package jalview.io.cache;


import java.util.Hashtable;
import java.util.LinkedHashSet;
import java.util.Set;

public class AppCache implements AppCacheI
{
  private static AppCache instance = null;

  private Hashtable<String, LinkedHashSet<String>> cacheItems;

  private AppCache()
  {
    cacheItems = new Hashtable<String, LinkedHashSet<String>>();
  }

  @Override
  public LinkedHashSet<String> getAllCachedItemsFor(String cacheKey)
  {
    LinkedHashSet<String> foundCache = cacheItems.get(cacheKey);
    if (foundCache == null)
    {
      foundCache = new LinkedHashSet<String>();
      cacheItems.put(cacheKey, foundCache);
    }
    return foundCache;
  }


  public static AppCache getInstance()
  {
    if (instance == null)
    {
      instance = new AppCache();
    }
    return instance;
  }

  @Override
  public void updateCache(Cacheable cacheable)
  {
    CacheBoxI<String> cacheComboBox = cacheable.getCacheComboBox();
    String cacheKey = cacheable.getCacheKey();
    cacheComboBox.looseFocus();
    String userInput = cacheComboBox.getUserInput();

    if (userInput != null && !userInput.isEmpty())
    {
      LinkedHashSet<String> foundCache = getAllCachedItemsFor(cacheKey);
      foundCache.add(userInput);
      cacheItems.put(cacheKey, foundCache);
    }

    String lastSearch = userInput;
    if (cacheComboBox.getItemCount() > 0)
    {
      cacheComboBox.removeAllItems();
    }

    Set<String> cacheItems = getAllCachedItemsFor(cacheKey);
    if (cacheItems != null && !cacheItems.isEmpty())
    {
      for (String cacheItem : cacheItems)
      {
        cacheComboBox.addItem(cacheItem);
      }
    }

    if (!lastSearch.isEmpty())
    {
      cacheComboBox.setSelectedItem(lastSearch);
      cacheComboBox.requestFocus();
    }
    else
    {
      cacheable.init();
      cacheComboBox.addItem("");
      cacheComboBox.setSelectedItem("");
    }
  }

}