<?php
declare(strict_types=1);

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}

// Prevent browser caching globally
header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
header('Cache-Control: post-check=0, pre-check=0', false);
header('Pragma: no-cache');

require_once __DIR__ . '/../db/config.php';

function h(?string $value): string
{
    return htmlspecialchars((string) $value, ENT_QUOTES, 'UTF-8');
}

function get_platform_profile(): array {
    static $profile = null;
    if ($profile === null) {
        $stmt = db()->query("SELECT * FROM platform_profile WHERE id = 1");
        $profile = $stmt->fetch(PDO::FETCH_ASSOC);
        if (!$profile) {
             $profile = ['name' => 'LMS Platform', 'description' => '', 'logo_path' => '', 'favicon_path' => ''];
        }
    }
    return $profile;
}
function app_name(): string
{
    $prof = get_platform_profile();
    if (!empty($prof['name'])) {
        return trim($prof['name']);
    }
    return trim((string) ($_SERVER['PROJECT_NAME'] ?? 'Aula')) ?: 'Aula';
}

function project_description(): string
{
    return (string) ($_SERVER['PROJECT_DESCRIPTION'] ?? 'Modern multilingual e-learning classrooms with subscriptions, teachers, students, Google Meet live sessions, Thawani billing, and WhatsApp notifications.');
}


function get_landing_settings(): array {
    static $settings = null;
    if ($settings === null) {
        $settings = [];
        try {
            $stmt = db()->query("SELECT setting_key, value_en, value_ar FROM landing_settings");
            while ($row = $stmt->fetch(PDO::FETCH_ASSOC)) {
                $settings[$row['setting_key']] = $row;
            }
        } catch (Exception $e) {
        }
    }
    return $settings;
}

function landing_setting(string $key, string $default_en, string $default_ar = ""): string {
    $settings = get_landing_settings();
    $lang = current_lang();
    if (isset($settings[$key])) {
        $val = $lang === 'ar' ? $settings[$key]['value_ar'] : $settings[$key]['value_en'];
        if (trim((string)$val) !== '') {
            return $val;
        }
    }
    return $lang === 'ar' ? $default_ar : $default_en;
}
function current_lang(): string
{
    $lang = $_GET['lang'] ?? $_SESSION['lang'] ?? 'ar';
    $lang = in_array($lang, ['en', 'ar'], true) ? $lang : 'ar';
    $_SESSION['lang'] = $lang;
    return $lang;
}

function is_rtl(): bool
{
    return current_lang() === 'ar';
}

function t(string $en, string $ar): string
{
    return current_lang() === 'ar' ? $ar : $en;
}

function asset_url(string $path): string
{
    $full = __DIR__ . '/../' . ltrim($path, '/');
    $version = is_file($full) ? (string) filemtime($full) : (string) time();
    return ltrim($path, '/') . '?v=' . $version;
}

function app_url(string $path, array $params = []): string
{
    if (!isset($params['lang'])) {
        $params['lang'] = current_lang();
    }
    $query = http_build_query($params);
    return $path . ($query ? '?' . $query : '');
}

function page_lang_link(string $lang): string
{
    $params = $_GET;
    $params['lang'] = $lang;
    $query = http_build_query($params);
    return basename($_SERVER['PHP_SELF']) . ($query ? '?' . $query : '');
}

function subjects_catalog_static(): array
{
    return [
        'english-fluency' => [
            'slug' => 'english-fluency',
            'title_en' => 'English Fluency Studio',
            'title_ar' => 'استوديو الطلاقة في الإنجليزية',
            'summary_en' => 'Speaking-first classrooms for teens and adults with weekly live workshops.',
            'summary_ar' => 'فصول تركّز على المحادثة للمراهقين والبالغين مع ورش مباشرة أسبوعية.',
            'teacher_en' => 'Sarah Coleman',
            'teacher_ar' => 'سارة كولمان',
            'level_en' => 'Intermediate',
            'level_ar' => 'متوسط',
            'duration_en' => '12 weeks',
            'duration_ar' => '12 أسبوعاً',
            'next_live_en' => 'Wednesday, April 8, 2026 · 6:00 PM UTC',
            'next_live_ar' => 'الأربعاء 8 أبريل 2026 · 6:00 مساءً UTC',
            'meet_url' => 'https://meet.google.com/',
            'modules_en' => ['Live speaking labs', 'Pronunciation clinic', 'Writing feedback', 'Weekly vocabulary sprints'],
            'modules_ar' => ['مختبرات محادثة مباشرة', 'عيادة النطق', 'ملاحظات على الكتابة', 'دفعات مفردات أسبوعية'],
        ],
        'stem-lab' => [
            'slug' => 'stem-lab',
            'title_en' => 'STEM Lab Foundations',
            'title_ar' => 'أساسيات مختبر STEM',
            'summary_en' => 'Math and science pathways with assignments, quizzes, and teacher office hours.',
            'summary_ar' => 'مسارات في الرياضيات والعلوم مع واجبات واختبارات وساعات مكتبية للمعلم.',
            'teacher_en' => 'Omar Al-Harthy',
            'teacher_ar' => 'عمر الحارثي',
            'level_en' => 'Beginner to Advanced',
            'level_ar' => 'من مبتدئ إلى متقدم',
            'duration_en' => '16 weeks',
            'duration_ar' => '16 أسبوعاً',
            'next_live_en' => 'Thursday, April 9, 2026 · 5:00 PM UTC',
            'next_live_ar' => 'الخميس 9 أبريل 2026 · 5:00 مساءً UTC',
            'meet_url' => 'https://meet.google.com/',
            'modules_en' => ['Algebra tracks', 'Physics demos', 'Guided worksheets', 'Lab challenge reviews'],
            'modules_ar' => ['مسارات الجبر', 'عروض فيزياء', 'أوراق عمل موجهة', 'مراجعات تحديات المختبر'],
        ],
        'arabic-academy' => [
            'slug' => 'arabic-academy',
            'title_en' => 'Arabic Language Academy',
            'title_ar' => 'أكاديمية اللغة العربية',
            'summary_en' => 'Modern Standard Arabic with reading circles and live grammar sessions.',
            'summary_ar' => 'العربية الفصحى مع حلقات قراءة وجلسات قواعد مباشرة.',
            'teacher_en' => 'Maha Al-Rashdi',
            'teacher_ar' => 'مها الراشدي',
            'level_en' => 'All levels',
            'level_ar' => 'جميع المستويات',
            'duration_en' => '10 weeks',
            'duration_ar' => '10 أسابيع',
            'next_live_en' => 'Saturday, April 11, 2026 · 4:00 PM UTC',
            'next_live_ar' => 'السبت 11 أبريل 2026 · 4:00 مساءً UTC',
            'meet_url' => 'https://meet.google.com/',
            'modules_en' => ['Reading comprehension', 'Live grammar board', 'Listening practice', 'Culture sessions'],
            'modules_ar' => ['فهم المقروء', 'سبورة قواعد مباشرة', 'تدريب الاستماع', 'جلسات ثقافية'],
        ],
        'design-systems' => [
            'slug' => 'design-systems',
            'title_en' => 'Design Systems for Creators',
            'title_ar' => 'أنظمة التصميم للمبدعين',
            'summary_en' => 'UI foundations, product thinking, and portfolio reviews in live cohorts.',
            'summary_ar' => 'أساسيات الواجهات والتفكير المنتج ومراجعات المحافظ ضمن مجموعات مباشرة.',
            'teacher_en' => 'Lina Mercer',
            'teacher_ar' => 'لينا ميرسر',
            'level_en' => 'Professional',
            'level_ar' => 'احترافي',
            'duration_en' => '8 weeks',
            'duration_ar' => '8 أسابيع',
            'next_live_en' => 'Monday, April 13, 2026 · 7:00 PM UTC',
            'next_live_ar' => 'الإثنين 13 أبريل 2026 · 7:00 مساءً UTC',
            'meet_url' => 'https://meet.google.com/',
            'modules_en' => ['UI critique rooms', 'Systems thinking', 'Component audits', 'Portfolio feedback'],
            'modules_ar' => ['غرف نقد الواجهات', 'تفكير الأنظمة', 'تدقيق المكونات', 'ملاحظات على المحفظة'],
        ],
    ];
}

function plans_catalog_static(): array
{
    return [
        'core' => [
            'key' => 'core',
            'name_en' => 'Core Plan',
            'name_ar' => 'الخطة الأساسية',
            'price_monthly' => 29,
            'price_yearly' => 290,
            'subjects_limit' => 2,
            'features_en' => ['Access to 2 subjects', 'Weekly live classroom', 'Student dashboard', 'Thawani-ready billing'],
            'features_ar' => ['الوصول إلى مادتين', 'فصل مباشر أسبوعي', 'لوحة الطالب', 'دفع جاهز لثواني'],
        ],
        'plus' => [
            'key' => 'plus',
            'name_en' => 'Plus Plan',
            'name_ar' => 'الخطة المتقدمة',
            'price_monthly' => 59,
            'price_yearly' => 590,
            'subjects_limit' => 4,
            'features_en' => ['All subjects', 'Unlimited live rooms', 'Teacher Q&A', 'WhatsApp reminders'],
            'features_ar' => ['جميع المواد', 'غرف مباشرة غير محدودة', 'أسئلة وأجوبة مع المعلم', 'تذكيرات عبر واتساب'],
        ],
        'pro' => [
            'key' => 'pro',
            'name_en' => 'Pro Campus',
            'name_ar' => 'الخطة الاحترافية',
            'price_monthly' => 89,
            'price_yearly' => 890,
            'subjects_limit' => 999,
            'features_en' => ['Priority support', 'Arabic + English tracks', 'Admin reporting', 'Live classroom operations'],
            'features_ar' => ['دعم أولوية', 'مسارات عربية وإنجليزية', 'تقارير إدارية', 'تشغيل الفصول المباشرة'],
        ],
    ];
}

function ensure_catalog_tables(): void
{
    db()->exec("
        CREATE TABLE IF NOT EXISTS subjects (
            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            slug VARCHAR(100) UNIQUE NOT NULL,
            title_en VARCHAR(255) NOT NULL,
            title_ar VARCHAR(255) NOT NULL,
            summary_en TEXT,
            summary_ar TEXT,
            teacher_en VARCHAR(120),
            teacher_ar VARCHAR(120),
            level_en VARCHAR(50),
            level_ar VARCHAR(50),
            duration_en VARCHAR(50),
            duration_ar VARCHAR(50),
            next_live_en VARCHAR(120),
            next_live_ar VARCHAR(120),
            meet_url VARCHAR(255),
            modules_en JSON,
            modules_ar JSON,
            created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

        CREATE TABLE IF NOT EXISTS plans (
            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            plan_key VARCHAR(50) UNIQUE NOT NULL,
            name_en VARCHAR(120) NOT NULL,
            name_ar VARCHAR(120) NOT NULL,
            price_monthly DECIMAL(10,3) NOT NULL,
            price_yearly DECIMAL(10,3) NOT NULL,
            subjects_limit INT DEFAULT 1,
            features_en JSON,
            features_ar JSON
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
    ");

    $count = db()->query("SELECT COUNT(*) FROM subjects")->fetchColumn();
    if ($count == 0) {
        $subjects = subjects_catalog_static();
        $stmt = db()->prepare("INSERT INTO subjects (slug, title_en, title_ar, summary_en, summary_ar, teacher_en, teacher_ar, level_en, level_ar, duration_en, duration_ar, next_live_en, next_live_ar, meet_url, modules_en, modules_ar) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
        foreach ($subjects as $s) {
            $stmt->execute([
                $s['slug'], $s['title_en'], $s['title_ar'], $s['summary_en'], $s['summary_ar'], $s['teacher_en'], $s['teacher_ar'], $s['level_en'], $s['level_ar'], $s['duration_en'], $s['duration_ar'], $s['next_live_en'], $s['next_live_ar'], $s['meet_url'], json_encode($s['modules_en']), json_encode($s['modules_ar'])
            ]);
        }
    }

    $count = db()->query("SELECT COUNT(*) FROM plans")->fetchColumn();
    if ($count == 0) {
        $plans = plans_catalog_static();
        $stmt = db()->prepare("INSERT INTO plans (plan_key, name_en, name_ar, price_monthly, price_yearly, subjects_limit, features_en, features_ar) VALUES (?, ?, ?, ?, ?, ?, ?, ?)");
        foreach ($plans as $p) {
            $stmt->execute([
                $p['key'], $p['name_en'], $p['name_ar'], $p['price_monthly'], $p['price_yearly'], $p['subjects_limit'], json_encode($p['features_en']), json_encode($p['features_ar'])
            ]);
        }
    }
}

function subjects_catalog(): array
{
    ensure_catalog_tables();
    $stmt = db()->query("SELECT s.* FROM subjects s LEFT JOIN classes c ON s.class_id = c.id WHERE s.status = 'active' AND (s.class_id IS NULL OR s.class_id = 0 OR c.status = 'active')");
    $rows = $stmt->fetchAll();
    $result = [];
    foreach ($rows as $row) {
        $row['modules_en'] = json_decode($row['modules_en'] ? (string)$row['modules_en'] : '[]', true) ?: [];
        $row['modules_ar'] = json_decode($row['modules_ar'] ? (string)$row['modules_ar'] : '[]', true) ?: [];
        
        $class_id = (int)$row['class_id'];
        $subject_id = (int)$row['id'];
        
        // Dynamically fetch active assigned teacher
        $teacher_stmt = db()->prepare(
            "SELECT t.name 
            FROM teacher_assignments ta
            JOIN teachers t ON ta.teacher_id = t.id
            WHERE t.status = 'active' 
              AND ta.class_id = ? 
              AND (ta.subject_id = ? OR ta.subject_id = 0)
            LIMIT 1"
        );
        $teacher_stmt->execute([$class_id, $subject_id]);
        $teacher_name = $teacher_stmt->fetchColumn();
        
        if ($teacher_name) {
            $row['teacher_en'] = $teacher_name;
            $row['teacher_ar'] = $teacher_name;
        } else {
            // Check if there is an inactive teacher assigned. If so, override with empty or "No Teacher".
            $inactive_stmt = db()->prepare(
                "SELECT t.name 
                FROM teacher_assignments ta
                JOIN teachers t ON ta.teacher_id = t.id
                WHERE t.status = 'inactive' 
                  AND ta.class_id = ? 
                  AND (ta.subject_id = ? OR ta.subject_id = 0)
                LIMIT 1"
            );
            $inactive_stmt->execute([$class_id, $subject_id]);
            if ($inactive_stmt->fetchColumn()) {
                $row['teacher_en'] = 'No Active Teacher';
                $row['teacher_ar'] = 'لا يوجد معلم نشط';
            }
        }
        
        $result[$row['slug']] = $row;
    }
    return $result;
}

function plans_catalog(): array
{
    ensure_catalog_tables();
    $stmt = db()->query('SELECT * FROM plans');
    $rows = $stmt->fetchAll();
    $result = [];
    foreach ($rows as $row) {
        $row['key'] = $row['plan_key'];
        $row['features_en'] = json_decode($row['features_en'] ?? '[]', true) ?: [];
        $row['features_ar'] = json_decode($row['features_ar'] ?? '[]', true) ?: [];
        $result[$row['key']] = $row;
    }
    return $result;
}


function ensure_progress_table(): void
{
    db()->exec("
        CREATE TABLE IF NOT EXISTS module_progress (
            id INT UNSIGNED AUTO_INCREMENT PRIMARY KEY,
            subscription_id INT UNSIGNED NOT NULL,
            subject_slug VARCHAR(100) NOT NULL,
            module_index INT UNSIGNED NOT NULL,
            completed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
            UNIQUE KEY(subscription_id, subject_slug, module_index)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;
    ");
}

function get_completed_modules(int $subscriptionId, string $subjectSlug): array
{
    ensure_progress_table();
    $stmt = db()->prepare("SELECT module_index FROM module_progress WHERE subscription_id = ? AND subject_slug = ?");
    $stmt->execute([$subscriptionId, $subjectSlug]);
    return $stmt->fetchAll(PDO::FETCH_COLUMN) ?: [];
}

function toggle_module_progress(int $subscriptionId, string $subjectSlug, int $moduleIndex, bool $completed): void
{
    ensure_progress_table();
    if ($completed) {
        $stmt = db()->prepare("INSERT IGNORE INTO module_progress (subscription_id, subject_slug, module_index) VALUES (?, ?, ?)");
        $stmt->execute([$subscriptionId, $subjectSlug, $moduleIndex]);
    } else {
        $stmt = db()->prepare("DELETE FROM module_progress WHERE subscription_id = ? AND subject_slug = ? AND module_index = ?");
        $stmt->execute([$subscriptionId, $subjectSlug, $moduleIndex]);
    }
}

function get_subject(string $slug): ?array
{
    $subjects = subjects_catalog();
    return $subjects[$slug] ?? null;
}

function get_plan(string $key): ?array
{
    $plans = plans_catalog();
    return $plans[$key] ?? null;
}

function plan_name(array $plan): string
{
    return current_lang() === 'ar' ? $plan['name_ar'] : $plan['name_en'];
}

function subject_title(array $subject): string
{
    return current_lang() === 'ar' ? $subject['title_ar'] : $subject['title_en'];
}

function subject_summary(array $subject): string
{
    return current_lang() === 'ar' ? $subject['summary_ar'] : $subject['summary_en'];
}

function subject_teacher(array $subject): string
{
    return (string)(current_lang() === 'ar' ? ($subject['teacher_ar'] ?? '') : ($subject['teacher_en'] ?? ''));
}

function subject_level(array $subject): string
{
    return (string)(current_lang() === 'ar' ? ($subject['level_ar'] ?? '') : ($subject['level_en'] ?? ''));
}

function subject_duration(array $subject): string
{
    return (string)(current_lang() === 'ar' ? ($subject['duration_ar'] ?? '') : ($subject['duration_en'] ?? ''));
}

function subject_next_live(array $subject): string
{
    return (string)(current_lang() === 'ar' ? ($subject['next_live_ar'] ?? '') : ($subject['next_live_en'] ?? ''));
}

function subject_modules(array $subject): array
{
    return current_lang() === 'ar' ? $subject['modules_ar'] : $subject['modules_en'];
}

function format_price(float $amount): string
{
    return number_format($amount, 3) . ' ' . t('OMR', 'ر.ع.');
}

function price_label(array $plan, string $cycle = 'monthly'): string
{
    $amount = $cycle === 'yearly' ? $plan['price_yearly'] : $plan['price_monthly'];
    $suffix = $cycle === 'yearly' ? t('/year', '/سنة') : t('/month', '/شهر');
    return format_price((float)$amount) . ' ' . $suffix;
}

function ensure_subscription_table(): void
{
    db()->exec(
        "CREATE TABLE IF NOT EXISTS student_subscriptions (
            id INT UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
            full_name VARCHAR(120) NOT NULL,
            email VARCHAR(190) NOT NULL,
            whatsapp VARCHAR(40) NOT NULL,
            preferred_language VARCHAR(5) NOT NULL DEFAULT 'en',
            plan_key VARCHAR(20) NOT NULL,
            billing_cycle VARCHAR(20) NOT NULL DEFAULT 'monthly',
            payment_status VARCHAR(20) NOT NULL DEFAULT 'active',
            payment_gateway VARCHAR(30) NOT NULL DEFAULT 'Thawani',
            thawani_reference VARCHAR(80) NOT NULL,
            wablas_opt_in TINYINT(1) NOT NULL DEFAULT 0,
            created_at TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4"
    );
}

function create_subscription(array $data): int
{
    ensure_subscription_table();
    $stmt = db()->prepare(
        'INSERT INTO student_subscriptions
        (full_name, email, whatsapp, preferred_language, plan_key, billing_cycle, payment_status, payment_gateway, thawani_reference, wablas_opt_in)
        VALUES (:full_name, :email, :whatsapp, :preferred_language, :plan_key, :billing_cycle, :payment_status, :payment_gateway, :thawani_reference, :wablas_opt_in)'
    );

    $stmt->bindValue(':full_name', $data['full_name']);
    $stmt->bindValue(':email', $data['email']);
    $stmt->bindValue(':whatsapp', $data['whatsapp']);
    $stmt->bindValue(':preferred_language', $data['preferred_language']);
    $stmt->bindValue(':plan_key', $data['plan_key']);
    $stmt->bindValue(':billing_cycle', $data['billing_cycle']);
    $stmt->bindValue(':payment_status', $data['payment_status']);
    $stmt->bindValue(':payment_gateway', $data['payment_gateway']);
    $stmt->bindValue(':thawani_reference', $data['thawani_reference']);
    $stmt->bindValue(':wablas_opt_in', $data['wablas_opt_in'], PDO::PARAM_INT);
    $stmt->execute();

    return (int) db()->lastInsertId();
}

function fetch_subscription(int $id): ?array
{
    ensure_subscription_table();
    $stmt = db()->prepare('SELECT * FROM student_subscriptions WHERE id = :id LIMIT 1');
    $stmt->bindValue(':id', $id, PDO::PARAM_INT);
    $stmt->execute();
    $row = $stmt->fetch();
    return $row ?: null;
}

function fetch_subscriptions_by_email(string $email): array
{
    ensure_subscription_table();
    $stmt = db()->prepare('SELECT * FROM student_subscriptions WHERE email = :email ORDER BY created_at DESC');
    $stmt->bindValue(':email', $email);
    $stmt->execute();
    return $stmt->fetchAll();
}

function fetch_recent_subscriptions(int $limit = 8): array
{
    ensure_subscription_table();
    $stmt = db()->prepare('SELECT * FROM student_subscriptions ORDER BY created_at DESC LIMIT :limit');
    $stmt->bindValue(':limit', $limit, PDO::PARAM_INT);
    $stmt->execute();
    return $stmt->fetchAll();
}

function subscription_metrics(): array
{
    ensure_subscription_table();
    $metrics = [
        'total' => 0,
        'arabic' => 0,
        'active' => 0,
        'latest' => null,
    ];

    $totals = db()->query("SELECT
        COUNT(*) AS total,
        SUM(preferred_language = 'ar') AS arabic,
        SUM(payment_status = 'active') AS active
        FROM student_subscriptions")->fetch();

    if ($totals) {
        $metrics['total'] = (int) ($totals['total'] ?? 0);
        $metrics['arabic'] = (int) ($totals['arabic'] ?? 0);
        $metrics['active'] = (int) ($totals['active'] ?? 0);
    }

    $latest = db()->query('SELECT * FROM student_subscriptions ORDER BY created_at DESC LIMIT 1')->fetch();
    $metrics['latest'] = $latest ?: null;
    return $metrics;
}

function current_subscription(): ?array
{
    $id = isset($_GET['subscription_id']) ? (int) $_GET['subscription_id'] : (int) ($_SESSION['subscription_id'] ?? 0);
    if ($id > 0) {
        $row = fetch_subscription($id);
        if ($row) {
            $_SESSION['subscription_id'] = (int) $row['id'];
            $_SESSION['student_email'] = $row['email'];
            return $row;
        }
    }

    $email = (string) ($_SESSION['student_email'] ?? '');
    if ($email !== '') {
        $rows = fetch_subscriptions_by_email($email);
        if ($rows) {
            $_SESSION['subscription_id'] = (int) $rows[0]['id'];
            return $rows[0];
        }
    }

    return null;
}

function page_title(string $title): string
{
    return $title . ' · ' . app_name();
}

function render_head(string $title, string $description = ''): void
{
    $pageDescription = $description !== '' ? $description : project_description();
    $projectDescription = $_SERVER['PROJECT_DESCRIPTION'] ?? '';
    $projectImageUrl = $_SERVER['PROJECT_IMAGE_URL'] ?? '';
    ?>
<!doctype html>
<html lang="<?= h(current_lang()) ?>" dir="<?= is_rtl() ? 'rtl' : 'ltr' ?>">
<head>
  <meta charset="utf-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <title><?= h(page_title($title)) ?></title>
<?php 
$prof = get_platform_profile();
if (!empty($prof['favicon_path'])): 
?>
  <link rel="icon" href="<?= h(asset_url($prof['favicon_path'])) ?>" />
<?php endif; ?>
  <meta name="description" content="<?= h($pageDescription) ?>" />
<?php if ($projectDescription): ?>
  <meta property="og:description" content="<?= h($projectDescription) ?>" />
  <meta property="twitter:description" content="<?= h($projectDescription) ?>" />
<?php endif; ?>
<?php if ($projectImageUrl): ?>
  <meta property="og:image" content="<?= h($projectImageUrl) ?>" />
  <meta property="twitter:image" content="<?= h($projectImageUrl) ?>" />
<?php endif; ?>
  <meta name="theme-color" content="#111827" />
  <meta name="author" content="<?= h(app_name()) ?>" />
  <link rel="preconnect" href="https://fonts.googleapis.com">
  <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin>
  <link href="https://fonts.googleapis.com/css2?family=Cairo:wght@400;500;600;700;800&family=Inter:wght@400;500;600;700;800&display=swap" rel="stylesheet">
  <link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-QWTKZyjpPEjISv5WaRU9OFeRpok6YctnYmDr5pNlyT2bRjXh0JMhjY6hW+ALEwIH" crossorigin="anonymous">
  <link href="https://cdn.jsdelivr.net/npm/bootstrap-icons@1.11.3/font/bootstrap-icons.min.css" rel="stylesheet">
  <link rel="stylesheet" href="<?= h(asset_url('assets/css/custom.css')) ?>">
</head>
<body class="app-shell <?= is_rtl() ? 'rtl' : 'ltr' ?>">
<?php
}

function nav_items(): array
{
    $items = [
        'index.php' => t('Home', 'الرئيسية'),
        'catalog.php' => t('Subjects', 'المواد'),
        'courses.php' => t('Courses', 'الدورات'),
        'pricing.php' => t('Plans', 'الخطط'),
    ];

    if (!empty($_SESSION['user_id'])) {
        $stmt = db()->prepare("SELECT role FROM users WHERE id = ?");
        $stmt->execute([$_SESSION['user_id']]);
        $user = $stmt->fetch(PDO::FETCH_ASSOC);
        if ($user) {
            if ($user['role'] === 'student') {
                $items['dashboard.php'] = t('Student', 'الطالب');
            } elseif ($user['role'] === 'teacher') {
                $items['teacher.php'] = t('Teacher', 'المعلم');
            } elseif ($user['role'] === 'admin') {
                $items['admin.php'] = t('Admin', 'الإدارة');
            }
        }
    }

    return $items;
}

function render_nav(string $active = ''): void
{
    $items = nav_items();
    ?>
<nav class="navbar navbar-expand-lg border-bottom bg-white sticky-top app-navbar">
  <div class="container">
    <a class="navbar-brand fw-semibold d-flex align-items-center" href="<?= h(app_url('index.php')) ?>">
      <?php $prof = get_platform_profile(); if (!empty($prof['logo_path'])): ?>
        <img src="<?= h(asset_url($prof['logo_path'])) ?>" alt="Logo" style="height: 32px; margin-right: 8px; border-radius: 4px;">
      <?php endif; ?>
      <span><?= h(app_name()) ?></span>
    </a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#mainNav" aria-controls="mainNav" aria-expanded="false" aria-label="Toggle navigation">
      <span class="navbar-toggler-icon"></span>
    </button>
    <div class="collapse navbar-collapse" id="mainNav">
      <ul class="navbar-nav me-auto mb-2 mb-lg-0 gap-lg-2">
        <?php foreach ($items as $file => $label): ?>
          <li class="nav-item"><a class="nav-link <?= $active === $file ? 'active' : '' ?>" href="<?= h(app_url($file)) ?>"><?= h($label) ?></a></li>
        <?php endforeach; ?>
      </ul>
      <div class="d-flex align-items-center gap-2 ms-lg-3">
        <span class="small text-secondary d-none d-md-inline"><?= h(t('Single platform LMS', 'منصة تعليم موحدة')) ?></span>
        <div class="btn-group btn-group-sm" role="group" aria-label="Language switcher">
          <a class="btn btn-outline-dark <?= current_lang() === 'en' ? 'active' : '' ?>" href="<?= h(page_lang_link('en')) ?>">EN</a>
          <a class="btn btn-outline-dark <?= current_lang() === 'ar' ? 'active' : '' ?>" href="<?= h(page_lang_link('ar')) ?>">AR</a>
        </div>
        <div class="d-flex gap-2 ms-2 align-items-center">
          <?php if (!empty($_SESSION['user_id'])): ?>
            <?php 
              $stmt = db()->prepare("SELECT * FROM users WHERE id = ?");
              $stmt->execute([$_SESSION['user_id']]);
              $user = $stmt->fetch(PDO::FETCH_ASSOC) ?: null;
            ?>
            <div class="dropdown">
              <a class="btn btn-light dropdown-toggle d-flex align-items-center gap-2 border-0 rounded-pill px-2 py-1 shadow-sm" href="#" role="button" data-bs-toggle="dropdown" aria-expanded="false" style="background: rgba(255,255,255,0.85); backdrop-filter: blur(10px);">
                <?php if (!empty($user['profile_picture'])): ?>
                  <img src="<?= h(asset_url($user['profile_picture'])) ?>" alt="Profile" class="rounded-circle shadow-sm" width="32" height="32" style="object-fit: cover;">
                <?php else: ?>
                  <div class="rounded-circle bg-primary text-white d-flex justify-content-center align-items-center shadow-sm" style="width:32px; height:32px; font-size:14px; font-weight:600;">
                    <?= h(strtoupper(mb_substr($user['name'] ?? 'U', 0, 1, 'UTF-8'))) ?>
                  </div>
                <?php endif; ?>
                <span class="d-none d-lg-inline small fw-bold text-dark px-1"><?= h($user['name'] ?? 'User') ?></span>
              </a>
              <ul class="dropdown-menu dropdown-menu-end shadow border-0 mt-2" style="border-radius: 12px; min-width: 180px;">
                <li><a class="dropdown-item py-2 fw-medium" href="<?= h(app_url('profile.php')) ?>"><?= h(t('My Profile', 'حسابي')) ?></a></li>
                <li><hr class="dropdown-divider"></li>
                <li><a class="dropdown-item py-2 text-danger fw-medium" href="<?= h(app_url('logout.php')) ?>"><?= h(t('Logout', 'تسجيل خروج')) ?></a></li>
              </ul>
            </div>
          <?php else: ?>
            <a href="<?= h(app_url('login.php')) ?>" class="btn btn-dark btn-sm px-4 rounded-pill shadow-sm fw-bold"><?= h(t('Login', 'تسجيل الدخول')) ?></a>
          <?php endif; ?>
        </div>
      </div>
    </div>
  </div>
</nav>
<?php
}

function render_footer(): void
{
    ?>
<footer class="border-top bg-white mt-5">
  <div class="container py-4 d-flex flex-column flex-lg-row justify-content-between gap-3 small text-secondary">
    <div>
      <strong class="text-dark"><?= h(app_name()) ?></strong>
      <div><?= h(t('Subscription-based classrooms in English and Arabic with Google Meet, Thawani, and WhatsApp workflows.', 'فصول باشتراكات بالإنجليزية والعربية مع تدفقات عمل Google Meet وThawani وواتساب.')) ?></div>
    </div>
    <div class="d-flex gap-3 flex-wrap">
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('catalog.php')) ?>"><?= h(t('Subject catalog', 'كتالوج المواد')) ?></a>
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('courses.php')) ?>"><?= h(t('Courses', 'الدورات')) ?></a>
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('pricing.php')) ?>"><?= h(t('Plans', 'الخطط')) ?></a>
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('dashboard.php')) ?>"><?= h(t('Student dashboard', 'لوحة الطالب')) ?></a>
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('terms.php')) ?>"><?= h(t('Terms of Conditions', 'الشروط والأحكام')) ?></a>
      <a class="text-decoration-none text-secondary" href="<?= h(app_url('policy.php')) ?>"><?= h(t('Privacy Policy', 'سياسة الخصوصية')) ?></a>
    </div>
  </div>
</footer>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.bundle.min.js" integrity="sha384-YvpcrYf0tY3lHB60NNkmXc5s9fDVZLESaAA55NDzOxhy9GkcIdslK1eN7N6jIeHz" crossorigin="anonymous"></script>
<script src="https://cdn.jsdelivr.net/npm/sweetalert2@11"></script>
<script src="<?= h(asset_url('assets/js/main.js')) ?>"></script>
</body>
</html>
<?php
}

function status_badge(string $status): string
{
    return match ($status) {
        'active' => 'badge bg-success-subtle text-success-emphasis border border-success-subtle',
        'pending' => 'badge bg-warning-subtle text-warning-emphasis border border-warning-subtle',
        default => 'badge bg-secondary-subtle text-secondary-emphasis border border-secondary-subtle',
    };
}