/**
 * Thin control-plane client. Mirrors the relevant subset of
 * a2a_pack.cli.api_client.ControlPlaneClient.
 */
export class ApiError extends Error {
  constructor(public status: number, message: string) {
    super(`API ${status}: ${message}`);
    this.name = "ApiError";
  }
}

export interface AgentRow {
  name: string;
  version: string;
  status: string;
  url?: string;
  description?: string;
}

export class ControlPlaneClient {
  constructor(
    private apiUrl: string,
    private token: string | null,
  ) {
    this.apiUrl = apiUrl.replace(/\/+$/, "");
  }

  private headers(): Record<string, string> {
    const h: Record<string, string> = { "content-type": "application/json" };
    if (this.token) h["authorization"] = `bearer ${this.token}`;
    return h;
  }

  private async request<T>(method: string, path: string, body?: unknown): Promise<T> {
    const resp = await fetch(`${this.apiUrl}${path}`, {
      method,
      headers: this.headers(),
      body: body !== undefined ? JSON.stringify(body) : undefined,
    });
    if (!resp.ok) {
      let detail: string;
      try {
        const j: any = await resp.json();
        detail = j?.detail ?? JSON.stringify(j);
      } catch {
        detail = await resp.text();
      }
      throw new ApiError(resp.status, detail);
    }
    if (resp.status === 204) return undefined as T;
    return (await resp.json()) as T;
  }

  login(email: string, password: string) {
    return this.request<{
      access_token: string;
      user: { id: number; email: string };
    }>("POST", "/v1/auth/login", { email, password });
  }

  signup(email: string, password: string) {
    return this.request<{
      access_token: string;
      user: { id: number; email: string };
    }>("POST", "/v1/auth/signup", { email, password });
  }

  me() {
    return this.request<{ id: number; email: string }>("GET", "/v1/me");
  }

  listAgents() {
    return this.request<AgentRow[]>("GET", "/v1/agents");
  }

  getAgent(name: string) {
    return this.request<AgentRow>("GET", `/v1/agents/${encodeURIComponent(name)}`);
  }
}