<?php
// includes/helpers.php
require_once __DIR__ . '/../config/app.php';
require_once __DIR__ . '/../config/database.php';

/* ============================================================
   HTTP Response helpers
   ============================================================ */
function jsonSuccess($data = [], string $message = 'OK', int $code = 200): void {
    http_response_code($code);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['success' => true, 'message' => $message, 'data' => $data], JSON_UNESCAPED_UNICODE);
    exit;
}

function jsonError(string $message = 'Error', int $code = 400, array $errors = []): void {
    http_response_code($code);
    header('Content-Type: application/json; charset=utf-8');
    echo json_encode(['success' => false, 'message' => $message, 'errors' => $errors], JSON_UNESCAPED_UNICODE);
    exit;
}

/* ============================================================
   Input sanitization
   ============================================================ */
function sanitize(string $val): string {
    return htmlspecialchars(strip_tags(trim($val)), ENT_QUOTES, 'UTF-8');
}

function getBody(): array {
    $raw = file_get_contents('php://input');
    $data = json_decode($raw, true);
    return is_array($data) ? $data : [];
}

function required(array $data, array $fields): array {
    $errors = [];
    foreach ($fields as $f) {
        if (!isset($data[$f]) || trim((string)$data[$f]) === '') {
            $errors[] = "Field '$f' wajib diisi";
        }
    }
    return $errors;
}

/* ============================================================
   Session / Auth
   ============================================================ */
function startSession(): void {
    if (session_status() === PHP_SESSION_NONE) {
        session_name(SESSION_NAME);
        session_start();
    }
}

function currentUser(): ?array {
    startSession();
    return $_SESSION['user'] ?? null;
}

function requireAuth(array $allowedRoles = []): array {
    $user = currentUser();
    if (!$user) jsonError('Unauthorized - silakan login', 401);
    if (!empty($allowedRoles) && !in_array($user['id_role'], $allowedRoles)) {
        jsonError('Forbidden - hak akses tidak cukup', 403);
    }
    return $user;
}

function login(string $username, string $password): array|false {
    $db = getDB();
    $stmt = $db->prepare(
        "SELECT u.*, r.nama_role FROM user u JOIN role r ON u.id_role = r.id
         WHERE u.username = ? AND u.aktif = 1 LIMIT 1"
    );
    $stmt->execute([$username]);
    $user = $stmt->fetch();
    if (!$user || !password_verify($password, $user['password_hash'])) return false;

    // Update last_login
    $db->prepare("UPDATE user SET last_login = NOW() WHERE id = ?")->execute([$user['id']]);
    unset($user['password_hash']);
    return $user;
}

/* ============================================================
   Activity Log
   ============================================================ */
function logActivity(string $aksi, string $tabel = '', string $idRecord = '',
                     array $dataLama = [], array $dataBaru = []): void {
    try {
        $user = currentUser();
        $db   = getDB();
        $db->prepare(
            "INSERT INTO log_aktivitas (id_user, aksi, tabel, id_record, data_lama, data_baru, ip_address)
             VALUES (?, ?, ?, ?, ?, ?, ?)"
        )->execute([
            $user['id'] ?? null,
            $aksi, $tabel, $idRecord,
            $dataLama ? json_encode($dataLama, JSON_UNESCAPED_UNICODE) : null,
            $dataBaru ? json_encode($dataBaru, JSON_UNESCAPED_UNICODE) : null,
            $_SERVER['REMOTE_ADDR'] ?? null,
        ]);
    } catch (Throwable $e) { /* silent */ }
}

/* ============================================================
   Haversine distance (km)
   ============================================================ */
function haversine(float $lat1, float $lng1, float $lat2, float $lng2): float {
    $R = 6371;
    $dLat = deg2rad($lat2 - $lat1);
    $dLng = deg2rad($lng2 - $lng1);
    $a = sin($dLat/2)**2 + cos(deg2rad($lat1)) * cos(deg2rad($lat2)) * sin($dLng/2)**2;
    return $R * 2 * asin(sqrt($a));
}

/* ============================================================
   Pagination helper
   ============================================================ */
function paginate(array $data, int $page, int $perPage = 20): array {
    $total  = count($data);
    $pages  = (int)ceil($total / $perPage);
    $offset = ($page - 1) * $perPage;
    return [
        'items'    => array_slice($data, $offset, $perPage),
        'total'    => $total,
        'page'     => $page,
        'per_page' => $perPage,
        'pages'    => $pages,
    ];
}

/* ============================================================
   Validasi umur vs pendidikan
   ============================================================ */
function validasiPendidikan(int $umur, string $pendidikanTerakhir, string $statusPendidikan): array {
    $warnings = [];
    if ($umur >= 7 && $umur <= 15) {
        if ($statusPendidikan === 'tidak_sekolah') {
            $warnings[] = "Anak usia $umur tahun seharusnya masih sekolah (wajib belajar 9 tahun)";
        }
        if (!in_array($pendidikanTerakhir, ['SD','SMP','tidak_sekolah'])) {
            $warnings[] = "Pendidikan terakhir tidak sesuai untuk usia $umur tahun";
        }
    } elseif ($umur >= 16 && $umur <= 18) {
        if ($statusPendidikan === 'tidak_sekolah' && in_array($pendidikanTerakhir, ['tidak_sekolah','SD'])) {
            $warnings[] = "Remaja usia $umur tahun disarankan melanjutkan ke SMA/SMK";
        }
    }
    return $warnings;
}

/* ============================================================
   Upload foto helper
   ============================================================ */
function uploadFoto(array $file, string $subfolder = 'foto_laporan'): string|false {
    $allowed = ['image/jpeg','image/png','image/webp'];
    if (!in_array($file['type'], $allowed)) return false;
    if ($file['size'] > 5 * 1024 * 1024) return false;

    $dir = UPLOAD_DIR . $subfolder . '/';
    if (!is_dir($dir)) mkdir($dir, 0755, true);

    $ext      = pathinfo($file['name'], PATHINFO_EXTENSION);
    $filename = uniqid('img_', true) . '.' . strtolower($ext);
    $dest     = $dir . $filename;

    if (!move_uploaded_file($file['tmp_name'], $dest)) return false;
    return $subfolder . '/' . $filename;
}