille['1-1'])&&($grille['1-1']==$grille['2-1'])&&($grille['2-1']!==""))
        OR  (($grille['0-2']==$grille['1-2'])&&($grille['1-2']==$grille['2-2'])&&($grille['2-2']!==""))
        OR  (($grille['0-0']==$grille['1-1'])&&($grille['1-1']==$grille['2-2'])&&($grille['2-2']!==""))
        OR  (($grille['0-2']==$grille['1-1'])&&($grille['1-1']==$grille['2-0'])&&($grille['2-0']!==""))
    ){
        return true;
    }
    return false;
    
}


$cases=array("0-0","0-1","0-2","1-0","1-1","1-2","2-0","2-1","2-2");
//filling array
$freeCases=array();
foreach($cases as $case){
	if (!isset($_GET[$case])){
		echo "wrong parameters ".$case; die;
	}
	if($_GET[$case]==""){
		$freeCases[]=$case;
	}else{
            if ($_GET[$case]!==$_GET['you']){
                $hisChar=$_GET[$case];
            }
	}
	$grille[$case]=$_GET[$case];
}
if(!isset($_GET['you'])){
	echo "wrong parameters 2"; die;
}
if (count($freeCases)==0){
	echo "error. Grid is full, beach!";
	die;
}
if (isGridWin($grille)){
    echo ("erreur, la grille a déjà été gagnée"); die;
}
if(!isset($hisChar)){
    // si le caractere ennemi n'a pas été trouvé (il n'a pas déjà joué), on le définit arbitrairement.
    if($_GET['you']=="!"){
        $hisChar="?";
   }else{
        $hisChar="!";
   }
}
$scoresDesCases=scoreCases($grille,htmlentities($_GET['you']),$hisChar);
$sc=-10000;
foreach($scoresDesCases as $key=>$caseValue){
	if($caseValue>$sc){
        $sc=$caseValue;
        $beastCase=$key;
    }
}
echo $beastCase;