<?php
/**
 * Export class
 *
 * Handles exporting product categories to CSV
 *
 * @since      1.0.0
 * @package    Studiou_WC_Product_Cat_Manage
 * @subpackage Studiou_WC_Product_Cat_Manage/includes
 */

// If this file is called directly, abort.
if (!defined('WPINC')) {
    die;
}

class Studiou_WC_Product_Cat_Manage_Export {
    
    /**
     * Database handler
     *
     * @var Studiou_WC_Product_Cat_Manage_DB
     */
    private $db;
    
    /**
     * Constructor
     *
     * @param Studiou_WC_Product_Cat_Manage_DB $db Database handler
     */
    public function __construct($db) {
        $this->db = $db;
        
        // Register AJAX handlers
        add_action('wp_ajax_studiou_wcpcm_export', array($this, 'handle_export_ajax'));
        
        // Add download handler
        add_action('admin_init', array($this, 'handle_export_download'));
    }
    
    /**
     * Handle AJAX export request
     */
    public function handle_export_ajax() {
        // Check nonce
        if (!isset($_POST['nonce']) || !wp_verify_nonce($_POST['nonce'], 'studiou-wcpcm-nonce')) {
            wp_send_json_error(array(
                'message' => __('Security check failed', 'studiou-wc-product-cat-manage')
            ));
        }
        
        // Check permissions
        if (!current_user_can('manage_woocommerce')) {
            wp_send_json_error(array(
                'message' => __('You do not have sufficient permissions', 'studiou-wc-product-cat-manage')
            ));
        }
        
        try {
            // Generate export file
            $filename = $this->generate_export_file();
            
            // Return success response
            wp_send_json_success(array(
                'message' => __('Product categories exported successfully', 'studiou-wc-product-cat-manage'),
                'download_url' => admin_url('edit.php?post_type=product&page=studiou-export-product-categories&action=download&nonce=' . wp_create_nonce('studiou-wcpcm-export-download'))
            ));
        } catch (Exception $e) {
            wp_send_json_error(array(
                'message' => $e->getMessage()
            ));
        }
    }
    
    /**
     * Handle export download
     */
    public function handle_export_download() {
        if (!isset($_GET['page']) || $_GET['page'] !== 'studiou-export-product-categories' || 
            !isset($_GET['action']) || $_GET['action'] !== 'download' || 
            !isset($_GET['nonce']) || !wp_verify_nonce($_GET['nonce'], 'studiou-wcpcm-export-download')) {
            return;
        }
        
        // Check permissions
        if (!current_user_can('manage_woocommerce')) {
            wp_die(__('You do not have sufficient permissions', 'studiou-wc-product-cat-manage'));
        }
        
        $uploads_dir = wp_upload_dir();
        $export_dir = trailingslashit($uploads_dir['basedir']) . 'studiou-wcpcm-exports/';
        $filename = $export_dir . 'product-categories-export.csv';
        
        if (!file_exists($filename)) {
            wp_die(__('Export file not found. Please try exporting again.', 'studiou-wc-product-cat-manage'));
        }
        
        // Set headers for download
        header('Content-Type: text/csv; charset=utf-8');
        header('Content-Disposition: attachment; filename=product-categories-export-' . date('Y-m-d') . '.csv');
        header('Pragma: no-cache');
        header('Expires: 0');
        
        // Output file content
        readfile($filename);
        exit;
    }
    
    /**
     * Generate export file
     *
     * @return string Path to the generated file
     * @throws Exception On error
     */
    public function generate_export_file() {
        // Create export directory if it doesn't exist
        $uploads_dir = wp_upload_dir();
        $export_dir = trailingslashit($uploads_dir['basedir']) . 'studiou-wcpcm-exports/';
        
        if (!file_exists($export_dir)) {
            wp_mkdir_p($export_dir);
            
            // Create an index.php file to prevent directory listing
            file_put_contents($export_dir . 'index.php', '<?php // Silence is golden');
        }
        
        // Get all categories
        $categories = $this->db->get_all_product_categories();
        
        // Define CSV headers
        $headers = array(
            'name',
            'url-name',
            'parent-name',
            'description',
            'display-type',
            'visibility',
            'protected-passwords',
            'operation'
        );
        
        // Generate CSV content
        $csv_content = $this->generate_csv($headers, $categories);
        
        // Save to file
        $filename = $export_dir . 'product-categories-export.csv';
        $result = file_put_contents($filename, $csv_content);
        
        if (false === $result) {
            throw new Exception(__('Failed to write export file', 'studiou-wc-product-cat-manage'));
        }
        
        return $filename;
    }
    
    /**
     * Generate CSV content
     *
     * @param array $headers CSV headers
     * @param array $data Data rows
     * @return string CSV content
     */
    private function generate_csv($headers, $data) {
        ob_start();
        $output = fopen('php://output', 'w');
        
        // Add UTF-8 BOM for Excel compatibility
        fprintf($output, chr(0xEF).chr(0xBB).chr(0xBF));
        
        // Add headers
        fputcsv($output, $headers);
        
        // Add data rows
        foreach ($data as $row) {
            // Ensure all headers are present in the row
            $csv_row = array();
            foreach ($headers as $header) {
                $csv_row[] = isset($row[$header]) ? $row[$header] : '';
            }
            
            fputcsv($output, $csv_row);
        }
        
        fclose($output);
        $csv_content = ob_get_clean();
        
        return $csv_content;
    }
}