/**
    * Copyright (C) 2014-2015 Philip Helger (www.helger.com)
    * philip[at]helger[dot]com
    *
    * 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.
   */
  package com.helger.schematron.pure.model;
  
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  import javax.annotation.concurrent.NotThreadSafe;
  
  import com.helger.commons.ValueEnforcer;
  import com.helger.commons.annotation.ReturnsMutableCopy;
  import com.helger.commons.collection.CollectionHelper;
  import com.helger.commons.microdom.IMicroElement;
  import com.helger.commons.microdom.MicroElement;
  import com.helger.commons.string.StringHelper;
  import com.helger.commons.string.ToStringGenerator;
  import com.helger.schematron.CSchematron;
  import com.helger.schematron.CSchematronXML;
  import com.helger.schematron.pure.errorhandler.IPSErrorHandler;
  
  /**
   * A single Schematron value-of-element.<br>
   * Finds or calculates values from the instance document to allow clearer
   * assertions and diagnostics. The required select attribute is an expression
   * evaluated in the current context that returns a string.<br>
   * Variable references in the select attribute are resolved in the scope of the
   * current schema, phase, pattern and rule.<br>
   * An implementation which does not report natural-language assertions is not
   * required to make use of this element.
   *
   * @author Philip Helger
   */
  @NotThreadSafe
  public class PSValueOf implements IPSClonableElement <PSValueOf>, IPSHasForeignAttributes
  {
    private String m_sSelect;
    private Map <String, String> m_aForeignAttrs;
  
    public PSValueOf ()
    {}
  
    public boolean isValid (@Nonnull final IPSErrorHandler aErrorHandler)
    {
      if (StringHelper.hasNoText (m_sSelect))
      {
        aErrorHandler.error (this, "<value-of> has no 'select'");
        return false;
      }
      return true;
    }
  
    public void validateCompletely (@Nonnull final IPSErrorHandler aErrorHandler)
    {
      if (StringHelper.hasNoText (m_sSelect))
        aErrorHandler.error (this, "<value-of> has no 'select'");
    }
  
    public boolean isMinimal ()
    {
      return true;
    }
  
    public void addForeignAttribute (@Nonnull final String sAttrName, @Nonnull final String sAttrValue)
    {
      ValueEnforcer.notNull (sAttrName, "AttrName");
      ValueEnforcer.notNull (sAttrValue, "AttrValue");
      if (m_aForeignAttrs == null)
        m_aForeignAttrs = new LinkedHashMap <String, String> ();
      m_aForeignAttrs.put (sAttrName, sAttrValue);
    }
  
    public void addForeignAttributes (@Nonnull final Map <String, String> aForeignAttrs)
    {
      ValueEnforcer.notNull (aForeignAttrs, "ForeignAttrs");
      for (final Map.Entry <String, String> aEntry : aForeignAttrs.entrySet ())
        addForeignAttribute (aEntry.getKey (), aEntry.getValue ());
    }
  
    public boolean hasForeignAttributes ()
    {
      return m_aForeignAttrs != null && !m_aForeignAttrs.isEmpty ();
    }
  
   @Nonnull
   @ReturnsMutableCopy
   public Map <String, String> getAllForeignAttributes ()
   {
     return CollectionHelper.newOrderedMap (m_aForeignAttrs);
   }
 
   /**
    * Set the expression to retrieve the value of
    *
    * @param sSelect
    *        The select expression string. May be <code>null</code>.
    */
   public void setSelect (@Nullable final String sSelect)
   {
     m_sSelect = sSelect;
   }
 
   /**
    * @return The select expression string. May be <code>null</code>.
    */
   @Nullable
   public String getSelect ()
   {
     return m_sSelect;
   }
 
   @Nonnull
   public IMicroElement getAsMicroElement ()
   {
     final IMicroElement ret = new MicroElement (CSchematron.NAMESPACE_SCHEMATRON, CSchematronXML.ELEMENT_VALUE_OF);
     ret.setAttribute (CSchematronXML.ATTR_SELECT, m_sSelect);
     if (m_aForeignAttrs != null)
       for (final Map.Entry <String, String> aEntry : m_aForeignAttrs.entrySet ())
         ret.setAttribute (aEntry.getKey (), aEntry.getValue ());
     return ret;
   }
 
   @Nonnull
   public PSValueOf getClone ()
   {
     final PSValueOf ret = new PSValueOf ();
     ret.setSelect (m_sSelect);
     if (hasForeignAttributes ())
       ret.addForeignAttributes (m_aForeignAttrs);
     return ret;
   }
 
   @Override
   public String toString ()
   {
     return new ToStringGenerator (this).appendIfNotNull ("select", m_sSelect)
                                        .appendIfNotEmpty ("foreignAttrs", m_aForeignAttrs)
                                        .toString ();
   }
 }