<?php
/**
 * Product Sync from Business Central to WooCommerce
 *
 * Iterates WooCommerce products and queries BC for each one (WooCommerce-first).
 * This is efficient when WooCommerce has far fewer products than BC.
 *
 * @package WooBusinessCentral
 */

// Prevent direct access
if ( ! defined( 'ABSPATH' ) ) {
    exit;
}

/**
 * Class WBC_Product_Sync
 *
 * Handles syncing stock and pricing from Business Central to WooCommerce.
 */
class WBC_Product_Sync {

    /**
     * Fields to select from BC items
     */
    const SELECT_FIELDS = 'id,number,gtin,displayName,unitPrice,inventory,itemCategoryCode';

    /**
     * In-memory cache of category code => info (description, parent_code) for this run
     *
     * @var array
     */
    private $category_cache = array();

    /**
     * Sync results
     *
     * @var array
     */
    private $results = array(
        'success'  => 0,
        'failed'   => 0,
        'skipped'  => 0,
        'total'    => 0,
        'errors'   => array(),
    );

    /**
     * Process a batch of WooCommerce products by ID (WooCommerce-first approach)
     *
     * Instead of pulling all 60k+ items from BC, we iterate WooCommerce
     * products and query BC for each one by reference/GTIN/number. This is
     * called per-batch by WBC_Batch_Sync so a single request never has to
     * process the whole catalog (which would exceed PHP/proxy timeouts at
     * real-world catalog sizes).
     *
     * @param int[] $product_ids WooCommerce product IDs to process.
     * @return array Sync results for this batch.
     */
    public function run_sync_for_ids( array $product_ids ) {
        foreach ( $product_ids as $product_id ) {
            $product = wc_get_product( $product_id );

            if ( ! $product || empty( $product->get_sku() ) ) {
                continue;
            }

            $this->process_wc_product( $product );

            // Small delay between API calls to avoid rate limiting
            usleep( 50000 ); // 50ms
        }

        return array(
            'success' => empty( $this->results['errors'] ),
            'results' => $this->results,
        );
    }

    /**
     * Process a single WooCommerce product - find it in BC and sync
     *
     * @param WC_Product $product WooCommerce product.
     */
    private function process_wc_product( $product ) {
        $this->results['total']++;

        $sku = $product->get_sku();
        $product_id = $product->get_id();

        // Query BC for this item by GTIN (since SKU = EAN = GTIN)
        $bc_item = $this->find_bc_item_by_sku( $sku );

        if ( is_wp_error( $bc_item ) ) {
            $this->results['failed']++;
            $this->results['errors'][] = sprintf( 'Product %d (SKU: %s): %s', $product_id, $sku, $bc_item->get_error_message() );
            WBC_Logger::error( 'ProductSync', 'API error looking up product in BC', array(
                'product_id' => $product_id,
                'sku'        => $sku,
                'error'      => $bc_item->get_error_message(),
            ) );
            return;
        }

        if ( ! $bc_item ) {
            $this->results['skipped']++;
            WBC_Logger::debug( 'ProductSync', 'No matching BC item found for WC product', array(
                'product_id' => $product_id,
                'sku'        => $sku,
            ) );
            return;
        }

        if ( ! $this->is_category_allowed( $bc_item ) ) {
            $this->results['skipped']++;
            WBC_Logger::debug( 'ProductSync', 'Item category not in allow-list, skipping', array(
                'product_id' => $product_id,
                'sku'        => $sku,
                'category'   => $bc_item['itemCategoryCode'] ?? '',
            ) );
            return;
        }

        // If location code is configured, get location-specific stock
        $location_code = get_option( 'wbc_location_code', '' );
        if ( ! empty( $location_code ) && get_option( 'wbc_enable_stock_sync', 'yes' ) === 'yes' ) {
            $location_stock = $this->get_location_stock( $bc_item, $location_code );
            if ( $location_stock !== false ) {
                $bc_item['inventory'] = $location_stock;
            }
        }

        // Update the WooCommerce product with BC data
        $updated = $this->update_product( $product, $bc_item );

        if ( $updated ) {
            $this->results['success']++;
        } else {
            $this->results['failed']++;
        }
    }

    /**
     * Find a BC item by WooCommerce SKU
     *
     * Tries, in order: GTIN, item number, then Item Reference (ReferenciasArticulo).
     * Item Reference is last on purpose: on this catalog's real data, Reference_No
     * is always identical to Item_No for every sampled row, so it never matches
     * anything the GTIN/number checks didn't already find - trying it first (as
     * originally implemented) cost an extra BC round trip on every single product
     * for zero benefit. Kept as a fallback in case that assumption doesn't hold
     * for some future item.
     *
     * @param string $sku WooCommerce product SKU.
     * @return array|false|WP_Error BC item data, false if not found, or WP_Error.
     */
    private function find_bc_item_by_sku( $sku ) {
        $escaped_sku = WBC_API_Client::escape_odata_string( $sku );

        // Try by GTIN (since SKU = EAN = GTIN in this setup)
        $result = WBC_API_Client::get( '/items', array(
            '$filter' => "gtin eq '" . $escaped_sku . "'",
            '$select' => self::SELECT_FIELDS,
            '$top'    => 1,
        ) );

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

        if ( ! empty( $result['value'] ) ) {
            return $result['value'][0];
        }

        // Fall back to item number match
        $result = WBC_API_Client::get( '/items', array(
            '$filter' => "number eq '" . $escaped_sku . "'",
            '$select' => self::SELECT_FIELDS,
            '$top'    => 1,
        ) );

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

        if ( ! empty( $result['value'] ) ) {
            return $result['value'][0];
        }

        // Last resort: Item Reference
        $item_number = $this->find_item_number_by_reference( $sku );

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

        if ( $item_number ) {
            $result = WBC_API_Client::get( '/items', array(
                '$filter' => "number eq '" . WBC_API_Client::escape_odata_string( $item_number ) . "'",
                '$select' => self::SELECT_FIELDS,
                '$top'    => 1,
            ) );

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

            if ( ! empty( $result['value'] ) ) {
                return $result['value'][0];
            }
        }

        return false;
    }

    /**
     * Look up an item number by cross-reference code using the custom
     * ReferenciasArticulo OData endpoint (exposes Item_No, Reference_No, Reference_Type).
     *
     * @param string $reference_no The reference/cross-reference code (WooCommerce SKU).
     * @return string|false|WP_Error Item number, false if no match, or WP_Error.
     */
    private function find_item_number_by_reference( $reference_no ) {
        $escaped = WBC_API_Client::escape_odata_string( $reference_no );

        $result = WBC_API_Client::odata_get( 'ReferenciasArticulo', array(
            '$filter' => "Reference_No eq '" . $escaped . "'",
            '$select' => 'Item_No,Reference_No,Reference_Type',
            '$top'    => 1,
        ) );

        if ( is_wp_error( $result ) ) {
            WBC_Logger::warning( 'ProductSync', 'Failed to query ReferenciasArticulo, continuing with GTIN/number lookup', array(
                'reference_no' => $reference_no,
                'error'        => $result->get_error_message(),
            ) );
            return false;
        }

        $entries = isset( $result['value'] ) ? $result['value'] : array();

        if ( empty( $entries ) ) {
            return false;
        }

        return $entries[0]['Item_No'] ?? false;
    }

    /**
     * Check whether an item's category passes the configured allow-list filter
     *
     * @param array $item BC item data.
     * @return bool True if allowed (or no filter configured).
     */
    private function is_category_allowed( $item ) {
        $filter = get_option( 'wbc_category_filter', '' );

        if ( empty( trim( $filter ) ) ) {
            return true;
        }

        $allowed = array_filter( array_map( 'trim', explode( ',', $filter ) ) );

        if ( empty( $allowed ) ) {
            return true;
        }

        $item_category = $item['itemCategoryCode'] ?? '';

        return in_array( $item_category, $allowed, true );
    }

    /**
     * Process a single BC item - find the matching WooCommerce product and sync
     *
     * Used by the category-filtered (BC-first) sync path: instead of iterating
     * every WooCommerce product and asking BC "do you have this SKU?", we
     * already fetched this item from BC (filtered server-side by category), so
     * we just need to find the corresponding WooCommerce product locally - no
     * further BC round trip needed in the common case.
     *
     * @param array $item BC item data (id, number, gtin, displayName, unitPrice, inventory, itemCategoryCode).
     */
    public function process_bc_item( $item ) {
        $this->results['total']++;

        $product = $this->find_wc_product_for_item( $item );
        $is_new = false;

        if ( ! $product && get_option( 'wbc_create_missing_products', 'no' ) === 'yes' ) {
            $product = $this->create_wc_product_from_item( $item );
            $is_new = (bool) $product;
        }

        if ( ! $product ) {
            $this->results['skipped']++;
            WBC_Logger::debug( 'ProductSync', 'No matching WooCommerce product for BC item', array(
                'item_number' => $item['number'] ?? '',
                'gtin'        => $item['gtin'] ?? '',
            ) );
            return;
        }

        // If location code is configured, get location-specific stock
        $location_code = get_option( 'wbc_location_code', '' );
        if ( ! empty( $location_code ) && get_option( 'wbc_enable_stock_sync', 'yes' ) === 'yes' ) {
            $location_stock = $this->get_location_stock( $item, $location_code );
            if ( $location_stock !== false ) {
                $item['inventory'] = $location_stock;
            }
        }

        $updated = $this->update_product( $product, $item );

        if ( $updated ) {
            $this->results['success']++;
            if ( $is_new ) {
                WBC_Logger::info( 'ProductSync', 'Created new WooCommerce product from BC item', array(
                    'product_id'  => $product->get_id(),
                    'item_number' => $item['number'] ?? '',
                    'sku'         => $product->get_sku(),
                ) );
            }
        } else {
            $this->results['failed']++;
        }
    }

    /**
     * Create a new WooCommerce product from a BC item
     *
     * Bare creation only (name, SKU, status) - stock/price/brand are filled
     * in right after by the normal update_product() call, so that logic
     * isn't duplicated here.
     *
     * @param array $item BC item data.
     * @return WC_Product|false
     */
    private function create_wc_product_from_item( $item ) {
        $sku = ! empty( $item['gtin'] ) ? $item['gtin'] : ( $item['number'] ?? '' );

        if ( empty( $sku ) ) {
            return false;
        }

        $product = new WC_Product_Simple();
        $product->set_name( $item['displayName'] ?? $sku );

        try {
            $product->set_sku( $sku );
            $product->set_status( get_option( 'wbc_new_product_status', 'draft' ) === 'publish' ? 'publish' : 'draft' );
            $product->save();
        } catch ( Exception $e ) {
            WBC_Logger::error( 'ProductSync', 'Failed to create WooCommerce product from BC item', array(
                'item_number' => $item['number'] ?? '',
                'sku'         => $sku,
                'error'       => $e->getMessage(),
            ) );
            return false;
        }

        return $product;
    }

    /**
     * Find the WooCommerce product matching a BC item, via a local SKU lookup
     * (no BC round trip) - tries GTIN, then item number, then Item Reference
     * as a last resort.
     *
     * @param array $item BC item data.
     * @return WC_Product|false
     */
    private function find_wc_product_for_item( $item ) {
        $gtin = $item['gtin'] ?? '';
        $number = $item['number'] ?? '';

        if ( ! empty( $gtin ) ) {
            $product_id = wc_get_product_id_by_sku( $gtin );
            if ( $product_id ) {
                return wc_get_product( $product_id );
            }
        }

        if ( ! empty( $number ) ) {
            $product_id = wc_get_product_id_by_sku( $number );
            if ( $product_id ) {
                return wc_get_product( $product_id );
            }
        }

        if ( ! empty( $number ) ) {
            $reference_no = $this->find_reference_no_by_item_number( $number );

            if ( $reference_no ) {
                $product_id = wc_get_product_id_by_sku( $reference_no );
                if ( $product_id ) {
                    return wc_get_product( $product_id );
                }
            }
        }

        return false;
    }

    /**
     * Look up a reference/barcode number for a BC item number via the custom
     * ReferenciasArticulo OData endpoint (reverse direction of find_item_number_by_reference).
     *
     * @param string $item_number BC item number.
     * @return string|false Reference number, or false if none found/on error.
     */
    private function find_reference_no_by_item_number( $item_number ) {
        $escaped = WBC_API_Client::escape_odata_string( $item_number );

        $result = WBC_API_Client::odata_get( 'ReferenciasArticulo', array(
            '$filter' => "Item_No eq '" . $escaped . "'",
            '$select' => 'Item_No,Reference_No,Reference_Type',
            '$top'    => 1,
        ) );

        if ( is_wp_error( $result ) ) {
            return false;
        }

        $entries = isset( $result['value'] ) ? $result['value'] : array();

        if ( empty( $entries ) ) {
            return false;
        }

        return $entries[0]['Reference_No'] ?? false;
    }

    /**
     * Get stock quantity for a specific BC location using ItemByLocation endpoint
     *
     * Uses the custom OData V4 endpoint "ItemByLocation" which returns
     * No, Description, Location_Code, Remaining_Quantity.
     *
     * Falls back to the item's total inventory if the OData call fails.
     *
     * @param array  $bc_item       BC item data.
     * @param string $location_code BC location code (e.g. 'ICP').
     * @return float|false Stock quantity at location, or false to use default.
     */
    private function get_location_stock( $bc_item, $location_code ) {
        $item_number = $bc_item['number'] ?? '';

        if ( empty( $item_number ) ) {
            return false;
        }

        $escaped_number = WBC_API_Client::escape_odata_string( $item_number );
        $escaped_location = WBC_API_Client::escape_odata_string( $location_code );

        $result = WBC_API_Client::odata_get( 'ItemByLocation', array(
            '$filter' => "No eq '" . $escaped_number . "' and Location_Code eq '" . $escaped_location . "'",
            '$select' => 'Remaining_Quantity',
        ) );

        if ( is_wp_error( $result ) ) {
            WBC_Logger::warning( 'ProductSync', 'Failed to get location stock from ItemByLocation, using total inventory', array(
                'item_number'   => $item_number,
                'location_code' => $location_code,
                'error'         => $result->get_error_message(),
            ) );
            return false;
        }

        $entries = isset( $result['value'] ) ? $result['value'] : array();

        if ( empty( $entries ) ) {
            WBC_Logger::debug( 'ProductSync', 'No ItemByLocation entry for item/location', array(
                'item_number'   => $item_number,
                'location_code' => $location_code,
            ) );
            return 0.0;
        }

        // Should return a single row for item + location
        $qty = (float) ( $entries[0]['Remaining_Quantity'] ?? 0 );

        WBC_Logger::debug( 'ProductSync', 'Got location-specific stock from ItemByLocation', array(
            'item_number'   => $item_number,
            'location_code' => $location_code,
            'stock'         => $qty,
        ) );

        return $qty;
    }

    /**
     * Get price from ListaPrecios custom endpoint
     *
     * Filters by: Price List Code, Status = Activo, and Product No. = item number.
     *
     * @param string $item_number    BC item number.
     * @param string $price_list_code Price list code (e.g. 'B2C').
     * @return float|false Unit price or false if not found.
     */
    private function get_price_from_list( $item_number, $price_list_code ) {
        if ( empty( $item_number ) || empty( $price_list_code ) ) {
            return false;
        }

        $escaped_number = WBC_API_Client::escape_odata_string( $item_number );
        $escaped_code = WBC_API_Client::escape_odata_string( $price_list_code );

        $result = WBC_API_Client::odata_get( 'ListaPrecios', array(
            '$filter' => "Price_List_Code eq '" . $escaped_code . "'"
                       . " and Status eq 'Active'"
                       . " and Asset_No eq '" . $escaped_number . "'",
            '$select' => 'Unit_Price',
            '$top'    => 1,
        ) );

        if ( is_wp_error( $result ) ) {
            WBC_Logger::warning( 'ProductSync', 'Failed to get price from ListaPrecios', array(
                'item_number'     => $item_number,
                'price_list_code' => $price_list_code,
                'error'           => $result->get_error_message(),
            ) );
            return false;
        }

        $entries = isset( $result['value'] ) ? $result['value'] : array();

        if ( empty( $entries ) ) {
            WBC_Logger::debug( 'ProductSync', 'No price list entry found', array(
                'item_number'     => $item_number,
                'price_list_code' => $price_list_code,
            ) );
            return false;
        }

        $price = (float) ( $entries[0]['Unit_Price'] ?? 0 );

        WBC_Logger::debug( 'ProductSync', 'Got price from ListaPrecios', array(
            'item_number'     => $item_number,
            'price_list_code' => $price_list_code,
            'price'           => $price,
        ) );

        return $price;
    }

    /**
     * Update WooCommerce product with BC data
     *
     * @param WC_Product $product WooCommerce product.
     * @param array      $item    BC item data.
     * @return bool Whether the product was updated.
     */
    private function update_product( $product, $item ) {
        $product_id = $product->get_id();

        try {
            $changed = false;

            // Update stock if enabled
            if ( get_option( 'wbc_enable_stock_sync', 'yes' ) === 'yes' ) {
                $stock = isset( $item['inventory'] ) ? (float) $item['inventory'] : 0;
                $current_stock = (float) $product->get_stock_quantity();

                if ( $stock !== $current_stock ) {
                    if ( ! $product->get_manage_stock() ) {
                        $product->set_manage_stock( true );
                    }

                    wc_update_product_stock( $product, $stock );
                    $changed = true;

                    WBC_Logger::debug( 'ProductSync', 'Updated stock', array(
                        'product_id' => $product_id,
                        'sku'        => $product->get_sku(),
                        'old_stock'  => $current_stock,
                        'new_stock'  => $stock,
                    ) );
                }
            }

            // Update prices if enabled
            if ( get_option( 'wbc_enable_price_sync', 'yes' ) === 'yes' ) {
                $item_number = $item['number'] ?? '';
                $regular_list = get_option( 'wbc_regular_price_list', '' );
                $sale_list = get_option( 'wbc_sale_price_list', '' );

                // Get regular price from price list, or fall back to item unitPrice
                if ( ! empty( $regular_list ) && ! empty( $item_number ) ) {
                    $price = $this->get_price_from_list( $item_number, $regular_list );
                    if ( $price === false ) {
                        $price = isset( $item['unitPrice'] ) ? (float) $item['unitPrice'] : 0;
                    }
                } else {
                    $price = isset( $item['unitPrice'] ) ? (float) $item['unitPrice'] : 0;
                }

                $current_price = (float) $product->get_regular_price();

                if ( $price > 0 && $price !== $current_price ) {
                    $product->set_regular_price( $price );
                    $changed = true;

                    WBC_Logger::debug( 'ProductSync', 'Updated regular price', array(
                        'product_id' => $product_id,
                        'sku'        => $product->get_sku(),
                        'old_price'  => $current_price,
                        'new_price'  => $price,
                        'source'     => ! empty( $regular_list ) ? 'ListaPrecios:' . $regular_list : 'unitPrice',
                    ) );
                }

                // Get sale price from price list
                if ( ! empty( $sale_list ) && ! empty( $item_number ) ) {
                    $sale_price = $this->get_price_from_list( $item_number, $sale_list );

                    if ( $sale_price !== false && $sale_price > 0 ) {
                        $current_sale = (float) $product->get_sale_price();

                        // Only set sale price if it's less than the regular price
                        if ( $sale_price < $price && $sale_price !== $current_sale ) {
                            $product->set_sale_price( $sale_price );
                            $changed = true;

                            WBC_Logger::debug( 'ProductSync', 'Updated sale price', array(
                                'product_id' => $product_id,
                                'sku'        => $product->get_sku(),
                                'old_sale'   => $current_sale,
                                'new_sale'   => $sale_price,
                                'source'     => 'ListaPrecios:' . $sale_list,
                            ) );
                        }
                    } else {
                        // No active sale price found - clear any existing sale price
                        if ( ! empty( $product->get_sale_price() ) ) {
                            $product->set_sale_price( '' );
                            $changed = true;

                            WBC_Logger::debug( 'ProductSync', 'Cleared sale price (no active entry in list)', array(
                                'product_id' => $product_id,
                                'sku'        => $product->get_sku(),
                                'sale_list'  => $sale_list,
                            ) );
                        }
                    }
                }
            }

            // Sync category/brand if enabled
            if ( get_option( 'wbc_enable_brand_sync', 'no' ) === 'yes' ) {
                if ( $this->sync_category_and_brand( $product, $item ) ) {
                    $changed = true;
                }
            }

            // Store BC item info in meta
            $product->update_meta_data( '_wbc_bc_item_id', $item['id'] ?? '' );
            $product->update_meta_data( '_wbc_bc_item_number', $item['number'] ?? '' );
            $product->update_meta_data( '_wbc_last_sync', current_time( 'mysql' ) );
            $product->save();

            if ( ! $changed ) {
                WBC_Logger::debug( 'ProductSync', 'Product already up to date', array(
                    'product_id' => $product_id,
                    'sku'        => $product->get_sku(),
                ) );
            }

            return true;

        } catch ( Exception $e ) {
            WBC_Logger::error( 'ProductSync', 'Failed to update product', array(
                'product_id' => $product_id,
                'error'      => $e->getMessage(),
            ) );
            $this->results['errors'][] = sprintf( 'Product %d: %s', $product_id, $e->getMessage() );
            return false;
        }
    }

    /**
     * Sync WooCommerce product_brand (BC item category) from BC, and its
     * WooCommerce parent product category from a manually configured map.
     *
     * BC's item categories here are flat (e.g. "DAVINES", "CANTABRIA LABS")
     * with no parent-category field on the Item Category table to walk up
     * from brand to a grouping like "Haircare" - confirmed against the
     * published CategProd endpoint, which only exposes Code and Description.
     * That grouping is maintained in wp-admin instead (wbc_category_parent_map).
     *
     * @param WC_Product $product WooCommerce product.
     * @param array      $item    BC item data.
     * @return bool Whether anything changed.
     */
    private function sync_category_and_brand( $product, $item ) {
        $category_code = $item['itemCategoryCode'] ?? '';

        if ( empty( $category_code ) ) {
            return false;
        }

        $category_info = $this->get_category_info( $category_code );
        $brand_name = ( $category_info ? $category_info['description'] : '' ) ?: $category_code;

        $changed = false;

        if ( taxonomy_exists( 'product_brand' ) ) {
            if ( $this->set_product_taxonomy_term( $product->get_id(), 'product_brand', $brand_name ) ) {
                $changed = true;
            }
        }

        $parent_name = $this->get_mapped_parent_category( $category_code );

        if ( ! empty( $parent_name ) ) {
            if ( $this->set_product_taxonomy_term( $product->get_id(), 'product_cat', $parent_name ) ) {
                $changed = true;
            }
        }

        return $changed;
    }

    /**
     * Get category info (description) from the custom CategProd OData
     * endpoint, cached per sync run.
     *
     * Uses the standard v2.0 itemCategories entity (id, code, displayName) -
     * no custom endpoint needed for this part, since the display name is
     * already exposed by the standard API. Only the WooCommerce parent
     * category grouping needs the manual map (see get_mapped_parent_category()),
     * because that's the part with no BC equivalent at all.
     *
     * @param string $category_code BC item category code.
     * @return array|false Array with 'description', or false.
     */
    private function get_category_info( $category_code ) {
        if ( isset( $this->category_cache[ $category_code ] ) ) {
            return $this->category_cache[ $category_code ];
        }

        $result = WBC_API_Client::get( '/itemCategories', array(
            '$filter' => "code eq '" . WBC_API_Client::escape_odata_string( $category_code ) . "'",
            '$select' => 'code,displayName',
            '$top'    => 1,
        ) );

        if ( is_wp_error( $result ) ) {
            WBC_Logger::warning( 'ProductSync', 'Failed to query itemCategories', array(
                'category_code' => $category_code,
                'error'         => $result->get_error_message(),
            ) );
            $this->category_cache[ $category_code ] = false;
            return false;
        }

        $entries = isset( $result['value'] ) ? $result['value'] : array();

        if ( empty( $entries ) ) {
            $this->category_cache[ $category_code ] = false;
            return false;
        }

        $info = array(
            'description' => $entries[0]['displayName'] ?? '',
        );

        $this->category_cache[ $category_code ] = $info;

        return $info;
    }

    /**
     * Look up the WooCommerce parent product category for a BC category code
     * from the manually configured map (wbc_category_parent_map option:
     * one "CODE=Parent Name" pair per line).
     *
     * @param string $category_code BC item category code.
     * @return string Parent category name, or '' if not mapped.
     */
    private function get_mapped_parent_category( $category_code ) {
        $raw = get_option( 'wbc_category_parent_map', '' );

        if ( empty( trim( $raw ) ) ) {
            return '';
        }

        foreach ( preg_split( '/\r\n|\r|\n/', $raw ) as $line ) {
            $line = trim( $line );

            if ( $line === '' || strpos( $line, '=' ) === false ) {
                continue;
            }

            list( $code, $parent_name ) = array_map( 'trim', explode( '=', $line, 2 ) );

            if ( strcasecmp( $code, $category_code ) === 0 ) {
                return $parent_name;
            }
        }

        return '';
    }

    /**
     * Assign a product to a single term in a taxonomy, creating the term if needed.
     *
     * @param int    $product_id Product ID.
     * @param string $taxonomy   Taxonomy name.
     * @param string $term_name  Term name.
     * @return bool Whether the assignment changed anything.
     */
    private function set_product_taxonomy_term( $product_id, $taxonomy, $term_name ) {
        $existing_terms = wp_get_object_terms( $product_id, $taxonomy, array( 'fields' => 'names' ) );

        if ( ! is_wp_error( $existing_terms ) && in_array( $term_name, $existing_terms, true ) && count( $existing_terms ) === 1 ) {
            return false;
        }

        $term = term_exists( $term_name, $taxonomy );

        if ( ! $term ) {
            $term = wp_insert_term( $term_name, $taxonomy );
        }

        if ( is_wp_error( $term ) ) {
            WBC_Logger::warning( 'ProductSync', 'Failed to create/find taxonomy term', array(
                'taxonomy' => $taxonomy,
                'term'     => $term_name,
                'error'    => $term->get_error_message(),
            ) );
            return false;
        }

        $term_id = is_array( $term ) ? (int) $term['term_id'] : (int) $term;

        $result = wp_set_object_terms( $product_id, array( $term_id ), $taxonomy, false );

        return ! is_wp_error( $result );
    }

    /**
     * Get sync results
     *
     * @return array
     */
    public function get_results() {
        return $this->results;
    }

    /**
     * Sync a single product by WooCommerce product ID
     *
     * @param int $product_id WooCommerce product ID.
     * @return array Sync result.
     */
    public function sync_single_product( $product_id ) {
        $product = wc_get_product( $product_id );

        if ( ! $product ) {
            return array(
                'success' => false,
                'message' => __( 'Product not found.', 'woo-business-central' ),
            );
        }

        $sku = $product->get_sku();

        if ( empty( $sku ) ) {
            return array(
                'success' => false,
                'message' => __( 'Product has no SKU.', 'woo-business-central' ),
            );
        }

        // Find item in BC by SKU
        $bc_item = $this->find_bc_item_by_sku( $sku );

        if ( is_wp_error( $bc_item ) ) {
            return array(
                'success' => false,
                'message' => $bc_item->get_error_message(),
            );
        }

        if ( ! $bc_item ) {
            return array(
                'success' => false,
                'message' => __( 'Item not found in Business Central.', 'woo-business-central' ),
            );
        }

        if ( ! $this->is_category_allowed( $bc_item ) ) {
            return array(
                'success' => false,
                'message' => __( 'Item category is not in the configured sync allow-list.', 'woo-business-central' ),
            );
        }

        // Check location stock
        $location_code = get_option( 'wbc_location_code', '' );
        if ( ! empty( $location_code ) ) {
            $location_stock = $this->get_location_stock( $bc_item, $location_code );
            if ( $location_stock !== false ) {
                $bc_item['inventory'] = $location_stock;
            }
        }

        $updated = $this->update_product( $product, $bc_item );

        return array(
            'success' => true,
            'message' => $updated
                ? __( 'Product synced successfully.', 'woo-business-central' )
                : __( 'Product sync failed.', 'woo-business-central' ),
        );
    }

    /**
     * Push a WooCommerce product's name and featured image back to Business Central.
     *
     * On-demand only (never run automatically): PATCHes the matching BC item's
     * displayName and, if a featured image is set, its picture. BC's displayName
     * field is limited to 100 characters (Item.Description is Text[100]), so the
     * WooCommerce product title is used rather than the (much longer) description.
     *
     * @param int $product_id WooCommerce product ID.
     * @return array Result with 'success' and 'message'.
     */
    public function push_product_to_bc( $product_id ) {
        $product = wc_get_product( $product_id );

        if ( ! $product ) {
            return array(
                'success' => false,
                'message' => __( 'Product not found.', 'woo-business-central' ),
            );
        }

        $sku = $product->get_sku();

        if ( empty( $sku ) ) {
            return array(
                'success' => false,
                'message' => __( 'Product has no SKU.', 'woo-business-central' ),
            );
        }

        $bc_item = $this->find_bc_item_by_sku( $sku );

        if ( is_wp_error( $bc_item ) ) {
            return array(
                'success' => false,
                'message' => $bc_item->get_error_message(),
            );
        }

        if ( ! $bc_item || empty( $bc_item['id'] ) ) {
            return array(
                'success' => false,
                'message' => __( 'Item not found in Business Central.', 'woo-business-central' ),
            );
        }

        $item_id = $bc_item['id'];
        $messages = array();

        // Push name -> displayName
        $name = substr( $product->get_name(), 0, 100 );

        $patch_result = WBC_API_Client::patch( '/items(' . $item_id . ')', array(
            'displayName' => $name,
        ) );

        if ( is_wp_error( $patch_result ) ) {
            WBC_Logger::error( 'ProductSync', 'Failed to push product name to BC', array(
                'product_id' => $product_id,
                'sku'        => $sku,
                'error'      => $patch_result->get_error_message(),
            ) );
            return array(
                'success' => false,
                'message' => sprintf(
                    /* translators: %s: error message */
                    __( 'Failed to update name in Business Central: %s', 'woo-business-central' ),
                    $patch_result->get_error_message()
                ),
            );
        }

        $messages[] = __( 'Name updated in Business Central.', 'woo-business-central' );

        // Push featured image -> picture
        $image_id = $product->get_image_id();

        if ( ! empty( $image_id ) ) {
            $file_path = get_attached_file( $image_id );

            if ( $file_path && file_exists( $file_path ) ) {
                $file_type = wp_check_filetype( $file_path );
                $content_type = ! empty( $file_type['type'] ) ? $file_type['type'] : 'application/octet-stream';
                $binary = file_get_contents( $file_path ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_get_contents_file_get_contents -- local media library file, not a remote URL.

                if ( $binary !== false ) {
                    $picture_result = WBC_API_Client::patch_binary(
                        '/items(' . $item_id . ')/picture/pictureContent',
                        $binary,
                        $content_type
                    );

                    if ( is_wp_error( $picture_result ) ) {
                        WBC_Logger::error( 'ProductSync', 'Failed to push product image to BC', array(
                            'product_id' => $product_id,
                            'sku'        => $sku,
                            'error'      => $picture_result->get_error_message(),
                        ) );
                        $messages[] = sprintf(
                            /* translators: %s: error message */
                            __( 'Image update failed: %s', 'woo-business-central' ),
                            $picture_result->get_error_message()
                        );
                    } else {
                        $messages[] = __( 'Image updated in Business Central.', 'woo-business-central' );
                    }
                }
            }
        }

        WBC_Logger::info( 'ProductSync', 'Pushed product to BC', array(
            'product_id' => $product_id,
            'sku'        => $sku,
            'item_id'    => $item_id,
        ) );

        return array(
            'success' => true,
            'message' => implode( ' ', $messages ),
        );
    }
}