package com.lodgon.chatserver.servlet;

import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;

/**
 * ChatStore
 */
public class ChatStore {
  private static List<String> history;
  private static int sequence = 0;
  
  private static Object sync = new Object();

  static {
    history = Collections.synchronizedList(new LinkedList<String>());
  }
  
  public static void addText(String line) {
    System.out.println("adding text");
    synchronized(sync) {
      history.add(line);
      sequence++;
      System.out.println("added line to history");
      sync.notifyAll();
      System.out.println("notified all");
    }
  }
  
  public static boolean hasNewText(int seq) {
    try {
      while (seq >= sequence) {
        synchronized(sync) {
          sync.wait();
        }
      }
    }catch(InterruptedException e) {
      e.printStackTrace();
    }
    return (seq < sequence);
  }
  
  public static Map getNewLines(int seq) {
    int returnSeq = sequence;
    int total = sequence - seq;
    StringBuffer b = new StringBuffer();
    for(int i = 0;i<total && i < 20;i++) {
      b.append(history.get(i+seq)).append("\n");
    }
    b.deleteCharAt(b.length() - 1);
    
    System.out.println("new text = \n"+b);
    
    Map result = new HashMap();
    result.put("sequence", returnSeq);
    result.put("text", b.toString());
    return result;    
  }
  
}