/**
    * Copyright (C) 2014-2016 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.Map;
  
  import javax.annotation.Nonnegative;
  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.collection.ext.CommonsArrayList;
  import com.helger.commons.collection.ext.CommonsLinkedHashMap;
  import com.helger.commons.collection.ext.ICommonsList;
  import com.helger.commons.collection.ext.ICommonsOrderedMap;
  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;
  import com.helger.xml.microdom.IMicroElement;
  import com.helger.xml.microdom.MicroElement;
  
  /**
   * A single Schematron rule-element.<br>
   * A list of assertions tested within the context specified by the required
   * context attribute. The context attribute specifies the rule context
   * expression.<br>
   * NOTE: It is not an error if a rule never fires in a document. In order to
   * test that a document always has some context, a new pattern should be created
   * from the context of the document, with an assertion requiring the element or
   * attribute.<br>
   * The icon, see and fpi attributes allow rich interfaces and documentation.<br>
   * The flag attribute allows more detailed outcomes.<br>
   * The role and subject attributes allow explicit identification of some part of
   * a pattern as part of the validation outcome.<br>
   * When the rule element has the attribute abstract with a value true, then the
   * rule is an abstract rule. An abstract rule shall not have a context
   * attribute. An abstract rule is a list of assertions that will be invoked by
   * other rules belonging to the same pattern using the extends element. Abstract
   * rules provide a mechanism for reducing schema size.
   *
   * @author Philip Helger
   */
  @NotThreadSafe
  public class PSRule implements
                      IPSElement,
                      IPSHasID,
                      IPSHasFlag,
                      IPSHasForeignElements,
                      IPSHasIncludes,
                      IPSHasLets,
                      IPSHasRichGroup,
                      IPSHasLinkableGroup
  {
    public static final boolean DEFAULT_ABSTRACT = false;
  
    private String m_sFlag;
    private PSRichGroup m_aRich;
    private PSLinkableGroup m_aLinkable;
    private boolean m_bAbstract = DEFAULT_ABSTRACT;
    private String m_sContext;
    private String m_sID;
    private final ICommonsList <PSInclude> m_aIncludes = new CommonsArrayList <> ();
    private final ICommonsList <PSLet> m_aLets = new CommonsArrayList <> ();
    private final ICommonsList <IPSElement> m_aContent = new CommonsArrayList <> ();
    private ICommonsOrderedMap <String, String> m_aForeignAttrs;
    private ICommonsList <IMicroElement> m_aForeignElements;
  
    public PSRule ()
    {}
  
    public boolean isValid (@Nonnull final IPSErrorHandler aErrorHandler)
    {
      // abstract rules need an ID
      if (m_bAbstract && StringHelper.hasNoText (m_sID))
      {
        aErrorHandler.error (this, "abstract <rule> has no 'id'");
        return false;
      }
      // abstract rules may not have a context
      if (m_bAbstract && StringHelper.hasText (m_sContext))
     {
       aErrorHandler.error (this, "abstract <rule> may not have a 'context'");
       return false;
     }
     // Non-abstract rules need a context
     if (!m_bAbstract && StringHelper.hasNoText (m_sContext))
     {
       aErrorHandler.error (this, "<rule> must have a 'context'");
       return false;
     }
     // At least one assert, report or extends must be present
     if (m_aContent.isEmpty ())
     {
       aErrorHandler.error (this, "<rule> has no content");
       return false;
     }
     for (final PSInclude aInclude : m_aIncludes)
       if (!aInclude.isValid (aErrorHandler))
         return false;
     for (final PSLet aLet : m_aLets)
       if (!aLet.isValid (aErrorHandler))
         return false;
     for (final IPSElement aContent : m_aContent)
       if (!aContent.isValid (aErrorHandler))
         return false;
     return true;
   }
 
   public void validateCompletely (@Nonnull final IPSErrorHandler aErrorHandler)
   {
     // abstract rules need an ID
     if (m_bAbstract && StringHelper.hasNoText (m_sID))
       aErrorHandler.error (this, "abstract <rule> has no 'id'");
     // abstract rules may not have a context
     if (m_bAbstract && StringHelper.hasText (m_sContext))
       aErrorHandler.error (this, "abstract <rule> may not have a 'context'");
     // Non-abstract rules need a context
     if (!m_bAbstract && StringHelper.hasNoText (m_sContext))
       aErrorHandler.error (this, "<rule> must have a 'context'");
     // At least one assert, report or extends must be present
     if (m_aContent.isEmpty ())
       aErrorHandler.error (this, "<rule> has no content");
     for (final PSInclude aInclude : m_aIncludes)
       aInclude.validateCompletely (aErrorHandler);
     for (final PSLet aLet : m_aLets)
       aLet.validateCompletely (aErrorHandler);
     for (final IPSElement aContent : m_aContent)
       aContent.validateCompletely (aErrorHandler);
   }
 
   public boolean isMinimal ()
   {
     for (final PSInclude aInclude : m_aIncludes)
       if (!aInclude.isMinimal ())
         return false;
     for (final PSLet aLet : m_aLets)
       if (!aLet.isMinimal ())
         return false;
     for (final IPSElement aContent : m_aContent)
       if (!aContent.isMinimal ())
         return false;
     return true;
   }
 
   public void addForeignElement (@Nonnull final IMicroElement aForeignElement)
   {
     ValueEnforcer.notNull (aForeignElement, "ForeignElement");
     if (aForeignElement.hasParent ())
       throw new IllegalArgumentException ("ForeignElement already has a parent!");
     if (m_aForeignElements == null)
       m_aForeignElements = new CommonsArrayList <> ();
     m_aForeignElements.add (aForeignElement);
   }
 
   public boolean hasForeignElements ()
   {
     return m_aForeignElements != null && m_aForeignElements.isNotEmpty ();
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <IMicroElement> getAllForeignElements ()
   {
     return new CommonsArrayList <> (m_aForeignElements);
   }
 
   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 CommonsLinkedHashMap <> ();
     m_aForeignAttrs.put (sAttrName, sAttrValue);
   }
 
   public boolean hasForeignAttributes ()
   {
     return m_aForeignAttrs != null && m_aForeignAttrs.isNotEmpty ();
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsOrderedMap <String, String> getAllForeignAttributes ()
   {
     return new CommonsLinkedHashMap <> (m_aForeignAttrs);
   }
 
   public void setFlag (@Nullable final String sFlag)
   {
     m_sFlag = sFlag;
   }
 
   @Nullable
   public String getFlag ()
   {
     return m_sFlag;
   }
 
   public void setRich (@Nullable final PSRichGroup aRich)
   {
     m_aRich = aRich;
   }
 
   @Nullable
   public PSRichGroup getRich ()
   {
     return m_aRich;
   }
 
   public void setLinkable (@Nullable final PSLinkableGroup aLinkable)
   {
     m_aLinkable = aLinkable;
   }
 
   @Nullable
   public PSLinkableGroup getLinkable ()
   {
     return m_aLinkable;
   }
 
   /**
    * @param bAbstract
    *        The abstract state of this rule.
    */
   public void setAbstract (final boolean bAbstract)
   {
     m_bAbstract = bAbstract;
   }
 
   /**
    * @return <code>true</code> if this rule is abstract, <code>false</code>
    *         otherwise. Default is {@value #DEFAULT_ABSTRACT}.
    */
   public boolean isAbstract ()
   {
     return m_bAbstract;
   }
 
   public void setContext (@Nullable final String sContext)
   {
     m_sContext = sContext;
   }
 
   @Nullable
   public String getContext ()
   {
     return m_sContext;
   }
 
   public void setID (@Nullable final String sID)
   {
     m_sID = sID;
   }
 
   @Nullable
   public String getID ()
   {
     return m_sID;
   }
 
   public void addInclude (@Nonnull final PSInclude aInclude)
   {
     ValueEnforcer.notNull (aInclude, "Include");
     m_aIncludes.add (aInclude);
   }
 
   public boolean hasAnyInclude ()
   {
     return m_aIncludes.isNotEmpty ();
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <PSInclude> getAllIncludes ()
   {
     return m_aIncludes.getClone ();
   }
 
   public void addLet (@Nonnull final PSLet aLet)
   {
     ValueEnforcer.notNull (aLet, "Let");
     m_aLets.add (aLet);
   }
 
   public boolean hasAnyLet ()
   {
     return m_aLets.isNotEmpty ();
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <PSLet> getAllLets ()
   {
     return m_aLets.getClone ();
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsOrderedMap <String, String> getAllLetsAsMap ()
   {
     final ICommonsOrderedMap <String, String> ret = new CommonsLinkedHashMap <> ();
     for (final PSLet aLet : m_aLets)
       ret.put (aLet.getName (), aLet.getValue ());
     return ret;
   }
 
   public void addAssertReport (@Nonnull final PSAssertReport aAssertReport)
   {
     ValueEnforcer.notNull (aAssertReport, "AssertReport");
     m_aContent.add (aAssertReport);
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <PSAssertReport> getAllAssertReports ()
   {
     return m_aContent.getAllInstanceOf (PSAssertReport.class);
   }
 
   public void addExtends (@Nonnull final PSExtends aExtends)
   {
     ValueEnforcer.notNull (aExtends, "Extends");
     m_aContent.add (aExtends);
   }
 
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <PSExtends> getAllExtends ()
   {
     return m_aContent.getAllInstanceOf (PSExtends.class);
   }
 
   @Nonnegative
   public int getExtendsCount ()
   {
     return m_aContent.getCount (e -> e instanceof PSExtends);
   }
 
   public boolean hasAnyExtends ()
   {
     return m_aContent.containsAny (e -> e instanceof PSExtends);
   }
 
   /**
    * @return A list consisting of {@link PSAssertReport} and {@link PSExtends}
    *         parameters
    */
   @Nonnull
   @ReturnsMutableCopy
   public ICommonsList <IPSElement> getAllContentElements ()
   {
     return m_aContent.getClone ();
   }
 
   @Nonnull
   public IMicroElement getAsMicroElement ()
   {
     final IMicroElement ret = new MicroElement (CSchematron.NAMESPACE_SCHEMATRON, CSchematronXML.ELEMENT_RULE);
     ret.setAttribute (CSchematronXML.ATTR_FLAG, m_sFlag);
     if (m_bAbstract)
       ret.setAttribute (CSchematronXML.ATTR_ABSTRACT, "true");
     ret.setAttribute (CSchematronXML.ATTR_CONTEXT, m_sContext);
     ret.setAttribute (CSchematronXML.ATTR_ID, m_sID);
     if (m_aRich != null)
       m_aRich.fillMicroElement (ret);
     if (m_aLinkable != null)
       m_aLinkable.fillMicroElement (ret);
     if (m_aForeignElements != null)
       for (final IMicroElement aForeignElement : m_aForeignElements)
         ret.appendChild (aForeignElement.getClone ());
     for (final PSInclude aInclude : m_aIncludes)
       ret.appendChild (aInclude.getAsMicroElement ());
     for (final PSLet aLet : m_aLets)
       ret.appendChild (aLet.getAsMicroElement ());
     for (final IPSElement aContent : m_aContent)
       ret.appendChild (aContent.getAsMicroElement ());
     if (m_aForeignAttrs != null)
       for (final Map.Entry <String, String> aEntry : m_aForeignAttrs.entrySet ())
         ret.setAttribute (aEntry.getKey (), aEntry.getValue ());
     return ret;
   }
 
   @Override
   public String toString ()
   {
     return new ToStringGenerator (this).appendIfNotNull ("flag", m_sFlag)
                                        .appendIfNotNull ("rich", m_aRich)
                                        .appendIfNotNull ("linkable", m_aLinkable)
                                        .append ("abstract", m_bAbstract)
                                        .appendIfNotNull ("context", m_sContext)
                                        .appendIfNotNull ("id", m_sID)
                                        .appendIf ("includes", m_aIncludes, CollectionHelper::isNotEmpty)
                                        .appendIf ("lets", m_aLets, CollectionHelper::isNotEmpty)
                                        .appendIf ("content", m_aContent, CollectionHelper::isNotEmpty)
                                        .appendIf ("foreignAttrs", m_aForeignAttrs, CollectionHelper::isNotEmpty)
                                        .appendIf ("foreignElements", m_aForeignElements, CollectionHelper::isNotEmpty)
                                        .toString ();
   }
 }