from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from fastapi.responses import FileResponse
from app.database import engine, Base
from app.routers import knowledge_base, rfp_processing, chatbot, health
from pathlib import Path
import os

# Create database tables
Base.metadata.create_all(bind=engine)

app = FastAPI(
    title="RFP Management System",
    description="AI-powered RFP management with intelligent answer generation",
    version="1.0.0"
)

# CORS middleware for frontend
app.add_middleware(
    CORSMiddleware,
    allow_origins=["http://localhost:5173", "http://localhost:5174", "http://localhost:3000"],  # SvelteKit default ports
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Include routers
app.include_router(health.router)
app.include_router(knowledge_base.router)
app.include_router(rfp_processing.router)
app.include_router(chatbot.router)

# Serve static frontend files
FRONTEND_BUILD_DIR = Path(__file__).parent.parent.parent / "frontend" / "build"

# Check if we're in deployment (frontend/build exists at different path)
if not FRONTEND_BUILD_DIR.exists():
    # In Docker deployment, frontend is at /app/frontend/build
    FRONTEND_BUILD_DIR = Path("/app/frontend/build")

if FRONTEND_BUILD_DIR.exists():
    # Mount static files
    app.mount("/_app", StaticFiles(directory=str(FRONTEND_BUILD_DIR / "_app")), name="app-assets")
    
    # Serve index.html for root and all other routes (SPA fallback)
    @app.get("/")
    async def serve_frontend():
        return FileResponse(str(FRONTEND_BUILD_DIR / "index.html"))
    
    @app.get("/{full_path:path}")
    async def serve_spa(full_path: str):
        # Don't intercept API routes
        
        # Serve static files if they exist
        file_path = FRONTEND_BUILD_DIR / full_path
        if file_path.is_file():
            return FileResponse(str(file_path))
        # Otherwise serve index.html for SPA routing
        return FileResponse(str(FRONTEND_BUILD_DIR / "index.html"))
else:
    # Fallback if frontend not found
    @app.get("/")
    def read_root():
        return {
            "message": "RFP Management System API",
            "version": "1.0.0",
            "docs": "/docs"
        }