<?php
/**
 * Product export class
 *
 * Handles product export to CSV files
 *
 * @since      1.4.0
 * @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_Manage_Product_Export {

    /**
     * @var Studiou_WC_Product_Manage_Product_DB
     */
    private $db;

    /**
     * Constructor
     *
     * @param Studiou_WC_Product_Manage_Product_DB $db Database instance
     */
    public function __construct($db) {
        $this->db = $db;
    }

    /**
     * Export products by category IDs
     *
     * @param array $category_ids Array of category IDs
     * @return string CSV content
     */
    public function export_products($category_ids) {
        $product_ids = $this->db->get_products_by_categories($category_ids);

        if (empty($product_ids)) {
            return '';
        }

        // Define CSV header
        $header = array(
            'ID', 'Typ', 'Katalogové číslo', 'Jméno', 'Nadřazené', 'Krátký popis', 'Popis',
            'Název 1 vlastnosti', 'Hodnota(y) 1 vlastnosti', 'Kategorie', 'Obrázky', 'Běžná cena',
            'Vlastnost 1 viditelnost', 'Vlastnost 1 globální', 'Vlastnost 1 varianta',
            'Povolit zákaznické recenze?', 'Minimum Quantity', 'Maximum Quantity'
        );

        // Start CSV output
        $csv = '';
        $csv .= '"' . implode('","', $header) . '"' . "\n";

        // Process each product
        foreach ($product_ids as $product_id) {
            $product = wc_get_product($product_id);
            if (!$product) {
                continue;
            }

            // Only export variable products and variations
            if (!$product->is_type('variable') && !$product->is_type('variation')) {
                continue;
            }

            $csv .= $this->format_product_row($product);
        }

        return $csv;
    }

    /**
     * Format product data as CSV row
     *
     * @param WC_Product $product Product object
     * @return string CSV row
     */
    private function format_product_row($product) {
        $row = array();

        // ID
        $row[] = $product->get_id();

        // Typ (Type)
        $row[] = $product->is_type('variation') ? 'variation' : 'variable';

        // Katalogové číslo (SKU)
        $row[] = $product->get_sku();

        // Jméno (Name)
        $row[] = $product->get_name();

        // Nadřazené (Parent) - only for variations
        if ($product->is_type('variation')) {
            $parent_id = $product->get_parent_id();
            if ($parent_id) {
                $parent = wc_get_product($parent_id);
                $row[] = $parent ? $parent->get_sku() : '';
            } else {
                $row[] = '';
            }
        } else {
            $row[] = '';
        }

        // Krátký popis (Short description)
        $row[] = $product->get_short_description();

        // Popis (Description)
        $row[] = $product->get_description();

        // Název 1 vlastnosti (Attribute 1 name)
        // Hodnota(y) 1 vlastnosti (Attribute 1 value(s))
        $attributes = $product->get_attributes();
        $attribute_name = '';
        $attribute_values = '';
        $attribute_visible = '0';
        $attribute_global = '0';
        $attribute_variation = '0';

        if (!empty($attributes)) {
            $first_attribute = reset($attributes);

            if ($first_attribute instanceof WC_Product_Attribute) {
                $attribute_name = $first_attribute->get_name();

                // Remove 'pa_' prefix if present
                if (strpos($attribute_name, 'pa_') === 0) {
                    $attribute_name = substr($attribute_name, 3);
                }

                // Get attribute values
                if ($product->is_type('variation')) {
                    // For variations, get the specific value
                    $variation_attributes = $product->get_variation_attributes();
                    if (!empty($variation_attributes)) {
                        $attribute_values = reset($variation_attributes);
                    }
                } else {
                    // For variable products, get all options
                    $options = $first_attribute->get_options();
                    if (is_array($options)) {
                        $attribute_values = implode('|', $options);
                    }
                }

                $attribute_visible = $first_attribute->get_visible() ? '1' : '0';
                $attribute_global = $first_attribute->is_taxonomy() ? '1' : '0';
                $attribute_variation = $first_attribute->get_variation() ? '1' : '0';
            }
        }

        $row[] = $attribute_name;
        $row[] = $attribute_values;

        // Kategorie (Categories) - with full hierarchy for subcategories
        $category_ids = $product->get_category_ids();
        $category_names = array();
        foreach ($category_ids as $cat_id) {
            $category_path = $this->get_category_path($cat_id);
            if ($category_path) {
                $category_names[] = $category_path;
            }
        }
        $row[] = implode('|', $category_names);

        // Obrázky (Images)
        $image_id = $product->get_image_id();
        $row[] = $image_id ? wp_get_attachment_url($image_id) : '';

        // Běžná cena (Regular price)
        $row[] = $product->get_regular_price();

        // Vlastnost 1 viditelnost (Attribute 1 visibility)
        $row[] = $attribute_visible;

        // Vlastnost 1 globální (Attribute 1 global)
        $row[] = $attribute_global;

        // Vlastnost 1 varianta (Attribute 1 variation)
        $row[] = $attribute_variation;

        // Povolit zákaznické recenze? (Enable reviews)
        $row[] = $product->get_reviews_allowed() ? '1' : '0';

        // Minimum Quantity
        $min_qty = $product->get_meta('_minimum_quantity');
        $row[] = $min_qty ? $min_qty : '';

        // Maximum Quantity
        $max_qty = $product->get_meta('_maximum_quantity');
        $row[] = $max_qty ? $max_qty : '';

        // Format as CSV row
        $formatted_row = array();
        foreach ($row as $value) {
            // Escape double quotes
            $value = str_replace('"', '""', $value);
            $formatted_row[] = '"' . $value . '"';
        }

        return implode(',', $formatted_row) . "\n";
    }

    /**
     * Get full category path (Parent > Child format for subcategories)
     *
     * @param int $category_id Category term ID
     * @return string Category path
     */
    private function get_category_path($category_id) {
        $term = get_term($category_id, 'product_cat');

        if (!$term || is_wp_error($term)) {
            return '';
        }

        // Build path from child to root
        $path = array($term->name);
        $current_term = $term;

        while ($current_term->parent != 0) {
            $parent_term = get_term($current_term->parent, 'product_cat');
            if (!$parent_term || is_wp_error($parent_term)) {
                break;
            }
            array_unshift($path, $parent_term->name);
            $current_term = $parent_term;
        }

        // Return full path with ">" separator if subcategory, otherwise just the name
        return count($path) > 1 ? implode(' > ', $path) : $path[0];
    }

    /**
     * Generate CSV file and return download URL
     *
     * @param array $category_ids Array of category IDs
     * @return array Result with download URL or error message
     */
    public function generate_export_file($category_ids) {
        $csv_content = $this->export_products($category_ids);

        if (empty($csv_content)) {
            return array(
                'success' => false,
                'message' => __('No products found in selected categories', 'studiou-wc-product-cat-manage')
            );
        }

        // Create uploads directory if it doesn't exist
        $upload_dir = wp_upload_dir();
        $export_dir = $upload_dir['basedir'] . '/studiou-wc-product-exports';

        if (!file_exists($export_dir)) {
            wp_mkdir_p($export_dir);
        }

        // Generate filename with timestamp
        $filename = 'product-export-' . date('Y-m-d-H-i-s') . '.csv';
        $file_path = $export_dir . '/' . $filename;

        // Write CSV content to file
        $result = file_put_contents($file_path, $csv_content);

        if ($result === false) {
            return array(
                'success' => false,
                'message' => __('Failed to create export file', 'studiou-wc-product-cat-manage')
            );
        }

        // Generate download URL
        $download_url = $upload_dir['baseurl'] . '/studiou-wc-product-exports/' . $filename;

        return array(
            'success' => true,
            'message' => sprintf(
                __('Export successful! %d products exported.', 'studiou-wc-product-cat-manage'),
                substr_count($csv_content, "\n") - 1 // Subtract header row
            ),
            'download_url' => $download_url
        );
    }
}