import java.util.*;
import java.io.*;

public class DVD_Collection 
 {

  private static final int MAX = 100;   // constant
  private int capacity = MAX;           // maximum size of the array
  private int size = 0;                 // actual size of the array
  private String sourceName = null;     //file name storing DVD collection
  private boolean modified = false;
  
  private DVD_Entry[] theCollection =  new DVD_Entry[capacity];


  private int find(String title) 
  {
    for (int i = 0; i < size; i++) 
      if (theCollection[i].getTitle().equals(title)) return i;   
    return -1;
  }


//Add an entry or change an existing entry.
   public boolean addOrChangeEntry(DVD_Entry newEntry)
   {
        modified = true;
        int index = find(newEntry.getTitle());
        if (index > -1) 
        {   theCollection[index].setCategory(newEntry.getCategory());
            theCollection[index].setRunningTime(newEntry.getRunningTime());
            return false;
         } // end if
         else 
         {   add(newEntry);
             return true;
         }  // end else
  }

 
//Add an entry to the collection.  
  private void add(DVD_Entry entry) 
  {   theCollection[size] = entry;
      size++;
  }


 
//Loads saved collection information
   public void loadData(String fileName) 
   {    sourceName = fileName;
        try
        {
            BufferedReader in = new BufferedReader(new FileReader(fileName));
            String nextLine = null;
            String title = null;
            String runningTime = null;
            String category = null;
            StringTokenizer st = null;

        while ( (nextLine = in.readLine()) != null) 
        {     st = new StringTokenizer(nextLine, ",");
              title = st.nextToken();
              category = st.nextToken();
              runningTime = st.nextToken();
              add(new DVD_Entry(title, category, runningTime));
        }  // end while

        in.close();
      }  // end try
      catch (FileNotFoundException ex) 
      {      return;    }
      catch (IOException ex) 
      {   System.err.println("Load of directory failed.");
          ex.printStackTrace();
          System.exit(1);
      }
  }

 
//Look up an entry.
  public String[] lookupEntry(String title) 
  { int index = find(title);
    if (index > -1) 
    {   String[] out = new String[2];
        out[0] = theCollection[index].getCategory();
        out[1] = theCollection[index].getRunningTime();
        return out;
    }
    else  return null;    
  }

 
 //Remove an entry from the collection
   public boolean removeEntry(String notWanted) 
   {    int index = find(notWanted);

        if (index == -1)  return false;
        else  // this is really inefficient
        {   DVD_Entry[] newCollection = new DVD_Entry[theCollection.length];
            modified = true;

            for (int i = 0; i < index; i++) newCollection[i] = theCollection[i];
            for (int i = index + 1; i < theCollection.length; i++)
                    newCollection[i - 1] = theCollection[i];
            theCollection = newCollection;
            size--;
    }
    return true;
  }

  
// Method to save the collection.
  public void save() 
  {    if (modified) 
      {
        try 
        {   PrintWriter out = new PrintWriter(new FileWriter(sourceName));
            for (int i = 0; i < size; i++) 
            {  out.println(theCollection[i].getTitle() + "," +
               theCollection[i].getCategory() + "," +
               theCollection[i].getRunningTime());  
            }  // end for
           out.close();
           modified = false;
        }  // end try block
      catch (Exception ex) 
      {   System.err.println("Save of dcollection failed");
          ex.printStackTrace();
          System.exit(1);
      }// end catch clause
    }  // end if
  }  // end method save


// Retrieves all titles falling under the specified category
 
  public String[] getTitlesinCategory(String category) 
  {     int count = 0;
        String temp = "";
        String[] out;

    for (int i = 0; i < size; i++) 
    {   if (theCollection[i].getCategory().equals(category))
        {   count++;
            temp += theCollection[i].getTitle() + ",";
        }  //end if
    }  //end for

    if (count == 0)   return null;
    else 
    {   temp = temp.substring(0, temp.length()-1);
        StringTokenizer st = new StringTokenizer(temp, ",");
        out = new String[st.countTokens()];
        for (int j = 0; j < out.length; j++)
        out[j] = st.nextToken();
    }  // end else
    return out;
  }
 
 //Sort the collection by title  
  public void sortByTitle()
  {
    DVD_Entry minEntry;
    DVD_Entry temp;
    int minIndex;

    for (int i = 0; i < size; i++) 
    {   minEntry = theCollection[i];
        minIndex = i;
        for (int j = i; j < size; j++) 
        {   if (theCollection[j].getTitle().compareTo(minEntry.getTitle()) < 0) 
            {   minEntry = theCollection[j];
                minIndex = j;
            }  // end if
        }// end inner for
      temp = theCollection[i];
      theCollection[i] = minEntry;
      theCollection[minIndex] = temp;
    }  // end outer for
    modified = true;
  }  // end method sort by title
  
  public String toString()
  {     String temp = "";
        for(int i =0; i<size; i++)
            temp = temp + theCollection[i] +"\n";
        return temp;
        
  }   // end toString

}  // end class DVD_Collection