/**
    * Copyright (C) 2014-2017 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.errorhandler;
  
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  
  import com.helger.commons.error.level.EErrorLevel;
  import com.helger.commons.error.level.IErrorLevel;
  import com.helger.commons.io.resource.IReadableResource;
  import com.helger.commons.string.ToStringGenerator;
  import com.helger.schematron.pure.model.IPSElement;
  
  /**
   * Abstract implementation of {@link IPSErrorHandler}.
   *
   * @author Philip Helger
   */
  public abstract class AbstractPSErrorHandler implements IPSErrorHandler
  {
    private final IPSErrorHandler m_aNestedErrorHandler;
  
    protected AbstractPSErrorHandler ()
    {
      this (null);
    }
  
    protected AbstractPSErrorHandler (@Nullable final IPSErrorHandler aNestedErrorHandler)
    {
      m_aNestedErrorHandler = aNestedErrorHandler;
    }
  
    /**
     * @return The nested error handler as passed in the constructor or
     *         <code>null</code> if none was provided.
     */
    @Nullable
    public IPSErrorHandler getNestedErrorHandler ()
    {
      return m_aNestedErrorHandler;
    }
  
    /**
     * The abstract method that is called for both warnings and errors.
     *
     * @param aRes
     *        The resource in which the error occurred.
     * @param aErrorLevel
     *        The error level. Never <code>null</code>.
     * @param aSourceElement
     *        The source schematron element, in which the error occurred. Maybe
     *        <code>null</code> for XPath errors.
     * @param sMessage
     *        The error message. Never <code>null</code>.
     * @param t
     *        The optional exception that might have occurred. May be
     *        <code>null</code>.
     */
    protected abstract void handle (@Nullable IReadableResource aRes,
                                    @Nonnull IErrorLevel aErrorLevel,
                                    @Nullable IPSElement aSourceElement,
                                    @Nonnull String sMessage,
                                    @Nullable Throwable t);
  
    public final void warn (@Nullable final IReadableResource aRes,
                            @Nullable final IPSElement aSourceElement,
                            @Nonnull final String sMessage)
    {
      handle (aRes, EErrorLevel.WARN, aSourceElement, sMessage, (Throwable) null);
  
      // Do we have a nested error handler?
      final IPSErrorHandler aNestedErrorHandler = getNestedErrorHandler ();
      if (aNestedErrorHandler != null)
        aNestedErrorHandler.warn (aRes, aSourceElement, sMessage);
    }
  
    public final void error (@Nullable final IReadableResource aRes,
                             @Nullable final IPSElement aSourceElement,
                             @Nonnull final String sMessage,
                             @Nullable final Throwable t)
    {
      handle (aRes, EErrorLevel.ERROR, aSourceElement, sMessage, t);
  
      // Do we have a nested error handler?
      final IPSErrorHandler aNestedErrorHandler = getNestedErrorHandler ();
     if (aNestedErrorHandler != null)
       aNestedErrorHandler.error (aRes, aSourceElement, sMessage, t);
   }
 
   @Override
   public String toString ()
   {
     return new ToStringGenerator (this).appendIfNotNull ("nestedErrorHandler", m_aNestedErrorHandler).getToString ();
   }
 }