/*******************************************************************************
 * Copyright (c) 2014 Jeff Martin.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Public License v3.0
 * which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/gpl.html
 * 
 * Contributors:
 *     Jeff Martin - initial API and implementation
 ******************************************************************************/
package cuchaz.enigma.convert;

import java.util.AbstractMap;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Map;

import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.BiMap;
import com.google.common.collect.HashBiMap;
import com.google.common.collect.Lists;
import com.google.common.collect.Maps;
import com.google.common.collect.Multimap;

public class ClassMatching {
	
	private Multimap<ClassIdentity,ClassIdentity> m_sourceClasses;
	private Multimap<ClassIdentity,ClassIdentity> m_matchedDestClasses;
	private List<ClassIdentity> m_unmatchedDestClasses;
	
	public ClassMatching() {
		m_sourceClasses = ArrayListMultimap.create();
		m_matchedDestClasses = ArrayListMultimap.create();
		m_unmatchedDestClasses = Lists.newArrayList();
	}
	
	public void addSource(ClassIdentity c) {
		m_sourceClasses.put(c, c);
	}
	
	public void matchDestClass(ClassIdentity destClass) {
		Collection<ClassIdentity> matchedSourceClasses = m_sourceClasses.get(destClass);
		if (matchedSourceClasses.isEmpty()) {
			// no match
			m_unmatchedDestClasses.add(destClass);
		} else {
			// found a match
			m_matchedDestClasses.put(destClass, destClass);
			
			// DEBUG
			ClassIdentity sourceClass = matchedSourceClasses.iterator().next();
			assert (sourceClass.hashCode() == destClass.hashCode());
			assert (sourceClass.equals(destClass));
		}
	}
	
	public void removeSource(ClassIdentity sourceClass) {
		m_sourceClasses.remove(sourceClass, sourceClass);
	}
	
	public void removeDest(ClassIdentity destClass) {
		m_matchedDestClasses.remove(destClass, destClass);
		m_unmatchedDestClasses.remove(destClass);
	}
	
	public List<ClassIdentity> getSourceClasses() {
		return new ArrayList<ClassIdentity>(m_sourceClasses.values());
	}
	
	public List<ClassIdentity> getDestClasses() {
		List<ClassIdentity> classes = Lists.newArrayList();
		classes.addAll(m_matchedDestClasses.values());
		classes.addAll(m_unmatchedDestClasses);
		return classes;
	}
	
	public BiMap<ClassIdentity,ClassIdentity> getUniqueMatches() {
		BiMap<ClassIdentity,ClassIdentity> uniqueMatches = HashBiMap.create();
		for (ClassIdentity sourceClass : m_sourceClasses.keySet()) {
			Collection<ClassIdentity> matchedSourceClasses = m_sourceClasses.get(sourceClass);
			Collection<ClassIdentity> matchedDestClasses = m_matchedDestClasses.get(sourceClass);
			if (matchedSourceClasses.size() == 1 && matchedDestClasses.size() == 1) {
				ClassIdentity matchedSourceClass = matchedSourceClasses.iterator().next();
				ClassIdentity matchedDestClass = matchedDestClasses.iterator().next();
				uniqueMatches.put(matchedSourceClass, matchedDestClass);
			}
		}
		return uniqueMatches;
	}
	
	public BiMap<List<ClassIdentity>,List<ClassIdentity>> getAmbiguousMatches() {
		BiMap<List<ClassIdentity>,List<ClassIdentity>> ambiguousMatches = HashBiMap.create();
		for (ClassIdentity sourceClass : m_sourceClasses.keySet()) {
			Collection<ClassIdentity> matchedSourceClasses = m_sourceClasses.get(sourceClass);
			Collection<ClassIdentity> matchedDestClasses = m_matchedDestClasses.get(sourceClass);
			if (matchedSourceClasses.size() > 1 && matchedDestClasses.size() > 1) {
				ambiguousMatches.put(
					new ArrayList<ClassIdentity>(matchedSourceClasses),
					new ArrayList<ClassIdentity>(matchedDestClasses)
				);
			}
		}
		return ambiguousMatches;
	}
	
	public int getNumAmbiguousSourceMatches() {
		int num = 0;
		for (Map.Entry<List<ClassIdentity>,List<ClassIdentity>> entry : getAmbiguousMatches().entrySet()) {
			num += entry.getKey().size();
		}
		return num;
	}
	
	public int getNumAmbiguousDestMatches() {
		int num = 0;
		for (Map.Entry<List<ClassIdentity>,List<ClassIdentity>> entry : getAmbiguousMatches().entrySet()) {
			num += entry.getValue().size();
		}
		return num;
	}
	
	public List<ClassIdentity> getUnmatchedSourceClasses() {
		List<ClassIdentity> classes = Lists.newArrayList();
		for (ClassIdentity sourceClass : getSourceClasses()) {
			if (m_matchedDestClasses.get(sourceClass).isEmpty()) {
				classes.add(sourceClass);
			}
		}
		return classes;
	}
	
	public List<ClassIdentity> getUnmatchedDestClasses() {
		return new ArrayList<ClassIdentity>(m_unmatchedDestClasses);
	}
	
	public Map<String,Map.Entry<ClassIdentity,List<ClassIdentity>>> getIndex() {
		Map<String,Map.Entry<ClassIdentity,List<ClassIdentity>>> conversion = Maps.newHashMap();
		for (Map.Entry<ClassIdentity,ClassIdentity> entry : getUniqueMatches().entrySet()) {
			conversion.put(
				entry.getKey().getClassEntry().getName(),
				new AbstractMap.SimpleEntry<ClassIdentity,List<ClassIdentity>>(entry.getKey(), Arrays.asList(entry.getValue()))
			);
		}
		for (Map.Entry<List<ClassIdentity>,List<ClassIdentity>> entry : getAmbiguousMatches().entrySet()) {
			for (ClassIdentity sourceClass : entry.getKey()) {
				conversion.put(
					sourceClass.getClassEntry().getName(),
					new AbstractMap.SimpleEntry<ClassIdentity,List<ClassIdentity>>(sourceClass, entry.getValue())
				);
			}
		}
		for (ClassIdentity sourceClass : getUnmatchedSourceClasses()) {
			conversion.put(
				sourceClass.getClassEntry().getName(),
				new AbstractMap.SimpleEntry<ClassIdentity,List<ClassIdentity>>(sourceClass, getUnmatchedDestClasses())
			);
		}
		return conversion;
	}
	
	@Override
	public String toString() {
		StringBuilder buf = new StringBuilder();
		buf.append(String.format("%12s%8s%8s\n", "", "Source", "Dest"));
		buf.append(String.format("%12s%8d%8d\n", "Classes", getSourceClasses().size(), getDestClasses().size()));
		buf.append(String.format("%12s%8d%8d\n", "Unique", getUniqueMatches().size(), getUniqueMatches().size()));
		buf.append(String.format("%12s%8d%8d\n", "Ambiguous", getNumAmbiguousSourceMatches(), getNumAmbiguousDestMatches()));
		buf.append(String.format("%12s%8d%8d\n", "Unmatched", getUnmatchedSourceClasses().size(), getUnmatchedDestClasses().size()));
		return buf.toString();
	}
}