import { message } from "@/utils/notify";
import type { ApiEnvelope, ApiErrorBody } from "./types";

export class ApiError extends Error {
  readonly code: string;
  readonly httpStatus: number;
  readonly data?: unknown;

  constructor(code: string, msg: string, httpStatus = 400, data?: unknown) {
    super(msg);
    this.name = "ApiError";
    this.code = code;
    this.httpStatus = httpStatus;
    this.data = data;
  }
}

export type HttpMethod = "GET" | "POST" | "PUT" | "PATCH" | "DELETE";

export interface RequestOptions {
  method?: HttpMethod;
  body?: unknown;
  headers?: Record<string, string>;
  /** 为 true 时不弹出错误提示（由调用方处理） */
  silent?: boolean;
  rawBody?: BodyInit | null;
  contentType?: string | null;
}

/**
 * 管理接口请求封装：自动带 credentials 与 X-Nixmsg-Request: 1，错误直接 message 显示。
 * W4 接真实后端时页面不必改，只需让 admin 模块走本函数。
 */
export async function requestAdmin<T>(path: string, opts: RequestOptions = {}): Promise<T> {
  const method = opts.method ?? (opts.body != null || opts.rawBody != null ? "POST" : "GET");
  const headers: Record<string, string> = {
    "X-Nixmsg-Request": "1",
    ...opts.headers,
  };

  let body: BodyInit | undefined | null = opts.rawBody;
  if (opts.rawBody === undefined && opts.body !== undefined) {
    headers["Content-Type"] = opts.contentType ?? "application/json";
    body = JSON.stringify(opts.body);
  } else if (opts.contentType) {
    headers["Content-Type"] = opts.contentType;
  }

  const res = await fetch(path, {
    method,
    credentials: "include",
    headers,
    body: body ?? undefined,
  });

  let envelope: ApiEnvelope<T>;
  try {
    envelope = (await res.json()) as ApiEnvelope<T>;
  } catch {
    const err = new ApiError("internal", `响应不是 JSON（HTTP ${res.status}）`, res.status);
    if (!opts.silent) {
      message.error(err.message);
    }
    throw err;
  }

  if (typeof envelope !== "object" || envelope === null) {
    const err = new ApiError("internal", "响应格式无效", res.status);
    if (!opts.silent) {
      message.error(err.message);
    }
    throw err;
  }

  if (envelope.ok) {
    return envelope.data;
  }

  const errBody: ApiErrorBody = envelope.error ?? { code: "internal", message: "未知错误" };
  const err = new ApiError(errBody.code, errBody.message, res.status, "data" in envelope ? envelope.data : undefined);
  if (!opts.silent) {
    message.error(err.message);
  }
  throw err;
}