# Implementation Plan

- [x] 1. Set up core package structure and exceptions
  - Create modular package structure with core, config, formatters, handlers modules
  - Define custom exception hierarchy for error handling
  - Set up package imports and public API structure
  - _Requirements: 1.1, 1.5_

- [x] 1.1 Create package module structure
  - Create core.py, config.py, formatters.py, handlers.py, exceptions.py files
  - Set up proper __init__.py imports for public API
  - _Requirements: 1.1, 1.5_

- [x] 1.2 Define exception hierarchy
  - Implement MypyloggerError base exception and specific error types
  - Create ConfigurationError, FormattingError, HandlerError classes
  - _Requirements: 5.1, 5.2, 5.3, 5.4, 5.5_

- [x] 2. Implement configuration management system
  - Create environment variable parsing with safe defaults
  - Implement configuration validation and error handling
  - Build configuration data model with proper type hints
  - _Requirements: 3.1, 3.2, 3.3, 3.4, 3.5_

- [x] 2.1 Create LogConfig data model
  - Implement LogConfig dataclass with all configuration fields
  - Add environment variable mapping and default values
  - _Requirements: 3.1, 3.2, 3.3, 3.4, 3.5_

- [x] 2.2 Implement ConfigResolver class
  - Create environment variable parsing logic with safe defaults
  - Add configuration validation for log levels and file paths
  - Implement graceful handling of invalid configuration values
  - _Requirements: 3.5, 5.4_

- [x] 3. Build JSON formatter with source location tracking
  - Implement custom JSON formatter that extracts source location from call stack
  - Create consistent JSON field ordering with timestamp first
  - Add support for custom fields via extra and custom parameters
  - _Requirements: 2.1, 2.2, 2.3, 2.4, 2.5, 6.1, 6.2, 6.3, 6.4, 6.5, 8.1, 8.2, 8.3, 8.4, 8.5_

- [x] 3.1 Implement SourceLocationJSONFormatter class
  - Create JSON formatter that inherits from logging.Formatter
  - Implement format() method with JSON output and consistent field ordering
  - _Requirements: 2.1, 2.2, 2.3, 2.4_

- [x] 3.2 Add source location extraction logic
  - Implement call stack inspection to extract module, filename, function_name, line
  - Handle relative path conversion for filename field
  - Ensure source location works correctly with nested calls
  - _Requirements: 2.5, 8.1, 8.2, 8.3, 8.4, 8.5_

- [x] 3.3 Implement custom fields support
  - Add logic to merge extra and custom parameters into JSON output
  - Prevent custom fields from overriding standard fields
  - Handle custom field serialization errors gracefully
  - _Requirements: 6.1, 6.2, 6.3, 6.4, 6.5_

- [x] 3.4 Add JSON formatting error handling
  - Implement fallback to plain text when JSON serialization fails
  - Ensure formatter never raises exceptions that could crash application
  - _Requirements: 5.2, 6.5_

- [x] 4. Create handler management system
  - Implement console and file handler creation with fallback logic
  - Add log file naming with {APP_NAME}_{date}_{hour}.log pattern
  - Build directory creation with graceful error handling
  - _Requirements: 4.1, 4.2, 4.3, 4.4, 4.5, 5.1, 5.3_

- [x] 4.1 Implement HandlerFactory class
  - Create factory class for console and file handler creation
  - Add immediate flush configuration for real-time log visibility
  - _Requirements: 4.1, 4.5_

- [x] 4.2 Add console handler creation
  - Implement stdout handler creation with JSON formatter
  - Ensure console handler always works as fallback
  - _Requirements: 4.1_

- [x] 4.3 Implement file handler with fallback logic
  - Create file handler with graceful fallback to stdout on failure
  - Add log file naming using {APP_NAME}_{date}_{hour}.log pattern
  - Implement directory creation with error handling
  - _Requirements: 4.2, 4.3, 4.4, 5.1, 5.3_

- [x] 4.4 Add log directory management
  - Implement safe directory creation with fallback to temp directory
  - Handle permission errors and filesystem issues gracefully
  - _Requirements: 4.4, 5.1, 5.3_

- [x] 5. Implement core logger management
  - Create logger creation and configuration logic
  - Implement logger name resolution with fallback chain
  - Add handler and formatter attachment to loggers
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 7.1, 7.2, 7.3, 7.4, 7.5_

- [x] 5.1 Create LoggerManager class
  - Implement logger creation and configuration management
  - Add logger caching to reuse existing loggers
  - _Requirements: 1.1, 1.5_

- [x] 5.2 Implement logger name resolution
  - Create fallback chain: provided name → APP_NAME → __name__ → "mypylogger"
  - Add call stack inspection to get calling module's __name__
  - _Requirements: 1.2, 1.3, 1.4_

- [x] 5.3 Add logger configuration logic
  - Attach handlers and formatters to logger instances
  - Implement log level configuration with global and per-logger support
  - _Requirements: 7.1, 7.2, 7.3, 7.4, 7.5_

- [x] 6. Implement public API
  - Create get_logger() function as main entry point
  - Integrate all components into cohesive public interface
  - Add comprehensive error handling and logging of library errors
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 5.5_

- [x] 6.1 Implement get_logger() function
  - Create main public API function with optional name parameter
  - Integrate LoggerManager, ConfigResolver, and all components
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5_

- [x] 6.2 Add comprehensive error handling
  - Ensure get_logger() never raises exceptions that crash applications
  - Implement dedicated internal logger for library errors to stderr
  - _Requirements: 5.5_

- [x] 7. Create comprehensive test suite
  - Implement unit tests for all components with 95%+ coverage
  - Create integration tests for end-to-end workflows
  - Add error handling and edge case testing
  - _Requirements: All requirements validation_

- [x] 7.1 Create unit tests for configuration management
  - Test environment variable parsing and default value handling
  - Test configuration validation and error scenarios
  - Mock environment variables for isolated testing
  - _Requirements: 3.1, 3.2, 3.3, 3.4, 3.5_

- [x] 7.2 Create unit tests for JSON formatter
  - Test JSON output format and field ordering
  - Test source location extraction with mocked call stacks
  - Test custom fields handling and error scenarios
  - _Requirements: 2.1, 2.2, 2.3, 2.4, 2.5, 6.1, 6.2, 6.3, 6.4, 6.5, 8.1, 8.2, 8.3, 8.4, 8.5_

- [x] 7.3 Create unit tests for handler management
  - Test console and file handler creation
  - Test fallback logic with mocked filesystem errors
  - Test log file naming and directory creation
  - _Requirements: 4.1, 4.2, 4.3, 4.4, 4.5, 5.1, 5.3_

- [x] 7.4 Create unit tests for core logger management
  - Test logger name resolution logic
  - Test logger configuration and level handling
  - Test logger caching and reuse
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 7.1, 7.2, 7.3, 7.4, 7.5_

- [x] 7.5 Create unit tests for public API
  - Test get_logger() function with various parameters
  - Test error handling and graceful degradation
  - Test integration of all components
  - _Requirements: 1.1, 1.2, 1.3, 1.4, 1.5, 5.5_

- [x] 7.6 Create integration tests for end-to-end workflows
  - Test complete logging workflow from get_logger() to file output
  - Test environment variable configuration integration
  - Test real file system operations and cleanup
  - _Requirements: All requirements end-to-end validation_

- [x] 7.7 Create performance and stress tests
  - Test logger initialization performance (<10ms target)
  - Test single log entry performance (<1ms target)
  - Test memory usage with multiple loggers
  - _Requirements: Performance validation_

- [x] 8. Final integration and validation
  - Verify all quality gates pass with master test script
  - Test package installation and import functionality
  - Validate complete feature set against requirements
  - _Requirements: All requirements final validation_

- [x] 8.1 Run comprehensive quality validation
  - Execute master test script to verify all quality gates pass
  - Ensure 95%+ test coverage across all modules
  - Verify linting, formatting, and type checking compliance
  - _Requirements: All requirements quality validation_

- [x] 8.2 Test package functionality end-to-end
  - Test package import and get_logger() usage
  - Verify JSON output format and all features work correctly
  - Test error handling and fallback scenarios in real environment
  - _Requirements: All requirements functional validation_