# services/inventory/app/main.py
"""
Inventory Service FastAPI Application
"""

import os
from contextlib import asynccontextmanager
from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse
import structlog

# Import core modules
from app.core.config import settings
from app.core.database import init_db, close_db
from app.api import ingredients, stock, classification
from shared.monitoring.health import router as health_router
from shared.monitoring.metrics import setup_metrics_early
# Auth decorators are used in endpoints, no global setup needed

logger = structlog.get_logger()


@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan management"""
    # Startup
    logger.info("Starting Inventory Service", version=settings.VERSION)
    
    try:
        # Initialize database
        await init_db()
        logger.info("Database initialized successfully")
        
        # Setup metrics is already done early - no need to do it here
        logger.info("Metrics setup completed")
        
        yield
        
    except Exception as e:
        logger.error("Startup failed", error=str(e))
        raise
    finally:
        # Shutdown
        logger.info("Shutting down Inventory Service")
        try:
            await close_db()
            logger.info("Database connections closed")
        except Exception as e:
            logger.error("Shutdown error", error=str(e))


# Create FastAPI application
app = FastAPI(
    title=settings.APP_NAME,
    description=settings.DESCRIPTION,
    version=settings.VERSION,
    openapi_url=f"{settings.API_V1_STR}/openapi.json",
    docs_url=f"{settings.API_V1_STR}/docs",
    redoc_url=f"{settings.API_V1_STR}/redoc",
    lifespan=lifespan
)

# Setup metrics BEFORE any middleware and BEFORE lifespan
metrics_collector = setup_metrics_early(app, "inventory-service")


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


# Auth is handled via decorators in individual endpoints


# Exception handlers
@app.exception_handler(ValueError)
async def value_error_handler(request: Request, exc: ValueError):
    """Handle validation errors"""
    return JSONResponse(
        status_code=400,
        content={
            "error": "Validation Error",
            "detail": str(exc),
            "type": "value_error"
        }
    )


@app.exception_handler(Exception)
async def general_exception_handler(request: Request, exc: Exception):
    """Handle general exceptions"""
    logger.error(
        "Unhandled exception",
        error=str(exc),
        path=request.url.path,
        method=request.method
    )
    
    return JSONResponse(
        status_code=500,
        content={
            "error": "Internal Server Error",
            "detail": "An unexpected error occurred",
            "type": "internal_error"
        }
    )


# Include routers
app.include_router(health_router, prefix="/health", tags=["health"])
app.include_router(ingredients.router, prefix=settings.API_V1_STR)
app.include_router(stock.router, prefix=settings.API_V1_STR)
app.include_router(classification.router, prefix=settings.API_V1_STR)


# Root endpoint
@app.get("/")
async def root():
    """Root endpoint with service information"""
    return {
        "service": settings.SERVICE_NAME,
        "version": settings.VERSION,
        "description": settings.DESCRIPTION,
        "status": "running",
        "docs_url": f"{settings.API_V1_STR}/docs",
        "health_url": "/health"
    }


# Service info endpoint
@app.get(f"{settings.API_V1_STR}/info")
async def service_info():
    """Service information endpoint"""
    return {
        "service": settings.SERVICE_NAME,
        "version": settings.VERSION,
        "description": settings.DESCRIPTION,
        "api_version": "v1",
        "environment": settings.ENVIRONMENT,
        "features": [
            "ingredient_management",
            "stock_tracking",
            "expiration_alerts",
            "low_stock_alerts",
            "batch_tracking",
            "fifo_consumption",
            "barcode_support"
        ]
    }


if __name__ == "__main__":
    import uvicorn
    
    uvicorn.run(
        "app.main:app",
        host="0.0.0.0",
        port=8000,
        reload=os.getenv("RELOAD", "false").lower() == "true",
        log_level="info"
    )