import java.io.Serializable;
import java.util.Hashtable;

public class SpamFilter implements Serializable
{

	private Hashtable badWords;
	
	/**
	 * Default constructor, creates a new hash table
	 */
	SpamFilter()
	{
		badWords = new Hashtable();
	}
	
	/**
	 * Inserts an element into the table
	 * @param s
	 * Element to insert
	 */
	public void insert(String s)
	{
		System.out.println("here");
		badWords.put(s.toLowerCase(), s.toLowerCase());
	}
	
	/**
	 * Removes an element from the table
	 * @param word
	 * Element to remove from table
	 * @throws ElementNotFoundException
	 * Thrown if the element is not found in the table.
	 */
	public void remove(String word) throws ElementNotFoundException
	{
		Object removed = badWords.remove(word.toLowerCase());
		if (removed == null)
		  throw new ElementNotFoundException(word + " was not found in"
		      + " the list of bad words");
	}
	/**
	 * Determines if a bad word exists in the table
	 * @param checkMe
	 * element to locate
	 * @return
	 * true if found, false otherwise
	 */
	public boolean isBadWord(String checkMe)
	{
			return badWords.containsKey(checkMe.toLowerCase());	
	}
	/**
	 * Checks an email message for bad words and counts them. Returns a ratio of
	 * bad words to total words
	 * @param message
	 * The email to be analyzed
	 * @return
	 * The ratio of bad words to total words
	 */
	public float checkEmail(String message)
	{
		String[] words = message.toLowerCase().split("[^a-zA-Z]");
		int badWordCount = 0;
		for (int i = words.length - 1; i > 0; --i)
		{
			if (isBadWord(words[i])) ++badWordCount;
		}
		return (float) badWordCount / (float) words.length;
	}
	
}