type ApiError = {
  status: number;
  bodyText: string;
};

function buildUrl(path: string) {
  const base = (import.meta.env.VITE_API_BASE_URL as string | undefined) ?? "/api";
  if (path.startsWith("http://") || path.startsWith("https://")) return path;
  if (path.startsWith("/")) return `${base}${path}`;
  return `${base}/${path}`;
}

export async function apiJson<T>(path: string, init?: RequestInit): Promise<T> {
  const url = buildUrl(path);
  const res = await fetch(url, {
    ...init,
    headers: {
      "Content-Type": "application/json",
      ...(init?.headers ?? {}),
    },
  });

  if (!res.ok) {
    const bodyText = await res.text().catch(() => "");
    const err: ApiError = { status: res.status, bodyText };
    throw err;
  }

  return (await res.json()) as T;
}

function normalizeLoopbackHost(rawUrl: string): string {
  const cleaned = rawUrl.trim().replace(/^['"`\s]+|['"`\s]+$/g, "");
  try {
    const url = new URL(cleaned, window.location.origin);
    const loopbacks = new Set(["127.0.0.1", "localhost", "::1"]);
    if (loopbacks.has(url.hostname) && !loopbacks.has(window.location.hostname)) {
      url.hostname = window.location.hostname;
    }
    return url.toString().replace(/\/+$/, "");
  } catch {
    return cleaned.replace(/\/+$/, "");
  }
}

export function getMediamtxWebrtcBaseUrl(configUrl?: string) {
  const env = import.meta.env.VITE_MEDIAMTX_WEBRTC_URL as string | undefined;
  return normalizeLoopbackHost(env ?? configUrl ?? "http://localhost:8889");
}