<?php
require_once '../includes/dbcon.php';

// Check if user is logged in and has admin privileges
if (!is_logged_in() || $_SESSION['user_role'] != 'admin') {
    redirect('login.php');
}

$action = $_GET['action'] ?? 'list';
$message = '';
$error = '';

// Handle form submissions
if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $csrf_token = $_POST['csrf_token'] ?? '';
    
    if (!validate_csrf_token($csrf_token)) {
        $error = "Security token invalid. Please try again.";
    } else {
        try {
            if (isset($_POST['add_gallery'])) {
                // Add new gallery item
                $caption = sanitize_input($_POST['caption']);
                $image_path = '';
                
                // Handle file upload
                if (isset($_FILES['image']) && $_FILES['image']['error'] === 0) {
                    $upload_dir = '../images/gallery/';
                    if (!is_dir($upload_dir)) {
                        mkdir($upload_dir, 0755, true);
                    }
                    
                    $file_extension = pathinfo($_FILES['image']['name'], PATHINFO_EXTENSION);
                    $allowed_extensions = ['jpg', 'jpeg', 'png', 'gif', 'webp'];
                    
                    if (in_array(strtolower($file_extension), $allowed_extensions)) {
                        $filename = 'gallery_' . time() . '_' . uniqid() . '.' . $file_extension;
                        $destination = $upload_dir . $filename;
                        
                        if (move_uploaded_file($_FILES['image']['tmp_name'], $destination)) {
                            $image_path = 'images/gallery/' . $filename;
                        } else {
                            throw new Exception("Failed to upload image.");
                        }
                    } else {
                        throw new Exception("Invalid file type. Only JPG, PNG, GIF, and WebP are allowed.");
                    }
                }
                
                if (!empty($image_path)) {
                    $stmt = $DBcon->prepare("INSERT INTO gallery (caption, images) VALUES (?, ?)");
                    $stmt->execute([$caption, $image_path]);
                    $message = "Gallery item added successfully!";
                } else {
                    $error = "Please select a valid image file.";
                }
                
            } elseif (isset($_POST['edit_gallery'])) {
                // Update gallery item
                $sn = $_POST['sn'];
                $caption = sanitize_input($_POST['caption']);
                
                if (isset($_FILES['image']) && $_FILES['image']['error'] === 0) {
                    // Handle new image upload
                    $upload_dir = '../images/gallery/';
                    $file_extension = pathinfo($_FILES['image']['name'], PATHINFO_EXTENSION);
                    $allowed_extensions = ['jpg', 'jpeg', 'png', 'gif', 'webp'];
                    
                    if (in_array(strtolower($file_extension), $allowed_extensions)) {
                        $filename = 'gallery_' . time() . '_' . uniqid() . '.' . $file_extension;
                        $destination = $upload_dir . $filename;
                        
                        if (move_uploaded_file($_FILES['image']['tmp_name'], $destination)) {
                            $image_path = 'images/gallery/' . $filename;
                            
                            // Delete old image
                            $stmt = $DBcon->prepare("SELECT images FROM gallery WHERE sn = ?");
                            $stmt->execute([$sn]);
                            $old_image = $stmt->fetchColumn();
                            
                            if ($old_image && file_exists('../' . $old_image)) {
                                unlink('../' . $old_image);
                            }
                            
                            $stmt = $DBcon->prepare("UPDATE gallery SET caption = ?, images = ? WHERE sn = ?");
                            $stmt->execute([$caption, $image_path, $sn]);
                            $message = "Gallery item updated successfully!";
                        } else {
                            throw new Exception("Failed to upload image.");
                        }
                    } else {
                        throw new Exception("Invalid file type. Only JPG, PNG, GIF, and WebP are allowed.");
                    }
                } else {
                    // Update caption only
                    $stmt = $DBcon->prepare("UPDATE gallery SET caption = ? WHERE sn = ?");
                    $stmt->execute([$caption, $sn]);
                    $message = "Gallery item updated successfully!";
                }
            }
        } catch (Exception $e) {
            $error = $e->getMessage();
        }
    }
}

// Handle delete action
if (isset($_GET['delete'])) {
    $sn = $_GET['delete'];
    $csrf_token = $_GET['csrf_token'] ?? '';
    
    if (validate_csrf_token($csrf_token)) {
        try {
            // Get image path before deletion
            $stmt = $DBcon->prepare("SELECT images FROM gallery WHERE sn = ?");
            $stmt->execute([$sn]);
            $image_path = $stmt->fetchColumn();
            
            // Delete from database
            $stmt = $DBcon->prepare("DELETE FROM gallery WHERE sn = ?");
            $stmt->execute([$sn]);
            
            // Delete image file
            if ($image_path && file_exists('../' . $image_path)) {
                unlink('../' . $image_path);
            }
            
            $message = "Gallery item deleted successfully!";
        } catch (Exception $e) {
            $error = "Error deleting gallery item: " . $e->getMessage();
        }
    } else {
        $error = "Security token invalid.";
    }
}

// Fetch gallery items for listing
try {
    $stmt = $DBcon->prepare("SELECT * FROM gallery ORDER BY sn DESC");
    $stmt->execute();
    $gallery_items = $stmt->fetchAll(PDO::FETCH_ASSOC);
} catch (Exception $e) {
    $error = "Error fetching gallery items: " . $e->getMessage();
    $gallery_items = [];
}

// Fetch single item for editing
$edit_item = null;
if ($action === 'edit' && isset($_GET['sn'])) {
    try {
        $stmt = $DBcon->prepare("SELECT * FROM gallery WHERE sn = ?");
        $stmt->execute([$_GET['sn']]);
        $edit_item = $stmt->fetch(PDO::FETCH_ASSOC);
        
        if (!$edit_item) {
            $error = "Gallery item not found.";
            $action = 'list';
        }
    } catch (Exception $e) {
        $error = "Error fetching gallery item: " . $e->getMessage();
        $action = 'list';
    }
}

// Generate CSRF token
$csrf_token = generate_csrf_token();
?>

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
  <title>Gallery Management - School Admin</title>
  <link rel="stylesheet" href="vendors/iconfonts/font-awesome/css/all.min.css">
  <link rel="stylesheet" href="vendors/css/vendor.bundle.base.css">
  <link rel="stylesheet" href="vendors/css/vendor.bundle.addons.css">
  <link rel="stylesheet" href="css/style.css">
  <style>
    .gallery-img {
        max-width: 150px;
        max-height: 100px;
        object-fit: cover;
        border-radius: 4px;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    }
    .action-buttons .btn {
        margin: 2px;
    }
    .preview-image {
        max-width: 200px;
        max-height: 150px;
        margin: 10px 0;
        border-radius: 4px;
    }
    .empty-state {
        text-align: center;
        padding: 40px;
        color: #6c757d;
    }
    .empty-state i {
        font-size: 48px;
        margin-bottom: 15px;
        color: #dee2e6;
    }
    .card-title {
        display: flex;
        justify-content: between;
        align-items: center;
    }
    @media (max-width: 768px) {
        .action-buttons .btn {
            display: block;
            width: 100%;
            margin: 5px 0;
        }
        .table-responsive table {
            font-size: 14px;
        }
    }
  </style>
</head>

<body>
  <div class="container-scroller">
    <?php include("header.php"); ?>
    <div class="container-fluid page-body-wrapper">
      <?php include("sidebar.php"); ?>
      <div class="main-panel">
        <div class="content-wrapper">
          <div class="page-header">
            <h3 class="page-title">
              <i class="fas fa-images"></i>
              Gallery Management
            </h3>
            <nav aria-label="breadcrumb">
              <ol class="breadcrumb">
                <li class="breadcrumb-item"><a href="dashboard.php">Dashboard</a></li>
                <li class="breadcrumb-item active" aria-current="page">Gallery</li>
              </ol>
            </nav>
          </div>

          <!-- Alert Messages -->
          <?php if ($message): ?>
            <div class="alert alert-success alert-dismissible fade show" role="alert">
              <i class="fas fa-check-circle"></i> <?php echo $message; ?>
              <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                <span aria-hidden="true">&times;</span>
              </button>
            </div>
          <?php endif; ?>
          
          <?php if ($error): ?>
            <div class="alert alert-danger alert-dismissible fade show" role="alert">
              <i class="fas fa-exclamation-circle"></i> <?php echo $error; ?>
              <button type="button" class="close" data-dismiss="alert" aria-label="Close">
                <span aria-hidden="true">&times;</span>
              </button>
            </div>
          <?php endif; ?>

          <div class="row">
            <div class="col-12">
              
              <?php if ($action === 'list' || $action === 'delete'): ?>
                <!-- Gallery List -->
                <div class="card">
                  <div class="card-body">
                    <div class="d-flex justify-content-between align-items-center mb-4">
                      <h4 class="card-title mb-0">
                        <i class="fas fa-list"></i>
                        Gallery Items
                      </h4>
                      <a href="?action=add" class="btn btn-primary btn-sm">
                        <i class="fas fa-plus"></i>
                        Add New Item
                      </a>
                    </div>
                    
                    <?php if (empty($gallery_items)): ?>
                      <div class="empty-state">
                        <i class="fas fa-images"></i>
                        <h4>No Gallery Items Found</h4>
                        <p>Get started by adding your first gallery item.</p>
                        <a href="?action=add" class="btn btn-primary">
                          <i class="fas fa-plus"></i>
                          Add Gallery Item
                        </a>
                      </div>
                    <?php else: ?>
                      <div class="table-responsive">
                        <table class="table table-striped">
                          <thead>
                            <tr>
                              <th>#</th>
                              <th>Image</th>
                              <th>Caption</th>
                              <th>Actions</th>
                            </tr>
                          </thead>
                          <tbody>
                            <?php foreach ($gallery_items as $index => $item): ?>
                              <tr>
                                <td><?php echo $index + 1; ?></td>
                                <td>
                                  <img src="../<?php echo htmlspecialchars($item['images']); ?>" 
                                       alt="<?php echo htmlspecialchars($item['caption']); ?>" 
                                       class="gallery-img"
                                       onerror="this.src='../images/placeholder.jpg'">
                                </td>
                                <td><?php echo htmlspecialchars($item['caption']); ?></td>
                                <td class="action-buttons">
                                  <a href="?action=edit&sn=<?php echo $item['sn']; ?>" 
                                     class="btn btn-outline-primary btn-sm">
                                    <i class="fas fa-edit"></i>
                                    Edit
                                  </a>
                                  <a href="?delete=<?php echo $item['sn']; ?>&csrf_token=<?php echo $csrf_token; ?>" 
                                     class="btn btn-outline-danger btn-sm" 
                                     onclick="return confirm('Are you sure you want to delete this item?')">
                                    <i class="fas fa-trash"></i>
                                    Delete
                                  </a>
                                </td>
                              </tr>
                            <?php endforeach; ?>
                          </tbody>
                        </table>
                      </div>
                    <?php endif; ?>
                  </div>
                </div>
              <?php endif; ?>

              <?php if ($action === 'add' || $action === 'edit'): ?>
                <!-- Add/Edit Form -->
                <div class="card">
                  <div class="card-body">
                    <h4 class="card-title">
                      <i class="fas <?php echo $action === 'add' ? 'fa-plus' : 'fa-edit'; ?>"></i>
                      <?php echo $action === 'add' ? 'Add New Gallery Item' : 'Edit Gallery Item'; ?>
                    </h4>
                    
                    <form method="POST" enctype="multipart/form-data" class="forms-sample">
                      <input type="hidden" name="csrf_token" value="<?php echo $csrf_token; ?>">
                      
                      <?php if ($action === 'edit'): ?>
                        <input type="hidden" name="sn" value="<?php echo $edit_item['sn']; ?>">
                      <?php endif; ?>
                      
                      <div class="form-group">
                        <label for="caption">Caption *</label>
                        <input type="text" class="form-control" id="caption" name="caption" 
                               value="<?php echo $edit_item['caption'] ?? ''; ?>" 
                               placeholder="Enter image caption" required>
                      </div>
                      
                      <div class="form-group">
                        <label for="image">Image <?php echo $action === 'add' ? '*' : ''; ?></label>
                        <input type="file" class="form-control-file" id="image" name="image" 
                               <?php echo $action === 'add' ? 'required' : ''; ?>
                               accept="image/jpeg,image/png,image/gif,image/webp">
                        <small class="form-text text-muted">
                          Supported formats: JPG, PNG, GIF, WebP. Max size: 5MB.
                        </small>
                        
                        <?php if ($action === 'edit' && !empty($edit_item['images'])): ?>
                          <div class="mt-2">
                            <p class="mb-1">Current Image:</p>
                            <img src="../<?php echo htmlspecialchars($edit_item['images']); ?>" 
                                 alt="Current image" class="preview-image"
                                 onerror="this.style.display='none'">
                          </div>
                        <?php endif; ?>
                      </div>
                      
                      <div class="mt-4">
                        <button type="submit" name="<?php echo $action === 'add' ? 'add_gallery' : 'edit_gallery'; ?>" 
                                class="btn btn-primary mr-2">
                          <i class="fas fa-save"></i>
                          <?php echo $action === 'add' ? 'Add Item' : 'Update Item'; ?>
                        </button>
                        <a href="?action=list" class="btn btn-light">
                          <i class="fas fa-arrow-left"></i>
                          Back to List
                        </a>
                      </div>
                    </form>
                  </div>
                </div>
              <?php endif; ?>
              
            </div>
          </div>
        </div>
        
        <footer class="footer">
          <div class="d-sm-flex justify-content-center justify-content-sm-between">
            <span class="text-muted text-center text-sm-left d-block d-sm-inline-block">
              Copyright © 2024. All rights reserved.
            </span>
          </div>
        </footer>
      </div>
    </div>
  </div>

  <script src="vendors/js/vendor.bundle.base.js"></script>
  <script src="vendors/js/vendor.bundle.addons.js"></script>
  <script src="js/off-canvas.js"></script>
  <script src="js/hoverable-collapse.js"></script>
  <script src="js/misc.js"></script>
  <script src="js/settings.js"></script>
  <script src="js/todolist.js"></script>
  
  <script>
    // Image preview functionality
    document.getElementById('image')?.addEventListener('change', function(e) {
      const file = e.target.files[0];
      if (file) {
        const reader = new FileReader();
        reader.onload = function(e) {
          // Remove existing preview
          const existingPreview = document.querySelector('.image-preview');
          if (existingPreview) {
            existingPreview.remove();
          }
          
          // Create new preview
          const preview = document.createElement('div');
          preview.className = 'image-preview mt-2';
          preview.innerHTML = `
            <p class="mb-1">New Image Preview:</p>
            <img src="${e.target.result}" alt="Preview" class="preview-image">
          `;
          e.target.parentNode.appendChild(preview);
        };
        reader.readAsDataURL(file);
      }
    });

    // Auto-dismiss alerts after 5 seconds
    setTimeout(() => {
      const alerts = document.querySelectorAll('.alert');
      alerts.forEach(alert => {
        const bsAlert = new bootstrap.Alert(alert);
        bsAlert.close();
      });
    }, 5000);
  </script>
</body>
</html>