"""
FastAPI URL Blink Application

Production-grade API for receiving encrypted user data,
decrypting it, and storing in SQLite database.
"""
import os
import logging
from contextlib import asynccontextmanager
from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

from core.database import init_db, DB_FILENAME
from routers import auth, blink, contact, credits, general, gemini, payments
from services.drive_service import DriveService

# Configure logging
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
)
logger = logging.getLogger(__name__)

# Initialize Drive Service
drive_service = DriveService()

@asynccontextmanager
async def lifespan(app: FastAPI):
    """
    Application lifespan manager.
    Initializes database on startup.
    """
    logger.info("Starting up - initializing database...")
    
    # Check for RESET_DB environment variable
    if os.getenv("RESET_DB", "").lower() == "true":
        logger.warning(f"RESET_DB is set to true. Skipping download and clearing local database ({DB_FILENAME}).")
        if os.path.exists(DB_FILENAME):
            os.remove(DB_FILENAME)
            logger.info("Local database deleted.")
    else:
        # Startup: Download DB from Drive ONLY if local file doesn't exist
        if not os.path.exists(DB_FILENAME):
            logger.info("Startup: Local DB missing. Attempting to download from Google Drive...")
            drive_service.download_db()
        else:
            logger.info("Startup: Local DB found. Skipping download to preserve data.")
    
    await init_db()
    logger.info("Database initialized successfully")
    
    # Start background job worker
    from services.gemini_job_worker import start_worker, stop_worker
    await start_worker()
    logger.info("Background job worker started")
    
    yield
    
    # Stop background job worker
    await stop_worker()
    logger.info("Background job worker stopped")
    
    # Shutdown: Upload DB to Drive
    logger.info("Shutdown: Uploading database to Google Drive...")
    drive_service.upload_db()
    logger.info("Shutting down...")


# Create FastAPI application
app = FastAPI(
    title="APIGateway",
    description="API for receiving and processing encrypted user data",
    version="1.0.0",
    lifespan=lifespan
)

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

# Include Routers
app.include_router(general.router)
app.include_router(auth.router)
app.include_router(blink.router)
app.include_router(gemini.router)
app.include_router(credits.router)
app.include_router(payments.router)
app.include_router(contact.router)


@app.exception_handler(Exception)
async def global_exception_handler(request: Request, exc: Exception):
    """
    Global exception handler for unhandled errors.
    """
    logger.error(f"Unhandled exception: {exc}")
    return JSONResponse(
        status_code=500,
        content={"detail": "Internal server error"}
    )


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