import { getToken } from "@/utils/auth";

export class AdminApiError extends Error {
  status: number;
  body: unknown;

  constructor(message: string, status: number, body: unknown) {
    super(message);
    this.name = "AdminApiError";
    this.status = status;
    this.body = body;
  }
}

export function adminToken() {
  return getToken()?.accessToken || localStorage.getItem("admin_token") || "";
}

export function friendlyError(error: unknown) {
  const anyError = error as any;
  if (anyError?.body?.detail) {
    return typeof anyError.body.detail === "string"
      ? anyError.body.detail
      : JSON.stringify(anyError.body.detail);
  }
  if (typeof anyError?.body === "string" && anyError.body) return anyError.body;
  return anyError?.message || String(error || "未知错误");
}

export async function adminRequest<T = any>(
  path: string,
  options: {
    method?: string;
    json?: unknown;
    body?: BodyInit;
    headers?: Record<string, string>;
  } = {}
): Promise<T> {
  const headers = new Headers(options.headers || {});
  const token = adminToken();
  if (token) headers.set("X-Admin-Token", token);

  let body = options.body;
  if (options.json !== undefined) {
    headers.set("Content-Type", "application/json");
    body = JSON.stringify(options.json);
  }

  const response = await fetch(path, {
    method: options.method || "GET",
    headers,
    body,
    cache: "no-store"
  });

  const text = await response.text();
  let parsed: unknown = null;
  if (text) {
    try {
      parsed = JSON.parse(text);
    } catch {
      parsed = text;
    }
  }

  if (!response.ok) {
    throw new AdminApiError(
      `HTTP ${response.status}: ${text || response.statusText}`,
      response.status,
      parsed
    );
  }

  return parsed as T;
}

export async function copyText(text: string) {
  if (navigator.clipboard && window.isSecureContext) {
    await navigator.clipboard.writeText(text);
    return;
  }
  const textarea = document.createElement("textarea");
  textarea.value = text;
  textarea.style.position = "fixed";
  textarea.style.opacity = "0";
  document.body.appendChild(textarea);
  textarea.select();
  document.execCommand("copy");
  textarea.remove();
}

export async function downloadAdminFile(
  path: string,
  filename: string,
  options: {
    method?: string;
    json?: unknown;
    body?: BodyInit;
    headers?: Record<string, string>;
  } = {}
) {
  const headers = new Headers(options.headers || {});
  headers.set("X-Admin-Token", adminToken());

  let body = options.body;
  if (options.json !== undefined) {
    headers.set("Content-Type", "application/json");
    body = JSON.stringify(options.json);
  }

  const response = await fetch(path, {
    method: options.method || "GET",
    cache: "no-store",
    headers,
    body
  });
  if (!response.ok) {
    const text = await response.text();
    throw new AdminApiError(
      `HTTP ${response.status}: ${text || response.statusText}`,
      response.status,
      text
    );
  }
  const blob = await response.blob();
  const url = URL.createObjectURL(blob);
  const link = document.createElement("a");
  link.href = url;
  link.download = filename;
  document.body.appendChild(link);
  link.click();
  link.remove();
  URL.revokeObjectURL(url);
}