platform/doc/core_architecture.md

Core Architecture

Overview

This document explains the architectural decisions, patterns, and system design of our core package. It provides insights into how the framework components interact and how to extend the system.

Related Documentation

• See Core Package Specification for implementation details
• See Foundation Integration Guide for integration patterns
• See Container Package Specification for dependency injection
• See Events Package Specification for event system

Architectural Patterns

1. Service Container Architecture

The framework is built around a central service container that manages dependencies and provides inversion of control:

┌─────────────────────────────────────────┐
│              Application                │
│                                         │
│  ┌─────────────────┐  ┌──────────────┐  │
│  │Service Container│  │Event Dispatch│  │
│  └─────────────────┘  └──────────────┘  │
│                                         │
│  ┌─────────────────┐  ┌──────────────┐  │
│  │Service Providers│  │   Pipeline   │  │
│  └─────────────────┘  └──────────────┘  │
│                                         │
└─────────────────────────────────────────┘

Key aspects:

• Central service container manages all dependencies
• Service providers bootstrap framework services
• Event system enables loose coupling
• Pipeline pattern for request/response handling

2. Request Lifecycle

The request flows through several layers:

┌──────────┐    ┌────────────┐    ┌─────────────┐
│  Server  │ -> │HTTP Kernel │ -> │  Pipeline   │
└──────────┘    └────────────┘    └─────────────┘
                                        |
┌──────────┐    ┌────────────┐    ┌─────▼─────┐
│ Response │ <- │ Controller │ <- │  Router   │
└──────────┘    └────────────┘    └───────────┘

Stages:

1. Server receives HTTP request
2. HTTP Kernel applies global middleware
3. Pipeline processes middleware stack
4. Router matches route
5. Controller handles request
6. Response flows back through layers

3. Service Provider Pattern

Service providers bootstrap framework components:

┌─────────────────┐
│   Application   │
└───────┬─────────┘
        |
┌───────▼─────────┐
│Register Providers│
└───────┬─────────┘
        |
┌───────▼─────────┐
│  Boot Providers │
└───────┬─────────┘
        |
┌───────▼─────────┐
│ Ready to Handle │
└─────────────────┘

Process:

1. Register core providers
2. Register package providers
3. Register application providers
4. Boot all providers
5. Application ready

4. Event-Driven Architecture

Events enable loose coupling between components:

┌────────────┐    ┌─────────────┐    ┌──────────┐
│ Dispatcher │ -> │   Events    │ -> │Listeners │
└────────────┘    └─────────────┘    └──────────┘
                                          |
┌────────────┐    ┌─────────────┐    ┌──────────┐
│  Queued    │ <- │   Handler   │ <- │ Process  │
└────────────┘    └─────────────┘    └──────────┘

Features:

• Event dispatching
• Synchronous/async listeners
• Event queueing
• Event subscribers
• Event broadcasting

Extension Points

1. Service Providers

Create custom service providers to:

• Register services
• Bootstrap components
• Configure framework
• Add middleware
• Register routes

class CustomServiceProvider extends ServiceProvider {
  @override
  void register() {
    // Register services
  }
  
  @override
  void boot() {
    // Bootstrap components
  }
}

2. Middleware

Add middleware to:

• Process requests
• Modify responses
• Handle authentication
• Rate limiting
• Custom processing

class CustomMiddleware implements Middleware {
  Future<Response> handle(Request request, Next next) async {
    // Process request
    var response = await next(request);
    // Modify response
    return response;
  }
}

3. Event Listeners

Create event listeners to:

• React to system events
• Handle async tasks
• Integrate external systems
• Add logging/monitoring
• Custom processing

class CustomListener {
  void handle(CustomEvent event) {
    // Handle event
  }
}

4. Console Commands

Add console commands to:

• Run maintenance tasks
• Process queues
• Generate files
• Custom CLI tools
• System management

class CustomCommand extends Command {
  String get name => 'custom:command';
  
  Future<void> handle() async {
    // Command logic
  }
}

Package Integration

1. Core Package Dependencies

┌─────────────┐
│    Core     │
└─────┬───────┘
      |
┌─────▼───────┐     ┌────────────┐
│  Container  │ --> │  Events    │
└─────────────┘     └────────────┘
      |
┌─────▼───────┐     ┌────────────┐
│  Pipeline   │ --> │   Route    │
└─────────────┘     └────────────┘

2. Optional Package Integration

┌─────────────┐
│    Core     │
└─────┬───────┘
      |
┌─────▼───────┐     ┌────────────┐
│   Queue     │ --> │    Bus     │
└─────────────┘     └────────────┘
      |
┌─────▼───────┐     ┌────────────┐
│    Cache    │ --> │    Mail    │
└─────────────┘     └────────────┘

Performance Considerations

1. Service Container

• Optimize bindings
• Use singletons where appropriate
• Lazy load services
• Cache resolved instances

2. Request Handling

• Efficient middleware pipeline
• Route caching
• Response caching
• Resource pooling

3. Event System

• Async event processing
• Event batching
• Queue throttling
• Listener optimization

4. Memory Management

• Clean up resources
• Limit instance caching
• Monitor memory usage
• Handle memory pressure

Security Considerations

1. Request Validation

• Input sanitization
• CSRF protection
• XSS prevention
• SQL injection prevention

2. Authentication

• Secure session handling
• Token management
• Password hashing
• Rate limiting

3. Authorization

• Role-based access
• Permission checking
• Policy enforcement
• Resource protection

4. Data Protection

• Encryption at rest
• Secure communication
• Data sanitization
• Audit logging

Development Guidelines

1. Core Development

• Follow framework patterns
• Maintain backward compatibility
• Document changes
• Write tests
• Consider performance

2. Package Development

• Use service providers
• Integrate with events
• Follow naming conventions
• Add package tests
• Document features

3. Application Development

• Use dependency injection
• Handle events properly
• Follow middleware patterns
• Write clean code
• Test thoroughly

Next Steps

1. Review architecture with team
2. Document design decisions
3. Create development guides
4. Set up monitoring
5. Plan optimizations
6. Schedule security review