/*
 * Copyright (C) 2015 hops.io.
 *
 * Licensed 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.
 */
package org.apache.hadoop.hdfs;

import io.hops.exception.StorageException;
import org.apache.hadoop.ipc.RemoteException;

import java.io.IOException;
import java.lang.reflect.Constructor;
import java.net.BindException;
import java.net.ConnectException;
import java.net.NoRouteToHostException;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import java.net.UnknownHostException;

public class ExceptionCheck {

  private static class RemoteRuntimeException extends RemoteException {

    public RemoteRuntimeException(RemoteException re) {
      this(re.getClassName(), re.getMessage());
    }

    public RemoteRuntimeException(String className, String msg) {
      super(className, msg);
    }

    public RuntimeException unwrapRemoteRuntimeException() {
      try {
        Class<?> realClass = Class.forName(getClassName());
        return instantiateRuntimeExceptionException(
            realClass.asSubclass(RuntimeException.class));
      } catch (Exception e) {
        // cannot instantiate the original exception, just return this
      }
      return null;
    }

    private RuntimeException instantiateRuntimeExceptionException(
        Class<? extends RuntimeException> cls) throws Exception {
      Constructor<? extends RuntimeException> cn =
          cls.getConstructor(String.class);
      cn.setAccessible(true);
      RuntimeException ex = cn.newInstance(this.getMessage());
      ex.initCause(this);
      return ex;
    }
  }

  public static boolean isLocalConnectException(Exception e) {
    //for these Exceptions RPC call will be retried
    if (e instanceof ConnectException || e instanceof SocketException ||
        e instanceof BindException || e instanceof UnknownHostException ||
        e instanceof SocketTimeoutException ||
        e instanceof NoRouteToHostException || (e instanceof IOException &&
        e.getMessage().contains("Failed on local exception")) ||
        e instanceof NoAliveNamenodeException) {
      return true;
    }

    if (e instanceof RemoteException) {
      Exception unwrappedException = ((RemoteException) e)
          .unwrapRemoteException(); //unwraps wrapped IOExceptions
      if (unwrappedException instanceof RemoteException) { //unable to unwrap
        unwrappedException = (new RemoteRuntimeException((RemoteException) e))
            .unwrapRemoteRuntimeException(); //unwraps wrapped RuntimeExceptions
      }

      if (unwrappedException != null &&
          !(unwrappedException instanceof RemoteException)) {
        if (unwrappedException instanceof StorageException ||
            unwrappedException instanceof StorageException) {
          return true;
        }
      }
    }
    return false;
  }
}