<?php
/**
 * Airline Tycoon - Game API
 * Hauptspiel-API für Flüge, Routen, Flugzeuge, etc.
 */

require_once dirname(__DIR__) . '/src/bootstrap.php';

header('Content-Type: application/json; charset=utf-8');

// Auth Check für alle Aktionen außer 'status'
$action = $_GET['action'] ?? $_POST['action'] ?? '';

$publicActions = ['status', 'info'];
if (!in_array($action, $publicActions) && !Session::isLoggedIn()) {
    jsonResponse(['error' => 'Nicht angemeldet'], 401);
}

switch ($action) {
    case 'status':
        handleStatus();
        break;
    
    case 'info':
        handleInfo();
        break;
    
    case 'purchase':
        handlePurchase();
        break;
    
    case 'flight':
        handleFlight();
        break;
    
    case 'routes':
        handleRoutes();
        break;
    
    case 'create_route':
        handleCreateRoute();
        break;
    
    case 'stats':
        handleStats();
        break;
    
    case 'leaderboard':
        handleLeaderboard();
        break;
    
    // NEU: Kredite
    case 'take_loan':
        handleTakeLoan();
        break;
    
    case 'repay_loan':
        handleRepayLoan();
        break;
    
    case 'loans':
        handleLoans();
        break;
    
    // NEU: Wartung
    case 'maintenance':
        handleMaintenance();
        break;
    
    case 'aircraft_details':
        handleAircraftDetails();
        break;
    
    // NEU: Finanzen
    case 'transactions':
        handleTransactions();
        break;
    
    case 'finance_summary':
        handleFinanceSummary();
        break;
    
    default:
        jsonResponse(['error' => 'Unbekannte Aktion'], 400);
}

function handleStatus() {
    global $db, $config;
    
    $response = [
        'success' => true,
        'authenticated' => Session::isLoggedIn(),
        'timestamp' => time(),
        'config' => [
            'start_balance' => $config['game']['start_balance'],
            'fuel_cost_per_km' => $config['game']['fuel_cost_per_km']
        ]
    ];
    
    if (Session::isLoggedIn()) {
        $userId = Session::getUserId();
        $user = $db->getUserById($userId);
        
        if ($user) {
            $response['user'] = [
                'id' => $user['id'],
                'username' => $user['username'],
                'airline_name' => $user['airline_name'],
                'balance' => $user['balance'],
                'level' => $user['level'],
                'experience' => $user['experience']
            ];
        }
    }
    
    jsonResponse($response);
}

function handleInfo() {
    global $config;
    
    jsonResponse([
        'success' => true,
        'app' => $config['app'],
        'game' => $config['game'],
        'aircraft_types' => $config['aircraft_types']
    ]);
}

function handlePurchase() {
    global $db, $config;
    
    $userId = Session::getUserId();
    $user = $db->getUserById($userId);
    
    $type = $_POST['aircraft_type'] ?? '';
    $name = trim($_POST['name'] ?? '');
    
    if (empty($type) || !isset($config['aircraft_types'][$type])) {
        jsonResponse(['error' => 'Ungültiger Flugzeugtyp'], 400);
    }
    
    $specs = $config['aircraft_types'][$type];
    $price = $specs['purchase_price'];
    
    if ($user['balance'] < $price) {
        jsonResponse([
            'error' => 'Nicht genug Geld!',
            'required' => $price,
            'available' => $user['balance']
        ], 400);
    }
    
    // Balance abziehen
    $newBalance = $user['balance'] - $price;
    $db->update('users', ['balance' => $newBalance], 'id = ?', [$userId]);
    
    // Aircraft erstellen
    $aircraftId = $db->purchaseAircraft($userId, $type, $name, $price);
    
    jsonResponse([
        'success' => true,
        'message' => "{$type} \"{$name}\" wurde gekauft!",
        'aircraft_id' => $aircraftId,
        'price' => $price,
        'new_balance' => $newBalance
    ]);
}

function handleFlight() {
    global $db;
    
    $userId = Session::getUserId();
    $user = $db->getUserById($userId);
    
    $routeId = (int) ($_POST['route_id'] ?? 0);
    $aircraftId = (int) ($_POST['aircraft_id'] ?? 0);
    
    if ($routeId <= 0 || $aircraftId <= 0) {
        jsonResponse(['error' => 'Route und Flugzeug erforderlich'], 400);
    }
    
    // Route prüfen
    $route = $db->selectOne(
        "SELECT r.*, a1.name as from_name, a2.name as to_name 
         FROM routes r
         JOIN airports a1 ON r.from_airport_id = a1.id
         JOIN airports a2 ON r.to_airport_id = a2.id
         WHERE r.id = ? AND r.user_id = ? AND r.is_active = 1",
        [$routeId, $userId]
    );
    
    if (!$route) {
        jsonResponse(['error' => 'Route nicht gefunden'], 404);
    }
    
    // Aircraft prüfen
    $aircraft = $db->selectOne(
        "SELECT * FROM aircraft WHERE id = ? AND user_id = ?",
        [$aircraftId, $userId]
    );
    
    if (!$aircraft) {
        jsonResponse(['error' => 'Flugzeug nicht gefunden'], 404);
    }
    
    if ($aircraft['condition'] <= 0) {
        jsonResponse(['error' => 'Flugzeug ist zu beschädigt!'], 400);
    }
    
    if ($aircraft['range_km'] < $route['distance_km']) {
        jsonResponse([
            'error' => 'Flugzeug hat nicht genug Reichweite!',
            'required' => $route['distance_km'],
            'available' => $aircraft['range_km']
        ], 400);
    }
    
    try {
        $result = $db->executeFlight($userId, $routeId, $aircraftId);
        
        // User-Daten aktualisieren
        $updatedUser = $db->getUserById($userId);
        
        jsonResponse([
            'success' => true,
            'message' => 'Flug erfolgreich!',
            'flight' => [
                'from' => $route['from_name'],
                'to' => $route['to_name'],
                'passengers' => $result['passengers'],
                'revenue' => $result['revenue'],
                'fuel_cost' => $result['fuel_cost'],
                'profit' => $result['profit']
            ],
            'user' => [
                'balance' => $updatedUser['balance'],
                'experience' => $updatedUser['experience'],
                'level' => $updatedUser['level']
            ]
        ]);
    } catch (Exception $e) {
        jsonResponse(['error' => 'Flug fehlgeschlagen: ' . $e->getMessage()], 500);
    }
}

function handleRoutes() {
    global $db;
    
    $userId = Session::getUserId();
    $routes = $db->getUserRoutes($userId);
    
    jsonResponse([
        'success' => true,
        'routes' => $routes,
        'count' => count($routes)
    ]);
}

function handleCreateRoute() {
    global $db;
    
    $userId = Session::getUserId();
    
    $fromId = (int) ($_POST['from_airport'] ?? 0);
    $toId = (int) ($_POST['to_airport'] ?? 0);
    
    if ($fromId <= 0 || $toId <= 0) {
        jsonResponse(['error' => 'Gültige Flughäfen erforderlich'], 400);
    }
    
    if ($fromId === $toId) {
        jsonResponse(['error' => 'Von und Nach müssen unterschiedlich sein'], 400);
    }
    
    // Flughäfen prüfen
    $fromAirport = $db->selectOne("SELECT * FROM airports WHERE id = ?", [$fromId]);
    $toAirport = $db->selectOne("SELECT * FROM airports WHERE id = ?", [$toId]);
    
    if (!$fromAirport || !$toAirport) {
        jsonResponse(['error' => 'Ein oder beide Flughäfen nicht gefunden'], 404);
    }
    
    // Prüfen ob Route bereits existiert
    $existing = $db->selectOne(
        "SELECT id FROM routes WHERE user_id = ? AND from_airport_id = ? AND to_airport_id = ?",
        [$userId, $fromId, $toId]
    );
    
    if ($existing) {
        jsonResponse(['error' => 'Diese Route existiert bereits'], 409);
    }
    
    // Distance berechnen
    $distance = $db->calculateDistance(
        $fromAirport['latitude'], $fromAirport['longitude'],
        $toAirport['latitude'], $toAirport['longitude']
    );
    
    // Route erstellen
    $routeId = $db->createRoute($userId, $fromId, $toId, $distance);
    
    jsonResponse([
        'success' => true,
        'message' => "Route {$fromAirport['iata_code']} → {$toAirport['iata_code']} erstellt!",
        'route_id' => $routeId,
        'distance' => $distance
    ]);
}

function handleStats() {
    global $db;
    
    $userId = Session::getUserId();
    $user = $db->getUserById($userId);
    
    $stats = $db->getUserStats($userId);
    $todayStats = $db->getTodayStats($userId);
    $aircraft = $db->getUserAircraft($userId);
    $routes = $db->getUserRoutes($userId);
    
    // Level-Berechnung
    $config = require dirname(__DIR__) . '/src/config.php';
    $expForNextLevel = $config['game']['level_up_threshold'] * pow($config['game']['level_multiplier'], $user['level'] - 1);
    
    jsonResponse([
        'success' => true,
        'user' => [
            'balance' => $user['balance'],
            'level' => $user['level'],
            'experience' => $user['experience'],
            'exp_for_next' => $expForNextLevel
        ],
        'stats' => $stats,
        'today' => $todayStats,
        'fleet_count' => count($aircraft),
        'routes_count' => count($routes)
    ]);
}

function handleLeaderboard() {
    global $db;
    
    $limit = min(50, (int) ($_GET['limit'] ?? 10));
    
    $leaders = $db->select(
        "SELECT id, username, airline_name, balance, level, experience,
                (SELECT COUNT(*) FROM routes WHERE user_id = users.id AND is_active = 1) as routes_count,
                (SELECT COUNT(*) FROM flights WHERE user_id = users.id) as total_flights
         FROM users
         WHERE is_active = 1
         ORDER BY balance DESC, level DESC, experience DESC
         LIMIT ?",
        [$limit]
    );
    
    jsonResponse([
        'success' => true,
        'leaderboard' => $leaders,
        'count' => count($leaders)
    ]);
}

// ============================================
// KREDIT HANDLERS
// ============================================
function handleTakeLoan() {
    global $db, $config;
    
    $userId = Session::getUserId();
    
    // CSRF Check
    if (!Session::validateCsrfToken($_POST['csrf_token'] ?? '')) {
        jsonResponse(['error' => 'Ungültiges CSRF-Token'], 403);
    }
    
    $amount = (float) ($_POST['amount'] ?? 0);
    
    if ($amount <= 0) {
        jsonResponse(['error' => 'Ungültiger Betrag'], 400);
    }
    
    try {
        $loanId = $db->createLoan($userId, $amount);
        
        // Update user balance
        $user = $db->getUserById($userId);
        
        jsonResponse([
            'success' => true,
            'message' => 'Kredit über ' . number_format($amount, 0, ',', '.') . ' € aufgenommen!',
            'loan_id' => $loanId,
            'amount' => $amount,
            'new_balance' => $user['balance'] + $amount,
            'interest_rate' => $config['loans']['interest_rate'],
            'daily_interest' => $amount * $config['loans']['interest_rate']
        ]);
    } catch (Exception $e) {
        jsonResponse(['error' => $e->getMessage()], 400);
    }
}

function handleRepayLoan() {
    global $db;
    
    $userId = Session::getUserId();
    
    // CSRF Check
    if (!Session::validateCsrfToken($_POST['csrf_token'] ?? '')) {
        jsonResponse(['error' => 'Ungültiges CSRF-Token'], 403);
    }
    
    $loanId = (int) ($_POST['loan_id'] ?? 0);
    $amount = (float) ($_POST['amount'] ?? 0);
    
    if ($loanId <= 0 || $amount <= 0) {
        jsonResponse(['error' => 'Ungültige Parameter'], 400);
    }
    
    try {
        $result = $db->repayLoan($userId, $loanId, $amount);
        
        jsonResponse([
            'success' => true,
            'message' => number_format($result['repaid'], 2, ',', '.') . ' € zurückgezahlt!',
            'repaid' => $result['repaid'],
            'remaining' => $result['remaining'],
            'new_balance' => $result['new_balance']
        ]);
    } catch (Exception $e) {
        jsonResponse(['error' => $e->getMessage()], 400);
    }
}

function handleLoans() {
    global $db;
    
    $userId = Session::getUserId();
    $loans = $db->getUserLoans($userId);
    $totalDebt = $db->getTotalDebt($userId);
    $totalDebtWithInterest = $db->getTotalDebtWithInterest($userId);
    
    jsonResponse([
        'success' => true,
        'loans' => $loans,
        'total_debt' => $totalDebt,
        'total_debt_with_interest' => $totalDebtWithInterest,
        'count' => count($loans)
    ]);
}

// ============================================
// WARTUNG HANDLERS
// ============================================
function handleMaintenance() {
    global $db, $config;
    
    $userId = Session::getUserId();
    
    // CSRF Check
    if (!Session::validateCsrfToken($_POST['csrf_token'] ?? '')) {
        jsonResponse(['error' => 'Ungültiges CSRF-Token'], 403);
    }
    
    $aircraftId = (int) ($_POST['aircraft_id'] ?? 0);
    
    if ($aircraftId <= 0) {
        jsonResponse(['error' => 'Flugzeug-ID erforderlich'], 400);
    }
    
    try {
        $result = $db->performMaintenance($userId, $aircraftId);
        
        jsonResponse([
            'success' => true,
            'message' => 'Wartung erfolgreich durchgeführt!',
            'cost' => $result['cost'],
            'condition_before' => $result['condition_before'],
            'condition_after' => $result['condition_after'],
            'new_balance' => $result['new_balance']
        ]);
    } catch (Exception $e) {
        jsonResponse(['error' => $e->getMessage()], 400);
    }
}

function handleAircraftDetails() {
    global $db;
    
    $userId = Session::getUserId();
    $aircraftId = (int) ($_GET['id'] ?? 0);
    
    if ($aircraftId <= 0) {
        jsonResponse(['error' => 'Flugzeug-ID erforderlich'], 400);
    }
    
    $aircraft = $db->selectOne(
        "SELECT * FROM aircraft WHERE id = ? AND user_id = ?",
        [$aircraftId, $userId]
    );
    
    if (!$aircraft) {
        jsonResponse(['error' => 'Flugzeug nicht gefunden'], 404);
    }
    
    // Get maintenance history for this aircraft
    $maintenanceHistory = $db->select(
        "SELECT * FROM maintenance_history WHERE aircraft_id = ? ORDER BY created_at DESC LIMIT 10",
        [$aircraftId]
    );
    
    // Get aircraft config for maintenance cost estimate
    $config = $db->getConfig();
    $aircraftConfig = $config['aircraft_types'][$aircraft['aircraft_type']] ?? [];
    $maintenanceCost = $aircraftConfig['maintenance_base_cost'] ?? 50000;
    
    // Adjust for condition
    $conditionLoss = 100 - $aircraft['condition'];
    $estimatedCost = $maintenanceCost + ($conditionLoss * 0.01 * $maintenanceCost);
    
    jsonResponse([
        'success' => true,
        'aircraft' => $aircraft,
        'maintenance_history' => $maintenanceHistory,
        'maintenance_cost' => $estimatedCost,
        'maintenance_interval' => $config['game']['maintenance_interval']
    ]);
}

// ============================================
// FINANZEN HANDLERS
// ============================================
function handleTransactions() {
    global $db;
    
    $userId = Session::getUserId();
    $limit = min(100, (int) ($_GET['limit'] ?? 50));
    
    $transactions = $db->getUserTransactions($userId, $limit);
    
    jsonResponse([
        'success' => true,
        'transactions' => $transactions,
        'count' => count($transactions)
    ]);
}

function handleFinanceSummary() {
    global $db;
    
    $userId = Session::getUserId();
    $user = $db->getUserById($userId);
    
    $today = date('Y-m-d');
    $weekAgo = date('Y-m-d', strtotime('-7 days'));
    $monthAgo = date('Y-m-d', strtotime('-30 days'));
    
    $todayStats = $db->getTransactionSummary($userId, $today, $today);
    $weekStats = $db->getTransactionSummary($userId, $weekAgo, $today);
    $monthStats = $db->getTransactionSummary($userId, $monthAgo, $today);
    
    $loans = $db->getUserLoans($userId);
    $totalDebt = $db->getTotalDebtWithInterest($userId);
    
    jsonResponse([
        'success' => true,
        'balance' => $user['balance'],
        'net_worth' => $user['balance'] - $totalDebt,
        'total_debt' => $totalDebt,
        'today' => $todayStats,
        'week' => $weekStats,
        'month' => $monthStats,
        'active_loans' => count($loans)
    ]);
}