Errors

{
  "error": {
    "code": "not_found",
    "message": "Person not found.",
    "request_id": "550e8400-e29b-41d4-a716-446655440000"
  }
}

{
  "error": {
    "code": "validation_error",
    "message": "Validation failed.",
    "fields": {
      "full_name": "String must contain at most 70 character(s).",
      "forecast_date": "Invalid ISO 8601 date format."
    },
    "request_id": "uuid"
  }
}

async function apiCall(url, options) {
  const res = await fetch(url, options);

  if (!res.ok) {
    const { error } = await res.json();

    switch (error.code) {
      case 'token_expired':
        // Refresh the token and retry once
        await refreshAccessToken();
        return apiCall(url, options);

      case 'invalid_grant':
        // Refresh token is invalid or expired. User must re-authorize.
        throw new Error('Authorization expired. User must re-authorize.');

      case 'invalid_client':
        // Credentials are wrong. Do not retry.
        throw new Error('Invalid client credentials. Check client_id and client_secret.');

      case 'rate_limit_exceeded': {
        const retryAfter = parseInt(res.headers.get('Retry-After') ?? '60');
        await new Promise((r) => setTimeout(r, retryAfter * 1000));
        return apiCall(url, options);
      }

      case 'not_found':
        return null;

      case 'internal_error':
        // Log the request_id for support, then surface to the caller
        console.error(`Server error. request_id: ${error.request_id}`);
        throw new Error(`Server error (request_id: ${error.request_id})`);

      default:
        throw new Error(`${error.code}: ${error.message} (request_id: ${error.request_id})`);
    }
  }

  return res.json();
}