from fastapi import FastAPI, Depends, HTTPException, status
from fastapi.middleware.cors import CORSMiddleware
from fastapi.staticfiles import StaticFiles
from sqlalchemy.orm import Session
import os

from backend.core.config import settings
from backend.api.v1 import (
    auth as auth_router, 
    challenges as challenges_router, 
    health as health_router,
    zepp as zepp_router
)
from slowapi import Limiter, _rate_limit_exceeded_handler
from slowapi.util import get_remote_address
from slowapi.errors import RateLimitExceeded

# Rate limiting setup
limiter = Limiter(key_func=get_remote_address)
app = FastAPI(title=settings.APP_NAME, version=settings.APP_VERSION)
app.state.limiter = limiter
app.add_exception_handler(RateLimitExceeded, _rate_limit_exceeded_handler)

# Create database tables on startup
@app.on_event("startup")
def on_startup():
    from backend.database import Base, engine
    from backend.models import User, Challenge, Tracking, DailyHealthMetrics, WorkoutSession
    Base.metadata.create_all(bind=engine)

# CORS - Use configured origins
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.CORS_ORIGINS,
    allow_credentials=settings.CORS_ALLOW_CREDENTIALS,
    allow_methods=settings.CORS_ALLOW_METHODS,
    allow_headers=settings.CORS_ALLOW_HEADERS,
)

# Include API v1 routers
app.include_router(auth_router.router)
app.include_router(challenges_router.router)
app.include_router(health_router.router)
app.include_router(zepp_router.router)

# Middleware to drop unexpected WebSocket connections (Fixes StaticFiles crash)
@app.middleware("http")
async def reject_websockets(request, call_next):
    return await call_next(request)

from starlette.websockets import WebSocket
@app.websocket("/{path:path}")
async def websocket_endpoint(websocket: WebSocket):
    await websocket.accept()
    await websocket.close()

@app.get("/api/static/images")
def get_static_images():
    """Retrieve list of available static images."""
    static_dir = os.path.join("frontend", "static")
    images = []
    if os.path.exists(static_dir):
        for filename in os.listdir(static_dir):
            if filename.lower().endswith(('.png', '.jpg', '.jpeg', '.gif', '.webp')):
                images.append(filename)
    return images

# Mount static files last to avoid intercepting API calls
app.mount("/", StaticFiles(directory="frontend", html=True), name="frontend")