api.ts

/**
 * Typed client for `GET /me` (ADR-0024). Sends the **ID token**, not the access token, as the
 * bearer: `lambda_handlers/me.py` reads `email` from the verified claims, and Cognito's access
 * token doesn't carry `email` by default — only the ID token does. This is a documented
 * assumption, not something verified against a live deployment (ADR-0030's consequences); if
 * `HttpUserPoolAuthorizer` turns out to reject ID tokens in practice, this is the one line that
 * needs to change.
 */
import type { StoredSession } from './session';

export interface MeResponse {
  readonly userId: string;
  readonly email: string;
  readonly created: boolean;
  readonly plan: string;
  readonly status: string;
  readonly forcedDryRun: boolean;
}

export class ApiError extends Error {
  constructor(
    message: string,
    public readonly status: number,
  ) {
    super(message);
  }
}

export async function fetchMe(
  apiBaseUrl: string,
  session: StoredSession,
  fetchImpl: typeof fetch = fetch,
): Promise<MeResponse> {
  const response = await fetchImpl(`${apiBaseUrl}/me`, {
    headers: { Authorization: `Bearer ${session.idToken}` },
  });
  if (!response.ok) {
    const text = await response.text().catch(() => '');
    throw new ApiError(`GET /me failed (${response.status}): ${text.slice(0, 300)}`, response.status);
  }
  return (await response.json()) as MeResponse;
}