/*
    * Copyright (c) 2007, James Leigh All rights reserved.
    * 
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted provided that the following conditions are met:
    * 
    * - Redistributions of source code must retain the above copyright notice, this
    *   list of conditions and the following disclaimer.
    * - Redistributions in binary form must reproduce the above copyright notice,
   *   this list of conditions and the following disclaimer in the documentation
   *   and/or other materials provided with the distribution. 
   * - Neither the name of the openrdf.org nor the names of its contributors may
   *   be used to endorse or promote products derived from this software without
   *   specific prior written permission.
   * 
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
   * POSSIBILITY OF SUCH DAMAGE.
   * 
   */
  package org.openrdf.elmo.sesame;
  
  import info.aduna.iteration.CloseableIteration;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.Set;
  
  import org.openrdf.elmo.exceptions.ElmoPersistException;
  import org.openrdf.elmo.exceptions.ElmoIOException;
  import org.openrdf.elmo.sesame.helpers.PropertyChanger;
  import org.openrdf.elmo.sesame.roles.SesameEntity;
  import org.openrdf.model.Literal;
  import org.openrdf.model.Statement;
  import org.openrdf.model.Value;
  import org.openrdf.repository.RepositoryException;
  import org.openrdf.repository.contextaware.ContextAwareConnection;
  
  /**
   * SesameProperty used for localized properties. Only the best set of literals
   * are included in the results.
   * 
   * @author James Leigh
   * 
   * @param <T>
   */
  public class LocalizedSesameProperty extends SesameProperty<String> {
  
  	public LocalizedSesameProperty(SesameEntity bean, PropertyChanger property) {
  		super(bean, property);
  	}
  
  	@Override
  	public void clear() {
  		ContextAwareConnection conn = getConnection();
  		try {
  			boolean autoCommit = conn.isAutoCommit();
  			if (autoCommit)
  				conn.setAutoCommit(false);
  			for (Statement stmt : bestValues()) {
  				remove(conn, stmt);
  			}
  			if (autoCommit)
  				conn.setAutoCommit(true);
  		} catch (RepositoryException e) {
  			throw new ElmoPersistException(e);
  		}
  	}
  
  	@Override
  	public String getSingle() {
  		Iterator<Statement> iter = bestValues().iterator();
  		if (iter.hasNext())
  			return createInstance(iter.next());
  		return null;
  	}
  
  	@Override
  	public boolean isEmpty() {
  		Iterator<Statement> iter = bestValues().iterator();
  		return iter.hasNext();
  	}
  
  	@Override
  	public Iterator<String> iterator() {
  		return new Iterator<String>() {
  			private Iterator<Statement> iter = bestValues().iterator();
  
  			private Statement stmt;
 
 			public boolean hasNext() {
 				return iter.hasNext();
 			}
 
 			public String next() {
 				return createInstance(stmt = iter.next());
 			}
 
 			public void remove() {
 				try {
 					ContextAwareConnection conn = getConnection();
 					LocalizedSesameProperty.this.remove(conn, stmt);
 				} catch (RepositoryException e) {
 					throw new ElmoPersistException(e);
 				}
 			}
 
 		};
 	}
 
 	@Override
 	public void setAll(Set<String> set) {
 		if (this == set)
 			return;
 		Set<String> c = new HashSet<String>(set);
 		ContextAwareConnection conn = getConnection();
 		try {
 			boolean autoCommit = conn.isAutoCommit();
 			if (autoCommit)
 				conn.setAutoCommit(false);
 			String language = getManager().getLanguage();
 			CloseableIteration<? extends Statement, RepositoryException> stmts;
 			stmts = getStatements();
 			try {
 				while (stmts.hasNext()) {
 					Statement stmt = stmts.next();
 					Literal lit = (Literal) stmt.getObject();
 					String l = lit.getLanguage();
 					if (language == l || language != null && language.equals(l)) {
 						Object next = createInstance(stmt);
 						if (c.contains(next)) {
 							c.remove(next);
 						} else {
 							remove(conn, stmt);
 						}
 					}
 				}
 			} finally {
 				stmts.close();
 			}
 			if (c.size() > 0)
 				addAll(c);
 			if (autoCommit)
 				conn.setAutoCommit(true);
 		} catch (RepositoryException e) {
 			throw new ElmoPersistException(e);
 		}
 	}
 
 	@Override
 	public int size() {
 		return bestValues().size();
 	}
 
 	@Override
 	public Object[] toArray() {
 		return bestValues().toArray();
 	}
 
 	@Override
 	public <T> T[] toArray(T[] a) {
 		return bestValues().toArray(a);
 	}
 
 	@Override
 	protected Value getValue(Object instance) {
 		return getManager().getLocalizedValue(instance);
 	}
 
 	Collection<Statement> bestValues() {
 		int score = -1;
 		Collection<Statement> values = new ArrayList<Statement>();
 		String language = getManager().getLanguage();
 		CloseableIteration<? extends Statement, RepositoryException> stmts;
 		try {
 			stmts = getStatements();
 			try {
 				while (stmts.hasNext()) {
 					Statement stmt = stmts.next();
 					score = addBestStatements(stmt, language, score, values);
 				}
 			} finally {
 				stmts.close();
 			}
 		} catch (RepositoryException e) {
 			throw new ElmoIOException(e);
 		}
 		return values;
 	}
 
 	private int addBestStatements(Statement stmt, String language, int best,
 			Collection<Statement> values) {
 		int score = best;
 		Literal lit = (Literal) stmt.getObject();
 		String l = lit.getLanguage();
 		if (language == l || language != null && language.equals(l)) {
 			if (score < Integer.MAX_VALUE)
 				values.clear();
 			values.add(stmt);
 			score = Integer.MAX_VALUE;
 		} else if (l != null && language != null && language.startsWith(l)) {
 			if (score < l.length())
 				values.clear();
 			values.add(stmt);
 			score = l.length();
 		} else if (l != null && language != null && score <= 1
 				&& l.length() > 2 && language.startsWith(l.substring(0, 2))) {
 			if (score < 1)
 				values.clear();
 			values.add(stmt);
 			score = 1;
 		} else if (l == null) {
 			if (score < 0)
 				values.clear();
 			values.add(stmt);
 			score = 0;
 		} else if (score < 0) {
 			values.add(stmt);
 		}
 		return score;
 	}
 
 }