# Changelog

All notable changes to this project will be documented in this file.

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

## [1.0.0] - 2025-01-XX

### 🎉 Major Release - Production Ready

This is a major release that transforms FFIEC Data Connect into an enterprise-grade library with comprehensive security, performance, and reliability improvements. This version represents a complete overhaul with backward compatibility maintained.

### 🚀 New Features

#### Async Support
- **AsyncCompatibleClient**: Full async/await support with rate limiting and concurrency control
- **Parallel Processing**: Collect data from multiple banks simultaneously 
- **Thread Pool Executor**: Efficient resource management for concurrent operations
- **Rate Limiting**: Configurable request rate limiting to respect API limits
- **Context Managers**: Automatic resource cleanup with `async with` support

#### Data Processing Enhancements
- **Direct Polars Conversion**: XBRL → Polars pipeline preserves maximum numerical precision
- **NumPy Dtype Consistency**: Type preservation throughout data pipeline
- **Multiple Output Formats**: Support for list, pandas DataFrame, and Polars DataFrame
- **Type-Specific Columns**: Separate int_data, float_data, bool_data, str_data columns

#### Advanced Error Handling  
- **Custom Exception Types**: `ValidationError`, `CredentialError`, `NoDataError`, `ConnectionError`
- **Legacy Compatibility Mode**: Backward compatible ValueError exceptions when enabled
- **Descriptive Error Messages**: Rich error context with field-specific information
- **Deprecation Warnings**: Clear migration path guidance

### 🔒 Security Improvements

- **Input Validation**: Comprehensive validation for all method parameters
- **Credential Security**: Secure password masking in string representations
- **XXE Prevention**: XML parser hardening against XML External Entity attacks
- **Immutable Credentials**: Credentials cannot be modified after initialization
- **Session Security**: Secure SOAP client caching and session management

### 🧠 Memory Management

- **Memory Leak Prevention**: Proper cleanup with `__del__` and `close()` methods
- **SOAP Client Caching**: Prevent expensive client recreation
- **Session Management**: Automatic session cleanup and resource management
- **XML Processing Optimization**: Reduced memory copies during XML processing
- **Context Manager Support**: Automatic resource cleanup with `with` statements

### 🔧 Thread Safety

- **Race Condition Resolution**: Thread-safe operations throughout
- **Connection Caching**: Thread-local connection management
- **Concurrent Access**: Safe parallel access to FFIEC webservice
- **Lock Management**: Proper synchronization primitives

### 📊 API Enhancements

#### New Collection Methods
- `collect_filers_on_reporting_period()`: Get all banks that filed for a specific period
- `collect_filers_since_date()`: Get banks that filed since a specific date  
- `collect_filers_submission_date_time()`: Get detailed submission timestamps

#### Enhanced Existing Methods
- All methods now support async variants via AsyncCompatibleClient
- Improved error handling and validation
- Better type hints and documentation
- Polars output support

### 📚 Documentation

- **Comprehensive Jupyter Notebook**: Interactive demonstration of all features
- **Technical Analysis Documents**: Detailed security, memory, and performance analysis
- **Data Type Handling Guide**: Complete documentation of type precision pipeline
- **API Documentation**: Improved docstrings and Sphinx integration
- **Migration Guides**: Clear upgrade path documentation

### 🧪 Testing

- **253 Comprehensive Tests**: Unit, integration, and performance tests
- **Memory Leak Testing**: Automated detection of memory issues
- **Thread Safety Testing**: Concurrent access validation
- **Async Integration Testing**: Full async workflow validation
- **Real SOAP Integration**: Testing with actual FFIEC webservice schemas
- **Coverage Reporting**: Detailed test coverage analysis

### 🛠️ Development Infrastructure

- **GitHub Actions**: Automated CI/CD pipeline
- **Code Coverage**: Comprehensive coverage reporting
- **Type Checking**: MyPy integration for type safety
- **Code Formatting**: Black and isort integration
- **Performance Benchmarks**: Async vs sync performance comparisons

### 🔄 Breaking Changes

While this version maintains backward compatibility, some advanced usage patterns may need updates:

#### Configuration Changes
- Environment variable `FFIEC_USE_LEGACY_ERRORS` now defaults to `true` for compatibility
- New configuration options for async clients and rate limiting

#### New Dependencies
- Added optional `polars` dependency for direct data conversion
- Enhanced `zeep` integration for SOAP client improvements

#### Enhanced Error Types
- New exception types provide richer error information
- Legacy `ValueError` exceptions still available via compatibility mode

### 📈 Performance Improvements

- **Async Operations**: Up to 5x faster for bulk data collection
- **Memory Efficiency**: Reduced memory usage through optimized XML processing
- **Connection Reuse**: SOAP client caching eliminates connection overhead
- **Parallel Processing**: Concurrent data collection for multiple banks

### 🔧 Configuration

#### New Environment Variables
```bash
# Error handling mode (default: true for compatibility)
FFIEC_USE_LEGACY_ERRORS=false

# Async client settings
FFIEC_MAX_CONCURRENT=5
FFIEC_RATE_LIMIT=10.0
```

#### New Configuration Options
- AsyncCompatibleClient configuration
- Rate limiting settings
- Connection pooling options
- Memory management settings

### 📦 Distribution

- **PyPI Ready**: Modern `pyproject.toml` configuration
- **Type Hints**: Full typing support with `py.typed` marker
- **ReadTheDocs Integration**: Comprehensive online documentation
- **Multiple Install Options**: Core, polars, dev, docs, notebook extras

### 🏗️ Internal Improvements

- **Code Organization**: Modular architecture with clear separation of concerns
- **Caching System**: Intelligent SOAP client caching
- **Error Propagation**: Consistent error handling throughout the stack
- **Resource Management**: Proper lifecycle management for all resources

### 🔍 Debugging and Monitoring

- **Enhanced Logging**: Detailed logging throughout the library
- **Performance Metrics**: Built-in performance monitoring capabilities
- **Error Context**: Rich error information for easier debugging
- **Session Tracking**: Connection and session state visibility

### 🧮 Data Precision

- **Maximum Precision Pipeline**: Direct XBRL → Polars conversion preserves full numerical precision
- **Type Safety**: NumPy dtypes maintained throughout conversion pipeline
- **Multiple Formats**: Choose optimal format for your use case
- **Precision Documentation**: Complete guide to data type handling

### 📋 Migration Guide

#### From 0.x.x to 1.0.0

**Basic Usage** (No Changes Required):
```python
# This code continues to work unchanged
from ffiec_data_connect import collect_data, WebserviceCredentials
# ... existing code works as before
```

**Enhanced Usage** (New Features):
```python
# New async capabilities
from ffiec_data_connect import AsyncCompatibleClient

async with AsyncCompatibleClient(credentials) as client:
    data = await client.collect_data_async(period, rssd_id)

# New polars support
data_polars = collect_data(session, creds, period, rssd_id, output_type="polars")

# New error handling
from ffiec_data_connect import ValidationError
try:
    data = collect_data(session, creds, period, invalid_rssd)
except ValidationError as e:
    print(f"Validation failed for field {e.field}: {e.value}")
```

### 🎯 Future Roadmap

This 1.0.0 release establishes a solid foundation for future enhancements:

- Enhanced caching strategies
- Additional output formats
- Performance optimizations
- Extended FFIEC API coverage

### 🙏 Acknowledgments

Special thanks to the financial data community for feedback and testing that helped shape this major release.

---

## [0.3.0] - 2024-XX-XX

### Added
- Direct XBRL to Polars conversion
- NumPy dtype consistency improvements
- Enhanced notebook demonstrations

### Fixed
- Memory management issues
- Thread safety improvements
- Connection stability

## [0.2.0] - Earlier versions

### Added
- Basic FFIEC webservice integration
- Pandas DataFrame support
- Core data collection methods

### Features
- collect_data() method
- collect_reporting_periods() method
- WebserviceCredentials class
- FFIECConnection class

---

[1.0.0]: https://github.com/civic-forge/ffiec-data-connect/compare/v0.3.0...v1.0.0
[0.3.0]: https://github.com/civic-forge/ffiec-data-connect/compare/v0.2.0...v0.3.0
[0.2.0]: https://github.com/civic-forge/ffiec-data-connect/releases/tag/v0.2.0