package org.opentrafficsim.editor;
   
   import java.rmi.RemoteException;
   import java.util.ArrayList;
   import java.util.LinkedHashMap;
   import java.util.List;
   import java.util.Map;
   import java.util.regex.Pattern;
   
  import org.djutils.event.Event;
  import org.djutils.event.EventListener;
  import org.djutils.exceptions.Throw;
  import org.djutils.immutablecollections.Immutable;
  import org.djutils.immutablecollections.ImmutableArrayList;
  import org.djutils.immutablecollections.ImmutableList;
  import org.opentrafficsim.editor.decoration.validation.XsdAllValidator;
  import org.w3c.dom.Node;
  
  /**
   * This class exists to keep {@code XsdTreeNode} at manageable size. It houses all static methods used in {@code XsdTreeNode}.
   * <p>
   * Copyright (c) 2023-2024 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://opentrafficsim.org/docs/license.html">OpenTrafficSim License</a>.
   * </p>
   * @author <a href="https://github.com/wjschakel">Wouter Schakel</a>
   */
  public final class XsdTreeNodeUtil
  {
  
      /** Pattern for regular expression to split string by upper case without disregarding the upper case itself. */
      private static final Pattern UPPER_PATTERN = Pattern.compile("(?=\\p{Lu})");
  
      /** Validators for xsd:all nodes and their children. */
      private final static Map<String, XsdAllValidator> XSD_ALL_VALIDATORS = new LinkedHashMap<>();
  
      /**
       * Private constructor.
       */
      private XsdTreeNodeUtil()
      {
  
      }
  
      /**
       * Add xsd all validator to the given node.
       * @param shared XsdTreeNode; shared xsd:all node.
       * @param node XsdTreeNode; xsd:all node, or one of its children.
       */
      public static void addXsdAllValidator(final XsdTreeNode shared, final XsdTreeNode node)
      {
          String path = shared.getPathString();
          XsdAllValidator validator = XSD_ALL_VALIDATORS.computeIfAbsent(path, (p) -> new XsdAllValidator(node.getRoot()));
          node.addNodeValidator(validator);
          validator.addNode(node);
      }
  
      /**
       * Parses the minOcccurs or maxOccurs value from given node. If it is not supplied, the default of 1 is given.
       * @param node Node; node.
       * @param attribute String; "minOccurs" or "maxOccurs".
       * @return int; value of occurs, -1 represents "unbounded".
       */
      static int getOccurs(final Node node, final String attribute)
      {
          String occurs = DocumentReader.getAttribute(node, attribute);
          if (occurs == null)
          {
              return 1;
          }
          if ("unbounded".equals(occurs))
          {
              return -1;
          }
          return Integer.valueOf(occurs);
      }
  
      /**
       * Main expansion algorithm. Loops all child XSD nodes, and selects those that define next elements.
       * @param node Node; node to get the children of.
       * @param parentNode XsdTreeNode; parent node for the created children.
       * @param children List&lt;XsdTreeNode&gt;; list to add the children to. This may be different from
       *            {@code parentNode.children} due to layered choice structures.
       * @param hiddenNodes ImmutableList&lt;Node&gt;; nodes between the XSD node of the parent, and this tree node's XSD node.
       * @param schema XsdSchema; schema to get types and referred elements from.
       * @param flattenSequence boolean; when true, treats an xsd:sequence child as an extension of the node. In the context of a
       *            choice this should remain separated.
       * @param skip int; child index to skip, this is used when copying choice options from an option that is already created.
       */
      static void addChildren(final Node node, final XsdTreeNode parentNode, final List<XsdTreeNode> children,
              final ImmutableList<Node> hiddenNodes, final Schema schema, final boolean flattenSequence, final int skip)
      {
          int skipIndex = skip;
          XsdTreeNode root = parentNode.getRoot();
          for (int childIndex = 0; childIndex < node.getChildNodes().getLength(); childIndex++)
          {
              Node child = node.getChildNodes().item(childIndex);
              switch (child.getNodeName())
              {
                  case "xsd:element":
                     if (children.size() == skipIndex)
                     {
                         skipIndex = -1;
                         break;
                     }
                     XsdTreeNode element;
                     String ref = DocumentReader.getAttribute(child, "ref");
                     String type = DocumentReader.getAttribute(child, "type");
                     if (ref != null)
                     {
                         element = new XsdTreeNode(parentNode, XsdTreeNodeUtil.ref(child, ref, schema),
                                 XsdTreeNodeUtil.append(hiddenNodes, node), child);
                     }
                     else if (type != null)
                     {
                         Node typedNode = XsdTreeNodeUtil.type(child, type, schema);
                         if (typedNode == null)
                         {
                             // xsd:string or other basic type
                             element = new XsdTreeNode(parentNode, child, XsdTreeNodeUtil.append(hiddenNodes, node));
                         }
                         else
                         {
                             element = new XsdTreeNode(parentNode, typedNode, XsdTreeNodeUtil.append(hiddenNodes, node), child);
                         }
                     }
                     else
                     {
                         element = new XsdTreeNode(parentNode, child, XsdTreeNodeUtil.append(hiddenNodes, node));
                     }
                     children.add(element);
                     root.fireEvent(XsdTreeNodeRoot.NODE_CREATED,
                             new Object[] {element, parentNode, parentNode.children.indexOf(element)});
                     break;
                 case "xsd:sequence":
                     if (children.size() == skipIndex)
                     {
                         skipIndex = -1;
                         break;
                     }
                     if (flattenSequence)
                     {
                         addChildren(child, parentNode, children, XsdTreeNodeUtil.append(hiddenNodes, node), schema,
                                 flattenSequence, -1);
                     }
                     else
                     {
                         // add sequence as option, 'children' is a list of options for a choice
                         XsdTreeNode sequence = new XsdTreeNode(parentNode, child, XsdTreeNodeUtil.append(hiddenNodes, node));
                         children.add(sequence);
                         root.fireEvent(XsdTreeNodeRoot.NODE_CREATED,
                                 new Object[] {sequence, parentNode, parentNode.children.indexOf(sequence)});
                     }
                     break;
                 case "xsd:choice":
                 case "xsd:all":
                     if (children.size() == skipIndex)
                     {
                         skipIndex = -1;
                         break;
                     }
                     XsdTreeNode choice = new XsdTreeNode(parentNode, child, XsdTreeNodeUtil.append(hiddenNodes, node));
                     root.fireEvent(XsdTreeNodeRoot.NODE_CREATED,
                             new Object[] {choice, parentNode, parentNode.children.indexOf(choice)});
                     choice.createOptions();
                     /*
                      * We add the choice node, which is usually overwritten by the consecutive setting of an option. But not if
                      * this choice is part of a sequence, that is itself an option in a parentChoice. Then, the option is set at
                      * the level of the parent choice. The sequence option of the parentChoice in fact needs to be populated by
                      * the choice nodes. If we don't add it here, the sequence will be empty.
                      */
                     children.add(choice);
                     choice.setOption(choice.options.get(0));
                     break;
                 case "xsd:extension":
                     if (children.size() == skipIndex)
                     {
                         skipIndex = -1;
                         break;
                     }
                     XsdTreeNode extension = new XsdTreeNode(parentNode, child, XsdTreeNodeUtil.append(hiddenNodes, node));
                     root.fireEvent(XsdTreeNodeRoot.NODE_CREATED,
                             new Object[] {extension, parentNode, parentNode.children.indexOf(extension)});
                     children.add(extension);
                     break;
                 case "xsd:attribute":
                 case "xsd:annotation":
                 case "xsd:simpleType": // only defines xsd:restriction with xsd:pattern/xsd:enumeration
                 case "xsd:restriction":
                 case "xsd:simpleContent": // bit of a late capture, followed "type" attribute and did not check what it was
                 case "xsd:union":
                 case "#text":
                     // nothing, not even report ignoring, these are not relevant regarding element structure
                     break;
                 default:
                     System.out.println("Ignoring a " + child.getNodeName());
             }
         }
     }
 
     /**
      * Returns a copy of the input list, with the extra node appended at the end.
      * @param hiddenNodes ImmutableList&lt;Node&gt;; hidden nodes list.
      * @param node Node; node to append.
      * @return ImmutableList&lt;Node&gt;; copy of the input list, with the extra node appended at the end.
      */
     static ImmutableList<Node> append(final ImmutableList<Node> hiddenNodes, final Node node)
     {
         List<Node> list = new ArrayList<>(hiddenNodes.size() + 1);
         list.addAll(hiddenNodes.toCollection());
         list.add(node);
         return new ImmutableArrayList<>(list, Immutable.WRAP);
     }
 
     /**
      * Returns a list of options derived from a list of restrictions (xsd:restriction).
      * @param restrictions List&lt;Node&gt;; list of restrictions.
      * @return List&lt;String&gt;; list of options.
      */
     static List<String> getOptionsFromRestrictions(final List<Node> restrictions)
     {
         List<String> options = new ArrayList<>();
         for (Node restriction : restrictions)
         {
             List<Node> enumerations = DocumentReader.getChildren(restriction, "xsd:enumeration");
             for (Node enumeration : enumerations)
             {
                 options.add(DocumentReader.getAttribute(enumeration, "value"));
             }
         }
         return options;
     }
 
     /**
      * Recursively throws creation events for all current nodes in the tree. This method is for {@code XsdTreeNodeRoot}.
      * @param node XsdTreeNode; node.
      * @param listener EventListener; listener.
      * @throws RemoteException if event cannot be fired.
      */
     protected static void fireCreatedEventOnExistingNodes(final XsdTreeNode node, final EventListener listener)
             throws RemoteException
     {
         List<XsdTreeNode> subNodes = node.children == null ? new ArrayList<>() : new ArrayList<>(node.children);
         // only selected node extends towards choice, otherwise infinite recursion
         if (node.choice != null && node.choice.selected.equals(node))
         {
             subNodes.add(node.choice);
             subNodes.addAll(node.choice.options);
             subNodes.remove(node);
         }
         for (XsdTreeNode child : subNodes)
         {
             fireCreatedEventOnExistingNodes(child, listener);
         }
         Event event = new Event(XsdTreeNodeRoot.NODE_CREATED, new Object[] {node, node.getParent(), subNodes.indexOf(node)});
         listener.notify(event);
     }
 
     /**
      * Takes the minimum of both indices, while ignoring negative values (indicating an element was not found for deletion).
      * @param insertIndex int; previously determined insertion index; may be updated to lower value.
      * @param removeIndex int; index of element that is removed.
      * @return int; minimum of both indices, while ignoring negative values.
      */
     static int resolveInsertion(final int insertIndex, final int removeIndex)
     {
         int tmp = insertIndex < 0 ? removeIndex : insertIndex;
         return tmp < removeIndex ? tmp : removeIndex;
     }
 
     /**
      * Returns from the XSD definition the appropriate nodes to take children from at the level of the input node, in the order
      * in which they should appear. This is often the xsd:complexType within an xsd:element, but can become as complex as
      * containing multiple xsd:extension and their referred base types. An xsd:sequence is also common. Adding children in the
      * order as they appear per {@code Node}, and in the order the {@code Node}'s are given, results in an overall order
      * suitable for XML.
      * @param node Node; node to expand further.
      * @param hiddenNodes ImmutableList&lt;Node&gt;; nodes between the XSD node of the parent, and this tree node's XSD node.
      * @param schema XsdSchema; schema to retrieve types.
      * @return Map&lt;Node, ImmutableList&lt;Node&gt;&gt;; map of nodes containing relevant children at the level of the input
      *         node, and their appropriate hidden nodes.
      */
     static Map<Node, ImmutableList<Node>> getRelevantNodesWithChildren(final Node node, final ImmutableList<Node> hiddenNodes,
             final Schema schema)
     {
         Node complexType =
                 node.getNodeName().equals("xsd:complexType") ? node : DocumentReader.getChild(node, "xsd:complexType");
         if (complexType != null)
         {
             Node sequence = DocumentReader.getChild(complexType, "xsd:sequence");
             if (sequence != null)
             {
                 return Map.of(sequence, append(hiddenNodes, complexType));
             }
             Node complexContent = DocumentReader.getChild(complexType, "xsd:complexContent");
             if (complexContent != null)
             {
                 Node extension = DocumentReader.getChild(complexContent, "xsd:extension");
                 if (extension != null)
                 {
                     ImmutableList<Node> hiddenExtension = append(append(hiddenNodes, complexType), complexContent);
                     LinkedHashMap<Node, ImmutableList<Node>> elements = new LinkedHashMap<>();
                     String base = DocumentReader.getAttribute(extension, "base");
                     if (base != null)
                     {
                         Node baseNode = schema.getType(base);
                         if (baseNode != null)
                         {
                             elements.putAll(getRelevantNodesWithChildren(baseNode, append(hiddenExtension, extension), schema));
                         }
                     }
                     elements.put(extension, hiddenExtension);
                     return elements;
                 }
             }
             return Map.of(complexType, hiddenNodes);
         }
         return Map.of(node, hiddenNodes);
     }
 
     /**
      * Returns whether nodes are of the same type. This regards the referring XSD node if it exists, otherwise it regards the
      * regular XSD node.
      * @param node1 XsdTreeNode; node 1.
      * @param node2 XsdTreeNode; node 1.
      * @return boolean; whether nodes are of the same type.
      */
     static boolean haveSameType(final XsdTreeNode node1, final XsdTreeNode node2)
     {
         return (node1.referringXsdNode != null && node1.referringXsdNode.equals(node2.referringXsdNode))
                 || (node1.referringXsdNode == null && node1.xsdNode.equals(node2.xsdNode));
     }
 
     /**
      * Returns the element referred to by ref={ref} in an xsd:element. Will return {@code XiIncludeNode.XI_INCLUDE} for
      * xi:include.
      * @param node Node; node, must have ref={ref} attribute.
      * @param ref String; value of ref={ref}.
      * @param schema XsdSchema; schema to take element from.
      * @return Node; element referred to by ref={ref} in an xsd:element.
      */
     static Node ref(final Node node, final String ref, final Schema schema)
     {
         if (ref.equals("xi:include"))
         {
             return XiIncludeNode.XI_INCLUDE;
         }
         Node refNode = schema.getElement(ref);
         Throw.when(refNode == null, RuntimeException.class, "Unable to load ref for %s from XSD schema.", ref);
         return refNode;
     }
 
     /**
      * Returns the element referred to by type={type} in an xsd:element. Ignores all types starting with "xsd:" as these are
      * standard types to which user input can be validated directly.
      * @param node Node; node, must have type={type} attribute.
      * @param type String; value of type={type}.
      * @param schema XsdSchema; schema to take type from.
      * @return Node; element referred to by type={type} in an xsd:element.
      */
     static Node type(final Node node, final String type, final Schema schema)
     {
         if (type.startsWith("xsd:"))
         {
             return null;
         }
         Node typeNode = schema.getType(type);
         Throw.when(typeNode == null, RuntimeException.class, "Unable to load type for %s from XSD schema.", type);
         return typeNode;
     }
 
     /**
      * Adds a thin space before each capital character in a {@code String}, except the first.
      * @param name String; name of node.
      * @return String; input string but with a thin space before each capital character, except the first.
      */
     static String separatedName(final String name)
     {
         String[] parts = UPPER_PATTERN.split(name);
         if (parts.length == 1)
         {
             return parts[0];
         }
         String separator = "";
         StringBuilder stringBuilder = new StringBuilder();
         for (String part : parts)
         {
             stringBuilder.append(separator).append(part);
             separator = " ";
         }
         return stringBuilder.toString();
     }
 
     /**
      * Returns whether the two values are equal, where {@code null} is consider equal to an empty string.
      * @param value1 String; value 1.
      * @param value2 String; value 2.
      * @return whether the two values are equal, where {@code null} is consider equal to an empty string.
      */
     public static boolean valuesAreEqual(final String value1, final String value2)
     {
         boolean value1Empty = value1 == null || value1.isEmpty();
         boolean value2Empty = value2 == null || value2.isEmpty();
         return (value1Empty && value2Empty) || (value1 != null && value1.equals(value2));
     }
 
 }