app/main.py

"""
FastAPI Main Application
"""
import sys
import os
from pathlib import Path
from contextlib import asynccontextmanager
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
from loguru import logger

from app.config import settings
from app.core.redis_client import get_redis_client
from app.api.routes import router


# Configure logging
logger.remove()
logger.add(
    sys.stdout,
    format="<green>{time:YYYY-MM-DD HH:mm:ss}</green> | <level>{level: <8}</level> | <cyan>{name}</cyan>:<cyan>{function}</cyan> - <level>{message}</level>",
    level=settings.LOG_LEVEL
)

# Create logs directory if it doesn't exist
try:
    log_dir = Path("logs")
    log_dir.mkdir(parents=True, exist_ok=True)
    
    logger.add(
        "logs/swara_api_{time:YYYY-MM-DD}.log",
        rotation="1 day",
        retention="7 days",
        format="{time:YYYY-MM-DD HH:mm:ss} | {level: <8} | {name}:{function} - {message}",
        level=settings.LOG_LEVEL
    )
except (PermissionError, OSError) as e:
    # If we can't write to logs directory, only use stdout
    logger.warning(f"Cannot create log file: {e}. Using stdout only.")


@asynccontextmanager
async def lifespan(app: FastAPI):
    """
    Application lifespan events
    """
    # Startup
    logger.info("=" * 70)
    logger.info("🚀 SWARA API Starting...")
    logger.info("=" * 70)
    logger.info(f"Environment: {settings.ENV}")
    logger.info(f"API Version: {settings.API_VERSION}")
    logger.info(f"Redis URL: {settings.REDIS_URL}")
    
    # Connect to Redis
    try:
        redis_client = get_redis_client()
        redis_client.connect()
        logger.info("✓ Redis connection established")
    except Exception as e:
        logger.error(f"✗ Failed to connect to Redis: {e}")
        logger.warning("⚠ API will start but background tasks will not work")
    
    # Create necessary directories
    settings.get_temp_dir()
    settings.get_models_dir()
    logger.info("✓ Directories created")
    
    logger.info("=" * 70)
    logger.info(f"✓ SWARA API Ready at http://{settings.API_HOST}:{settings.API_PORT}")
    logger.info("=" * 70)
    
    yield
    
    # Shutdown
    logger.info("=" * 70)
    logger.info("🛑 SWARA API Shutting down...")
    logger.info("=" * 70)
    
    # Disconnect from Redis
    try:
        redis_client = get_redis_client()
        redis_client.disconnect()
        logger.info("✓ Redis disconnected")
    except:
        pass
    
    logger.info("✓ Shutdown complete")
    logger.info("=" * 70)


# Create FastAPI application
app = FastAPI(
    title=settings.API_TITLE,
    version=settings.API_VERSION,
    description=settings.API_DESCRIPTION,
    lifespan=lifespan,
    docs_url="/docs",
    redoc_url="/redoc",
    openapi_url="/openapi.json"
)


# CORS Middleware
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # In production, specify allowed origins
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


# Include routers
app.include_router(router)


# Global exception handler
@app.exception_handler(Exception)
async def global_exception_handler(request, exc):
    """Global exception handler"""
    logger.error(f"Unhandled exception: {exc}")
    return JSONResponse(
        status_code=500,
        content={
            "error": "Internal server error",
            "detail": str(exc) if settings.ENV == "development" else "An unexpected error occurred"
        }
    )


if __name__ == "__main__":
    import uvicorn
    
    uvicorn.run(
        "app.main:app",
        host=settings.API_HOST,
        port=settings.API_PORT,
        reload=settings.ENV == "development",
        workers=settings.API_WORKERS
    )