<?php
header('Content-Type: application/json');
require_once __DIR__ . '/../db/config.php';

$action = $_GET['action'] ?? '';
$input = json_decode(file_get_contents('php://input'), true);

try {
    $pdo = db();
    
    switch ($action) {
        case 'set_nickname':
            $nickname = trim($input['nickname'] ?? '');
            $session_id = $input['player_id'] ?? '';
            if (!$nickname || !$session_id) {
                echo json_encode(['success' => false, 'error' => 'Missing data']);
                break;
            }
            $stmt = $pdo->prepare("INSERT INTO players (nickname, session_id, last_seen) VALUES (?, ?, NOW()) ON DUPLICATE KEY UPDATE nickname = ?, last_seen = NOW()");
            $stmt->execute([$nickname, $session_id, $nickname]);
            echo json_encode(['success' => true]);
            break;

        case 'heartbeat':
            $session_id = $input['player_id'] ?? '';
            if ($session_id) {
                $stmt = $pdo->prepare("UPDATE players SET last_seen = NOW() WHERE session_id = ?");
                $stmt->execute([$session_id]);
            }
            echo json_encode(['success' => true]);
            break;

        case 'get_online':
            $session_id = $_GET['player_id'] ?? '';
            $stmt = $pdo->prepare("SELECT id, nickname, session_id FROM players WHERE last_seen > DATE_SUB(NOW(), INTERVAL 30 SECOND) AND session_id != ? LIMIT 20");
            $stmt->execute([$session_id]);
            $players = $stmt->fetchAll();
            echo json_encode(['success' => true, 'players' => $players]);
            break;

        case 'invite':
            $from_session = $input['from_player_id'] ?? '';
            $to_session = $input['to_player_id'] ?? '';
            $room_code = strtoupper(substr(md5(uniqid()), 0, 6));

            $stmt = $pdo->prepare("SELECT id FROM players WHERE session_id = ?");
            $stmt->execute([$from_session]);
            $from = $stmt->fetch();
            
            $stmt = $pdo->prepare("SELECT id FROM players WHERE session_id = ?");
            $stmt->execute([$to_session]);
            $to = $stmt->fetch();

            if ($from && $to) {
                $stmt = $pdo->prepare("INSERT INTO invitations (from_player_id, to_player_id, room_code) VALUES (?, ?, ?)");
                $stmt->execute([$from['id'], $to['id'], $room_code]);
                
                // Pre-create the room
                $stmt = $pdo->prepare("INSERT INTO rooms (room_code, player1_id, status) VALUES (?, ?, 'waiting')");
                $stmt->execute([$room_code, $from_session]);
                
                echo json_encode(['success' => true, 'room_code' => $room_code]);
            } else {
                echo json_encode(['success' => false, 'error' => 'Player not found']);
            }
            break;

        case 'check_invites':
            $session_id = $_GET['player_id'] ?? '';
            $stmt = $pdo->prepare("
                SELECT i.id, p.nickname as from_nickname, i.room_code 
                FROM invitations i 
                JOIN players p ON i.from_player_id = p.id 
                JOIN players target ON i.to_player_id = target.id 
                WHERE target.session_id = ? AND i.status = 'pending' AND i.created_at > DATE_SUB(NOW(), INTERVAL 1 MINUTE)
            ");
            $stmt->execute([$session_id]);
            $invites = $stmt->fetchAll();
            echo json_encode(['success' => true, 'invites' => $invites]);
            break;

        case 'respond_invite':
            $invite_id = $input['invite_id'] ?? 0;
            $status = $input['status'] ?? 'rejected';
            $stmt = $pdo->prepare("UPDATE invitations SET status = ? WHERE id = ?");
            $stmt->execute([$status, $invite_id]);
            echo json_encode(['success' => true]);
            break;

        case 'create':
            $player_id = $input['player_id'] ?? '';
            $room_code = $input['room_code'] ?? strtoupper(substr(md5(uniqid()), 0, 6));
            
            $stmt = $pdo->prepare("INSERT INTO rooms (room_code, player1_id, status) VALUES (?, ?, 'waiting') ON DUPLICATE KEY UPDATE player1_id = VALUES(player1_id)");
            $stmt->execute([$room_code, $player_id]);
            $room_id = $pdo->lastInsertId();
            if (!$room_id) {
                $stmt = $pdo->prepare("SELECT id FROM rooms WHERE room_code = ?");
                $stmt->execute([$room_code]);
                $room_id = $stmt->fetchColumn();
            }
            
            echo json_encode(['success' => true, 'room_code' => $room_code, 'room_id' => $room_id]);
            break;

        case 'join':
            $player_id = $input['player_id'] ?? '';
            $room_code = strtoupper($input['room_code'] ?? '');
            
            $stmt = $pdo->prepare("SELECT id, player1_id, player2_id FROM rooms WHERE room_code = ? AND (status = 'waiting' OR status = 'playing')");
            $stmt->execute([$room_code]);
            $room = $stmt->fetch();
            
            if ($room) {
                if ($room['player1_id'] === $player_id) {
                     echo json_encode(['success' => true, 'room_id' => $room['id']]);
                } else {
                    $stmt = $pdo->prepare("UPDATE rooms SET player2_id = ?, status = 'playing' WHERE id = ?");
                    $stmt->execute([$player_id, $room['id']]);
                    echo json_encode(['success' => true, 'room_id' => $room['id']]);
                }
            } else {
                echo json_encode(['success' => false, 'error' => 'Room not found or full']);
            }
            break;

        case 'update':
            $room_id = $input['room_id'] ?? 0;
            $player_id = $input['player_id'] ?? '';
            $board = json_encode($input['board'] ?? []);
            $score = $input['score'] ?? 0;
            $is_game_over = $input['is_game_over'] ? 1 : 0;
            
            $stmt = $pdo->prepare("INSERT INTO game_states (room_id, player_id, board, score, is_game_over) 
                                   VALUES (?, ?, ?, ?, ?) 
                                   ON DUPLICATE KEY UPDATE board = VALUES(board), score = VALUES(score), is_game_over = VALUES(is_game_over)");
            $stmt->execute([$room_id, $player_id, $board, $score, $is_game_over]);
            
            echo json_encode(['success' => true]);
            break;

        case 'poll':
            $room_id = $_GET['room_id'] ?? 0;
            $player_id = $_GET['player_id'] ?? '';
            
            $stmt = $pdo->prepare("SELECT player_id, board, score, is_game_over FROM game_states WHERE room_id = ? AND player_id != ?");
            $stmt->execute([$room_id, $player_id]);
            $opponent = $stmt->fetch();
            
            $stmt = $pdo->prepare("SELECT pending_debuffs FROM game_states WHERE room_id = ? AND player_id = ?");
            $stmt->execute([$room_id, $player_id]);
            $self = $stmt->fetch();
            $debuffs = [];
            if ($self && $self['pending_debuffs']) {
                $debuffs = explode(',', $self['pending_debuffs']);
                $stmt = $pdo->prepare("UPDATE game_states SET pending_debuffs = NULL WHERE room_id = ? AND player_id = ?");
                $stmt->execute([$room_id, $player_id]);
            }
            
            $stmt = $pdo->prepare("SELECT status FROM rooms WHERE id = ?");
            $stmt->execute([$room_id]);
            $room = $stmt->fetch();
            
            echo json_encode([
                'success' => true, 
                'opponent' => $opponent ? [
                    'board' => json_decode($opponent['board']),
                    'score' => $opponent['score'],
                    'is_game_over' => (bool)$opponent['is_game_over']
                ] : null,
                'status' => $room['status'] ?? 'unknown',
                'debuffs' => $debuffs
            ]);
            break;

        case 'send_debuff':
            $room_id = $input['room_id'] ?? 0;
            $player_id = $input['player_id'] ?? '';
            $debuff = $input['debuff'] ?? '';
            
            $stmt = $pdo->prepare("SELECT player_id FROM game_states WHERE room_id = ? AND player_id != ?");
            $stmt->execute([$room_id, $player_id]);
            $opponent = $stmt->fetch();
            
            if ($opponent) {
                $stmt = $pdo->prepare("UPDATE game_states SET pending_debuffs = IF(pending_debuffs IS NULL, ?, CONCAT(pending_debuffs, ',', ?)) WHERE room_id = ? AND player_id = ?");
                $stmt->execute([$debuff, $debuff, $room_id, $opponent['player_id']]);
                echo json_encode(['success' => true]);
            } else {
                echo json_encode(['success' => false, 'error' => 'Opponent not found']);
            }
            break;

        default:
            echo json_encode(['success' => false, 'error' => 'Invalid action']);
    }
} catch (Exception $e) {
    echo json_encode(['success' => false, 'error' => $e->getMessage()]);
}