/*
    * 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.chukwa.util;
  
  
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.util.regex.*;
  import java.util.*;
  import java.io.*;
  import org.apache.hadoop.chukwa.*;
  import org.apache.hadoop.chukwa.conf.ChukwaConfiguration;
  import org.apache.hadoop.chukwa.util.RegexUtil.CheckedPatternSyntaxException;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.fs.FileUtil;
  import org.apache.hadoop.io.SequenceFile;
  import org.apache.hadoop.conf.Configuration;
  
  public class DumpChunks {
  
    
    /**
     * Tries to find chunks matching a given pattern.
     * Takes as input a set of &-delimited patterns, followed
     * by a list of file names.
     * 
     * E.g:  Dump datatype=Iostat&source=/my/log/.* *.done
     */
    public static void main(String[] args) throws IOException, URISyntaxException {
      
      if(args.length < 2) {
        System.out.println("usage: Dump [-s] pattern1,pattern2,pattern3... file1 file2 file3...");
        System.exit(-1);
      }
      
      ChukwaConfiguration conf = new ChukwaConfiguration();
  
      dump(args, conf, System.out);
    }
    
    static FileSystem getFS(Configuration conf, String uri) throws IOException, URISyntaxException {
      FileSystem fs;
      if(uri.contains("://")) {
        fs = FileSystem.get(new URI(uri), conf);
      } else {
        String fsName = conf.get("writer.hdfs.filesystem");
        if(fsName == null)
          fs = FileSystem.getLocal(conf);
        else
          fs = FileSystem.get(conf);
      }
      System.err.println("filesystem is " + fs.getUri());
      return fs;
    }
  
    static void dump(String[] args, Configuration conf, PrintStream out) throws IOException, URISyntaxException {
      
      int filterArg = 0;
      boolean summarize = false;
      boolean nosort = false;
      if(args[0].equals("-s")) {
        filterArg++;
        summarize = true;
      } else if(args[0].equals("--nosort")) {
        filterArg++;
        nosort = true;
      }
      
      Filter patterns = null;
      if(args[filterArg].toLowerCase().equals("all"))
        patterns = Filter.ALL;
      else {
        try {
          patterns = new Filter(args[filterArg]);
        } catch (CheckedPatternSyntaxException pse) {
          System.err.println("Error parsing \"tags\" regular expression: " + pse.getMessage());
          return;
        }
      }
  
      System.err.println("Patterns:" + patterns);
      ArrayList<Path> filesToSearch = new ArrayList<Path>();
  
     FileSystem fs = getFS(conf, args[filterArg + 1]);
     for(int i=filterArg + 1; i < args.length; ++i){
       Path[] globbedPaths = FileUtil.stat2Paths(fs.globStatus(new Path(args[i])));
       if(globbedPaths != null)
         for(Path p: globbedPaths)
           filesToSearch.add(p);
     }
     
     System.err.println("expands to " + filesToSearch.size() + " actual files");
 
     DumpChunks dc;
     if(summarize)
       dc = new DumpAndSummarize();
     else if(nosort)
       dc = new DumpNoSort(out);
     else
       dc= new DumpChunks();
     
     try {
       for(Path p: filesToSearch) {
       
         SequenceFile.Reader r = new SequenceFile.Reader(fs, p, conf);
   
         ChukwaArchiveKey key = new ChukwaArchiveKey();
         ChunkImpl chunk = ChunkImpl.getBlankChunk();
         while (r.next(key, chunk)) {
           if(patterns.matches(chunk)) {
             dc.updateMatchCatalog(key.getStreamName(), chunk);
             chunk = ChunkImpl.getBlankChunk();
           }
         }
       }
       
       dc.displayResults(out);
       
     } catch (Exception e) {
       e.printStackTrace();
     }
   }
 
   public DumpChunks() {
     matchCatalog = new HashMap<String, SortedMap<Long, ChunkImpl> >();
   }
 
   Map<String, SortedMap<Long, ChunkImpl>> matchCatalog;
   
   protected void displayResults(PrintStream out) throws IOException{
     for(Map.Entry<String,SortedMap<Long, ChunkImpl>> streamE: matchCatalog.entrySet()) {
       String header = streamE.getKey();
       SortedMap<Long, ChunkImpl> stream = streamE.getValue();
       long nextToPrint = 0;
       if(stream.firstKey() > 0)
         System.err.println("---- map starts at "+ stream.firstKey());
       for(Map.Entry<Long, ChunkImpl> e: stream.entrySet()) {
         if(e.getKey() >= nextToPrint) {
           if(e.getKey() > nextToPrint)
             System.err.println("---- printing bytes starting at " + e.getKey());
           
           out.write(e.getValue().getData());
           nextToPrint = e.getValue().getSeqID();
         } else if(e.getValue().getSeqID() < nextToPrint) {
           continue; //data already printed
         } else {
           //tricky case: chunk overlaps with already-printed data, but not completely
           ChunkImpl c = e.getValue();
           long chunkStartPos = e.getKey();
           int numToPrint = (int) (c.getSeqID() - nextToPrint);
           int printStartOffset = (int) ( nextToPrint -  chunkStartPos);
           out.write(c.getData(), printStartOffset, numToPrint);
           nextToPrint = c.getSeqID();
         }
       }
       out.println("\n--------"+header + "--------");
     }
   }
  
   protected void updateMatchCatalog(String streamName,  ChunkImpl chunk) throws IOException {
 
     SortedMap<Long, ChunkImpl> chunksInStream = matchCatalog.get(streamName);
     if(chunksInStream == null ) {
       chunksInStream = new TreeMap<Long, ChunkImpl>();
       matchCatalog.put(streamName, chunksInStream);
     }
     
     long startPos = chunk.getSeqID() - chunk.getLength();
     
     ChunkImpl prevMatch = chunksInStream.get(startPos);
     if(prevMatch == null)
       chunksInStream.put(startPos, chunk);
     else { //pick longest
       if(chunk.getLength() > prevMatch.getLength())
         chunksInStream.put (startPos, chunk);
     }
   }
 
   static class DumpAndSummarize extends DumpChunks {
     Map<String, Integer> matchCounts = new LinkedHashMap<String, Integer>();
     Map<String, Long> byteCounts = new LinkedHashMap<String, Long>();
     
 
     protected void displayResults(PrintStream out) throws IOException{
       for(Map.Entry<String, Integer> s: matchCounts.entrySet()) {
         out.print(s.getKey());
         out.print(" ");
         out.print(s.getValue());
         out.print(" chunks ");
         out.print(byteCounts.get(s.getKey()));
         out.println(" bytes");
       }
         
     }
     
     protected void updateMatchCatalog(String streamName,  ChunkImpl chunk) {
       Integer i = matchCounts.get(streamName);
       if(i != null) {
         matchCounts.put(streamName, i+1);
         Long b = byteCounts.get(streamName);
         byteCounts.put(streamName, b + chunk.getLength());
       } else {
         matchCounts.put(streamName, new Integer(1));
         byteCounts.put(streamName, new Long(chunk.getLength()));
       }
     }
     
   }
   
   static class DumpNoSort extends DumpChunks {
     
     PrintStream out; 
     public DumpNoSort(PrintStream out) {
       this.out = out;
     }
     //Do some display
     protected void updateMatchCatalog(String streamName,  ChunkImpl chunk) throws IOException {
       out.write(chunk.getData());
     }
     
     protected void displayResults(PrintStream out) throws IOException{
       //did this in updateMatchCatalog
     }
     
   }
 
 }