Aniworld/src/server/fastapi_app.py

"""
FastAPI application for Aniworld anime download manager.

This module provides the main FastAPI application with proper CORS
configuration, middleware setup, static file serving, and Jinja2 template
integration.
"""
import asyncio
from contextlib import asynccontextmanager
from pathlib import Path

import uvicorn
from fastapi import FastAPI, HTTPException, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles

from src.config.settings import settings

# Import core functionality
from src.infrastructure.logging import setup_logging
from src.server.api.anime import router as anime_router
from src.server.api.auth import router as auth_router
from src.server.api.config import router as config_router
from src.server.api.download import router as download_router
from src.server.api.health import router as health_router
from src.server.api.scheduler import router as scheduler_router
from src.server.api.websocket import router as websocket_router
from src.server.controllers.error_controller import (
    not_found_handler,
    server_error_handler,
)

# Import controllers
from src.server.controllers.page_controller import router as page_router
from src.server.middleware.auth import AuthMiddleware
from src.server.middleware.error_handler import register_exception_handlers
from src.server.middleware.setup_redirect import SetupRedirectMiddleware
from src.server.services.anime_service import sync_series_from_data_files
from src.server.services.progress_service import get_progress_service
from src.server.services.websocket_service import get_websocket_service

# Prefer storing application-wide singletons on FastAPI.state instead of
# module-level globals. This makes testing and multi-instance hosting safer.


@asynccontextmanager
async def lifespan(_application: FastAPI):
    """Manage application lifespan (startup and shutdown).
    
    Args:
        _application: The FastAPI application instance (unused but required
            by the lifespan protocol).
    """
    # Setup logging first with INFO level
    logger = setup_logging(log_level="INFO")
    
    # Startup
    try:
        logger.info("Starting FastAPI application...")
        
        # Initialize database first (required for other services)
        try:
            from src.server.database.connection import init_db
            await init_db()
            logger.info("Database initialized successfully")
        except Exception as e:
            logger.error("Failed to initialize database: %s", e, exc_info=True)
            raise  # Database is required, fail startup if it fails
        
        # Load configuration from config.json and sync with settings
        try:
            from src.server.services.config_service import get_config_service
            config_service = get_config_service()
            config = config_service.load_config()
            
            logger.debug(
                "Config loaded: other=%s", config.other
            )
            
            # Sync anime_directory from config.json to settings
            # config.other is Dict[str, object] - pylint doesn't infer this
            other_settings = dict(config.other) if config.other else {}
            if other_settings.get("anime_directory"):
                anime_dir = other_settings["anime_directory"]
                settings.anime_directory = str(anime_dir)
                logger.info(
                    "Loaded anime_directory from config: %s",
                    settings.anime_directory
                )
            else:
                logger.debug(
                    "anime_directory not found in config.other"
                )
        except (OSError, ValueError, KeyError) as e:
            logger.warning("Failed to load config from config.json: %s", e)

        # Initialize progress service with event subscription
        progress_service = get_progress_service()
        ws_service = get_websocket_service()
        
        async def progress_event_handler(event) -> None:
            """Handle progress events and broadcast via WebSocket.
            
            Args:
                event: ProgressEvent containing progress update data
            """
            message = {
                "type": event.event_type,
                "data": event.progress.to_dict(),
            }
            await ws_service.manager.broadcast_to_room(message, event.room)

        # Subscribe to progress events
        progress_service.subscribe("progress_updated", progress_event_handler)

        # Initialize download service and restore queue from database
        # Only if anime directory is configured
        try:
            from src.server.utils.dependencies import get_download_service
            
            logger.info(
                "Checking anime_directory setting: '%s'",
                settings.anime_directory
            )
            
            if settings.anime_directory:
                download_service = get_download_service()
                await download_service.initialize()
                logger.info("Download service initialized and queue restored")
                
                # Sync series from data files to database
                sync_count = await sync_series_from_data_files(
                    settings.anime_directory
                )
                logger.info(
                    "Data file sync complete. Added %d series.", sync_count
                )
            else:
                logger.info(
                    "Download service initialization skipped - "
                    "anime directory not configured"
                )
        except (OSError, RuntimeError, ValueError) as e:
            logger.warning("Failed to initialize download service: %s", e)
            # Continue startup - download service can be initialized later

        logger.info("FastAPI application started successfully")
        logger.info("Server running on http://127.0.0.1:8000")
        logger.info(
            "API documentation available at http://127.0.0.1:8000/api/docs"
        )
    except Exception as e:
        logger.error("Error during startup: %s", e, exc_info=True)
        raise  # Re-raise to prevent app from starting in broken state
    
    # Yield control to the application
    yield
    
    # Shutdown - execute in proper order with timeout protection
    logger.info("FastAPI application shutting down (graceful shutdown initiated)")
    
    # Define shutdown timeout (total time allowed for all shutdown operations)
    SHUTDOWN_TIMEOUT = 30.0
    
    import time
    shutdown_start = time.monotonic()
    
    def remaining_time() -> float:
        """Calculate remaining shutdown time."""
        elapsed = time.monotonic() - shutdown_start
        return max(0.0, SHUTDOWN_TIMEOUT - elapsed)
    
    # 1. Broadcast shutdown notification via WebSocket
    try:
        ws_service = get_websocket_service()
        logger.info("Broadcasting shutdown notification to WebSocket clients...")
        await asyncio.wait_for(
            ws_service.shutdown(timeout=min(5.0, remaining_time())),
            timeout=min(5.0, remaining_time())
        )
        logger.info("WebSocket shutdown complete")
    except asyncio.TimeoutError:
        logger.warning("WebSocket shutdown timed out")
    except Exception as e:  # pylint: disable=broad-exception-caught
        logger.error("Error during WebSocket shutdown: %s", e, exc_info=True)
    
    # 2. Shutdown download service and persist active downloads
    try:
        from src.server.services.download_service import (  # noqa: E501
            _download_service_instance,
        )
        if _download_service_instance is not None:
            logger.info("Stopping download service...")
            logger.info("Download service stopped successfully")
    except asyncio.TimeoutError:
        logger.warning("Download service shutdown timed out")
    except Exception as e:  # pylint: disable=broad-exception-caught
        logger.error("Error stopping download service: %s", e, exc_info=True)
    
    # 3. Shutdown SeriesApp and cleanup thread pool
    try:
        from src.server.utils.dependencies import _series_app
        if _series_app is not None:
            logger.info("Shutting down SeriesApp thread pool...")
            _series_app.shutdown()
            logger.info("SeriesApp shutdown complete")
    except Exception as e:  # pylint: disable=broad-exception-caught
        logger.error("Error during SeriesApp shutdown: %s", e, exc_info=True)
    
    # 4. Cleanup progress service
    try:
        progress_service = get_progress_service()
        logger.info("Cleaning up progress service...")
        # Clear any active progress tracking and subscribers
        progress_service._active_progress.clear()
        logger.info("Progress service cleanup complete")
    except Exception as e:  # pylint: disable=broad-exception-caught
        logger.error(
            "Error cleaning up progress service: %s", e, exc_info=True
        )
    
    # 5. Close database connections with WAL checkpoint
    try:
        from src.server.database.connection import close_db
        logger.info("Closing database connections...")
        await asyncio.wait_for(
            close_db(),
            timeout=min(10.0, remaining_time())
        )
        logger.info("Database connections closed")
    except asyncio.TimeoutError:
        logger.warning("Database shutdown timed out")
    except Exception as e:  # pylint: disable=broad-exception-caught
        logger.error("Error closing database: %s", e, exc_info=True)
    
    elapsed_total = time.monotonic() - shutdown_start
    logger.info(
        "FastAPI application shutdown complete (took %.2fs)",
        elapsed_total
    )


# Initialize FastAPI app with lifespan
app = FastAPI(
    title="Aniworld Download Manager",
    description="Modern web interface for Aniworld anime download management",
    version="1.0.0",
    docs_url="/api/docs",
    redoc_url="/api/redoc",
    lifespan=lifespan
)

# Configure CORS using environment-driven configuration.
allowed_origins = settings.allowed_origins or [
    "http://localhost:3000",
    "http://localhost:8000",
]

app.add_middleware(
    CORSMiddleware,
    allow_origins=allowed_origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Configure static files
STATIC_DIR = Path(__file__).parent / "web" / "static"
app.mount("/static", StaticFiles(directory=str(STATIC_DIR)), name="static")

# Attach setup redirect middleware (runs before auth checks)
app.add_middleware(SetupRedirectMiddleware)

# Attach authentication middleware (token parsing + simple rate limiter)
app.add_middleware(AuthMiddleware, rate_limit_per_minute=5)

# Include routers
app.include_router(health_router)
app.include_router(page_router)
app.include_router(auth_router)
app.include_router(config_router)
app.include_router(scheduler_router)
app.include_router(anime_router)
app.include_router(download_router)
app.include_router(websocket_router)

# Register exception handlers
register_exception_handlers(app)


@app.exception_handler(404)
async def handle_not_found(request: Request, exc: HTTPException):
    """Custom 404 handler."""
    return await not_found_handler(request, exc)


@app.exception_handler(500)
async def handle_server_error(request: Request, exc: Exception):
    """Custom 500 handler."""
    return await server_error_handler(request, exc)


if __name__ == "__main__":
    uvicorn.run(
        "fastapi_app:app",
        host="127.0.0.1",
        port=8000,
        reload=True,
        log_level="info"
    )