"""Main FastAPI application entry point."""
from contextlib import asynccontextmanager
from typing import AsyncGenerator

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

from app.core.config import settings
from app.core.database import close_db, init_db


@asynccontextmanager
async def lifespan(app: FastAPI) -> AsyncGenerator[None, None]:
    """
    Lifespan context manager for FastAPI application.

    Handles startup and shutdown events.
    """
    # Startup
    print("Starting up...")
    if settings.DEBUG:
        print("Debug mode is ON")
        print(f"Database URL: {settings.DATABASE_URL}")
        print(f"Redis URL: {settings.FULL_REDIS_URL}")

    # Initialize database
    await init_db()
    print("Database initialized")

    yield

    # Shutdown
    print("Shutting down...")
    await close_db()
    print("Database connections closed")


# Create FastAPI application
app = FastAPI(
    title=settings.APP_NAME,
    version=settings.APP_VERSION,
    description="Alternative to Spotify with YouTube streaming",
    docs_url="/api/docs",
    redoc_url="/api/redoc",
    openapi_url="/api/openapi.json",
    lifespan=lifespan,
)


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


@app.get("/")
async def root() -> dict[str, str]:
    """Root endpoint with API information."""
    return {
        "name": settings.APP_NAME,
        "version": settings.APP_VERSION,
        "status": "running",
        "docs": "/api/docs",
    }


@app.get("/health")
async def health_check() -> dict[str, str]:
    """Health check endpoint."""
    return {"status": "healthy"}


@app.get("/api/v1")
async def api_v1_info() -> dict[str, str]:
    """API v1 information endpoint."""
    return {
        "version": "v1",
        "prefix": settings.API_V1_PREFIX,
        "docs": "/api/docs",
    }


# Exception handlers
@app.exception_handler(Exception)
async def global_exception_handler(request, exc) -> JSONResponse:
    """Global exception handler for unhandled exceptions."""
    if settings.DEBUG:
        # In debug mode, return full error details
        return JSONResponse(
            status_code=500,
            content={
                "detail": str(exc),
                "type": type(exc).__name__,
            },
        )
    # In production, return generic error message
    return JSONResponse(
        status_code=500,
        content={"detail": "Internal server error"},
    )


# API routes
from app.api.v1 import auth, music, playlists

app.include_router(auth.router, prefix=settings.API_V1_PREFIX, tags=["authentication"])
app.include_router(music.router, prefix=settings.API_V1_PREFIX, tags=["music"])
app.include_router(playlists.router, prefix=settings.API_V1_PREFIX, tags=["playlists"])


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(
        "app.main:app",
        host=settings.HOST,
        port=settings.PORT,
        reload=settings.DEBUG,
        log_level=settings.LOG_LEVEL.lower(),
    )