from typing import Union, Optional, Dict, Any
from pathlib import Path

from fastapi import FastAPI, Request, HTTPException
from fastapi.responses import HTMLResponse, FileResponse, Response
from chat_simple import get_response
import uvicorn
import json
import logging
from logging.handlers import RotatingFileHandler

app = FastAPI()

# Logging: write to logs/access.log with rotation
logger = logging.getLogger("access")
logger.setLevel(logging.INFO)
if not logger.handlers:
    logs_dir = Path(__file__).with_name("logs")
    logs_dir.mkdir(exist_ok=True)
    handler = RotatingFileHandler(logs_dir / "access.log", maxBytes=1_000_000, backupCount=3, encoding="utf-8")
    handler.setFormatter(logging.Formatter("%(asctime)s %(levelname)s %(message)s"))
    logger.addHandler(handler)


def get_client_ip(request: Request) -> str:
    xff = request.headers.get("x-forwarded-for")
    if xff:
        return xff.split(",")[0].strip()
    xri = request.headers.get("x-real-ip")
    if xri:
        return xri.strip()
    return request.client.host if request.client else "unknown"


@app.get("/", response_class=HTMLResponse)
def serve_root() -> Response:
    html_path = Path(__file__).with_name("chat_ui.html")
    if not html_path.exists():
        raise HTTPException(status_code=404, detail="File not found")
    return FileResponse(html_path)


@app.post("/chat")
async def chat(request: Request):
    body = await request.json()
    query = body.get("query")
    config = body.get("config")

    # Optional client meta sent by the UI
    meta = body.get("meta") or {}
    lat = meta.get("lat")
    lon = meta.get("lon")
    user_agent = meta.get("userAgent")
    platform = meta.get("platform")
    language = meta.get("language")
    timezone = meta.get("timezone")
    screen = meta.get("screen")

    client_ip = get_client_ip(request)
    q_preview = (query or "")[:500]
    logger.info(
        "client_ip=%s lat=%s lon=%s ua=%s platform=%s lang=%s tz=%s screen=%s thread_id=%s query=%s",
        client_ip,
        lat,
        lon,
        (user_agent or "")[:200],
        platform,
        language,
        timezone,
        screen,
        ((config or {}).get("configurable") or {}).get("thread_id"),
        q_preview,
    )

    response = get_response(query, config)
    logger.info("client_ip=%s response_len=%s", client_ip, len(str(response) if response is not None else ""))
    return {"response": response}

if __name__ == "__main__":
    uvicorn.run("chat_simple_app:app", host="0.0.0.0", port=8000, reload=True)