# CLAUDE.md — Maple Local Fonts WordPress Plugin

## Quick Reference

| Document | When to Reference |
|----------|-------------------|
| **CLAUDE.md** (this file) | Architecture, file structure, build order |
| **SECURITY.md** | Writing ANY PHP code |
| **GOOGLE_FONTS_API.md** | Building the font downloader class |
| **WORDPRESS_COMPATIBILITY.md** | Building the font registry, FSE integration |

---

## Project Overview

Build a WordPress plugin called **Maple Local Fonts** that:
1. Imports Google Fonts to local storage (one-time download)
2. Registers them with WordPress's native Font Library API
3. Fonts appear in FSE typography dropdowns alongside theme fonts

**Key principle:** Work WITH WordPress, not around it. We're a font importer — WordPress handles everything else.

---

## Requirements

- **Minimum PHP:** 7.4
- **Minimum WordPress:** 6.5 (required for Font Library API)
- **License:** GPL-2.0-or-later

---

## User Flow

```
Admin enters "Open Sans" → selects weights (400, 700) → selects styles (normal, italic)
                ↓
Plugin hits Google Fonts CSS2 API (ONE TIME)
                ↓
Downloads WOFF2 files to wp-content/fonts/
                ↓
Registers font via WP Font Library API
                ↓
Font appears in Appearance → Editor → Styles → Typography dropdown
                ↓
User applies font using standard WordPress FSE controls
                ↓
GOOGLE NEVER CONTACTED AGAIN — fonts served locally
```

---

## File Structure

```
maple-local-fonts/
├── maple-local-fonts.php          # Main plugin file
├── index.php                       # Silence is golden
├── uninstall.php                   # Clean removal
├── readme.txt                      # WordPress.org readme
├── includes/
│   ├── index.php                   # Silence is golden
│   ├── class-mlf-font-downloader.php
│   ├── class-mlf-font-registry.php
│   ├── class-mlf-admin-page.php
│   └── class-mlf-ajax-handler.php
├── assets/
│   ├── index.php                   # Silence is golden
│   ├── admin.css
│   └── admin.js
└── languages/
    ├── index.php                   # Silence is golden
    └── maple-local-fonts.pot
```

---

## Class Responsibilities

### MLF_Font_Downloader
- Build Google Fonts CSS2 URL
- Fetch CSS (with correct user-agent for WOFF2)
- Parse CSS to extract font face data
- Download WOFF2 files to wp-content/fonts/
- **Reference:** GOOGLE_FONTS_API.md

### MLF_Font_Registry
- Register fonts with WP Font Library (wp_font_family, wp_font_face post types)
- Delete fonts (remove posts and files)
- List imported fonts
- **Reference:** WORDPRESS_COMPATIBILITY.md

### MLF_Admin_Page
- Render settings page under Appearance menu
- Font name input, weight checkboxes, style checkboxes
- Display installed fonts with delete buttons
- **Reference:** SECURITY.md for output escaping

### MLF_Ajax_Handler
- Handle download requests
- Handle delete requests
- **Reference:** SECURITY.md for nonce/capability checks

---

## Admin Page UI

```
┌─────────────────────────────────────────────────────────┐
│ Maple Local Fonts                                       │
├─────────────────────────────────────────────────────────┤
│ IMPORT FROM GOOGLE FONTS                                │
│ ┌─────────────────────────────────────────────────────┐ │
│ │ Font Name: [Open Sans_________________________]    │ │
│ │                                                     │ │
│ │ Weights:                                            │ │
│ │ ☑ 400 (Regular)   ☐ 300 (Light)   ☐ 500 (Medium)  │ │
│ │ ☑ 700 (Bold)      ☐ 600 (Semi)    ☐ 800 (Extra)   │ │
│ │                                                     │ │
│ │ Styles:                                             │ │
│ │ ☑ Normal   ☑ Italic                                │ │
│ │                                                     │ │
│ │ Files to download: 4                                │ │
│ │                              [Download & Install]   │ │
│ └─────────────────────────────────────────────────────┘ │
│                                                         │
│ INSTALLED FONTS                                         │
│ ┌─────────────────────────────────────────────────────┐ │
│ │ Open Sans                                           │ │
│ │ 400 normal, 400 italic, 700 normal, 700 italic     │ │
│ │                                          [Delete]   │ │
│ ├─────────────────────────────────────────────────────┤ │
│ │ Roboto                                              │ │
│ │ 400 normal, 500 normal, 700 normal                 │ │
│ │                                          [Delete]   │ │
│ └─────────────────────────────────────────────────────┘ │
│                                                         │
│ ℹ️ Use Appearance → Editor → Styles → Typography to    │
│   apply fonts to your site.                            │
└─────────────────────────────────────────────────────────┘
```

---

## Build Order

### Phase 1: Foundation
1. `maple-local-fonts.php` — Plugin header, constants, autoloader, activation hook
2. `index.php` files in all directories (silence is golden)
3. `includes/class-mlf-ajax-handler.php` — With full security checks (nonce, capability, validation)

### Phase 2: Core Functionality
4. `includes/class-mlf-font-downloader.php` — Google Fonts fetching/parsing/downloading
5. `includes/class-mlf-font-registry.php` — WP Font Library integration

### Phase 3: Admin Interface
6. `includes/class-mlf-admin-page.php` — Settings page render
7. `assets/admin.css` — Admin page styles
8. `assets/admin.js` — AJAX handling for download/delete

### Phase 4: Cleanup & Polish
9. `uninstall.php` — Clean removal of fonts and data
10. `readme.txt` — WordPress.org readme with privacy section
11. Testing against all compatibility targets

---

## Critical Reminders

### Security (see SECURITY.md)
- ABSPATH check on EVERY PHP file
- index.php in EVERY directory
- Nonce verification FIRST in every AJAX handler
- Capability check SECOND
- Input validation THIRD
- Escape ALL output

### Performance
- Zero JavaScript on frontend
- Zero CSS on frontend
- All plugin code is admin-side only (except lightweight font registration)
- Timeout handling on all external requests
- Maximum limits to prevent infinite loops

### GDPR
- No user data collected
- External requests only during admin import
- Fonts served locally after import
- Document in readme.txt

### Compatibility (see WORDPRESS_COMPATIBILITY.md)
- Declare WooCommerce HPOS compatibility
- Use wp_get_font_dir() not hardcoded paths
- Use Font Library API (post types) not theme.json filtering
- Don't touch frontend, let Global Styles handle everything

---

## Constants

```php
define('MLF_VERSION', '1.0.0');
define('MLF_PLUGIN_DIR', plugin_dir_path(__FILE__));
define('MLF_PLUGIN_URL', plugin_dir_url(__FILE__));
define('MLF_PLUGIN_BASENAME', plugin_basename(__FILE__));

// Limits
define('MLF_MAX_FONTS_PER_REQUEST', 10);
define('MLF_MAX_WEIGHTS_PER_FONT', 9);
define('MLF_REQUEST_TIMEOUT', 30);
```

---

## WordPress Hooks Used

```php
// Activation
register_activation_hook(__FILE__, 'mlf_activate');

// Admin menu
add_action('admin_menu', 'mlf_register_menu');

// Admin assets (our page only)
add_action('admin_enqueue_scripts', 'mlf_enqueue_admin_assets');

// AJAX (admin only, no nopriv)
add_action('wp_ajax_mlf_download_font', 'mlf_ajax_download');
add_action('wp_ajax_mlf_delete_font', 'mlf_ajax_delete');

// WooCommerce HPOS
add_action('before_woocommerce_init', 'mlf_declare_hpos_compatibility');
```

---

## Testing Checklist

### Functional
- [ ] Import Open Sans 400, 700 normal + italic → 4 files created
- [ ] Font appears in FSE typography dropdown
- [ ] Apply font in Global Styles → frontend shows local font
- [ ] Delete font → files and posts removed
- [ ] Re-import same font → appropriate error message

### Security
- [ ] AJAX without nonce → 403
- [ ] AJAX as subscriber → 403
- [ ] Path traversal in font name → rejected
- [ ] XSS in font name → sanitized
- [ ] Direct PHP file access → blank/exit

### Performance
- [ ] No frontend network requests from plugin
- [ ] Import 5 fonts → completes without timeout
- [ ] Admin page load < 500ms added time

### Compatibility
- [ ] WordPress 6.5, 6.6+
- [ ] Twenty Twenty-Five theme
- [ ] WooCommerce (HPOS enabled)
- [ ] Wordfence (enabled)
- [ ] LearnDash
- [ ] WPForms
