# CLAUDE.md

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

## Project Overview

This is a comprehensive WordPress plugin for Twilio voice and SMS integration, featuring:
- **Call Center Functionality**: Agent groups, call queues, call distribution
- **Business Hours Management**: Schedules for workflow routing
- **Outbound Calling**: Click-to-call with proper caller ID
- **SMS Notifications**: Agent notifications and callback management
- **Workflow Builder**: Visual call flow creation
- **Voicemail System**: Recording and transcription
- **Real-time Dashboard**: Agent queue management

## Plugin Architecture

### Core Classes (`includes/` directory)
- **TWP_Core**: Main plugin initialization and hook registration
- **TWP_Activator**: Database table creation and plugin activation
- **TWP_Twilio_API**: Official Twilio PHP SDK wrapper (requires SDK v8.7.0)
- **TWP_Webhooks**: Handles all Twilio webhook endpoints
- **TWP_Scheduler**: Business hours and schedule management
- **TWP_Workflow**: Call flow processing and TwiML generation
- **TWP_Call_Queue**: Queue management and position tracking
- **TWP_Agent_Groups**: Group management for call distribution
- **TWP_Agent_Manager**: Agent status and call acceptance
- **TWP_Callback_Manager**: Callback requests and processing
- **TWP_Call_Logger**: Call logging and statistics

### Database Tables
Created by `TWP_Activator::create_tables()`:
- `twp_phone_schedules` - Business hours definitions
- `twp_call_queues` - Queue configurations
- `twp_queued_calls` - Active calls in queues
- `twp_workflows` - Call flow definitions
- `twp_call_log` - Complete call history
- `twp_sms_log` - SMS message tracking
- `twp_voicemails` - Voicemail recordings and transcriptions
- `twp_agent_groups` - Agent group definitions
- `twp_group_members` - User-to-group relationships
- `twp_agent_status` - Real-time agent availability
- `twp_callbacks` - Callback request queue

### Admin Interface (`admin/` directory)
- **TWP_Admin**: Complete admin interface with pages for:
  - Dashboard with real-time statistics
  - Business Hours Schedules management
  - Workflow Builder with drag-drop interface
  - Call Queues configuration
  - Phone Numbers management (purchase/configure)
  - Voicemail inbox with playback
  - Call Logs with filtering
  - Agent Groups management
  - Agent Queue dashboard
  - **Outbound Calls interface** (click-to-call)

### Webhook Endpoints
All registered in `TWP_Webhooks::register_endpoints()`:
- `/voice` - Main voice webhook for incoming calls
- `/sms` - SMS webhook (handles agent "1" responses)
- `/ivr-response` - IVR menu selections
- `/queue-wait` - Queue hold music and position announcements
- `/ring-group-result` - Handle no-answer scenarios and requeuing
- `/agent-connect` - Connect SMS-responding agents to calls
- `/callback-*` - Callback system webhooks
- `/outbound-agent-with-from` - Outbound calling with from number

## Key Features Implementation

### Agent Group System
- **Simultaneous Ring**: All group members called at once
- **Priority Ordering**: Members have priority levels
- **SMS Notifications**: Automatic alerts when no agents available
- **One-Click Accept**: Agents can text "1" to receive calls
- **Real-time Status**: Available/busy/offline tracking

### Call Queue Management
- **Position Tracking**: Callers know their queue position
- **Timeout Handling**: Offers callback instead of hanging up
- **Auto-requeue**: Failed agent connections return to queue
- **Real-time Dashboard**: Agents see waiting calls

### Callback System
- **Smart Callbacks**: Replace timeout hangups
- **SMS Confirmations**: Notify customers of callback requests
- **Automatic Processing**: Cron-based callback execution
- **Statistics Tracking**: Success rates and timing

### Outbound Calling
- **From Number Selection**: Choose business line for caller ID
- **Conference Routing**: Agent-to-customer connection
- **Call Logging**: Track all outbound attempts
- **Proper Caller ID**: Target sees business number

## WordPress Plugin Conventions

### File Structure
```
twilio-wp-plugin/
├── twilio-wp-plugin.php (main plugin file)
├── includes/ (core functionality)
├── admin/ (admin interface)
├── assets/ (CSS/JS/images)
├── CLAUDE.md (this file)
```

### Class Naming
- Prefix: `TWP_` for all classes
- Database tables: `twp_` prefix
- Options: `twp_` prefix
- AJAX actions: `twp_` prefix

### Database Operations
- Use WordPress `$wpdb` global for all database operations
- Always sanitize inputs with `sanitize_text_field()`, `intval()`, etc.
- Use prepared statements with `$wpdb->prepare()`
- Call `TWP_Activator::ensure_tables_exist()` before database operations

### AJAX Handling
All AJAX endpoints registered in `TWP_Core::define_admin_hooks()`:
```php
$this->loader->add_action('wp_ajax_twp_action_name', $plugin_admin, 'ajax_action_name');
```

### User Profile Integration
Agent phone numbers stored as user meta:
- Meta key: `twp_phone_number`
- Validation: `TWP_Agent_Manager::validate_phone_number()`
- Duplicate checking: `TWP_Agent_Manager::is_phone_number_duplicate()`

## Twilio Integration

### Current Implementation (SDK-Only)
- **Official Twilio SDK**: Uses `twilio/sdk` v8.7.0 for all operations
- **TwiML Generation**: Uses `\Twilio\TwiML\VoiceResponse` classes
- **Response Handling**: Native Twilio SDK response objects
- **Error Handling**: Proper `\Twilio\Exceptions\TwilioException` handling

### Installation Requirements
**IMPORTANT**: The Twilio PHP SDK v8.7.0 is **REQUIRED** for this plugin to function.

**Installation Methods**:
1. **Script Installation** (Recommended):
   ```bash
   chmod +x install-twilio-sdk.sh
   ./install-twilio-sdk.sh
   ```

2. **Composer Installation**:
   ```bash
   composer install
   ```

**PHP Requirements**: PHP 8.0+ required for SDK compatibility

### API Response Structure
Current Twilio API responses follow this pattern:
```php
// Success response
[
    'success' => true,
    'data' => [...] // Twilio response data
]

// Error response  
[
    'success' => false,
    'error' => 'Error message',
    'code' => 400
]

// Call SID location
$call_sid = $response['data']['sid']; // NOT $response['call_sid']
```

### TwiML Best Practices
Always include XML declaration:
```php
$twiml = '<?xml version="1.0" encoding="UTF-8"?>';
$twiml .= '<Response>';
$twiml .= '<Say voice="alice">Message</Say>';
$twiml .= '</Response>';
```

## Development Commands

```bash
# Install WordPress development dependencies
composer install

# Install JavaScript dependencies  
npm install

# Run PHP CodeSniffer for WordPress coding standards
vendor/bin/phpcs

# Fix PHP coding standards automatically
vendor/bin/phpcbf

# Run PHPUnit tests
vendor/bin/phpunit

# Install Twilio SDK (recommended migration)
composer require twilio/sdk
```

## Testing Approach

### Unit Testing
- Use PHPUnit for PHP code testing
- Mock WordPress functions using Brain Monkey or WP_Mock
- Mock Twilio API responses for reliable testing

### Integration Testing
- Test webhook endpoints with Twilio webhook simulator
- Test complete call flows end-to-end
- Verify database operations and data integrity

### Manual Testing
- Use Twilio Console to monitor webhook calls
- Check WordPress error logs for debugging
- Test with real phone numbers for user experience

## Common Issues & Solutions

### Database Issues
- **Missing Tables**: Call `TWP_Activator::ensure_tables_exist()`
- **White Admin Modals**: Check for PHP errors in workflow loading

### Webhook Issues
- **500 Errors**: Check PHP error logs for fatal errors
- **Missing Parameters**: Parameters must be in webhook URL, not just POST data
- **TwiML Parse Errors**: Always include XML declaration

### API Issues
- **Call SID Access**: Use `$response['data']['sid']` not `$response['call_sid']`
- **Phone Number Format**: Store with + prefix (e.g., "+1234567890")
- **From Number**: Must be a verified Twilio number

### Agent Management
- **SMS Responses**: Agents text "1" to receive calls
- **Phone Validation**: Auto-formats US numbers to +1 format
- **Duplicate Prevention**: Checks phone numbers across all users

This plugin provides a complete call center solution with professional-grade features suitable for business use.