/*
    *
    * 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 org.apache.hadoop.hbase.DoNotRetryIOException;
  import org.apache.hadoop.hbase.util.Bytes;
  
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.util.Collection;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  /**
   * This subclass of {@link org.apache.hadoop.hbase.client.RetriesExhaustedException}
   * is thrown when we have more information about which rows were causing which
   * exceptions on what servers.  You can call {@link #mayHaveClusterIssues()}
   * and if the result is false, you have input error problems, otherwise you
   * may have cluster issues.  You can iterate over the causes, rows and last
   * known server addresses via {@link #getNumExceptions()} and
   * {@link #getCause(int)}, {@link #getRow(int)} and {@link #getHostnamePort(int)}.
   */
  @SuppressWarnings("serial")
  @InterfaceAudience.Public
  @InterfaceStability.Stable
  public class RetriesExhaustedWithDetailsException
  extends RetriesExhaustedException {
    List<Throwable> exceptions;
    List<Row> actions;
    List<String> hostnameAndPort;
  
    public RetriesExhaustedWithDetailsException(List<Throwable> exceptions,
                                                List<Row> actions,
                                                List<String> hostnameAndPort) {
      super("Failed " + exceptions.size() + " action" +
          pluralize(exceptions) + ": " +
          getDesc(exceptions, actions, hostnameAndPort));
  
      this.exceptions = exceptions;
      this.actions = actions;
      this.hostnameAndPort = hostnameAndPort;
    }
  
    public List<Throwable> getCauses() {
      return exceptions;
    }
  
    public int getNumExceptions() {
      return exceptions.size();
    }
  
    public Throwable getCause(int i) {
      return exceptions.get(i);
    }
  
    public Row getRow(int i) {
      return actions.get(i);
    }
  
    public String getHostnamePort(final int i) {
      return this.hostnameAndPort.get(i);
    }
  
    public boolean mayHaveClusterIssues() {
      boolean res = false;
  
      // If all of the exceptions are DNRIOE not exception
      for (Throwable t : exceptions) {
        if ( !(t instanceof DoNotRetryIOException ||
               t instanceof NeedUnmanagedConnectionException)) {
          res = true;
        }
      }
      return res;
    }
  
  
   public static String pluralize(Collection<?> c) {
     return pluralize(c.size());
   }
 
   public static String pluralize(int c) {
     return c > 1 ? "s" : "";
   }
 
   public static String getDesc(List<Throwable> exceptions,
                                List<? extends Row> actions,
                                List<String> hostnamePort) {
     String s = getDesc(classifyExs(exceptions));
     StringBuilder addrs = new StringBuilder(s);
     addrs.append("servers with issues: ");
     Set<String> uniqAddr = new HashSet<String>();
     uniqAddr.addAll(hostnamePort);
 
     for (String addr : uniqAddr) {
       addrs.append(addr).append(", ");
     }
     return uniqAddr.isEmpty() ? addrs.toString() : addrs.substring(0, addrs.length() - 2);
   }
 
   public String getExhaustiveDescription() {
     StringWriter errorWriter = new StringWriter();
     PrintWriter pw = new PrintWriter(errorWriter);
     for (int i = 0; i < this.exceptions.size(); ++i) {
       Throwable t = this.exceptions.get(i);
       Row action = this.actions.get(i);
       String server = this.hostnameAndPort.get(i);
       pw.append("exception");
       if (this.exceptions.size() > 1) {
         pw.append(" #" + i);
       }
       pw.append(" from " + server + " for "
         + ((action == null) ? "unknown key" : Bytes.toStringBinary(action.getRow())));
       if (t != null) {
         pw.println();
         t.printStackTrace(pw);
       }
     }
     pw.flush();
     return errorWriter.toString();
   }
 
 
   public static Map<String, Integer> classifyExs(List<Throwable> ths) {
     Map<String, Integer> cls = new HashMap<String, Integer>();
     for (Throwable t : ths) {
       if (t == null) continue;
       String name = "";
       if (t instanceof DoNotRetryIOException) {
         name = t.getMessage();
       } else {
         name = t.getClass().getSimpleName();
       }
       Integer i = cls.get(name);
       if (i == null) {
         i = 0;
       }
       i += 1;
       cls.put(name, i);
     }
     return cls;
   }
 
   public static String getDesc(Map<String,Integer> classificaton) {
     StringBuilder classificatons =new StringBuilder(11);
     for (Map.Entry<String, Integer> e : classificaton.entrySet()) {
       classificatons.append(e.getKey());
       classificatons.append(": ");
       classificatons.append(e.getValue());
       classificatons.append(" time");
       classificatons.append(pluralize(e.getValue()));
       classificatons.append(", ");
     }
     return classificatons.toString();
   }
 
 }