from urllib.parse import quote

import httpx
from fastapi import APIRouter, Request
from fastapi.responses import Response, StreamingResponse

from config import settings

router = APIRouter(tags=["chatlog-proxy"])

HOP_BY_HOP_HEADERS = {
    "connection",
    "keep-alive",
    "proxy-authenticate",
    "proxy-authorization",
    "te",
    "trailers",
    "transfer-encoding",
    "upgrade",
}


def _copy_headers(headers: httpx.Headers) -> dict[str, str]:
    copied: dict[str, str] = {}
    for key, value in headers.items():
        if key.lower() not in HOP_BY_HOP_HEADERS:
            copied[key] = value
    return copied


async def _proxy_chatlog(request: Request, upstream_path: str) -> Response:
    query = request.url.query
    target = f"{settings.chatlog_base_url}{upstream_path}"
    if query:
        target = f"{target}?{query}"

    body = await request.body()
    headers = {
        key: value
        for key, value in request.headers.items()
        if key.lower() not in HOP_BY_HOP_HEADERS and key.lower() != "host"
    }

    async with httpx.AsyncClient(timeout=None, trust_env=False, follow_redirects=True) as client:
        upstream = await client.request(
            request.method,
            target,
            content=body if body else None,
            headers=headers,
        )

    response_headers = _copy_headers(upstream.headers)
    return StreamingResponse(
        iter([upstream.content]),
        status_code=upstream.status_code,
        media_type=upstream.headers.get("content-type"),
        headers=response_headers,
    )


@router.api_route("/api/v1/{path:path}", methods=["GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS"])
async def proxy_api_v1(path: str, request: Request):
    return await _proxy_chatlog(request, f"/api/v1/{path}")


async def _proxy_media(kind: str, path: str, request: Request):
    safe_path = "/".join(quote(part, safe="") for part in path.split("/"))
    return await _proxy_chatlog(request, f"/{kind}/{safe_path}")


@router.api_route("/image/{path:path}", methods=["GET", "POST", "OPTIONS"])
async def proxy_image(path: str, request: Request):
    return await _proxy_media("image", path, request)


@router.api_route("/voice/{path:path}", methods=["GET", "POST", "OPTIONS"])
async def proxy_voice(path: str, request: Request):
    return await _proxy_media("voice", path, request)


@router.api_route("/video/{path:path}", methods=["GET", "POST", "OPTIONS"])
async def proxy_video(path: str, request: Request):
    return await _proxy_media("video", path, request)


@router.api_route("/file/{path:path}", methods=["GET", "POST", "OPTIONS"])
async def proxy_file(path: str, request: Request):
    return await _proxy_media("file", path, request)


@router.api_route("/data/{path:path}", methods=["GET", "POST", "OPTIONS"])
async def proxy_data(path: str, request: Request):
    return await _proxy_media("data", path, request)