from __future__ import annotations

from urllib.parse import parse_qsl, urlencode, urlsplit, urlunsplit

from fastapi import Request, WebSocket

from vocero_api.core import config as settings


def _url_with_query(url: str, **params: str) -> str:
    target = urlsplit(url)
    merged_query = dict(parse_qsl(target.query, keep_blank_values=True))
    for key, value in params.items():
        if value:
            merged_query[key] = value
    return urlunsplit(
        (
            target.scheme,
            target.netloc,
            target.path,
            urlencode(merged_query, doseq=True),
            target.fragment,
        )
    )


def _proxy_public_url(request: Request) -> str:
    if not settings.S2S_PROXY_TARGET:
        return ""
    forwarded_proto = (request.headers.get("x-forwarded-proto") or request.url.scheme).split(",")[0].strip()
    forwarded_host = (
        (request.headers.get("x-forwarded-host") or request.headers.get("host") or request.url.netloc)
        .split(",")[0]
        .strip()
    )
    ws_scheme = "wss" if forwarded_proto in {"https", "wss"} else "ws"
    root_path = (request.scope.get("root_path") or "").rstrip("/")
    return f"{ws_scheme}://{forwarded_host}{root_path}/v1/realtime"


def _proxy_upstream_url(ws: WebSocket) -> str:
    target = urlsplit(settings.S2S_PROXY_TARGET)
    merged_query = dict(parse_qsl(target.query, keep_blank_values=True))
    merged_query.update(parse_qsl(ws.url.query, keep_blank_values=True))
    return urlunsplit(
        (
            target.scheme,
            target.netloc,
            target.path or "/v1/realtime",
            urlencode(merged_query, doseq=True),
            target.fragment,
        )
    )