/*
    * 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.
   */
  package org.apache.hadoop.hbase.client;
  
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  
  import java.io.IOException;
  import java.util.Date;
  import java.util.List;
  
  /**
   * Exception thrown by HTable methods when an attempt to do something (like
   * commit changes) fails after a bunch of retries.
   */
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class RetriesExhaustedException extends IOException {
    private static final long serialVersionUID = 1876775844L;
  
    public RetriesExhaustedException(final String msg) {
      super(msg);
    }
  
    public RetriesExhaustedException(final String msg, final IOException e) {
      super(msg, e);
    }
  
    /**
     * Datastructure that allows adding more info around Throwable incident.
     */
    @InterfaceAudience.Private
    public static class ThrowableWithExtraContext {
      private final Throwable t;
      private final long when;
      private final String extras;
  
      public ThrowableWithExtraContext(final Throwable t, final long when,
          final String extras) {
        this.t = t;
        this.when = when;
        this.extras = extras;
      }
  
      @Override
      public String toString() {
        return new Date(this.when).toString() + ", " + extras + ", " + t.toString();
      }
    }
  
    /**
     * Create a new RetriesExhaustedException from the list of prior failures.
     * @param callableVitals Details from the Callable we were using
     * when we got this exception.
     * @param numTries The number of tries we made
     * @param exceptions List of exceptions that failed before giving up
     */
    public RetriesExhaustedException(final String callableVitals, int numTries,
        List<Throwable> exceptions) {
      super(getMessage(callableVitals, numTries, exceptions));
    }
  
    /**
     * Create a new RetriesExhaustedException from the list of prior failures.
     * @param numTries
     * @param exceptions List of exceptions that failed before giving up
     */
    @InterfaceAudience.Private
    public RetriesExhaustedException(final int numTries,
                                     final List<ThrowableWithExtraContext> exceptions) {
      super(getMessage(numTries, exceptions),
        exceptions.isEmpty()? null: exceptions.get(exceptions.size() - 1).t);
    }
  
    private static String getMessage(String callableVitals, int numTries,
        List<Throwable> exceptions) {
      StringBuilder buffer = new StringBuilder("Failed contacting ");
      buffer.append(callableVitals);
      buffer.append(" after ");
      buffer.append(numTries + 1);
      buffer.append(" attempts.\nExceptions:\n");
      for (Throwable t : exceptions) {
        buffer.append(t.toString());
       buffer.append("\n");
     }
     return buffer.toString();
   }
 
   private static String getMessage(final int numTries,
       final List<ThrowableWithExtraContext> exceptions) {
     StringBuilder buffer = new StringBuilder("Failed after attempts=");
     buffer.append(numTries + 1);
     buffer.append(", exceptions:\n");
     for (ThrowableWithExtraContext t : exceptions) {
       buffer.append(t.toString());
       buffer.append("\n");
     }
     return buffer.toString();
   }
 }