# Task ID: 3
# Title: Develop Fabric API Client
# Status: pending
# Dependencies: 1
# Priority: high
# Description: Create an internal client to communicate with the Fabric REST API (fabric --serve).
# Details:
1. Implement a client that can connect to the Fabric REST API.
2. Create methods for all required API endpoints (/patterns, /chat, /models/names, /strategies, /config).
3. Implement authentication using the Fabric API key.
4. Add error handling for API connection issues, authentication failures, and invalid responses.
5. Create a configuration mechanism for specifying the Fabric API endpoint and credentials.
6. Implement request/response logging for debugging purposes.

# Test Strategy:
Create unit tests with mock responses for each Fabric API endpoint. Test error handling by simulating various failure scenarios.

# Subtasks:
## 1. Implement Core API Client Infrastructure [pending]
### Dependencies: None
### Description: Create the foundational API client class with configuration management, authentication, and base HTTP methods
### Details:
1. Create a `FabricApiClient` class with configurable base URL, API key, and region parameters
2. Implement session management with connection pooling for performance optimization
3. Set up authentication headers using the Fabric API key
4. Create base HTTP methods (GET, POST, PUT, DELETE) with proper error handling
5. Implement retry logic with exponential backoff for transient failures (3 retries with 0.3 backoff factor)
6. Add request/response logging with sensitive data redaction
7. Create a configuration mechanism for API endpoint and credentials (support environment variables and config files)
8. Add proper timeout handling to prevent hanging processes
9. Write unit tests using mocked HTTP responses to verify core functionality
10. Ensure all HTTP connections use HTTPS for security

## 2. Implement Fabric API Endpoint Methods [pending]
### Dependencies: 3.1
### Description: Create specific methods for all required Fabric API endpoints with proper request/response handling
### Details:
1. Implement method for `/patterns` endpoint to retrieve pattern data
2. Implement method for `/chat` endpoint to handle chat interactions
3. Implement method for `/models/names` endpoint to get available model names
4. Implement method for `/strategies` endpoint to work with strategies
5. Implement method for `/config` endpoint to retrieve configuration
6. Add proper type hints and documentation for each method
7. Implement parameter validation before sending requests
8. Add response parsing and error handling specific to each endpoint
9. Create data models/classes for structured response data
10. Write unit tests for each endpoint method using mocked responses
11. Ensure region awareness in endpoint implementations for optimal performance

## 3. Implement Advanced Error Handling and Diagnostics [pending]
### Dependencies: 3.1, 3.2
### Description: Enhance the client with comprehensive error handling, diagnostics, and performance monitoring
### Details:
1. Create custom exception classes for different error scenarios (AuthenticationError, ConnectionError, TimeoutError, etc.)
2. Implement detailed error messages with troubleshooting guidance
3. Add comprehensive logging with different verbosity levels (DEBUG, INFO, WARNING, ERROR)
4. Implement request/response timing metrics for performance monitoring
5. Create a diagnostic mode that provides detailed information about API interactions
6. Add support for correlation IDs to track requests across systems
7. Implement a mechanism to export logs to external monitoring systems
8. Create helper methods for common error resolution scenarios
9. Add health check functionality to verify API connectivity
10. Write integration tests that verify error handling with actual API responses
11. Document all error scenarios and resolution steps

## 4. Set up API Authentication [pending]
### Dependencies: None
### Description: Implement authentication mechanism using Fabric API keys
### Details:
Create a module to handle API key management, implement token acquisition using MSAL.Net library for Microsoft Fabric or appropriate authentication for Fabric API, and store credentials securely. Include functionality to refresh tokens when needed.

## 5. Implement Core API Client [pending]
### Dependencies: 3.4
### Description: Create the base API client with connection handling
### Details:
Develop a core client class that establishes connection to the Fabric REST API endpoint, handles HTTP requests/responses using HttpClient or similar, and implements proper connection pooling and timeout handling.

## 6. Develop Endpoint-Specific Methods [pending]
### Dependencies: 3.5
### Description: Implement methods for all required API endpoints
### Details:
Create dedicated methods for each required endpoint (/patterns, /chat, /models/names, /strategies, /config) with appropriate request parameters and response parsing. Ensure proper data serialization/deserialization.

## 7. Implement Error Handling [pending]
### Dependencies: 3.5, 3.6
### Description: Create comprehensive error handling for API interactions
### Details:
Develop error handling mechanisms for API connection issues, authentication failures, invalid responses, rate limiting, and unexpected server errors. Implement appropriate retry logic and meaningful error messages.

## 8. Create Configuration and Logging System [pending]
### Dependencies: 3.5
### Description: Implement configuration management and request/response logging
### Details:
Develop a configuration system for specifying API endpoints, credentials, and client behavior options. Implement comprehensive logging for all API requests and responses to facilitate debugging, with appropriate log levels and sensitive data masking.

