Feature: Implement HTTP Server with Comprehensive Testing

[wadearnold]

Feature Request: HTTP Server Implementation

Summary

Implement a production-ready HTTP server for wire20022 library with comprehensive testing, proper error handling, and full API documentation.

Background

The HTTP server implementation was moved from master to the feature/http-server-implementation branch due to:

• Zero test coverage - No test files exist for server code
• Incomplete implementation - Basic framework without full functionality
• Code quality standards - Does not meet production readiness requirements

Current State

• Branch: feature/http-server-implementation (pushed to upstream)
• Location: internal/server/
• Files: 4 Go files (424 lines removed from master)
• Test Coverage: 0% (no test files)
• Status: Basic HTTP framework using Gorilla Mux

Requirements

Core Functionality

• Message Validation API - Endpoints for validating ISO 20022 messages
• Message Conversion API - Convert between different message versions
• Message Processing API - Process XML/JSON message formats
• Health Check Endpoints - Standard health and readiness checks
• Metrics and Monitoring - Prometheus metrics integration
• Configuration Management - YAML/ENV configuration support

Quality Standards

• Test Coverage: Minimum 80% test coverage for all server code
• Integration Tests: Full API integration test suite
• Error Handling: Comprehensive error responses with proper HTTP codes
• Input Validation: Proper request validation and sanitization
• Logging: Structured logging with appropriate levels
• Documentation: OpenAPI/Swagger specification

Security & Production

• Authentication: API key or token-based authentication
• Rate Limiting: Request rate limiting and throttling
• CORS Support: Configurable CORS policies
• Request Timeouts: Proper timeout handling
• Graceful Shutdown: Clean server shutdown handling

DevOps Integration

• Docker Support: Containerized deployment
• CI/CD Integration: Automated testing and deployment
• Load Testing: Performance benchmarks and load tests
• Monitoring: Application metrics and alerting

Implementation Plan

Phase 1: Foundation (Weeks 1-2)

1. Set up comprehensive test framework
2. Implement basic message validation endpoints
3. Add health check and metrics endpoints
4. Achieve >80% test coverage for basic functionality

Phase 2: Core Features (Weeks 3-4)

1. Message conversion API endpoints
2. XML/JSON processing capabilities
3. Error handling and response standardization
4. Integration test suite

Phase 3: Production Readiness (Weeks 5-6)

1. Security features (auth, rate limiting)
2. Performance optimization and load testing
3. Documentation (OpenAPI spec)
4. Docker containerization

Phase 4: DevOps Integration (Week 7)

1. CI/CD pipeline integration
2. Monitoring and alerting setup
3. Production deployment documentation

Definition of Done

• All server code has ≥80% test coverage
• All integration tests pass
• OpenAPI documentation complete
• Docker deployment working
• Performance benchmarks meet requirements
• Security review completed
• Ready for merge to master

Technical Specifications

API Endpoints (Proposed)

POST /api/v1/messages/validate     - Validate ISO 20022 message
POST /api/v1/messages/convert      - Convert message between versions  
GET  /api/v1/messages/types        - List supported message types
GET  /health                       - Health check
GET  /ready                        - Readiness check
GET  /metrics                      - Prometheus metrics

Message Type Support

All 16 supported message types:

• CustomerCreditTransfer (pacs.008)
• PaymentReturn (pacs.004)
• PaymentStatusRequest (pacs.028)
• FedwireFundsAcknowledgement (admi.004)
• AccountReportingRequest (camt.060)
• ActivityReport (camt.086)
• ConnectionCheck (admi.001)
• DrawdownRequest (pain.013)
• DrawdownResponse (pain.014)
• EndpointDetailsReport (camt.090)
• EndpointGapReport (camt.087)
• EndpointTotalsReport (camt.089)
• FedwireFundsPaymentStatus (pacs.002)
• FedwireFundsSystemResponse (admi.010)
• ReturnRequestResponse (camt.029)
• Master (camt.052)

Dependencies

• HTTP Framework: Gorilla Mux (already in use)
• Testing: Standard Go testing + testify
• Metrics: Prometheus client
• Documentation: go-swagger or similar

Related Work

• Branch: feature/http-server-implementation (upstream)
• Previous State: Server code preserved in feature branch
• Documentation: See internal/server/ in feature branch

Priority

Medium - Important for API use cases but not blocking core library functionality

Impact

This server implementation will provide HTTP API access to the wire20022 library's message processing capabilities, enabling:

• Web application integration
• Microservices architecture support
• REST API for ISO 20022 message processing
• Container-based deployments

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Note: The incomplete server implementation has been moved to a feature branch to maintain code quality standards in master. This issue tracks the complete implementation with proper testing and production readiness.