# Aniworld Web Application Development Instructions

This document provides detailed tasks for AI agents to implement a modern web application for the Aniworld anime download manager. All tasks should follow the coding guidelines specified in the project's copilot instructions.

## Project Overview

The goal is to create a FastAPI-based web application that provides a modern interface for the existing Aniworld anime download functionality. The core anime logic should remain in `SeriesApp.py` while the web layer provides REST API endpoints and a responsive UI.

## Architecture Principles

-   **Single Responsibility**: Each file/class has one clear purpose
-   **Dependency Injection**: Use FastAPI's dependency system
-   **Clean Separation**: Web layer calls core logic, never the reverse
-   **File Size Limit**: Maximum 500 lines per file
-   **Type Hints**: Use comprehensive type annotations
-   **Error Handling**: Proper exception handling and logging

## Additional Implementation Guidelines

### Code Style and Standards

-   **Type Hints**: Use comprehensive type annotations throughout all modules
-   **Docstrings**: Follow PEP 257 for function and class documentation
-   **Error Handling**: Implement custom exception classes with meaningful messages
-   **Logging**: Use structured logging with appropriate log levels
-   **Security**: Validate all inputs and sanitize outputs
-   **Performance**: Use async/await patterns for I/O operations

## 📞 Escalation

If you encounter:

-   Architecture issues requiring design decisions
-   Tests that conflict with documented requirements
-   Breaking changes needed
-   Unclear requirements or expectations

**Document the issue and escalate rather than guessing.**

---

## 🎯 Current Task: Migrate Series Data from File Storage to Database

### Background

The current implementation stores anime series metadata in `data` files (JSON format without `.json` extension) located in each series folder (e.g., `{anime_directory}/{series_folder}/data`). This task migrates that storage to the SQLite database using the existing `AnimeSeries` model.

### Files Involved

**Current Data File Storage:**

-   `src/core/entities/series.py` - `Serie` class with `save_to_file()` and `load_from_file()` methods
-   `src/core/entities/SerieList.py` - `SerieList` class that loads/saves data files
-   `src/core/SerieScanner.py` - Scanner that creates data files during scan

**Database Components (Already Exist):**

-   `src/server/database/models.py` - `AnimeSeries` model (already defined)
-   `src/server/database/service.py` - `AnimeSeriesService` with CRUD operations
-   `src/server/database/init.py` - Database initialization

**API Endpoints:**

-   `src/server/api/anime.py` - `/api/anime/add` endpoint that adds new series

---

### Task 1: Create Data File Migration Service ✅

**File:** `src/server/services/data_migration_service.py`

**Description:** Create a service that migrates existing `data` files to the database.

**Requirements:**

1. Create `DataMigrationService` class with the following methods:

    - `scan_for_data_files(anime_directory: str) -> List[Path]` - Find all `data` files in the anime directory
    - `migrate_data_file(data_path: Path, db: AsyncSession) -> bool` - Migrate single data file to DB
    - `migrate_all(anime_directory: str, db: AsyncSession) -> MigrationResult` - Migrate all found data files
    - `is_migration_needed(anime_directory: str) -> bool` - Check if there are data files to migrate

2. Migration logic:

    - Read the `data` file using `Serie.load_from_file()`
    - Check if series with same `key` already exists in DB using `AnimeSeriesService.get_by_key()`
    - If not exists, create new `AnimeSeries` record using `AnimeSeriesService.create()`
    - If exists, optionally update the `episode_dict` if it has changed
    - Log all operations with appropriate log levels

3. Create `MigrationResult` dataclass:

    ```python
    @dataclass
    class MigrationResult:
        total_found: int
        migrated: int
        skipped: int
        failed: int
        errors: List[str]
    ```

4. Handle errors gracefully - don't stop migration on individual file failures

**Testing Requirements:**

-   Unit tests in `tests/unit/test_data_migration_service.py`
-   Test data file scanning
-   Test single file migration
-   Test migration when series already exists
-   Test error handling for corrupted files

---

### Task 2: Create Startup Migration Script ✅

**File:** `src/server/services/startup_migration.py`

**Description:** Create a migration runner that executes on every application startup.

**Requirements:**

1. Create `run_startup_migration(anime_directory: str) -> MigrationResult` async function
2. This function should:

    - Check if migration is needed using `DataMigrationService.is_migration_needed()`
    - If needed, run `DataMigrationService.migrate_all()`
    - Log migration results
    - Return the `MigrationResult`

3. Create `ensure_migration_on_startup()` async function that:
    - Gets the anime directory from settings/config
    - Runs `run_startup_migration()` if directory is configured
    - Handles cases where directory is not yet configured (first run)

**Testing Requirements:**

-   Unit tests in `tests/unit/test_startup_migration.py`
-   Test migration runs when data files exist
-   Test migration skips when no data files exist
-   Test handling of unconfigured anime directory

---

### Task 3: Integrate Migration into FastAPI Lifespan ✅

**File:** `src/server/fastapi_app.py`

**Description:** Add the startup migration to the FastAPI application lifespan.

**Requirements:**

1. Import `ensure_migration_on_startup` from startup migration service
2. Call `await ensure_migration_on_startup()` in the `lifespan` function after config is loaded
3. Log migration results
4. Do NOT block application startup on migration failure - log error and continue

**Example Integration:**

```python
@asynccontextmanager
async def lifespan(app: FastAPI):
    # ... existing startup code ...

    # Run data file to database migration
    try:
        from src.server.services.startup_migration import ensure_migration_on_startup
        migration_result = await ensure_migration_on_startup()
        if migration_result:
            logger.info(
                "Data migration complete: %d migrated, %d skipped, %d failed",
                migration_result.migrated,
                migration_result.skipped,
                migration_result.failed
            )
    except Exception as e:
        logger.error("Data migration failed: %s", e, exc_info=True)
        # Continue startup - migration failure should not block app

    # ... rest of startup ...
```

**Testing Requirements:**

-   Integration test that verifies migration runs on startup
-   Test that app starts even if migration fails

---

### Task 4: Update SerieList to Use Database ✅

**File:** `src/core/entities/SerieList.py`

**Description:** Modify `SerieList` class to read from database instead of data files.

**Requirements:**

1. Add optional `db_session` parameter to `__init__`
2. Modify `load_series()` method:

    - If `db_session` is provided, load from database using `AnimeSeriesService.get_all()`
    - Convert `AnimeSeries` models to `Serie` objects
    - Fall back to file-based loading if no `db_session` (for backward compatibility)

3. Modify `add()` method:

    - If `db_session` is provided, save to database using `AnimeSeriesService.create()`
    - Do NOT create data files anymore
    - Fall back to file-based saving if no `db_session`

4. Add new method `load_series_from_db(db: AsyncSession) -> None`
5. Add new method `add_to_db(serie: Serie, db: AsyncSession) -> None`

**Important:** Keep backward compatibility - file-based operations should still work when no `db_session` is provided.

**Testing Requirements:**

-   Unit tests for database-based loading
-   Unit tests for database-based adding
-   Test backward compatibility with file-based operations
-   Test conversion between `AnimeSeries` model and `Serie` entity

---

### Task 5: Update SerieScanner to Use Database ✅

**File:** `src/core/SerieScanner.py`

**Description:** Modify `SerieScanner` to save scan results to database instead of data files.

**Requirements:**

1. Add optional `db_session` parameter to `__init__`
2. Modify scanning logic (around line 185-188):

    - If `db_session` is provided, save to database instead of file
    - Use `AnimeSeriesService.create()` or `AnimeSeriesService.update()` for upserting
    - Do NOT create data files anymore when using database

3. Create helper method `_save_serie_to_db(serie: Serie, db: AsyncSession) -> None`
4. Create helper method `_update_serie_in_db(serie: Serie, db: AsyncSession) -> None`

**Important:** Keep backward compatibility for CLI usage without database.

**Testing Requirements:**

-   Unit tests for database-based saving during scan
-   Test that scan results persist to database
-   Test upsert behavior (update existing series)

---

### Task 6: Update Anime API Endpoints ✅

**File:** `src/server/api/anime.py`

**Description:** Update the `/api/anime/add` endpoint to save to database instead of file.

**Requirements:**

1. Modify `add_series()` endpoint:

    - Get database session using dependency injection
    - Use `AnimeSeriesService.create()` to save new series
    - Remove or replace file-based `series_app.list.add(serie)` call
    - Return the created series info including database ID

2. Add database session dependency:

    ```python
    from src.server.database import get_db_session

    @router.post("/add")
    async def add_series(
        request: AddSeriesRequest,
        _auth: dict = Depends(require_auth),
        series_app: Any = Depends(get_series_app),
        db: AsyncSession = Depends(get_db_session),
    ) -> dict:
    ```

3. Update list/get endpoints to optionally read from database

**Testing Requirements:**

-   API test for adding series via database
-   Test that added series appears in database
-   Test duplicate key handling

**Implementation Notes:**
- Added `get_optional_database_session()` dependency in `dependencies.py` for graceful fallback
- Endpoint saves to database when available, falls back to file-based storage when not
- All 55 API tests and 809 unit tests pass

---

### Task 7: Update Dependencies and SeriesApp ⬜

**File:** `src/server/utils/dependencies.py` and `src/core/SeriesApp.py`

**Description:** Update dependency injection to provide database sessions to core components.

**Requirements:**

1. Update `get_series_app()` dependency:

    - Initialize `SerieList` with database session when available
    - Pass database session to `SerieScanner` when available

2. Create `get_series_app_with_db()` dependency that provides database-aware `SeriesApp`

3. Update `SeriesApp.__init__()`:
    - Add optional `db_session` parameter
    - Pass to `SerieList` and `SerieScanner`

**Testing Requirements:**

-   Test `SeriesApp` initialization with database session
-   Test dependency injection provides correct sessions

---

### Task 8: Write Integration Tests ⬜

**File:** `tests/integration/test_data_file_migration.py`

**Description:** Create comprehensive integration tests for the migration workflow.

**Test Cases:**

1. `test_migration_on_fresh_start` - No data files, no database entries
2. `test_migration_with_existing_data_files` - Data files exist, migrate to DB
3. `test_migration_skips_existing_db_entries` - Series already in DB, skip migration
4. `test_add_series_saves_to_database` - New series via API saves to DB
5. `test_scan_saves_to_database` - Scan results save to DB
6. `test_list_reads_from_database` - Series list reads from DB
7. `test_search_and_add_workflow` - Search -> Add -> Verify in DB

**Setup:**

-   Use pytest fixtures with temporary directories
-   Use test database (in-memory SQLite)
-   Create sample data files for migration tests

---

### Task 9: Clean Up Legacy Code ⬜

**Description:** Remove or deprecate file-based storage code after database migration is stable.

**Requirements:**

1. Add deprecation warnings to file-based methods:

    - `Serie.save_to_file()` - Add `warnings.warn()` with deprecation notice
    - `Serie.load_from_file()` - Add `warnings.warn()` with deprecation notice
    - `SerieList.add()` file path - Log deprecation when creating data files

2. Update documentation:

    - Document that data files are deprecated
    - Document database storage as the primary method
    - Update `infrastructure.md` with new architecture

3. Do NOT remove file-based code yet - keep for backward compatibility

**Testing Requirements:**

-   Test that deprecation warnings are raised
-   Verify existing file-based tests still pass

---

### Task 10: Final Validation ⬜

**Description:** Validate the complete migration implementation.

**Validation Checklist:**

-   [ ] All unit tests pass: `conda run -n AniWorld python -m pytest tests/unit/ -v`
-   [ ] All integration tests pass: `conda run -n AniWorld python -m pytest tests/integration/ -v`
-   [ ] All API tests pass: `conda run -n AniWorld python -m pytest tests/api/ -v`
-   [ ] Migration runs automatically on server startup
-   [ ] New series added via API are saved to database
-   [ ] Scan results are saved to database
-   [ ] Series list is read from database
-   [ ] Existing data files are migrated to database on first run
-   [ ] Application starts successfully even with no data files
-   [ ] Application starts successfully even with no anime directory configured
-   [ ] Deprecation warnings appear in logs when file-based methods are used
-   [ ] No new data files are created after migration

**Manual Testing:**

1. Start fresh server: `conda run -n AniWorld python -m uvicorn src.server.fastapi_app:app --host 127.0.0.1 --port 8000 --reload`
2. Login and configure anime directory
3. Run rescan - verify series appear in database
4. Search and add new series - verify saved to database
5. Restart server - verify migration detects no new files to migrate
6. Check database for all series entries

---

## 📚 Helpful Commands

```bash
# Run all tests
conda run -n AniWorld python -m pytest tests/ -v --tb=short

# Run specific test file
conda run -n AniWorld python -m pytest tests/unit/test_websocket_service.py -v

# Run specific test class
conda run -n AniWorld python -m pytest tests/unit/test_websocket_service.py::TestWebSocketService -v

# Run specific test
conda run -n AniWorld python -m pytest tests/unit/test_websocket_service.py::TestWebSocketService::test_broadcast_download_progress -v

# Run with extra verbosity
conda run -n AniWorld python -m pytest tests/ -vv

# Run with full traceback
conda run -n AniWorld python -m pytest tests/ -v --tb=long

# Run and stop at first failure
conda run -n AniWorld python -m pytest tests/ -v -x

# Run tests matching pattern
conda run -n AniWorld python -m pytest tests/ -v -k "auth"

# Show all print statements
conda run -n AniWorld python -m pytest tests/ -v -s

#Run app
conda run -n AniWorld python -m uvicorn src.server.fastapi_app:app --host 127.0.0.1 --port 8000 --reload
```

---

## Final Implementation Notes

1. **Incremental Development**: Implement features incrementally, testing each component thoroughly before moving to the next
2. **Code Review**: Review all generated code for adherence to project standards
3. **Documentation**: Document all public APIs and complex logic
4. **Testing**: Maintain test coverage above 80% for all new code
5. **Performance**: Profile and optimize critical paths, especially download and streaming operations
6. **Security**: Regular security audits and dependency updates
7. **Monitoring**: Implement comprehensive monitoring and alerting
8. **Maintenance**: Plan for regular maintenance and updates

## Task Completion Checklist

For each task completed:

-   [ ] Implementation follows coding standards
-   [ ] Unit tests written and passing
-   [ ] Integration tests passing
-   [ ] Documentation updated
-   [ ] Error handling implemented
-   [ ] Logging added
-   [ ] Security considerations addressed
-   [ ] Performance validated
-   [ ] Code reviewed
-   [ ] Task marked as complete in instructions.md
-   [ ] Infrastructure.md updated
-   [ ] Changes committed to git; keep your messages in git short and clear
-   [ ] Take the next task

---

### Prerequisites

1. Server is running: `conda run -n AniWorld python -m uvicorn src.server.fastapi_app:app --host 127.0.0.1 --port 8000 --reload`
2. Password: `Hallo123!`
3. Login via browser at `http://127.0.0.1:8000/login`

### Notes

-   This is a simplification that removes complexity while maintaining core functionality
-   Improves user experience with explicit manual control
-   Easier to understand, test, and maintain
-   Good foundation for future enhancements if needed

---