<?php
header('Content-Type: application/json; charset=utf-8');
header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, GET, OPTIONS');
header('Access-Control-Allow-Headers: Content-Type');

// Handle preflight requests
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    exit(0);
}

include_once 'includes/db.php';

// Egyptian cities with approximate coordinates
$egyptianCities = [
    'القاهرة' => ['lat' => 30.0444, 'lng' => 31.2357],
    'الجيزة' => ['lat' => 30.0131, 'lng' => 31.2089],
    'الإسكندرية' => ['lat' => 31.2001, 'lng' => 29.9187],
    'الشرقية' => ['lat' => 30.5965, 'lng' => 31.5041],
    'المنوفية' => ['lat' => 30.5972, 'lng' => 30.9876],
    'القليوبية' => ['lat' => 30.1792, 'lng' => 31.2045],
    'كفر الشيخ' => ['lat' => 31.1107, 'lng' => 30.9388],
    'الغربية' => ['lat' => 30.8754, 'lng' => 31.0364],
    'المنيا' => ['lat' => 28.0871, 'lng' => 30.7618],
    'بني سويف' => ['lat' => 29.0661, 'lng' => 31.0994],
    'الفيوم' => ['lat' => 29.2985, 'lng' => 30.8418],
    'أسيوط' => ['lat' => 27.1809, 'lng' => 31.1837],
    'سوهاج' => ['lat' => 26.5569, 'lng' => 31.6948],
    'قنا' => ['lat' => 26.1551, 'lng' => 32.7160],
    'الأقصر' => ['lat' => 25.6872, 'lng' => 32.6396],
    'أسوان' => ['lat' => 24.0889, 'lng' => 32.8998],
    'البحر الأحمر' => ['lat' => 26.0667, 'lng' => 33.8116],
    'الوادي الجديد' => ['lat' => 25.4518, 'lng' => 30.5414],
    'مطروح' => ['lat' => 31.3543, 'lng' => 27.2373],
    'شمال سيناء' => ['lat' => 31.1342, 'lng' => 33.8059],
    'جنوب سيناء' => ['lat' => 28.4693, 'lng' => 33.9715],
    'دمياط' => ['lat' => 31.8133, 'lng' => 31.8067],
    'الدقهلية' => ['lat' => 31.0409, 'lng' => 31.3785],
    'بورسعيد' => ['lat' => 31.2653, 'lng' => 32.3019],
    'الإسماعيلية' => ['lat' => 30.5965, 'lng' => 32.2715],
    'السويس' => ['lat' => 29.9668, 'lng' => 32.5498]
];

// Function to calculate distance between two points
function calculateDistance($lat1, $lon1, $lat2, $lon2) {
    $earthRadius = 6371;
    $dLat = deg2rad($lat2 - $lat1);
    $dLon = deg2rad($lon2 - $lon1);
    $a = sin($dLat/2) * sin($dLat/2) + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * sin($dLon/2) * sin($dLon/2);
    $c = 2 * atan2(sqrt($a), sqrt(1-$a));
    return $earthRadius * $c;
}

$input = json_decode(file_get_contents('php://input'), true);

if (!isset($input['city'])) {
    echo json_encode([
        'success' => false,
        'message' => 'الرجاء تحديد المحافظة'
    ]);
    exit;
}

$selectedCity = $input['city'];

if (!isset($egyptianCities[$selectedCity])) {
    echo json_encode([
        'success' => false,
        'message' => 'المحافظة غير موجودة'
    ]);
    exit;
}

$cityCoords = $egyptianCities[$selectedCity];

try {
    // Get all branches from database
    $sql = "SELECT id, name, address, phone, lat, lng FROM branches WHERE lat IS NOT NULL AND lng IS NOT NULL";
    $result = $conn->query($sql);
    
    if ($result->num_rows == 0) {
        echo json_encode([
            'success' => false,
            'message' => 'لا توجد فروع متاحة حالياً'
        ]);
        exit;
    }
    
    $nearestBranch = null;
    $minDistance = PHP_FLOAT_MAX;
    
    // Calculate distance to each branch
    while ($branch = $result->fetch_assoc()) {
        $distance = calculateDistance(
            $cityCoords['lat'], 
            $cityCoords['lng'], 
            floatval($branch['lat']), 
            floatval($branch['lng'])
        );
        
        if ($distance < $minDistance) {
            $minDistance = $distance;
            $nearestBranch = $branch;
            $nearestBranch['distance'] = round($distance, 2);
        }
    }
    
    if ($nearestBranch) {
        echo json_encode([
            'success' => true,
            'branch' => [
                'name' => $nearestBranch['name'],
                'address' => $nearestBranch['address'],
                'phone' => $nearestBranch['phone'],
                'distance' => $nearestBranch['distance']
            ]
        ]);
    } else {
        echo json_encode([
            'success' => false,
            'message' => 'لم يتم العثور على فروع قريبة'
        ]);
    }
    
} catch (Exception $e) {
    echo json_encode([
        'success' => false,
        'message' => 'حدث خطأ في النظام'
    ]);
}

$conn->close();
?>