/**
    * 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.wal;
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.PrintStream;
  import java.util.ArrayList;
  import java.util.Date;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  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.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.classification.InterfaceStability;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.Cell;
  import org.apache.hadoop.hbase.CellUtil;
  import org.apache.hadoop.hbase.HBaseConfiguration;
  import org.apache.hadoop.hbase.HBaseInterfaceAudience;
  import org.apache.hadoop.hbase.Tag;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.codehaus.jackson.map.ObjectMapper;
  
  import org.apache.hadoop.hbase.regionserver.wal.ProtobufLogReader;
  // imports for things that haven't moved yet.
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  
  /**
   * WALPrettyPrinter prints the contents of a given WAL with a variety of
   * options affecting formatting and extent of content.
   *
   * It targets two usage cases: pretty printing for ease of debugging directly by
   * humans, and JSON output for consumption by monitoring and/or maintenance
   * scripts.
   *
   * It can filter by row, region, or sequence id.
   *
   * It can also toggle output of values.
   *
   */
  @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.TOOLS)
  @InterfaceStability.Evolving
  public class WALPrettyPrinter {
    private boolean outputValues;
    private boolean outputJSON;
    // The following enable filtering by sequence, region, and row, respectively
    private long sequence;
    private String region;
    private String row;
    // enable in order to output a single list of transactions from several files
    private boolean persistentOutput;
    private boolean firstTxn;
    // useful for programmatic capture of JSON output
    private PrintStream out;
    // for JSON encoding
    private static final ObjectMapper MAPPER = new ObjectMapper();
  
    /**
     * Basic constructor that simply initializes values to reasonable defaults.
     */
    public WALPrettyPrinter() {
      outputValues = false;
      outputJSON = false;
      sequence = -1;
      region = null;
      row = null;
      persistentOutput = false;
      firstTxn = true;
      out = System.out;
    }
  
    /**
     * Fully specified constructor.
    *
    * @param outputValues
    *          when true, enables output of values along with other log
    *          information
    * @param outputJSON
    *          when true, enables output in JSON format rather than a
    *          "pretty string"
    * @param sequence
    *          when nonnegative, serves as a filter; only log entries with this
    *          sequence id will be printed
    * @param region
    *          when not null, serves as a filter; only log entries from this
    *          region will be printed
    * @param row
    *          when not null, serves as a filter; only log entries from this row
    *          will be printed
    * @param persistentOutput
    *          keeps a single list running for multiple files. if enabled, the
    *          endPersistentOutput() method must be used!
    * @param out
    *          Specifies an alternative to stdout for the destination of this
    *          PrettyPrinter's output.
    */
   public WALPrettyPrinter(boolean outputValues, boolean outputJSON,
       long sequence, String region, String row, boolean persistentOutput,
       PrintStream out) {
     this.outputValues = outputValues;
     this.outputJSON = outputJSON;
     this.sequence = sequence;
     this.region = region;
     this.row = row;
     this.persistentOutput = persistentOutput;
     if (persistentOutput) {
       beginPersistentOutput();
     }
     this.out = out;
     this.firstTxn = true;
   }
 
   /**
    * turns value output on
    */
   public void enableValues() {
     outputValues = true;
   }
 
   /**
    * turns value output off
    */
   public void disableValues() {
     outputValues = false;
   }
 
   /**
    * turns JSON output on
    */
   public void enableJSON() {
     outputJSON = true;
   }
 
   /**
    * turns JSON output off, and turns on "pretty strings" for human consumption
    */
   public void disableJSON() {
     outputJSON = false;
   }
 
   /**
    * sets the region by which output will be filtered
    *
    * @param sequence
    *          when nonnegative, serves as a filter; only log entries with this
    *          sequence id will be printed
    */
   public void setSequenceFilter(long sequence) {
     this.sequence = sequence;
   }
 
   /**
    * sets the region by which output will be filtered
    *
    * @param region
    *          when not null, serves as a filter; only log entries from this
    *          region will be printed
    */
   public void setRegionFilter(String region) {
     this.region = region;
   }
 
   /**
    * sets the region by which output will be filtered
    *
    * @param row
    *          when not null, serves as a filter; only log entries from this row
    *          will be printed
    */
   public void setRowFilter(String row) {
     this.row = row;
   }
 
   /**
    * enables output as a single, persistent list. at present, only relevant in
    * the case of JSON output.
    */
   public void beginPersistentOutput() {
     if (persistentOutput)
       return;
     persistentOutput = true;
     firstTxn = true;
     if (outputJSON)
       out.print("[");
   }
 
   /**
    * ends output of a single, persistent list. at present, only relevant in the
    * case of JSON output.
    */
   public void endPersistentOutput() {
     if (!persistentOutput)
       return;
     persistentOutput = false;
     if (outputJSON)
       out.print("]");
   }
 
   /**
    * reads a log file and outputs its contents, one transaction at a time, as
    * specified by the currently configured options
    *
    * @param conf
    *          the HBase configuration relevant to this log file
    * @param p
    *          the path of the log file to be read
    * @throws IOException
    *           may be unable to access the configured filesystem or requested
    *           file.
    */
   public void processFile(final Configuration conf, final Path p)
       throws IOException {
     FileSystem fs = p.getFileSystem(conf);
     if (!fs.exists(p)) {
       throw new FileNotFoundException(p.toString());
     }
     if (!fs.isFile(p)) {
       throw new IOException(p + " is not a file");
     }
 
     WAL.Reader log = WALFactory.createReader(fs, p, conf);
     
     if (log instanceof ProtobufLogReader) {
       List<String> writerClsNames = ((ProtobufLogReader) log).getWriterClsNames();
       if (writerClsNames != null && writerClsNames.size() > 0) {
         out.print("Writer Classes: ");
         for (int i = 0; i < writerClsNames.size(); i++) {
           out.print(writerClsNames.get(i));
           if (i != writerClsNames.size() - 1) {
             out.print(" ");
           }
         }
         out.println();
       }
       
       String cellCodecClsName = ((ProtobufLogReader) log).getCodecClsName();
       if (cellCodecClsName != null) {
         out.println("Cell Codec Class: " + cellCodecClsName);
       }
     }
     
     if (outputJSON && !persistentOutput) {
       out.print("[");
       firstTxn = true;
     }
     
     try {
       WAL.Entry entry;
       while ((entry = log.next()) != null) {
         WALKey key = entry.getKey();
         WALEdit edit = entry.getEdit();
         // begin building a transaction structure
         Map<String, Object> txn = key.toStringMap();
         long writeTime = key.getWriteTime();
         // check output filters
         if (sequence >= 0 && ((Long) txn.get("sequence")) != sequence)
           continue;
         if (region != null && !((String) txn.get("region")).equals(region))
           continue;
         // initialize list into which we will store atomic actions
         List<Map> actions = new ArrayList<Map>();
         for (Cell cell : edit.getCells()) {
           // add atomic operation to txn
           Map<String, Object> op = new HashMap<String, Object>(toStringMap(cell));
           if (outputValues) op.put("value", Bytes.toStringBinary(cell.getValue()));
           // check row output filter
           if (row == null || ((String) op.get("row")).equals(row)) {
             actions.add(op);
           }
         }
         if (actions.size() == 0)
           continue;
         txn.put("actions", actions);
         if (outputJSON) {
           // JSON output is a straightforward "toString" on the txn object
           if (firstTxn)
             firstTxn = false;
           else
             out.print(",");
           // encode and print JSON
           out.print(MAPPER.writeValueAsString(txn));
         } else {
           // Pretty output, complete with indentation by atomic action
           out.println("Sequence=" + txn.get("sequence") + " "
               + ", region=" + txn.get("region") + " at write timestamp=" + new Date(writeTime));
           for (int i = 0; i < actions.size(); i++) {
             Map op = actions.get(i);
             out.println("row=" + op.get("row") +
                 ", column=" + op.get("family") + ":" + op.get("qualifier"));
             if (op.get("tag") != null) {
               out.println("    tag: " + op.get("tag"));
             }
             if (outputValues) out.println("    value: " + op.get("value"));
           }
         }
       }
     } finally {
       log.close();
     }
     if (outputJSON && !persistentOutput) {
       out.print("]");
     }
   }
 
   private static Map<String, Object> toStringMap(Cell cell) {
     Map<String, Object> stringMap = new HashMap<String, Object>();
     stringMap.put("row",
         Bytes.toStringBinary(cell.getRowArray(), cell.getRowOffset(), cell.getRowLength()));
     stringMap.put("family", Bytes.toStringBinary(cell.getFamilyArray(), cell.getFamilyOffset(),
                 cell.getFamilyLength()));
     stringMap.put("qualifier",
         Bytes.toStringBinary(cell.getQualifierArray(), cell.getQualifierOffset(),
             cell.getQualifierLength()));
     stringMap.put("timestamp", cell.getTimestamp());
     stringMap.put("vlen", cell.getValueLength());
     if (cell.getTagsLength() > 0) {
       List<String> tagsString = new ArrayList<String>();
       Iterator<Tag> tagsIterator = CellUtil.tagsIterator(cell.getTagsArray(), cell.getTagsOffset(),
           cell.getTagsLength());
       while (tagsIterator.hasNext()) {
         Tag tag = tagsIterator.next();
         tagsString.add((tag.getType()) + ":"
             + Bytes.toStringBinary(tag.getBuffer(), tag.getTagOffset(), tag.getTagLength()));
       }
       stringMap.put("tag", tagsString);
     }
     return stringMap;
   }
 
   public static void main(String[] args) throws IOException {
     run(args);
   }
 
   /**
    * 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 static void run(String[] args) throws IOException {
     // create options
     Options options = new Options();
     options.addOption("h", "help", false, "Output help message");
     options.addOption("j", "json", false, "Output JSON");
     options.addOption("p", "printvals", false, "Print values");
     options.addOption("r", "region", true,
         "Region to filter by. Pass encoded region name; e.g. '9192caead6a5a20acb4454ffbc79fa14'");
     options.addOption("s", "sequence", true,
         "Sequence to filter by. Pass sequence number.");
     options.addOption("w", "row", true, "Row to filter by. Pass row name.");
 
     WALPrettyPrinter printer = new WALPrettyPrinter();
     CommandLineParser parser = new PosixParser();
     List<?> files = null;
     try {
       CommandLine cmd = parser.parse(options, args);
       files = cmd.getArgList();
       if (files.size() == 0 || cmd.hasOption("h")) {
         HelpFormatter formatter = new HelpFormatter();
         formatter.printHelp("WAL <filename...>", options, true);
         System.exit(-1);
       }
       // configure the pretty printer using command line options
       if (cmd.hasOption("p"))
         printer.enableValues();
       if (cmd.hasOption("j"))
         printer.enableJSON();
       if (cmd.hasOption("r"))
         printer.setRegionFilter(cmd.getOptionValue("r"));
       if (cmd.hasOption("s"))
         printer.setSequenceFilter(Long.parseLong(cmd.getOptionValue("s")));
       if (cmd.hasOption("w"))
         printer.setRowFilter(cmd.getOptionValue("w"));
     } catch (ParseException e) {
       e.printStackTrace();
       HelpFormatter formatter = new HelpFormatter();
       formatter.printHelp("HFile filename(s) ", options, true);
       System.exit(-1);
     }
     // get configuration, file system, and process the given files
     Configuration conf = HBaseConfiguration.create();
     FSUtils.setFsDefault(conf, FSUtils.getRootDir(conf));
 
     // begin output
     printer.beginPersistentOutput();
     for (Object f : files) {
       Path file = new Path((String) f);
       FileSystem fs = file.getFileSystem(conf);
       if (!fs.exists(file)) {
         System.err.println("ERROR, file doesnt exist: " + file);
         return;
       }
       printer.processFile(conf, file);
     }
     printer.endPersistentOutput();
   }
 }