app/main.py

"""
Main FastAPI application for FinAgent backend.
Chat2Sanction - AI-powered loan processing platform.
"""

import os
from contextlib import asynccontextmanager

from app.config import settings
from app.routers import admin, auth, chat, loan
from app.utils.logger import setup_logger
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import JSONResponse

# Setup logger
logger = setup_logger("finagent", log_file="finagent.log")


@asynccontextmanager
async def lifespan(app: FastAPI):
    """
    Lifespan context manager for startup and shutdown events.
    """
    # Startup
    logger.info("=" * 80)
    logger.info(f"Starting {settings.APP_NAME} v{settings.APP_VERSION}")
    logger.info("=" * 80)
    logger.info(f"Environment: {'Development' if settings.DEBUG else 'Production'}")
    logger.info(f"Firebase Project: {settings.FIREBASE_PROJECT_ID}")
    logger.info(f"LLM Model: {getattr(settings, 'GEMINI_MODEL', 'Not configured')}")


    # Initialize services
    try:
        from app.agents.master_agent import master_agent
        from app.services.firebase_service import firebase_service
        from app.services.pdf_service import pdf_service
        from app.services.session_service import session_service
        from app.services.underwriting_service import underwriting_service

        logger.info("All services initialized successfully")
    except Exception as e:
        logger.error(f"Failed to initialize services: {str(e)}")

    # Create output directories
    os.makedirs(settings.PDF_OUTPUT_DIR, exist_ok=True)
    logger.info(f"PDF output directory: {settings.PDF_OUTPUT_DIR}")

    logger.info("✓ Application startup complete")
    logger.info("=" * 80)

    yield

    # Shutdown
    logger.info("=" * 80)
    logger.info("Shutting down application")
    logger.info("=" * 80)


# Create FastAPI app
app = FastAPI(
    title=settings.APP_NAME,
    description="AI-powered loan processing platform with conversational interface",
    version=settings.APP_VERSION,
    lifespan=lifespan,
    docs_url="/api/docs",
    redoc_url="/api/redoc",
    openapi_url="/api/openapi.json",
)

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


# Health check endpoint
@app.get("/")
async def root():
    """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():
    """Health check endpoint."""
    from app.services.firebase_service import firebase_service

    return {
        "status": "healthy",
        "firebase": "connected" if firebase_service.initialized else "disconnected",
        "gemini": "configured" if settings.GOOGLE_API_KEY else "not configured",
    }


# Include routers
app.include_router(auth.router, prefix="/api/auth", tags=["Authentication"])
app.include_router(chat.router, prefix="/api/chat", tags=["Chat"])
app.include_router(loan.router, prefix="/api/loan", tags=["Loans"])
app.include_router(admin.router, prefix="/api/admin", tags=["Admin"])


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


# Request logging middleware
@app.middleware("http")
async def log_requests(request, call_next):
    """Log all HTTP requests."""
    from time import time

    start_time = time()

    # Process request
    response = await call_next(request)

    # Log request
    duration = (time() - start_time) * 1000  # Convert to milliseconds
    logger.info(
        f"{request.method} {request.url.path} - {response.status_code} ({duration:.2f}ms)"
    )

    return response


if __name__ == "__main__":
    import uvicorn

    uvicorn.run(
        "app.main:app",
        host=settings.HOST,
        port=settings.PORT,
        reload=settings.DEBUG,
        workers=settings.WORKERS,
    )