<?php
session_start();
require_once '../config/database.php';

// Check if user is logged in and is admin
if (!isset($_SESSION['user_id']) || ($_SESSION['role'] !== 'admin' && $_SESSION['role'] !== 'director')) {
    header('Location: login.php');
    exit();
}

if ($_SERVER['REQUEST_METHOD'] === 'POST') {
    $slider_id = (int)$_POST['slider_id'];
    $title = trim($_POST['title'] ?? '');
    $description = trim($_POST['description'] ?? '');
    $link_url = trim($_POST['link_url'] ?? '');
    $status = $_POST['status'] ?? 'active';
    
    $errors = [];
    
    // Validate title
    if (empty($title)) {
        $errors[] = "Title is required";
    }
    
    // Validate status
    $valid_statuses = ['active', 'inactive'];
    if (!in_array($status, $valid_statuses)) {
        $errors[] = "Invalid status";
    }
    
    if (empty($errors)) {
        // Handle image upload if new image is provided
        if (isset($_FILES['image']) && $_FILES['image']['error'] === UPLOAD_ERR_OK) {
            $file = $_FILES['image'];
            $allowed_types = ['image/jpeg', 'image/png', 'image/gif'];
            $max_size = 5 * 1024 * 1024; // 5MB
            
            if (!in_array($file['type'], $allowed_types)) {
                $errors[] = "Invalid file type. Only JPG, PNG, and GIF are allowed";
            }
            
            if ($file['size'] > $max_size) {
                $errors[] = "File size too large. Maximum size is 5MB";
            }
            
            if (empty($errors)) {
                // Create uploads directory if it doesn't exist
                $upload_dir = '../uploads/slider/';
                if (!file_exists($upload_dir)) {
                    mkdir($upload_dir, 0777, true);
                }
                
                // Generate unique filename
                $file_extension = pathinfo($file['name'], PATHINFO_EXTENSION);
                $filename = uniqid() . '.' . $file_extension;
                $filepath = $upload_dir . $filename;
                
                // Move uploaded file
                if (move_uploaded_file($file['tmp_name'], $filepath)) {
                    // Get current image URL
                    $stmt = $conn->prepare("SELECT image_url FROM slider_images WHERE id = ?");
                    $stmt->bind_param("i", $slider_id);
                    $stmt->execute();
                    $result = $stmt->get_result();
                    $current_image = $result->fetch_assoc()['image_url'];
                    
                    // Delete old image file
                    if ($current_image && file_exists('../' . $current_image)) {
                        unlink('../' . $current_image);
                    }
                    
                    // Update with new image
                    $image_url = 'uploads/slider/' . $filename;
                    $stmt = $conn->prepare("
                        UPDATE slider_images 
                        SET title = ?, description = ?, image_url = ?, link_url = ?, status = ?
                        WHERE id = ?
                    ");
                    $stmt->bind_param("sssssi", $title, $description, $image_url, $link_url, $status, $slider_id);
                } else {
                    $errors[] = "Error uploading file";
                }
            }
        } else {
            // Update without changing image
            $stmt = $conn->prepare("
                UPDATE slider_images 
                SET title = ?, description = ?, link_url = ?, status = ?
                WHERE id = ?
            ");
            $stmt->bind_param("ssssi", $title, $description, $link_url, $status, $slider_id);
        }
        
        if (empty($errors) && $stmt->execute()) {
            $_SESSION['success_message'] = "Slider updated successfully";
            header('Location: slider.php');
            exit();
        } else {
            $errors[] = "Error updating slider: " . $conn->error;
        }
    }
    
    // If there are errors, store them in session and redirect back
    $_SESSION['error_messages'] = $errors;
    $_SESSION['form_data'] = $_POST;
    header('Location: slider.php');
    exit();
}

// If not POST request, redirect to slider page
header('Location: slider.php');
exit();