/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

/**
 * Used to extract error from the backend-thrown error
 * @param err
 */
export function extractErrorMessage(err: unknown): string {
  if (err instanceof Error) {
    return err.message;
  }

  if (typeof err === "object" && err !== null && "error" in err) {
    const backendErr = (err as any).error;
    if (typeof backendErr === "string") {
      return backendErr;
    }
    if (typeof backendErr === "object" && "message" in backendErr) {
      return backendErr.message;
    }
  }

  return "An unknown error occurred.";
}
