<?php
class WPI_Product_Mapper
{

    public static function upsert($data)
    {
        if (empty($data['sku'])) return;

        $product_id = wc_get_product_id_by_sku($data['sku']);

        $product = $product_id
            ? wc_get_product($product_id)
            : new WC_Product_Simple();

        $product->set_name($data['name'] ?? '');
        $product->set_sku($data['sku']);
        $product->set_regular_price($data['price'] ?? 0);
        $product->set_stock_quantity($data['stock'] ?? 0);
        $product->set_manage_stock(true);


        if (!empty($data['description'])) {
            $product->set_description(wp_kses_post($data['description']));
        }

        if (!empty($data['short_description'])) {
            $product->set_short_description(wp_kses_post($data['short_description']));
        }

        return $product->save();
    }

    protected static function attach_images(int $product_id, array $urls)
    {
        require_once ABSPATH . 'wp-admin/includes/file.php';
        require_once ABSPATH . 'wp-admin/includes/media.php';
        require_once ABSPATH . 'wp-admin/includes/image.php';

        $gallery_ids = [];

        foreach ($urls as $index => $url) {
            if (!filter_var($url, FILTER_VALIDATE_URL)) {
                continue;
            }

            $attachment_id = media_sideload_image($url, $product_id, null, 'id');

            if (is_wp_error($attachment_id)) {
                continue;
            }

            if ($index === 0) {
                set_post_thumbnail($product_id, $attachment_id);
            } else {
                $gallery_ids[] = $attachment_id;
            }
        }

        if ($gallery_ids) {
            update_post_meta(
                $product_id,
                '_product_image_gallery',
                implode(',', $gallery_ids)
            );
        }
    }


    public static function upsert_from_api(array $data)
    {
        if (empty($data['sku'])) return;

        $product_id = self::upsert($data);

        if (!$product_id) return;

        if (!empty($data['brand'])) {
            self::sync_brand($product_id, $data['brand']);
        }

        if (!empty($data['categories'])) {
            self::sync_categories($product_id, $data['categories']);
        }

        if (!empty($data['images'])) {
            self::sync_images($product_id, $data['images']);
        }

        return $product_id;
    }

    protected static function sync_categories(int $product_id, array $categories)
    {
        if (empty($categories)) return;

        $term_ids = [];

        foreach ($categories as $cat_id) {
            // chỉ nhận số
            if (is_numeric($cat_id)) {
                $term_ids[] = (int) $cat_id;
            }
        }

        if (!$term_ids) return;

        // gán trực tiếp, KHÔNG tạo mới
        wp_set_object_terms(
            $product_id,
            array_unique($term_ids),
            'product_cat'
        );
    }


    protected static function sync_images(int $product_id, array $images)
    {
        if (empty($images)) return;

        $urls = array_filter(array_map('trim', $images));
        if (!$urls) return;

        self::attach_images($product_id, $urls);
    }


    protected static function sync_brand(int $product_id, string $brand)
    {
        $brand = trim($brand);
        if (!$brand) return;

        $taxonomy = 'product_brand';

        // Kiểm tra taxonomy tồn tại
        if (!taxonomy_exists($taxonomy)) {
            return;
        }

        // Check brand đã tồn tại chưa
        $term = term_exists($brand, $taxonomy);

        // Chưa có → tạo mới
        if (!$term) {
            $term = wp_insert_term($brand, $taxonomy);
        }

        if (is_wp_error($term)) {
            return;
        }

        $term_id = (int) $term['term_id'];

        // Gán brand cho product
        wp_set_object_terms($product_id, [$term_id], $taxonomy);

        // Đảm bảo attribute xuất hiện trong product
        $product = wc_get_product($product_id);
        if (!$product) return;

        $attributes = $product->get_attributes();

        if (!isset($attributes[$taxonomy])) {
            $attr = new WC_Product_Attribute();
            $attr->set_name($taxonomy);
            $attr->set_options([$brand]);
            $attr->set_visible(true);
            $attr->set_variation(false);

            $attributes[$taxonomy] = $attr;
            $product->set_attributes($attributes);
            $product->save();
        }
    }

    protected static function create_wp_categories_from_tree(
        array $categories,
        int $parent_id = 0,
        string $taxonomy = 'category'
    ) {
        foreach ($categories as $item) {
            if (empty($item['name']) || empty($item['id'])) {
                continue;
            }

            $name = $item['name'];
            $slug = sanitize_title($name);
            $description = (string) $item['id']; // 👈 external ID

            // Check if term exists under same parent
            $existing = term_exists($slug, $taxonomy, $parent_id);

            if ($existing) {
                $term_id = is_array($existing)
                    ? $existing['term_id']
                    : $existing;

                // Update description if changed
                wp_update_term($term_id, $taxonomy, [
                    'description' => $description,
                ]);
            } else {
                $result = wp_insert_term($name, $taxonomy, [
                    'slug'        => $slug,
                    'parent'      => $parent_id,
                    'description' => $description,
                ]);

                if (is_wp_error($result)) {
                    error_log('[CATEGORY_SYNC] ' . $result->get_error_message());
                    continue;
                }

                $term_id = $result['term_id'];
            }

            // Recurse children
            if (!empty($item['children']) && is_array($item['children'])) {
                self::create_wp_categories_from_tree(
                    $item['children'],
                    $term_id,
                    $taxonomy
                );
            }
        }
    }
}