/src/spelling/corrector/DefaultSpellingCorrector.java

package spelling.corrector;



import java.util.ArrayList;

import java.util.Collection;

import java.util.Collections;

import java.util.List;

import java.util.Locale;



import spelling.dictionary.Dictionary;



public class DefaultSpellingCorrector implements SpellingCorrector {

	private final Dictionary dictionnary;

	private final SpellingCorrectorHelper helper;

	protected DefaultSpellingCorrector(SpellingCorrectorHelper helper){

		this(helper,Locale.ENGLISH);

	}

	protected DefaultSpellingCorrector(SpellingCorrectorHelper helper,Locale locale){

		this.helper = helper;

		this.dictionnary = Dictionary.getDictionnary(locale);

	}



	public String correct(final String word){

		String correction = "";

		if(word == null || word.equals("")){

			return correction;

		}

		

		Collection<String> candidates = getCandidates(word.toLowerCase());

		int max = 0;

		for(String candidate : candidates){

			if(dictionnary.getOccurences(candidate) > max){

				correction = candidate;

			}

		}

		return correction;

	}

	



	public Collection<String> getCandidates(final String word){

		List<String> words = new ArrayList<String>();

		words.add(word);

		Collection<String> knownWords = dictionnary.known(words);

		if(knownWords.size() >0){

			return knownWords;

		}

		

		Collection<String> alternatives = helper.getFirstDegreeAlternatives(word);

		knownWords = dictionnary.known(alternatives);

		if(knownWords.size() > 0){

			return knownWords;

		}

		

		Collection<String> secondDegreeAlternatives =  helper.getSecondDegreeAlternatives(alternatives);

		knownWords = dictionnary.known(secondDegreeAlternatives);

		if(knownWords.size() > 0){

			return knownWords;

		}

		

		return Collections.unmodifiableCollection(words);

	}



}