code: /*
   * #%L
   * Simmetrics Core
   * %%
   * Copyright (C) 2014 - 2016 Simmetrics Authors
   * %%
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   * 
   *      http://www.apache.org/licenses/LICENSE-2.0
   * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   * #L%
   */
  
  package org.simmetrics.builders;
  
  import static com.google.common.base.Preconditions.checkNotNull;
  import static org.simmetrics.simplifiers.Simplifiers.chain;
  
  import java.util.List;
  import java.util.Set;
  
  import org.simmetrics.Distance;
  import org.simmetrics.StringDistance;
  import org.simmetrics.simplifiers.Simplifier;
  import org.simmetrics.tokenizers.Tokenizer;
  
  import com.google.common.collect.Multiset;
  
  final class StringDistances {
  
  	public static StringDistance create(Distance<String> distance) {
  		if (distance instanceof StringDistance) {
  			return (StringDistance) distance;
  		}
  
  		return new ForString(distance);
  	}
  
  	public static StringDistance create(Distance<String> distance, Simplifier simplifier) {
  		if (distance instanceof ForString) {
  			ForString forString = (ForString) distance;
  			return new ForStringWithSimplifier(forString.getDistance(), simplifier);
  		} else if (distance instanceof ForStringWithSimplifier) {
  			ForStringWithSimplifier fsws = (ForStringWithSimplifier) distance;
  			return new ForStringWithSimplifier(fsws.getDistance(), chain(simplifier, fsws.getSimplifier()));
  		} else if (distance instanceof ForList) {
  			ForList fl = (ForList) distance;
  			return createForListDistance(fl.getDistance(), simplifier, fl.getTokenizer());
  		} else if (distance instanceof ForListWithSimplifier) {
  			ForListWithSimplifier fl = (ForListWithSimplifier) distance;
  			return createForListDistance(fl.getDistance(), chain(simplifier, fl.getSimplifier()), fl.getTokenizer());
  		} else if (distance instanceof ForSet) {
  			ForSet fl = (ForSet) distance;
  			return createForSetDistance(fl.getDistance(), simplifier, fl.getTokenizer());
  		} else if (distance instanceof ForSetWithSimplifier) {
  			ForSetWithSimplifier fl = (ForSetWithSimplifier) distance;
  			return createForSetDistance(fl.getDistance(), chain(simplifier, fl.getSimplifier()), fl.getTokenizer());
  		}
  
  		return new ForStringWithSimplifier(distance, simplifier);
  	}
  
  	public static StringDistance createForListDistance(Distance<List<String>> distance, Simplifier simplifier,
  			Tokenizer tokenizer) {
  		return new ForListWithSimplifier(distance, simplifier, tokenizer);
  	}
  
  	public static StringDistance createForListDistance(Distance<List<String>> distance, Tokenizer tokenizer) {
  		return new ForList(distance, tokenizer);
  	}
  
  	public static StringDistance createForSetDistance(Distance<Set<String>> distance, Simplifier simplifier,
  			Tokenizer tokenizer) {
  		return new ForSetWithSimplifier(distance, simplifier, tokenizer);
  	}
  
  	public static StringDistance createForSetDistance(Distance<Set<String>> distance, Tokenizer tokenizer) {
  		return new ForSet(distance, tokenizer);
  	}
  
  	public static StringDistance createForMultisetDistance(Distance<Multiset<String>> distance, Simplifier simplifier,
  			Tokenizer tokenizer) {
  		return new ForMultisetWithSimplifier(distance, simplifier, tokenizer);
  	}
  
  	public static StringDistance createForMultisetDistance(Distance<Multiset<String>> distance, Tokenizer tokenizer) {
  		return new ForMultiset(distance, tokenizer);
  	}
  	
  	static final class ForList implements StringDistance {
  		private final Distance<List<String>> distance;
  		private final Tokenizer tokenizer;
  
  		ForList(Distance<List<String>> distance, Tokenizer tokenizer) {
  
  			checkNotNull(distance);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToList(a), tokenizer.tokenizeToList(b));
  		}
  
  		Distance<List<String>> getDistance() {
  			return distance;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + tokenizer + "]";
  		}
  	}
  
  	static final class ForListWithSimplifier implements StringDistance {
  		private final Distance<List<String>> distance;
  		private final Simplifier simplifier;
  		private final Tokenizer tokenizer;
  
  		ForListWithSimplifier(Distance<List<String>> distance, Simplifier simplifier, Tokenizer tokenizer) {
  
  			checkNotNull(distance);
  			checkNotNull(simplifier);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.simplifier = simplifier;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToList(simplifier.simplify(a)),
  					tokenizer.tokenizeToList(simplifier.simplify(b)));
  		}
  
  		Distance<List<String>> getDistance() {
  			return distance;
  		}
  
  		Simplifier getSimplifier() {
  			return simplifier;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + simplifier + " -> " + tokenizer + "]";
  		}
  	}
  
  	static final class ForSet implements StringDistance {
  
  		private final Distance<Set<String>> distance;
  		private final Tokenizer tokenizer;
  
  		ForSet(Distance<Set<String>> distance, Tokenizer tokenizer) {
  			checkNotNull(distance);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToSet(a), tokenizer.tokenizeToSet(b));
  		}
  
  		Distance<Set<String>> getDistance() {
  			return distance;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + tokenizer + "]";
  		}
  
  	}
  
  	static final class ForSetWithSimplifier implements StringDistance {
  
  		private final Distance<Set<String>> distance;
  		private final Simplifier simplifier;
  		private final Tokenizer tokenizer;
  
  		ForSetWithSimplifier(Distance<Set<String>> distance, Simplifier simplifier, Tokenizer tokenizer) {
  			checkNotNull(distance);
  			checkNotNull(simplifier);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.simplifier = simplifier;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToSet(simplifier.simplify(a)),
  					tokenizer.tokenizeToSet(simplifier.simplify(b)));
  		}
  
  		Distance<Set<String>> getDistance() {
  			return distance;
  		}
  
  		Simplifier getSimplifier() {
  			return simplifier;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + simplifier + " -> " + tokenizer + "]";
  		}
  
  	}
  	static final class ForMultiset implements StringDistance {
  
  		private final Distance<Multiset<String>> distance;
  		private final Tokenizer tokenizer;
  
  		ForMultiset(Distance<Multiset<String>> distance, Tokenizer tokenizer) {
  			checkNotNull(distance);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToMultiset(a), tokenizer.tokenizeToMultiset(b));
  		}
  
  		Distance<Multiset<String>> getDistance() {
  			return distance;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + tokenizer + "]";
  		}
  
  	}
  
  	static final class ForMultisetWithSimplifier implements StringDistance {
  
  		private final Distance<Multiset<String>> distance;
  		private final Simplifier simplifier;
  		private final Tokenizer tokenizer;
  
  		ForMultisetWithSimplifier(Distance<Multiset<String>> distance, Simplifier simplifier, Tokenizer tokenizer) {
  			checkNotNull(distance);
  			checkNotNull(simplifier);
  			checkNotNull(tokenizer);
  
  			this.distance = distance;
  			this.simplifier = simplifier;
  			this.tokenizer = tokenizer;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(tokenizer.tokenizeToMultiset(simplifier.simplify(a)),
  					tokenizer.tokenizeToMultiset(simplifier.simplify(b)));
  		}
  
  		Distance<Multiset<String>> getDistance() {
  			return distance;
  		}
  
  		Simplifier getSimplifier() {
  			return simplifier;
  		}
  
  		Tokenizer getTokenizer() {
  			return tokenizer;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + simplifier + " -> " + tokenizer + "]";
  		}
  
  	}
  	static final class ForString implements StringDistance {
  		private final Distance<String> distance;
  
  		ForString(Distance<String> distance) {
  			this.distance = distance;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(a, b);
  		}
  
  		@Override
  		public String toString() {
  			return distance.toString();
  		}
  
  		Distance<String> getDistance() {
  			return distance;
  		}
  
  	}
  
  	static final class ForStringWithSimplifier implements StringDistance {
  
  		private final Distance<String> distance;
  
  		private final Simplifier simplifier;
  
  		ForStringWithSimplifier(Distance<String> distance, Simplifier simplifier) {
  			checkNotNull(distance);
  			checkNotNull(simplifier);
  
  			this.distance = distance;
  			this.simplifier = simplifier;
  		}
  
  		@Override
  		public float distance(String a, String b) {
  			return distance.distance(simplifier.simplify(a), simplifier.simplify(b));
  		}
  
  		Distance<String> getDistance() {
  			return distance;
  		}
  
  		Simplifier getSimplifier() {
  			return simplifier;
  		}
  
  		@Override
  		public String toString() {
  			return distance + " [" + simplifier + "]";
  		}
  
  	}
  
  	private StringDistances() {
  		// Utility class.
  	}
  
  }
  