/**
 * ============================================================================
 * BEFORE & AFTER CODE COMPARISON
 * ============================================================================
 * 
 * This document shows exact code changes made to fix the permission system
 * 
 * ============================================================================
 * FILE 1: admin_dashboard.php
 * ============================================================================
 * 
 * BEFORE (BROKEN - Blocked subadmins):
 * ────────────────────────────────────
 * 
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: // Permission Enforcement
 *  5: require_once __DIR__ . '/helpers/enforce_manage_settings.php';
 *  6: require_once __DIR__ . '/helpers/enforce_manage_logo.php';
 *  7: require_once __DIR__ . '/helpers/enforce_manage_site_title.php';
 *  8: require_once __DIR__ . '/helpers/enforce_manage_colors.php';
 *  9: require_once __DIR__ . '/helpers/enforce_manage_slider_images.php';
 * 10: require_once __DIR__ . '/helpers/enforce_manage_marquee.php';
 * 11: require_once __DIR__ . '/helpers/enforce_manage_footer_marquee.php';
 * 12: require_once __DIR__ . '/helpers/enforce_manage_categories.php';
 * 13: EnforceManageSettings::guardPage();  // ← Delegates to empty AdminPageHeader
 * 14:
 * 15: // Check if user is logged in as admin
 * 16: if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
 * 17:     header('Location: admin_login.php');
 * 18:     exit;  // ← BLOCKS ALL SUBADMINS!
 * 19: }
 * 
 * 
 * AFTER (FIXED - Allows authorized subadmins):
 * ─────────────────────────────────────────────
 * 
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: // Permission Enforcement & Helpers
 *  5: require_once __DIR__ . '/helpers/subadmin_page_guard.php';
 *  6: require_once __DIR__ . '/helpers/get_back_button.php';
 *  7:
 *  8: // Check permissions - allows full admins and subadmins with view access
 *  9: $pageGuard = new SubAdminPageGuard('manage_settings');
 * 10: $pageGuard->enforceView();  // ← ALLOWS ADMINS + PERMED SUBADMINS!
 * 
 * 
 * KEY DIFFERENCES:
 * ├─ Consolidated 8 enforce_manage_*.php requires into 1 subadmin_page_guard.php
 * ├─ Removed the empty AdminPageHeader delegation
 * ├─ Removed the hardcoded is_admin check that was blocking everyone
 * ├─ Added SubAdminPageGuard with proper permission checking
 * └─ Result: Admins pass, subadmins with permission pass, others redirected appropriately
 * 
 * ============================================================================
 * FILE 2: admin_add_news.php
 * ============================================================================
 * 
 * SECTION A: PAGE ENTRY (similar to admin_dashboard.php)
 * 
 * BEFORE (BROKEN):
 * ───────────────
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: require_once __DIR__ . '/helpers/enforce_manage_news.php';
 *  5: require_once __DIR__ . '/helpers/get_back_button.php';
 *  6: EnforceManageNews::guardPage();  // ← Empty AdminPageHeader
 *  7:
 *  8: // Check if user is logged in as admin
 *  9: if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
 * 10:     header("Location: admin_login.php");
 * 11:     exit;  // ← BLOCKS SUBADMINS!
 * 12: }
 * 
 * AFTER (FIXED):
 * ──────────────
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: require_once __DIR__ . '/helpers/subadmin_page_guard.php';
 *  5: require_once __DIR__ . '/helpers/get_back_button.php';
 *  6:
 *  7: // Check permissions
 *  8: $pageGuard = new SubAdminPageGuard('manage_news');
 *  9: $pageGuard->enforceView();  // ← PROPER PERMISSION CHECK
 * 
 * 
 * SECTION B: FORM VISIBILITY (NEW - Viewer protection)
 * 
 * BEFORE (BROKEN - form always shown):
 * ────────────────────────────────────
 * 768: <div class="card">
 * 769:     <h2><?php echo $editNews ? '✏️ Edit' : '➕ Add New News'; ?></h2>
 * 770:     
 * 771:     <form method="POST">
 * 772:         <!-- Form always shows regardless of permission -->
 * 773:
 * 
 * AFTER (FIXED - form hidden for viewers):
 * ─────────────────────────────────────────
 * 768: <div class="card">
 * 769:     <h2><?php echo $editNews ? '✏️ Edit' : '➕ Add New News'; ?></h2>
 * 770:
 * 771:     <?php if (!$pageGuard->can(($editNews ? 'edit' : 'create'))): ?>
 * 772:         <div class="alert alert-error">
 * 773:             ❌ You don't have permission to <?php echo $editNews ? 'edit' : 'add'; ?> news items.
 * 774:         </div>
 * 775:     <?php else: ?>
 * 776:         <form method="POST">
 * 777:             <!-- Form only shown if user has 'create' or 'edit' permission -->
 * 778:
 * 
 * SECTION C: BUTTON VISIBILITY (NEW - Delete/Edit protection)
 * 
 * BEFORE (BROKEN - buttons always shown):
 * ────────────────────────────────────────
 * 886: <div class="news-item-actions">
 * 887:     <a href="?action=edit&id=<?php echo $news['id']; ?>">✏️ Edit</a>
 * 888:     <a href="?action=delete&id=<?php echo $news['id']; ?>">🗑️ Delete</a>
 * 889: </div>
 * 
 * AFTER (FIXED - conditional rendering):
 * ────────────────────────────────────────
 * 886: <div class="news-item-actions">
 * 887:     <?php if ($pageGuard->can('edit')): ?>
 * 888:         <a href="?action=edit&id=<?php echo $news['id']; ?>">✏️ Edit</a>
 * 889:     <?php else: ?>
 * 890:         <span style="color: #ccc; cursor: not-allowed;">✏️ Edit</span>
 * 891:     <?php endif; ?>
 * 892:
 * 893:     <?php if ($pageGuard->can('delete')): ?>
 * 894:         <a href="?action=delete&id=<?php echo $news['id']; ?>">🗑️ Delete</a>
 * 895:     <?php else: ?>
 * 896:         <span style="color: #ccc; cursor: not-allowed;">🗑️ Delete</span>
 * 897:     <?php endif; ?>
 * 898: </div>
 * 
 * 
 * SECTION D: FORM CLOSING (NEW - endif for form permission)
 * 
 * BEFORE (no endif):
 * ──────────────────
 * 863: </form>
 * 864: </div>
 * 865: 
 * 866: <!-- News List -->
 * 
 * AFTER (added endif):
 * ────────────────────
 * 863: </form>
 * 864: <?php endif; ?>  // ← CLOSES THE FORM PERMISSION CHECK
 * 865: </div>
 * 866:
 * 867: <!-- News List -->
 * 
 * ============================================================================
 * FILE 3: admin_manage_users.php
 * ============================================================================
 * 
 * BEFORE (BROKEN - Complex DB check):
 * ────────────────────────────────────
 *  1: <?php
 *  2: require __DIR__ . '/db_config.php';
 *  3: session_start();
 *  4:
 *  5: require_once __DIR__ . '/helpers/enforce_manage_users.php';
 *  6: require_once __DIR__ . '/helpers/get_back_button.php';
 *  7: EnforceManageUsers::guardPage();  // ← Empty AdminPageHeader
 *  8:
 *  9: // verify admin (either session or check DB)
 * 10: if (empty($_SESSION['user_id'])) {
 * 11:     header('Location: index.php');
 * 12:     exit;
 * 13: }
 * 14: $isAdmin = !empty($_SESSION['is_admin']);
 * 15: if (!$isAdmin) {
 * 16:     // double-check DB
 * 17:     $stmt = $conn->prepare('SELECT id FROM admins WHERE user_id = ? LIMIT 1');
 * 18:     $stmt->bind_param('i', $_SESSION['user_id']);
 * 19:     $stmt->execute();
 * 20:     $res = $stmt->get_result();
 * 21:     if ($res && $res->num_rows > 0) {
 * 22:         $isAdmin = true;
 * 23:     }
 * 24: }
 * 25: if (!$isAdmin) {
 * 26:     echo "Access denied.";
 * 27:     exit;
 * 28: }
 * 
 * AFTER (FIXED - SubAdminPageGuard):
 * ───────────────────────────────────
 *  1: <?php
 *  2: require __DIR__ . '/db_config.php';
 *  3: session_start();
 *  4:
 *  5: require_once __DIR__ . '/helpers/subadmin_page_guard.php';
 *  6: require_once __DIR__ . '/helpers/get_back_button.php';
 *  7:
 *  8: // Check permissions
 *  9: $pageGuard = new SubAdminPageGuard('manage_users');
 * 10: $pageGuard->enforceView();  // ← PROPER CHECK, ALLOWS SUBADMINS
 * 11:
 * 12: // Check user is logged in
 * 13: if (empty($_SESSION['user_id']) && !isset($_SESSION['is_subadmin'])) {
 * 14:     header('Location: admin_login.php');
 * 15:     exit;
 * 16: }
 * 
 * 
 * KEY CHANGES:
 * ├─ Removed 18 lines of complex database checking
 * ├─ Removed fallback to index.php redirect
 * ├─ Now uses single SubAdminPageGuard enforcement
 * ├─ Also allows subadmins with proper permissions
 * └─ Cleaner, more readable, properly enforced
 * 
 * ============================================================================
 * FILE 4: admin_subadmins.php
 * ============================================================================
 * 
 * BEFORE (BROKEN - Empty enforcement):
 * ─────────────────────────────────────
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: require_once __DIR__ . '/helpers/enforce_manage_subadmins.php';
 *  5: require_once __DIR__ . '/helpers/get_back_button.php';
 *  6: EnforceManageSubadmins::guardPage();  // ← Empty AdminPageHeader
 *  7:
 *  8: // Only admin can access
 *  9: if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
 * 10:     header('Location: admin_login.php');
 * 11:     exit;
 * 12: }
 * 
 * AFTER (FIXED - Proper admin-only check):
 * ─────────────────────────────────────────
 *  1: <?php
 *  2: session_start();
 *  3:
 *  4: require_once __DIR__ . '/helpers/subadmin_page_guard.php';
 *  5: require_once __DIR__ . '/helpers/get_back_button.php';
 *  6:
 *  7: // Only full admins can manage subadmins (not subadmins themselves)
 *  8: $pageGuard = new SubAdminPageGuard('manage_subadmins');
 *  9: if (!$pageGuard->isAdmin()) {
 * 10:     header('Location: admin_login.php');
 * 11:     exit;
 * 12: }
 * 
 * 
 * NOTE: This page is explicitly ADMIN-ONLY by design
 *       Only full admins should be able to create/manage subadmin accounts
 *       The change is for clarity and consistency with other pages
 * 
 * ============================================================================
 * PATTERN EXPLANATION
 * ============================================================================
 * 
 * OLD PATTERN (BROKEN):
 * ────────────────────
 * 
 *     require_once 'enforce_manage_products.php';
 *     EnforceManageProducts::guardPage();  // Calls AdminPageHeader::requirePage()
 *                                           // AdminPageHeader.php is EMPTY
 *                                           // So this does nothing!
 *     
 *     if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
 *         header('Location: admin_login.php');  // ALWAYS BLOCKS SUBADMINS
 *         exit;
 *     }
 * 
 * RESULT: Permission enforcement is bypassed, subadmins always blocked
 * 
 * 
 * NEW PATTERN (WORKING):
 * ─────────────────────
 * 
 *     require_once 'subadmin_page_guard.php';
 *     $pageGuard = new SubAdminPageGuard('manage_products');
 *     $pageGuard->enforceView();  // Properly checks:
 *                                 // - Is admin? → ALLOW
 *                                 // - Is subadmin? → Check permission
 *                                 //   - Has permission? → ALLOW
 *                                 //   - No permission? → REDIRECT to dashboard
 *                                 // - Not logged in? → REDIRECT to login
 * 
 * RESULT: Proper permission enforcement, subadmins allowed if they have permission
 * 
 * ============================================================================
 * HOW TO APPLY TO OTHER PAGES
 * ============================================================================
 * 
 * For any admin page that needs to work with subadmins:
 * 
 * STEP 1: Add at very top (after session_start()):
 * ───────────────────────────────────────────────
 *     require_once __DIR__ . '/helpers/subadmin_page_guard.php';
 *     
 *     $pageGuard = new SubAdminPageGuard('manage_feature_name');
 *     $pageGuard->enforceView();
 * 
 * STEP 2: Replace any hardcoded is_admin checks:
 * ─────────────────────────────────────────────
 *     REMOVE:
 *     if (!isset($_SESSION['is_admin']) || $_SESSION['is_admin'] !== true) {
 *         header('Location: admin_login.php');
 *         exit;
 *     }
 * 
 * STEP 3: Add conditional button rendering:
 * ──────────────────────────────────────────
 *     DELETE BUTTON:
 *     <?php if ($pageGuard->can('delete')): ?>
 *         <button onclick="deleteItem(<?php echo $id; ?>)">Delete</button>
 *     <?php else: ?>
 *         <span style="color: #ccc;">Delete</span>
 *     <?php endif; ?>
 * 
 *     EDIT BUTTON:
 *     <?php if ($pageGuard->can('edit')): ?>
 *         <button onclick="editItem(<?php echo $id; ?>)">Edit</button>
 *     <?php else: ?>
 *         <span style="color: #ccc;">Edit</span>
 *     <?php endif; ?>
 * 
 *     ADD BUTTON:
 *     <?php if ($pageGuard->can('create')): ?>
 *         <button onclick="showAddForm()">+ Add New</button>
 *     <?php else: ?>
 *         <span style="color: #ccc;">+ Add New</span>
 *     <?php endif; ?>
 * 
 * ============================================================================
 */
?>
