package jalview.io.cache;

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;

import javax.swing.JComboBox;
import javax.swing.SwingUtilities;

public class JvCacheableInputBox<E> extends JComboBox<String>
{

  private static final long serialVersionUID = 5774610435079326695L;

  private String cacheKey;

  private AppCache appCache;

  public JvCacheableInputBox(String cacheKey)
  {
    super();
    this.cacheKey = cacheKey;
    setEditable(true);
    setPrototypeDisplayValue("XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX");
    appCache = AppCache.getInstance();
    appCache.initCache(cacheKey);
    updateCache();
  }


  /**
   * Answers true if input text is an integer
   * 
   * @param text
   * @return
   */
  private boolean isInteger(String text)
  {
    try
    {
      Integer.parseInt(text);
      return true;
    } catch (NumberFormatException e)
    {
      return false;
    }
  }

  /**
   * Method called to update the cache with the last user input
   */
  public void updateCache()
  {
    SwingUtilities.invokeLater(new Runnable()
    {
      @Override
      public void run()
      {
        String userInput = getUserInput();
        if (userInput != null && !userInput.isEmpty())
        {
          LinkedHashSet<String> foundCache = appCache
                  .getAllCachedItemsFor(cacheKey);
          // remove old cache item so as to place current input at the top of
          // the result
          foundCache.remove(userInput);
          foundCache.add(userInput);
          appCache.putCache(cacheKey, foundCache);
        }

        String lastSearch = userInput;
        if (getItemCount() > 0)
        {
          removeAllItems();
        }
        Set<String> cacheItems = appCache.getAllCachedItemsFor(cacheKey);
        List<String> reversedCacheItems = new ArrayList<String>();
        reversedCacheItems.addAll(cacheItems);
        cacheItems = null;
        Collections.reverse(reversedCacheItems);
        if (lastSearch.isEmpty())
        {
          addItem("");
        }
        if (reversedCacheItems != null && !reversedCacheItems.isEmpty())
        {
          for (String cacheItem : reversedCacheItems)
          {
            addItem(cacheItem);
          }
        }
        setSelectedItem(lastSearch.isEmpty() ? "" : lastSearch);
      }
    });
  }


  public String getUserInput()
  {
    return getEditor().getItem() == null ? "" : getEditor().getItem()
            .toString().trim();
  }

}