# CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

## Project Overview

This is a WordPress plugin that extends WooCommerce functionality to manage print orders sent to third-party providers. It adds custom order statuses ("Prepare to Printing" and "In Printing"), bulk actions, CSV export/import capabilities, and tracking fields specific to the printing workflow.

**Plugin Details:**
- Text Domain: `studiou-wc-ord-print-statuses`
- Current Version: 1.4.1
- Requires: WordPress 5.8+, WooCommerce 3.0+, PHP 7.2+
- Tested with: WordPress 6.9.4, WooCommerce 10.7.0 (HPOS enabled)

## Documentation

User-facing and historical documentation lives at the project root and under `docs/`. Consult these alongside this file before making changes:

- [`README.md`](README.md) — Primary, up-to-date plugin documentation (features, install, CSV formats, architecture, changelog).
- [`docs/readme.md`](docs/readme.md) — Previous user-facing readme; retained for history.
- [`docs/instructions.txt`](docs/instructions.txt) — Original feature specification used to scaffold the plugin. Useful when verifying intended behaviour against current implementation.
- [`docs/translations.txt`](docs/translations.txt) — EN → CS translation reference for the bundled `cs_CZ` locale.
- [`docs/revise-1.3.2.md`](docs/revise-1.3.2.md) — Analytical review of v1.3.2. Every finding listed there is resolved in 1.4.0 (see README changelog).
- [`docs/revise-1.4.0.md`](docs/revise-1.4.0.md) — Analytical review of v1.4.0. All in-scope findings are resolved in 1.4.1; the doc carries per-item status annotations.

When adding new documentation files, place them in `docs/` and add a one-line pointer here.

## Recent Changes

### Version 1.4.1 (2026-05-12)

Bug-fix release resolving findings from `docs/revise-1.4.0.md`. Key code changes:

- **SQL strict-mode safety** in `Studiou_DB_Manager::get_orders_for_printing()` — non-aggregated SELECT columns wrapped in `MIN()`; `SET SESSION group_concat_max_len = 65535` before the query.
- **CSV BOM handling** in `parse_csv()` — strips a leading UTF-8 BOM (which our own export writes); `normalise_header()` also defensively strips one.
- **Datetime round-trip** in `Order_Fields_Manager` — switched to pure string reformatting (`YYYY-MM-DD HH:MM:SS` ↔ `YYYY-MM-DDTHH:MM`). No `strtotime()`/`date()` so server-vs-WP-timezone drift is eliminated.
- **Capability check** added to `Order_Fields_Manager::save_custom_order_fields()`.
- **Single order note** in `set_order_processing_status()` — the second `add_order_note()` call was removed.
- **Bulk action UX** — `notify_moved_count()` helper suppresses notices when count is zero.
- **`output_csv()` safety** — fails loudly via `wp_die()` if `headers_sent()`, logging the source file/line.
- **PHP 8.4 compatibility** — `fputcsv`/`fgetcsv` now pass an explicit empty-string escape character.
- **Import dispatch map** — `Import_Manager::protocol_dispatch()` centralises the protocol → handler mapping; `run_import()` uses explicit `return $this->redirect_back()` on every non-happy branch.
- **Dedup case-insensitive** — `dedupe_by_order_no()` lowercases keys.
- **`normalise_csv_date()`** returns `''` and logs on parse failure (was returning the raw unparseable string).
- **Notice TTL** bumped 60 s → 300 s.

Deferred (not addressed in 1.4.1): live HPOS search-filter verification, `Network:` header, `uninstall.php`, block-based order edit screen.

### Version 1.4.0 (2026-05-12)

Comprehensive fix-up release addressing every finding in `docs/revise-1.3.2.md`:

- **Search by External Order Number** is now functional. Reworked `Order_Search_Manager` uses `woocommerce_shop_order_search_fields` (legacy) and `woocommerce_order_table_search_query_meta_keys` (HPOS) — the standard "Search orders" input now matches `external_ref_ord_no`. Removed all broken hooks (`parse_query` with CPT-only guard, columns-filter-as-search-fields-filter, search input rendered inside table cells).
- **HPOS metadata stamping** fixed in `Order_Status_Manager::handle_status_transitions()` — now uses `wc_get_order() + update_meta_data() + save()` instead of `update_post_meta()`.
- **`set_order_processing_status()`** now treats `to-print`, `in-print`, and `completed` as protected; late `woocommerce_payment_complete` no longer demotes print-state orders.
- **Bulk export atomicity:** CSV is built fully in memory before any status change. UTF-8 BOM prepended; `Content-Type: text/csv; charset=utf-8`; `nocache_headers()`.
- **Export SQL** now uses `$wpdb->prepare()` with `%d` placeholders (replaces the `intval()`-only defense). `GROUP_CONCAT(DISTINCT t.name)` + `GROUP BY orders.id, product_id, variation_id` collapses multi-category products to one row per line item.
- **CSV import** deduplicates by `order_no`; headers are normalised (lowercased, internal whitespace → `_`), so both spec casing (`Order No`) and the documented lowercase form (`order_no`) work; orders in terminal statuses are skipped with a per-row error.
- **File-upload validation:** `$_FILES[...]['error']`, `is_uploaded_file()`, and non-empty header row are now checked server-side.
- **Cap checks:** bulk-action handler guards with `current_user_can('edit_shop_orders')` before dispatch.
- **UtilsLog:** `log()` guard relaxed to `defined('WP_DEBUG') && WP_DEBUG`; `message()` implemented as per-user transient → `admin_notices` hook. Bulk actions and imports now produce visible feedback.
- **Order_Fields_Manager:** added `external_ref_ord_date` field to the Print Information panel; datetime values round-trip through `strtotime()` → MySQL datetime.
- **Custom_Columns_Manager:** column-content callback parameter renamed to `$order_or_id` to reflect HPOS contract; passes through `wc_get_order()`.
- **Bootstrap:** `STUDIOU_WC_OPS_VERSION` / `STUDIOU_WC_OPS_FILE` constants defined. Text domain loader pinned to `plugins_loaded` priority 5; plugin init at default priority 10 — guarantees translations are loaded before any manager instantiates.
- **Translations:** `docs/translations.txt` extended with previously-missing strings. The `.mo` file must be rebuilt by hand (e.g. `wp i18n make-mo languages/` or Poedit); 1.4.0 ships only the source updates.
- **Docs:** README architecture, install, usage, and changelog updated. Misleading "SQL prepare via intval" claim in CLAUDE.md removed.

### Version 1.3.2 (2025-10-18)
**Bug Fix: Empty prod_var_type column in CSV export**

Fixed an issue where the `prod_var_type` column was always empty in the "Prepare to Printing Export" CSV file.

**Root Cause:**
The SQL query in `Studiou_DB_Manager::get_orders_for_printing()` was incorrectly using the `wc_product_attributes_lookup` table to retrieve product variation attributes. This table stores product-level attribute data (for parent products), not the specific attribute values for individual variations.

**Solution:**
Modified the query (lines 55-65 in `includes/class-db-manager.php`) to:
1. Join with `wp_postmeta` table instead of `wc_product_attributes_lookup`
2. Look for meta_key = 'attribute_pa_format' which stores the variation's format attribute value
3. Join with `wp_terms` using the slug field (matching against meta_value) instead of term_id

**HPOS Compatibility Declaration**

Added explicit HPOS (High-Performance Order Storage) compatibility declaration to prevent WooCommerce warnings.

**Solution:**
Added `before_woocommerce_init` hook in the main plugin file to declare compatibility with WooCommerce custom order tables using `FeaturesUtil::declare_compatibility()`.

**Files Changed:**
- `includes/class-db-manager.php` - Updated LEFT JOIN logic for product_variations_attr and product_variations_name tables
- `studiou-wc-ord-print-statuses.php` - Added HPOS compatibility declaration

**Impact:**
- The `prod_var_type` column in exported CSV files now correctly displays the Format attribute value (e.g., "A4", "A5") for each product variation
- Plugin no longer shows HPOS incompatibility warnings in WooCommerce

**Tested On:**
- WordPress 6.8.3
- WooCommerce 10.2.2 (with HPOS enabled)

## Architecture

### Manager-Based Pattern

The plugin uses a manager-based architecture where the main plugin class (`Studiou_WC_Ord_Print_Statuses`) initializes specialized manager classes that handle distinct concerns:

1. **Order_Status_Manager** (`includes/class-order-status-manager.php`)
   - Registers custom order statuses: `wc-to-print` and `wc-in-print`
   - Handles status transitions and automatically updates metadata timestamps
   - Hooks into WooCommerce payment completion to set orders to "processing"

2. **Order_Fields_Manager** (`includes/class-order-fields-manager.php`)
   - Adds "Print Information" section to order edit pages
   - Manages fields: `to_print_date`, `in_print_date`, `external_ref_ord_no`, `external_ref_ord_date`, `external_ref_ord_delivered`
   - Datetime fields round-trip via `strtotime()`/MySQL datetime so admin edits stay consistent with values written by imports.

3. **Bulk_Actions_Manager** (`includes/class-bulk-actions-manager.php`)
   - Registers bulk actions: "Prepare to Printing Export", "Set Status to Prepare to Printing", "Set Status to In Printing"
   - Generates CSV exports with complex product data (categories, variations, images)

4. **Custom_Columns_Manager** (`includes/class-custom-columns-manager.php`)
   - Adds custom columns to WooCommerce orders list: "To Print Date", "In Print Date", "External Order Number"

5. **Import_Manager** (`includes/class-import-manager.php`)
   - Provides admin UI under WooCommerce menu for importing CSV protocols
   - Handles InPrint Protocol (sets orders to "in-print" with external references)
   - Handles Delivered Protocol (sets orders to "completed" with delivery timestamp)

6. **Order_Search_Manager** (`includes/class-order-search-manager.php`)
   - Extends WooCommerce order search to include the `external_ref_ord_no` meta key.
   - Hooks `woocommerce_shop_order_search_fields` (legacy CPT) and `woocommerce_order_table_search_query_meta_keys` (HPOS) with the same callback. No separate UI input — the standard "Search orders" box handles it.

7. **Studiou_DB_Manager** (`includes/class-db-manager.php`)
   - Centralized database operations using static methods
   - Contains complex SQL for export query joining orders, products, variations, categories, and images
   - Handles CSV parsing and protocol imports

### Key Database Operations

The export query in `Studiou_DB_Manager::get_orders_for_printing()` performs a complex join across:
- `wp_wc_orders` (order data)
- `wp_wc_order_product_lookup` (order products)
- `wp_posts` (products and variations)
- `wp_postmeta` (product variation attributes - specifically 'attribute_pa_format')
- `wp_terms` and `wp_term_taxonomy` (product categories and variation attribute values)
- `wp_postmeta` (product images via '_thumbnail_id' meta)

This query extracts: order number, product category, product name, variation name, variation type, image URL, quantity, and customer email.

### Order Metadata Keys

- `to_print_date` - Timestamp when order moved to "Prepare to Printing" status
- `in_print_date` - Timestamp when order moved to "In Printing" status
- `external_ref_ord_no` - External order number from print provider
- `external_ref_ord_date` - Date from external print provider
- `external_ref_ord_delivered` - Delivery timestamp

## Development Commands

### Logging & user notices

The plugin includes a logging + notice utility (`includes/utils-log.php`):
- `UtilsLog::log($message)` - Writes to the WordPress error log when `WP_DEBUG` is truthy (guarded as `defined('WP_DEBUG') && WP_DEBUG`). Check `wp-content/debug.log` when `WP_DEBUG_LOG` is on.
- `UtilsLog::message($message, $type)` - Queues a dismissible WordPress admin notice (`info` / `success` / `warning` / `error`) for the current user via a 60-second transient + `admin_notices` hook. Survives the redirect that follows bulk actions and imports.

### WordPress/WooCommerce Hooks

All managers register their hooks in constructors. Common patterns:
- `add_action('init', ...)` - Register post statuses
- `add_filter('wc_order_statuses', ...)` - Modify WooCommerce status lists
- `add_filter('bulk_actions-woocommerce_page_wc-orders', ...)` - Add bulk actions
- `add_action('woocommerce_admin_order_data_after_order_details', ...)` - Display custom fields

### Testing

When testing status changes:
1. Enable `WP_DEBUG` in `wp-config.php` to see log output
2. Check that metadata is properly set when statuses change
3. Test bulk actions with multiple orders to verify CSV generation
4. Test import functionality with properly formatted CSV files

### CSV Formats

**Export Format (Prepare to Printing):**
- Headers: `order_no`, `prod_cat`, `prod_name`, `prod_var`, `prod_var_type`, `prod_img_url`, `qty`, `email`

**InPrint Protocol Import Format:**
- Required headers: `order_no`, `externalorder`, `externalorderdate`

**Delivered Protocol Import Format:**
- Required header: `order_no`

## Localization

The plugin supports internationalization:
- Text domain: `studiou-wc-ord-print-statuses`
- Translation files in `languages/` directory
- Czech localization (cs_CZ) already implemented
- Use WordPress `__()`, `_e()`, `_n_noop()`, `_x()` functions for all user-facing strings

## Important Considerations

1. **HPOS Compatibility**: The plugin is fully compatible with WooCommerce High-Performance Order Storage (HPOS)
   - Uses `woocommerce_page_wc-orders` hooks for HPOS compatibility
   - Uses `{$wpdb->prefix}wc_orders` table (HPOS custom table) in SQL queries
   - Uses `wc_get_order()` which works with both HPOS and legacy systems
   - Declares compatibility via `FeaturesUtil::declare_compatibility('custom_order_tables', ...)`

2. **Status Slug Naming**: Custom statuses use `wc-` prefix internally but display without prefix (`wc-to-print` vs "Prepare to Printing")

3. **CSV Output**: The `prepare_to_printing_export` bulk action terminates with `exit` after outputting CSV headers, preventing further PHP execution

4. **Database Queries**: The export query in `Studiou_DB_Manager::get_orders_for_printing()` uses `$wpdb->prepare()` with `%d` placeholders for the order ID list. When adding new SQL, prefer `$wpdb->prepare()` over inline coercion. Order IDs are also pre-filtered with `array_map('intval', …)` as defense in depth.

5. **Admin Menu**: Import functionality is added as a submenu under WooCommerce admin menu, requires `manage_woocommerce` capability