"""
FastAPI Main Application
"""
import logging
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.exceptions import RequestValidationError
from starlette.exceptions import HTTPException as StarletteHTTPException

from app.core.config import settings
from app.core.logging_config import logger
from app.api.v1 import api_router


def create_app() -> FastAPI:
    """Create application instance"""
    logger.info("Creating FastAPI application instance...")
    
    app = FastAPI(
        title=settings.APP_NAME,
        version=settings.APP_VERSION,
        description="""
## Hospital Performance Management System API

### Function Modules
- **Basic Data Management**: Department, Staff, Indicators
- **Performance Assessment**: Assessment records, review workflow
- **Data Analysis Reports**: Department statistics, trends, rankings
- **Salary Calculation**: Performance-based payroll

### Tech Stack
- FastAPI + SQLAlchemy 2.0
- PostgreSQL
- Async IO support
        """,
        openapi_url=f"{settings.API_PREFIX}/openapi.json",
        docs_url=f"{settings.API_PREFIX}/docs",
        redoc_url=f"{settings.API_PREFIX}/redoc",
    )

    # CORS middleware
    app.add_middleware(
        CORSMiddleware,
        allow_origins=settings.CORS_ORIGINS,
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # Register router
    app.include_router(api_router, prefix=settings.API_PREFIX)

    # Health check
    @app.get("/health", tags=["System"])
    async def health_check():
        return {"status": "healthy", "version": settings.APP_VERSION}

    # HTTP exception handler
    @app.exception_handler(StarletteHTTPException)
    async def http_exception_handler(request, exc):
        logger.warning(f"HTTP Exception: {request.method} {request.url} - {exc.status_code} - {exc.detail}")
        raise exc

    # Request validation exception handler
    @app.exception_handler(RequestValidationError)
    async def validation_exception_handler(request, exc):
        logger.error(f"Validation Error: {request.method} {request.url} - {exc}")
        raise exc

    # Global exception handler
    @app.exception_handler(Exception)
    async def global_exception_handler(request, exc):
        logger.error(f"Global Exception: {request.method} {request.url} - {exc}", exc_info=True)
        raise exc

    logger.info("FastAPI application instance created successfully")
    return app


app = create_app()


if __name__ == "__main__":
    import uvicorn
    uvicorn.run(
        "app.main:app",
        host="0.0.0.0",
        port=8000,
        reload=True,
        log_level="info"
    )