<?php
require_once 'config.php';

$method = $_SERVER['REQUEST_METHOD'];
$action = $_GET['action'] ?? '';

switch ($method) {
    case 'GET':
        if ($action === 'stats') {
            getUserStats();
        } elseif ($action === 'leaderboard') {
            getLeaderboard();
        } else {
            getUserPredictions();
        }
        break;
    
    case 'POST':
        $user = requireAuth();
        makePrediction($user);
        break;
    
    default:
        jsonResponse(['error' => 'Méthode non autorisée'], 405);
}

function getUserPredictions() {
    $user = requireAuth();
    $db = getDB();
    
    $stmt = $db->prepare("
        SELECT p.*, m.match_date, m.round, m.status,
            p1.name as p1_name, p2.name as p2_name,
            pw.name as predicted_winner_name,
            mw.name as actual_winner_name
        FROM predictions p
        JOIN matches m ON p.match_id = m.id
        JOIN players p1 ON m.player1_id = p1.id
        JOIN players p2 ON m.player2_id = p2.id
        JOIN players pw ON p.predicted_winner_id = pw.id
        LEFT JOIN players mw ON m.winner_id = mw.id
        WHERE p.user_id = ?
        ORDER BY m.match_date DESC
    ");
    $stmt->execute([$user['id']]);
    
    jsonResponse(['success' => true, 'predictions' => $stmt->fetchAll()]);
}

function makePrediction($user) {
    $data = getJsonInput();
    
    if (!isset($data['match_id']) || !isset($data['predicted_winner_id'])) {
        jsonResponse(['error' => 'match_id et predicted_winner_id requis'], 400);
    }
    
    $db = getDB();
    
    // Vérifier que le match existe et est à venir
    $stmt = $db->prepare("SELECT id, status, player1_id, player2_id FROM matches WHERE id = ?");
    $stmt->execute([$data['match_id']]);
    $match = $stmt->fetch();
    
    if (!$match) {
        jsonResponse(['error' => 'Match non trouvé'], 404);
    }
    
    if ($match['status'] !== 'upcoming') {
        jsonResponse(['error' => 'Ce match est déjà terminé ou annulé'], 400);
    }
    
    // Vérifier que le gagnant prédit est l'un des deux joueurs
    if ($data['predicted_winner_id'] != $match['player1_id'] && $data['predicted_winner_id'] != $match['player2_id']) {
        jsonResponse(['error' => 'Le gagnant prédit doit être l\'un des deux joueurs du match'], 400);
    }
    
    // Vérifier si l'utilisateur a déjà fait un pronostic pour ce match
    $stmt = $db->prepare("SELECT id FROM predictions WHERE user_id = ? AND match_id = ?");
    $stmt->execute([$user['id'], $data['match_id']]);
    
    if ($stmt->fetch()) {
        jsonResponse(['error' => 'Vous avez déjà fait un pronostic pour ce match'], 409);
    }
    
    // Créer le pronostic
    $stmt = $db->prepare("
        INSERT INTO predictions (user_id, match_id, predicted_winner_id, points_earned) 
        VALUES (?, ?, ?, ?)
    ");
    $stmt->execute([
        $user['id'],
        $data['match_id'],
        $data['predicted_winner_id'],
        POINTS_NEW_PREDICTION
    ]);
    
    // Ajouter les points à l'utilisateur
    $stmt = $db->prepare("UPDATE users SET points = points + ? WHERE id = ?");
    $stmt->execute([POINTS_NEW_PREDICTION, $user['id']]);
    
    jsonResponse([
        'success' => true, 
        'message' => 'Pronostic enregistré avec succès',
        'points_earned' => POINTS_NEW_PREDICTION
    ]);
}

function getUserStats() {
    $user = requireAuth();
    $db = getDB();
    
    // Total de pronostics
    $stmt = $db->prepare("SELECT COUNT(*) as total FROM predictions WHERE user_id = ?");
    $stmt->execute([$user['id']]);
    $total = $stmt->fetch()['total'];
    
    // Pronostics corrects
    $stmt = $db->prepare("
        SELECT COUNT(*) as correct 
        FROM predictions p
        JOIN matches m ON p.match_id = m.id
        WHERE p.user_id = ? AND p.is_correct = 1
    ");
    $stmt->execute([$user['id']]);
    $correct = $stmt->fetch()['correct'];
    
    // Taux de réussite
    $rate = $total > 0 ? round(($correct / $total) * 100) : 0;
    
    // Points totaux
    $stmt = $db->prepare("SELECT points FROM users WHERE id = ?");
    $stmt->execute([$user['id']]);
    $points = $stmt->fetch()['points'];
    
    jsonResponse([
        'success' => true,
        'stats' => [
            'total_predictions' => (int)$total,
            'correct_predictions' => (int)$correct,
            'success_rate' => $rate,
            'total_points' => (int)$points
        ]
    ]);
}

function getLeaderboard() {
    $db = getDB();
    
    $stmt = $db->query("
        SELECT u.id, u.username, u.points,
            COUNT(p.id) as total_predictions,
            SUM(CASE WHEN p.is_correct = 1 THEN 1 ELSE 0 END) as correct_predictions
        FROM users u
        LEFT JOIN predictions p ON u.id = p.user_id
        WHERE u.role = 'user'
        GROUP BY u.id
        ORDER BY u.points DESC, correct_predictions DESC
        LIMIT 50
    ");
    
    $leaderboard = [];
    $rank = 1;
    while ($row = $stmt->fetch()) {
        $leaderboard[] = [
            'rank' => $rank++,
            'user_id' => $row['id'],
            'username' => $row['username'],
            'points' => (int)$row['points'],
            'total_predictions' => (int)$row['total_predictions'],
            'correct_predictions' => (int)$row['correct_predictions']
        ];
    }
    
    jsonResponse(['success' => true, 'leaderboard' => $leaderboard]);
}
?>