# Task ID: 19
# Title: Implement Error Handling and Recovery
# Status: done
# Dependencies: 1, 3, 5, 9, 16, 17
# Priority: high
# Description: Create robust error handling throughout the system with helpful error messages and recovery options.
# Details:
Implement error handling including:
- Consistent error message format
- Helpful error messages with recovery suggestions
- API error handling with retries
- File system error recovery
- Data validation errors with specific feedback
- Command syntax error guidance
- System state recovery after failures

# Test Strategy:
Deliberately trigger various error conditions and verify that the system handles them gracefully. Check that error messages are helpful and provide clear guidance on how to resolve issues.

# Subtasks:
## 1. Define Error Message Format and Structure [done]
### Dependencies: None
### Description: Create a standardized error message format that includes error codes, descriptive messages, and recovery suggestions. Implement a centralized ErrorMessage class or module that enforces this structure across the application. This should include methods for generating consistent error messages and translating error codes to user-friendly descriptions.
### Details:


## 2. Implement API Error Handling with Retry Logic [done]
### Dependencies: None
### Description: Develop a robust error handling system for API calls, including automatic retries with exponential backoff. Create a wrapper for API requests that catches common errors (e.g., network timeouts, rate limiting) and implements appropriate retry logic. This should be integrated with both the Claude and Perplexity API calls.
### Details:


## 3. Develop File System Error Recovery Mechanisms [done]
### Dependencies: 19.1
### Description: Implement error handling and recovery mechanisms for file system operations, focusing on tasks.json and individual task files. This should include handling of file not found errors, permission issues, and data corruption scenarios. Implement automatic backups and recovery procedures to ensure data integrity.
### Details:


## 4. Enhance Data Validation with Detailed Error Feedback [done]
### Dependencies: 19.1, 19.3
### Description: Improve the existing data validation system to provide more specific and actionable error messages. Implement detailed validation checks for all user inputs and task data, with clear error messages that pinpoint the exact issue and how to resolve it. This should cover task creation, updates, and any data imported from external sources.
### Details:


## 5. Implement Command Syntax Error Handling and Guidance [done]
### Dependencies: 19.2
### Description: Enhance the CLI to provide more helpful error messages and guidance when users input invalid commands or options. Implement a "did you mean?" feature for close matches to valid commands, and provide context-sensitive help for command syntax errors. This should integrate with the existing Commander.js setup.
### Details:


## 6. Develop System State Recovery After Critical Failures [done]
### Dependencies: 19.1, 19.3
### Description: Implement a system state recovery mechanism to handle critical failures that could leave the task management system in an inconsistent state. This should include creating periodic snapshots of the system state, implementing a recovery procedure to restore from these snapshots, and providing tools for manual intervention if automatic recovery fails.
### Details:


