import os

from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware
from prometheus_fastapi_instrumentator import Instrumentator
from slowapi import _rate_limit_exceeded_handler as _slowapi_handler
from slowapi.errors import RateLimitExceeded
from starlette.requests import Request
from starlette.responses import Response

from app.api.limiter import limiter
from app.api.routes import router


def handle_rate_limit(request: Request, exc: Exception) -> Response:
    return _slowapi_handler(request, exc)  # type: ignore[arg-type, return-value, unused-ignore]


app = FastAPI(
    title="AI Code Review Agent",
    description="Multi-agent AI platform that simulates a software engineering team",
    version="0.1.0",
)
Instrumentator().instrument(app).expose(app, endpoint="/metrics/prometheus")

app.state.limiter = limiter
app.add_exception_handler(RateLimitExceeded, handle_rate_limit)  # type: ignore[arg-type, unused-ignore]

# Allow Gradio frontend to talk to FastAPI
app.add_middleware(
    CORSMiddleware,
    allow_origins=os.getenv("ALLOWED_ORIGINS", "http://localhost:7860").split(","),
    allow_methods=["POST", "GET"],
    allow_headers=["X-API-Key", "Content-Type"],
)

app.include_router(router, prefix="/api/v1")


@app.get("/")
def root() -> dict[str, str]:
    return {"message": "AI Code Review Agent", "version": "0.1.0", "docs": "/docs"}