/**
    * 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.procedure2.store.wal;
  
  import java.io.IOException;
  import java.io.PrintStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.cli.CommandLine;
  import org.apache.commons.cli.CommandLineParser;
  import org.apache.commons.cli.HelpFormatter;
  import org.apache.commons.cli.Options;
  import org.apache.commons.cli.ParseException;
  import org.apache.commons.cli.PosixParser;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.conf.Configured;
  import org.apache.hadoop.fs.FSDataInputStream;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.hbase.procedure2.Procedure;
  import org.apache.hadoop.hbase.protobuf.generated.ProcedureProtos.ProcedureWALEntry;
  import org.apache.hadoop.hbase.protobuf.generated.ProcedureProtos.ProcedureWALHeader;
  import org.apache.hadoop.util.Tool;
  import org.apache.hadoop.util.ToolRunner;
  
  /**
   * ProcedureWALPrettyPrinter prints the contents of a given ProcedureWAL file
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.TOOLS)
  @InterfaceStability.Evolving
  public class ProcedureWALPrettyPrinter extends Configured implements Tool {
    private final PrintStream out;
  
    public ProcedureWALPrettyPrinter() {
      out = System.out;
    }
  
    /**
     * Reads a log file and outputs its contents.
     *
     * @param conf   HBase configuration relevant to this log file
     * @param p       path of the log file to be read
     * @throws IOException  IOException
     */
    public void processFile(final Configuration conf, final Path p)
        throws IOException {
  
      FileSystem fs = p.getFileSystem(conf);
      if (!fs.exists(p)) {
        System.err.println("ERROR, file doesnt exist: " + p);
        return;
      }
      if (!fs.isFile(p)) {
        System.err.println(p + " is not a file");
        return;
      }
  
      FileStatus logFile = fs.getFileStatus(p);
      if (logFile.getLen() == 0) {
        out.println("Zero length file: " + p);
        return;
      }
  
      out.println("Opening procedure state-log: " + p);
      ProcedureWALFile log = new ProcedureWALFile(fs, logFile);
      processProcedureWALFile(log);
    }
  
    public void processProcedureWALFile(ProcedureWALFile log) throws IOException {
      log.open();
      ProcedureWALHeader header = log.getHeader();
      printHeader(header);
  
      FSDataInputStream stream = log.getStream();
      try {
        boolean hasMore = true;
        while (hasMore) {
          ProcedureWALEntry entry = ProcedureWALFormat.readEntry(stream);
         if (entry == null) {
           out.println("No more entry, exiting with missing EOF");
           hasMore = false;
           break;
         }
         switch (entry.getType()) {
           case EOF:
             hasMore = false;
             break;
           default:
             printEntry(entry);
         }
       }
     } catch (IOException e) {
       out.println("got an exception while reading the procedure WAL " + e.getMessage());
     }
     finally {
       log.close();
     }
   }
 
   private void printEntry(ProcedureWALEntry entry) throws IOException {
     out.println("EntryType=" + entry.getType());
     int procCount = entry.getProcedureCount();
     for (int i = 0; i < procCount; i++) {
       Procedure<?> proc = Procedure.convert(entry.getProcedure(i));
       printProcedure(proc);
     }
   }
 
   private void printProcedure(Procedure<?> proc) {
     out.println(proc.toStringDetails());
   }
 
   private void printHeader(ProcedureWALHeader header) {
     out.println("ProcedureWALHeader: ");
     out.println("  Version: " + header.getVersion());
     out.println("  Type: " + header.getType());
     out.println("  LogId: " + header.getLogId());
     out.println("  MinProcId: " + header.getMinProcId());
     out.println();
   }
 
   /**
    * Pass one or more log file names and formatting options and it will dump out
    * a text version of the contents on <code>stdout</code>.
    *
    * @param args
    *          Command line arguments
    * @throws IOException
    *           Thrown upon file system errors etc.
    */
   public int run(final String[] args) throws IOException {
     // create options
     Options options = new Options();
     options.addOption("h", "help", false, "Output help message");
     options.addOption("f", "file", true, "File to print");
 
     final List<Path> files = new ArrayList<Path>();
     try {
       CommandLine cmd = new PosixParser().parse(options, args);
 
       if (cmd.hasOption("f")) {
         files.add(new Path(cmd.getOptionValue("f")));
       }
 
       if (files.size() == 0 || cmd.hasOption("h")) {
         HelpFormatter formatter = new HelpFormatter();
         formatter.printHelp("ProcedureWALPrettyPrinter ", options, true);
         return(-1);
       }
     } catch (ParseException e) {
       e.printStackTrace();
       HelpFormatter formatter = new HelpFormatter();
       formatter.printHelp("ProcedureWALPrettyPrinter ", options, true);
       return(-1);
     }
     // get configuration, file system, and process the given files
     for (Path file : files) {
       processFile(getConf(), file);
     }
     return(0);
   }
 
   public static void main(String[] args) throws Exception {
     final Configuration conf = HBaseConfiguration.create();
     int exitCode = ToolRunner.run(conf, new ProcedureWALPrettyPrinter(), args);
     System.exit(exitCode);
   }
 }