/* This file is part of the project "Hilbert II" - http://www.qedeq.org" target="alexandria_uri">http://www.qedeq.org
    *
    * Copyright 2000-2014,  Michael Meyling <mime@qedeq.org>.
    *
    * "Hilbert II" is free software; you can redistribute
    * it and/or modify it under the terms of the GNU General Public
    * License as published by the Free Software Foundation; either
    * version 2 of the License, or (at your option) any later version.
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   */
  
  package org.qedeq.kernel.bo.module;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.qedeq.base.trace.Trace;
  import org.qedeq.base.utility.EqualsUtility;
  import org.qedeq.kernel.bo.common.ModuleReferenceList;
  import org.qedeq.kernel.bo.common.QedeqBo;
  import org.qedeq.kernel.se.common.IllegalModuleDataException;
  import org.qedeq.kernel.se.common.ModuleContext;
  
  
  /**
   * Represents a reference list of modules. Every entry has a symbolic name for one referenced QEDEQ
   * module. This module label acts as a prefix for all references to that module. The module label
   * must be an unique String.
   *
   * @author  Michael Meyling
   */
  public class KernelModuleReferenceList implements ModuleReferenceList {
  
      /** This class. */
      private static final Class CLASS = KernelModuleReferenceList.class;
  
      /** Contains all labels. */
      private final List labels;
  
      /** Contains all module props. */
      private final List props;
  
      /** Contains all module import contexts. */
      private final List contexts;
  
      /** Maps labels to context. */
      private final Map label2Context;
  
      /**
       * Constructs an empty list of module references.
       */
      public KernelModuleReferenceList() {
          labels = new ArrayList();
          props = new ArrayList();
          contexts = new ArrayList();
          label2Context = new HashMap();
      }
  
      /**
       * Add module reference to list.
       *
       * @param   context Within this context.
       * @param   label   Referenced module gets this label. Must not be <code>null</code> or empty.
       * @param   prop    Referenced module has this properties. Must not be <code>null</code>.
       * @throws  IllegalModuleDataException  The <code>label</code> is empty or <code>null</code>.
       */
      public void add(final ModuleContext context, final String label, final QedeqBo prop)
              throws IllegalModuleDataException {
          if (label == null || label.length() <= 0) {
              throw new IllegalModuleDataException(10003, "An label was not defined.",
                  new ModuleContext(context), null,
                  null);  // LATER mime 20071026: organize exception codes
          }
          final ModuleContext con = new ModuleContext(context);
          labels.add(label);
          label2Context.put(label, con);
          contexts.add(con);
          Trace.param(CLASS, "add(ModuleContext, String, QedeqBo)", "context", con);
          props.add(prop);
      }
  
      /**
       * Add module reference to list.
       *
       * @param   context Within this context.
       * @param   label   Referenced module gets this label. Must not be <code>null</code> or empty.
       * @param   prop    Referenced module has this properties. Must not be <code>null</code>.
       * @throws  IllegalModuleDataException  The <code>id</code> already exists or is
       *          <code>null</code>. Also if <code>label</code> is empty or <code>null</code>.
       */
      public void addLabelUnique(final ModuleContext context, final String label,
              final QedeqBo prop) throws IllegalModuleDataException {
          if (labels.contains(label)) {
             // LATER mime 20071026: organize exception codes
             throw new IllegalModuleDataException(10004, "Label \"" + label
                 + "\" defined more than once.", new ModuleContext(context), // use copy constructor!
                 (ModuleContext) label2Context.get(label), null);
         }
         add(new ModuleContext(context), label, prop);
     }
 
     public int size() {
         return labels.size();
     }
 
     public String getLabel(final int index) {
         return (String) labels.get(index);
     }
 
     public QedeqBo getQedeqBo(final int index) {
         return (QedeqBo) props.get(index);
     }
 
     /**
      * Get {@link QedeqBo} of referenced module.
      *
      * @param   index   Entry index.
      * @return  Module properties for that module.
      */
     public KernelQedeqBo getKernelQedeqBo(final int index) {
         return (KernelQedeqBo) props.get(index);
     }
 
     public ModuleContext getModuleContext(final int index) {
         return (ModuleContext) contexts.get(index);
     }
 
     public QedeqBo getQedeqBo(final String label) {
         final int index = labels.indexOf(label);
         if (index < 0) {
             return null;
         }
         return (QedeqBo) props.get(index);
     }
 
     /**
      * Get KernelQedeqBo of referenced module via label. Might be <code>null</code>.
      *
      * @param   label   Label for referenced module or <code>null</code> if not found.
      * @return  QEQDEQ BO.
      */
     public KernelQedeqBo getKernelQedeqBo(final String label) {
         final int index = labels.indexOf(label);
         if (index < 0) {
             return null;
         }
         return (KernelQedeqBo) props.get(index);
     }
 
     /**
      * Is the given QEDEQ BO already in this list?
      *
      * @param   bo  QEDEQ BO.
      * @return  Already in list?
      */
     public boolean contains(final KernelQedeqBo bo) {
         return props.contains(bo);
     }
 
     /**
      * Delete a given QEDEQ BO already from list.
      *
      * @param   bo  QEDEQ BO.
      */
     public void remove(final KernelQedeqBo bo) {
         int index;
         while (0 <= (index = props.indexOf(bo))) {
             final String label = (String) labels.get(index);
             label2Context.remove(label);
             props.remove(index);
             labels.remove(index);
             contexts.remove(index);
         }
     }
 
     public boolean equals(final Object obj) {
         if (!(obj instanceof KernelModuleReferenceList)) {
             return false;
         }
         final ModuleReferenceList otherList = (ModuleReferenceList) obj;
         if (size() != otherList.size()) {
             return false;
         }
         for (int i = 0; i < size(); i++) {
             if (!EqualsUtility.equals(getLabel(i), otherList.getLabel(i))
                     || !EqualsUtility.equals(getQedeqBo(i),
                         otherList.getQedeqBo(i))) {
                 return false;
             }
         }
         return true;
     }
 
     /**
      * Empty reference list.
      */
     public void clear() {
         labels.clear();
         props.clear();
         contexts.clear();
         label2Context.clear();
     }
 
     /**
      * Copy all list entry references of <code>list</code> to this instance.
      *
      * @param   list    Copy from here.
      */
     public void set(final KernelModuleReferenceList list) {
         clear();
         this.labels.addAll(list.labels);
         this.props.addAll(list.props);
         this.contexts.addAll(list.contexts);
         this.label2Context.putAll(list.label2Context);
     }
 
     public int hashCode() {
         int hash = 0;
         for (int i = 0; i < size(); i++) {
             hash = hash ^ (i + 1);
             if (getLabel(i) != null) {
                 hash = hash ^ getLabel(i).hashCode();
                 hash = hash ^ getQedeqBo(i).hashCode();
             }
         }
         return hash;
     }
 
     public String toString() {
         final StringBuffer buffer = new StringBuffer("module reference list:\n");
         for (int i = 0; i < size(); i++) {
             if (i != 0) {
                 buffer.append("\n");
             }
             buffer.append((i + 1) + ":\t");
             buffer.append(getLabel(i)).append(": ").append(getQedeqBo(i)).append("\n");
         }
         return buffer.toString();
     }
 
 }