# Product Requirements Document: Event Management System

## Overview
Create a custom Drupal module for managing community events with registration, email notifications, and calendar display. Target audience: community organizations running Drupal 10/11 sites.

## Core Features

### 1. Event Content Type
- **Event Details**: Title, description, location (physical/virtual)
- **Date & Time**: Start/end dates with timezone support
- **Capacity Management**: Maximum attendees, waitlist support
- **Registration**: Open/closed status, early bird pricing
- **Categories**: Event types (workshop, webinar, social, conference)

### 2. Registration System
- **User Registration**: Authenticated users can register
- **Anonymous Registration**: Optional anonymous user support
- **Cancellation**: Users can cancel their registration
- **Confirmation Emails**: Automated email notifications
- **Attendance Tracking**: Check-in functionality for organizers

### 3. Display & Navigation
- **Calendar View**: Monthly calendar using Views
- **Event Listings**: Filterable list of upcoming events
- **Search**: Text search with date range filters
- **My Events**: Dashboard showing user's registered events

### 4. Admin Features
- **Event Management**: Create, edit, delete events
- **Attendee List**: Export registered users to CSV
- **Email Notifications**: Custom email templates
- **Reporting**: Basic event statistics and attendance

## Technical Requirements

### Drupal Architecture
- **Drupal 10/11** compatibility
- **Custom Module**: `event_management`
- **Dependencies**: Views, Token, Email systems
- **PHP 8.3+** with strict typing

### Data Model
```php
// Event content type fields
event_management_event:
  - field_event_date (daterange)
  - field_location (text)
  - field_virtual_link (link)
  - field_capacity (integer)
  - field_registration_status (list_string)
  - field_event_category (entity_reference: taxonomy)

// Registration entity
event_registration:
  - event_id (entity_reference: node)
  - user_id (entity_reference: user)
  - registration_date (datetime)
  - status (confirmed|cancelled|waitlist)
  - check_in_time (datetime, nullable)
```

### Development Standards
- **Drupal Coding Standards** (PHPCS with Drupal/DrupalPractice)
- **Static Analysis** (PHPStan level 6)
- **Security**: Input sanitization, access control, CSRF protection
- **Performance**: Caching strategies, efficient queries
- **Accessibility**: WCAG 2.1 AA compliance
- **Testing**: Behat for functional testing, PHPUnit for unit tests

## User Stories

1. **As a site visitor**, I want to browse upcoming events so I can find interesting activities
2. **As an authenticated user**, I want to register for events so I can attend
3. **As a registered user**, I want to receive confirmation emails so I have event details
4. **As a user**, I want to cancel my registration so I can free up my spot if plans change
5. **As an event organizer**, I want to see attendee lists so I can plan accordingly
6. **As an administrator**, I want to export attendee data so I can manage communications

## Success Criteria

- ✅ Event content type with all required fields
- ✅ Registration system with email notifications
- ✅ Calendar view displaying events
- ✅ User dashboard showing registered events
- ✅ Admin interface for managing events and attendees
- ✅ Passes PHPCS/PHPStan validation
- ✅ Security review passes (XSS, access control, SQL injection prevention)
- ✅ WCAG 2.1 AA accessibility compliance
- ✅ Behat tests for key user journeys
- ✅ Configuration exportable via `drush cex`

## Implementation Plan

### Phase 1: Core Module Setup
- Create custom module structure
- Define event content type in `config/install/`
- Create registration entity type
- Implement basic permission system

### Phase 2: Registration System
- Build registration form with validation
- Implement capacity checking logic
- Create email notification system using Token
- Add cancellation functionality

### Phase 3: Display & Views
- Create calendar view using Views module
- Build event listing page with filters
- Create "My Events" dashboard
- Implement search functionality

### Phase 4: Admin Features
- Build attendee management interface
- Create CSV export functionality
- Add email template configuration
- Implement basic reporting

### Phase 5: Quality Assurance
- Write Behat tests for registration flow
- PHPUnit tests for business logic
- Security review and validation
- Accessibility audit
- Performance optimization (caching, query optimization)

## Integration Requirements

### Contrib Modules (Evaluate First)
- **Simple Registration**: Check if existing module meets needs
- **Calendar**: Consider contrib calendar modules vs custom Views
- **Email**: Use core Mail API with Token module
- **Search**: Leverage core Search API or custom Views filters

### Drupal Core Integration
- Content type using Field API
- Views for all listings and displays
- Permissions and access control
- Configuration management (`drush cex/cim`)
- Update hooks for schema changes

## Non-Functional Requirements

### Security
- All user inputs sanitized using Drupal APIs
- Access control enforced at all levels
- CSRF protection for all forms
- SQL injection prevention via Entity API

### Performance
- Render caching for event lists and calendar
- Cache tags for event node changes
- Efficient entity queries (no N+1 problems)
- Lazy loading for large attendee lists

### Maintainability
- Follow Drupal coding standards strictly
- Comprehensive inline documentation
- Configuration in `config/install/` not `hook_install()`
- Update hooks for all schema changes
- README with installation and usage instructions

This event management system demonstrates modern Drupal development with custom entities, Views integration, and quality standards enforcement.