bakery-ia/services/auth/app/main.py

"""
Authentication Service Main Application - Fixed middleware issue
"""

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

from app.core.config import settings
from app.core.database import engine, create_tables
from app.api import auth, users
from app.services.messaging import setup_messaging, cleanup_messaging
from shared.monitoring import setup_logging, HealthChecker
from shared.monitoring.metrics import setup_metrics_early

# Setup logging first
setup_logging("auth-service", settings.LOG_LEVEL)
logger = structlog.get_logger()

# Global variables for lifespan access
metrics_collector = None
health_checker = None

# Create FastAPI app FIRST
app = FastAPI(
    title="Authentication Service",
    description="Handles user authentication and authorization for bakery forecasting platform",
    version="1.0.0",
    docs_url="/docs",
    redoc_url="/redoc"
)

# Setup metrics BEFORE any middleware and BEFORE lifespan
# This must happen before the app starts
metrics_collector = setup_metrics_early(app, "auth-service")

@asynccontextmanager
async def lifespan(app: FastAPI):
    """Application lifespan events - NO MIDDLEWARE ADDED HERE"""
    global health_checker
    
    # Startup
    logger.info("Starting Authentication Service...")
    
    try:
        # Create database tables
        await create_tables()
        logger.info("Database tables created")
        
        # Setup messaging
        await setup_messaging()
        logger.info("Messaging setup complete")
        
        # Register custom metrics (metrics_collector already exists)
        metrics_collector.register_counter(
            "registration_total",
            "Total user registrations by status",
            labels=["status"] # Add this line
        )
        metrics_collector.register_counter(
            "login_success_total",
            "Total successful user logins"
        )
        metrics_collector.register_counter(
            "login_failure_total",
            "Total failed user logins by reason",
            labels=["reason"] # Add this line, based on auth.py usage
        )
        metrics_collector.register_counter(
            "token_refresh_total",
            "Total token refreshes by status",
            labels=["status"] # Add this line
        )
        metrics_collector.register_counter(
            "token_verify_total",
            "Total token verifications by status",
            labels=["status"] # Add this line
        )
        metrics_collector.register_counter(
            "logout_total",
            "Total user logouts by status",
            labels=["status"] # Add this line
        )
        metrics_collector.register_counter("errors_total", "Total errors", labels=["type"]) # Add this line
        metrics_collector.register_histogram("registration_duration_seconds", "Registration request duration")
        metrics_collector.register_histogram("login_duration_seconds", "Login request duration")
        metrics_collector.register_histogram("token_refresh_duration_seconds", "Token refresh duration")
        
        # Setup health checker
        health_checker = HealthChecker("auth-service")
        
        # Add database health check
        async def check_database():
            try:
                from app.core.database import get_db
                from sqlalchemy import text
                async for db in get_db():
                    await db.execute(text("SELECT 1"))
                    return True
            except Exception as e:
                return f"Database error: {e}"
        
        health_checker.add_check("database", check_database, timeout=5.0, critical=True)
        
        # Add messaging health check
        def check_messaging():
            try:
                # Add your messaging health check logic here
                return True
            except Exception as e:
                return f"Messaging error: {e}"
        
        health_checker.add_check("messaging", check_messaging, timeout=3.0, critical=False)
        
        # Store health checker in app state
        app.state.health_checker = health_checker
        
        logger.info("Authentication Service started successfully")
        
    except Exception as e:
        logger.error(f"Failed to start Authentication Service: {e}")
        raise
    
    yield
    
    # Shutdown
    logger.info("Shutting down Authentication Service...")
    try:
        await cleanup_messaging()
        await engine.dispose()
        logger.info("Authentication Service shutdown complete")
    except Exception as e:
        logger.error(f"Error during shutdown: {e}")

# Set lifespan AFTER metrics setup
app.router.lifespan_context = lifespan

# CORS middleware (added after metrics setup)
app.add_middleware(
    CORSMiddleware,
    allow_origins=["*"],  # Configure properly for production
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(auth.router, prefix="/api/v1/auth", tags=["authentication"])
app.include_router(users.router, prefix="/api/v1/users", tags=["users"])

# Health check endpoint with comprehensive checks
@app.get("/health")
async def health_check():
    """Comprehensive health check endpoint"""
    if health_checker:
        return await health_checker.check_health()
    else:
        return {
            "service": "auth-service",
            "status": "healthy",
            "version": "1.0.0"
        }

# Exception handlers
@app.exception_handler(Exception)
async def global_exception_handler(request: Request, exc: Exception):
    """Global exception handler with metrics"""
    logger.error(f"Unhandled exception: {exc}", exc_info=True)
    
    # Record error metric if available
    if metrics_collector:
        metrics_collector.increment_counter("errors_total", labels={"type": "unhandled"})
    
    return JSONResponse(
        status_code=500,
        content={"detail": "Internal server error"}
    )