package org.daisy.pipeline.nlp.impl;
   
   import org.daisy.pipeline.nlp.TextCategorizer.CategorizedWord;
   import org.daisy.pipeline.nlp.TextCategorizer.Category;
   import org.daisy.pipeline.nlp.TextCategorizer.MatchMode;
   
   /**
    * Mapping between a string matching method (e.g. some regex) and a word
    * category, associated to a priority so as to rank the match rules.
   */
  public abstract class MatchRule {
  	private final int mPriority;
  	private final Category mCategory;
  	protected final MatchMode mMatchMode;
  	protected final boolean mCaseSensitive;
  
  	/**
  	 * 
  	 * @param category the classification applied to the words that match the
  	 *            rule
  	 * @param priority allows us to select a rule when several rules match the
  	 *            word. High value means it will be chosen over lower ones. When
  	 *            two priorities are equal, the one that returns the longest
  	 *            match is chosen.
  	 */
  	public MatchRule(Category category, int priority, boolean caseSensitive,
  	        MatchMode matchMode) {
  		mCategory = category;
  		mPriority = priority;
  		mCaseSensitive = caseSensitive;
  		mMatchMode = matchMode;
  	}
  
  	public int getPriority() {
  		return mPriority;
  	}
  
  	public CategorizedWord match(String input, String lowerCaseInput) {
  		String res;
  		if (mCaseSensitive)
  			res = match(input);
  		else
  			res = match(lowerCaseInput);
  		if (res == null)
  			return null;
  		CategorizedWord cw = new CategorizedWord();
  		cw.category = mCategory;
  		cw.word = res;
  		return cw;
  	}
  
  	protected abstract String match(String input);
  
  	/**
  	 * Can return false before returning true, but not the other way around.
  	 */
  	public abstract boolean threadsafe();
  }