import { readErrorBody } from "../utils/fetch";

/** Modrinth API v2 的基础请求客户端，封装鉴权与 User-Agent。 */
export class ModrinthClient {
  private base = "https://api.modrinth.com/v2";
  private token: string;
  private userAgent?: string;

  constructor(token: string, userAgent?: string) {
    this.token = token;
    this.userAgent = userAgent;
  }

  /** 构造通用请求头（Authorization，以及可选的 User-Agent）。 */
  private headers(): Record<string, string> {
    const h: Record<string, string> = {
      Authorization: this.token,
    };
    if (this.userAgent) {
      h["User-Agent"] = this.userAgent;
    }
    return h;
  }

  /** 发送 GET 请求并解析 JSON 响应体。 */
  async get<T>(path: string): Promise<T> {
    const res = await fetch(`${this.base}${path}`, {
      headers: this.headers(),
    });
    if (!res.ok) {
      const body = await readErrorBody(res);
      throw new Error(
        `Modrinth API GET ${path} failed: ${res.status} ${res.statusText}\n${body}`,
      );
    }
    return res.json() as Promise<T>;
  }

  /**
   * 发送 POST 请求，body 为 FormData（multipart/form-data）。
   * 不手动设置 Content-Type，让 fetch 自动生成含 boundary 的头。
   */
  async post<T>(path: string, body: FormData): Promise<T> {
    const res = await fetch(`${this.base}${path}`, {
      method: "POST",
      headers: this.headers(),
      body,
    });
    if (!res.ok) {
      const resBody = await readErrorBody(res);
      throw new Error(
        `Modrinth API POST ${path} failed: ${res.status} ${res.statusText}\n${resBody}`,
      );
    }
    return res.json() as Promise<T>;
  }
}