# Implementation Tasks

## 1. Implementation

- [x] 1.1 Add `write_parquet_dataset` method to `DuckDBParquetHandler` class
- [x] 1.2 Implement unique filename generation (UUID-based by default)
- [x] 1.3 Implement `mode="overwrite"` logic to clear existing dataset
- [x] 1.4 Implement `mode="append"` logic to preserve existing files
- [x] 1.5 Add `max_rows_per_file` parameter to split large tables
- [x] 1.6 Add `basename_template` parameter for custom filenames
- [x] 1.7 Implement dataset directory validation and creation
- [x] 1.8 Add comprehensive type hints and docstrings with examples
- [x] 1.9 Add helper method `_generate_unique_filename` for filename generation
- [x] 1.10 Add helper method `_clear_dataset` for overwrite mode

## 2. Testing

- [x] 2.1 Add test fixtures for dataset write scenarios
- [x] 2.2 Write tests for basic dataset write with unique filenames
- [x] 2.3 Write tests for `mode="overwrite"` functionality
- [x] 2.4 Write tests for `mode="append"` functionality
- [x] 2.5 Write tests for `max_rows_per_file` splitting
- [x] 2.6 Write tests for `basename_template` customization
- [x] 2.7 Write tests for dataset write to remote storage
- [x] 2.8 Write tests for error handling (invalid mode, permissions)
- [x] 2.9 Write tests for concurrent writes (multiple files)
- [x] 2.10 Write integration tests combining dataset read and write

## 3. Documentation

- [x] 3.1 Add comprehensive docstring to `write_parquet_dataset` method
- [x] 3.2 Update module docstring with dataset write examples
- [x] 3.3 Create example script demonstrating dataset write patterns
- [x] 3.4 Document best practices for dataset organization

## 4. Validation

- [x] 4.1 Run `pytest tests/test_utils/test_duckdb.py -v` (all tests including new ones)
- [x] 4.2 Run `ruff check src/fsspeckit/utils/duckdb.py`
- [x] 4.3 Run `mypy src/fsspeckit/utils/duckdb.py`
- [x] 4.4 Verify test coverage remains above 80%
- [x] 4.5 Run example scripts to validate functionality
- [x] 4.6 Validate OpenSpec: `openspec validate add-duckdb-dataset-write --strict`
