/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.
   */
  package javax.faces.component;
  
  import java.lang.reflect.Array;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.Iterator;
  
  import javax.el.ValueExpression;
  import javax.faces.application.FacesMessage;
  import javax.faces.context.FacesContext;
  import javax.faces.convert.Converter;
  import javax.faces.convert.ConverterException;
  import javax.faces.el.ValueBinding;
  import javax.faces.model.SelectItem;
  import javax.faces.render.Renderer;
  
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFComponent;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspProperties;
  import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspProperty;
  
  /**
   * Base class for the various component classes that allow a user to select zero or more options from a set.
   * <p>
   * This is not an abstract class; java code can create an instance of this, configure its rendererType appropriately,
   * and add it to a view. However there is no tag class for this component, ie it cannot be added directly to a page when
   * using JSP (and other presentation technologies are expected to behave similarly). Instead, there is a family of
   * subclasses that extend this base functionality, and they do have tag classes.
   * </p>
   * <p>
   * See the javadoc for this class in the <a href="http://java.sun.com/j2ee/javaserverfaces/1.2/docs/api/index.html">JSF
   * Specification</a> for further details.
   * </p>
   */
  @JSFComponent(defaultRendererType = "javax.faces.Listbox")
  @JSFJspProperties
  (properties={
          @JSFJspProperty(name="hideNoSelectionOption", returnType="boolean"),
          @JSFJspProperty(name="collectionType", returnType="java.lang.String")
  }
  )
  public class UISelectMany extends UIInput
  {
      public static final String COMPONENT_TYPE = "javax.faces.SelectMany";
      public static final String COMPONENT_FAMILY = "javax.faces.SelectMany";
  
      public static final String INVALID_MESSAGE_ID = "javax.faces.component.UISelectMany.INVALID";
  
      public UISelectMany()
      {
          setRendererType("javax.faces.Listbox");
      }
  
      @Override
      public String getFamily()
      {
          return COMPONENT_FAMILY;
      }
      
      public Object[] getSelectedValues()
      {
          return (Object[]) getValue();
      }
  
      public void setSelectedValues(Object[] selectedValues)
      {
          setValue(selectedValues);
      }
  
      /**
       * @deprecated Use getValueExpression instead
       */
      @Override
      public ValueBinding getValueBinding(String name)
      {
          if (name == null)
          {
              throw new NullPointerException("name");
          }
          if (name.equals("selectedValues"))
         {
             return super.getValueBinding("value");
         }
         else
         {
             return super.getValueBinding(name);
         }
     }
 
     /**
      * @deprecated Use setValueExpression instead
      */
     @Override
     public void setValueBinding(String name, ValueBinding binding)
     {
         if (name == null)
         {
             throw new NullPointerException("name");
         }
         if (name.equals("selectedValues"))
         {
             super.setValueBinding("value", binding);
         }
         else
         {
             super.setValueBinding(name, binding);
         }
     }
 
     @Override
     public ValueExpression getValueExpression(String name)
     {
         if (name == null)
         {
             throw new NullPointerException("name");
         }
         if (name.equals("selectedValues"))
         {
             return super.getValueExpression("value");
         }
         else
         {
             return super.getValueExpression(name);
         }
     }
 
     @Override
     public void setValueExpression(String name, ValueExpression binding)
     {
         if (name == null)
         {
             throw new NullPointerException("name");
         }
         if (name.equals("selectedValues"))
         {
             super.setValueExpression("value", binding);
         }
         else
         {
             super.setValueExpression(name, binding);
         }
     }
 
     /**
      * @return true if Objects are different (!)
      */
     @Override
     protected boolean compareValues(Object previous, Object value)
     {
         if (previous == null)
         {
             // one is null, the other not
             return value != null;
         }
         else if (value == null)
         {
             // one is null, the other not
             return true;
         }
         else
         {
             if (previous instanceof Object[] && value instanceof Object[])
             {
                 return compareObjectArrays((Object[]) previous, (Object[]) value);
             }
             else if (previous instanceof Collection && value instanceof Collection)
             {
                 return compareCollections((Collection<?>) previous, (Collection<?>) value);
             }
             else if (previous.getClass().isArray() && value.getClass().isArray())
             {
                 return comparePrimitiveArrays(previous, value);
             }
             else
             {
                 // Objects have different classes
                 return true;
             }
         }
     }
 
     private boolean compareObjectArrays(Object[] previous, Object[] value)
     {
         int length = value.length;
         if (previous.length != length)
         {
             // different length
             return true;
         }
 
         boolean[] scoreBoard = new boolean[length];
         for (int i = 0; i < length; i++)
         {
             Object p = previous[i];
             boolean found = false;
             for (int j = 0; j < length; j++)
             {
                 if (scoreBoard[j] == false)
                 {
                     Object v = value[j];
                     if ((p == null && v == null) || (p != null && v != null && p.equals(v)))
                     {
                         scoreBoard[j] = true;
                         found = true;
                         break;
                     }
                 }
             }
             if (!found)
             {
                 return true; // current element of previous array not found in new array
             }
         }
 
         return false; // arrays are identical
     }
 
     private boolean compareCollections(Collection<?> previous, Collection<?> value)
     {
         int length = value.size();
         if (previous.size() != length)
         {
             // different length
             return true;
         }
 
         boolean[] scoreBoard = new boolean[length];
         for (Iterator<?> itPrevious = previous.iterator(); itPrevious.hasNext();)
         {
             Object p = itPrevious.next();
             boolean found = false;
             int j = 0;
             for (Iterator<?> itValue = value.iterator(); itValue.hasNext(); j++)
             {
                 Object v = itValue.next();
                 if (scoreBoard[j] == false)
                 {
                     if ((p == null && v == null) || (p != null && v != null && p.equals(v)))
                     {
                         scoreBoard[j] = true;
                         found = true;
                         break;
                     }
                 }
             }
             if (!found)
             {
                 return true; // current element of previous Collection not found in new Collection
             }
         }
 
         return false; // Collections are identical
     }
 
     private boolean comparePrimitiveArrays(Object previous, Object value)
     {
         int length = Array.getLength(value);
         if (Array.getLength(previous) != length)
         {
             // different length
             return true;
         }
 
         boolean[] scoreBoard = new boolean[length];
         for (int i = 0; i < length; i++)
         {
             Object p = Array.get(previous, i);
             boolean found = false;
             for (int j = 0; j < length; j++)
             {
                 if (scoreBoard[j] == false)
                 {
                     Object v = Array.get(value, j);
                     if ((p == null && v == null) || (p != null && v != null && p.equals(v)))
                     {
                         scoreBoard[j] = true;
                         found = true;
                         break;
                     }
                 }
             }
             if (!found)
             {
                 return true; // current element of previous array not found in new array
             }
         }
 
         return false; // arrays are identical
     }
 
     @Override
     protected void validateValue(FacesContext context, Object convertedValue)
     {
         Iterator<?> itemValues = _createItemValuesIterator(convertedValue);
 
         // verify that iterator was successfully created for convertedValue type
         if (itemValues == null)
         {
             _MessageUtils.addErrorMessage(context, this, INVALID_MESSAGE_ID, new Object[] { _MessageUtils.getLabel(
                 context, this) });
             setValid(false);
             return;
         }
 
         boolean hasValues = itemValues.hasNext();
 
         // if UISelectMany is required, then there must be some selected values
         if (isRequired() && !hasValues)
         {
             if (getRequiredMessage() != null)
             {
                 String requiredMessage = getRequiredMessage();
                 context.addMessage(this.getClientId(context), new FacesMessage(FacesMessage.SEVERITY_ERROR,
                     requiredMessage, requiredMessage));
             }
             else
             {
                 _MessageUtils.addErrorMessage(context, this, REQUIRED_MESSAGE_ID,
                     new Object[] { _MessageUtils.getLabel(context, this) });
             }
             setValid(false);
             return;
         }
 
         // run the validators only if there are item values to validate
         if (hasValues)
         {
             _ComponentUtils.callValidators(context, this, convertedValue);
         }
 
         if (isValid() && hasValues)
         {
             // all selected values must match to the values of the available options
 
             Collection<SelectItem> items = new ArrayList<SelectItem>();
             for (Iterator<SelectItem> iter = new _SelectItemsIterator(this, context); iter.hasNext();)
             {
                 items.add(iter.next());
             }
             Converter converter = getConverter();
             while (itemValues.hasNext())
             {
                 Object itemValue = itemValues.next();
 
                 // selected value must match to one of the available options
                 // and if required is true it must not match an option with noSelectionOption set to true (since 2.0)
                 if (!_SelectItemsUtil.matchValue(context, this, itemValue, items.iterator(), converter)
                         || (
                             this.isRequired()
                             && _SelectItemsUtil.isNoSelectionOption(context, this, itemValue, items.iterator(), converter)
                         ))
                 {    
                     _MessageUtils.addErrorMessage(context, this, INVALID_MESSAGE_ID,
                         new Object[] { _MessageUtils.getLabel(context, this) });
                     setValid(false);
                     return;
                 }
             }
         }
     }
 
     /**
      * First part is identical to super.validate except the empty condition. Second part: iterate through UISelectItem
      * and UISelectItems and check current values against these items
      */
     @Override
     public void validate(FacesContext context)
     {
         // TODO : Setting the submitted value to null in the super class causes a bug, if set to
         // null, you'll get the following error :
         // java.lang.NullPointerException at
         //org.apache.myfaces.renderkit._SharedRendererUtils.getConvertedUISelectManyValue(_SharedRendererUtils.java:118)
         super.validate(context);
     }
 
     @Override
     protected Object getConvertedValue(FacesContext context, Object submittedValue) throws ConverterException
     {
         Renderer renderer = getRenderer(context);
         if (renderer != null)
         {
             return renderer.getConvertedValue(context, this, submittedValue);
         }
         else if (submittedValue == null)
         {
             return null;
         }
         else if (submittedValue instanceof String[])
         {
             return _SharedRendererUtils.getConvertedUISelectManyValue(context, this, (String[]) submittedValue);
         }
         return submittedValue;
     }
 
     private Iterator<?> _createItemValuesIterator(Object convertedValue)
     {
         if (convertedValue == null)
         {
             return Collections.emptyList().iterator();
         }
         else
         {
             Class<? extends Object> valueClass = convertedValue.getClass();
             if (valueClass.isArray())
             {
                 return new _PrimitiveArrayIterator(convertedValue);
             }
             else if (convertedValue instanceof Object[])
             {
                 Object[] values = (Object[]) convertedValue;
                 return Arrays.asList(values).iterator();
             }
             else if (convertedValue instanceof Collection)
             {
                 Collection<?> values = (Collection<?>) convertedValue;
                 return values.iterator();
             }
             else
             {
                 // unsupported type for iteration
                 return null;
             }
         }
     }
 }