/*
    * Metis: Java Data Framework
    * Copyright 2012-2026. Tony Washer
    *
    * 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 io.github.tonywasher.joceanus.metis.viewer;
  
  import io.github.tonywasher.joceanus.metis.data.MetisDataItem.MetisDataList;
  import io.github.tonywasher.joceanus.metis.data.MetisDataItem.MetisDataMap;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem.MetisFieldDef;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  
  /**
   * Data Viewer Entry.
   */
  public class MetisViewerEntryImpl
          implements MetisViewerEntry {
      /**
       * Entry name prefix.
       */
      private static final String ENTRY_PREFIX = "TreeItem";
  
      /**
       * The ViewerManager.
       */
      private final MetisViewerManager theManager;
  
      /**
       * The Parent.
       */
      private final MetisViewerEntry theParent;
  
      /**
       * The id of the entry.
       */
      private final int theId;
  
      /**
       * The Child List.
       */
      private List<MetisViewerEntry> theChildList;
  
      /**
       * The unique name of the entry.
       */
      private final String theUniqueName;
  
      /**
       * The name of the entry.
       */
      private final String theDisplayName;
  
      /**
       * The object for the entry.
       */
      private Object theObject;
  
      /**
       * Is the entry visible?.
       */
      private boolean isVisible;
  
      /**
       * Constructor.
       *
       * @param pManager the viewer manager
       * @param pParent  the parent entry
       * @param pName    the entry display name
       */
      MetisViewerEntryImpl(final MetisViewerManager pManager,
                           final MetisViewerEntry pParent,
                           final String pName) {
          /* Store parameters */
          theManager = pManager;
          theParent = pParent;
          theDisplayName = pName;
  
          /* Obtain entry id. */
          theId = pManager.getNextId();
  
          /* Determine unique name */
          theUniqueName = ENTRY_PREFIX
                 + theId;
 
         /* Initialise to visible */
         isVisible = true;
 
         /* If we have a parent */
         if (pParent != null) {
             /* Add the entry to the child list */
             ((MetisViewerEntryImpl) pParent).addChild(this);
         }
     }
 
     /**
      * Get viewer manager.
      *
      * @return the manager
      */
     protected MetisViewerManager getManager() {
         return theManager;
     }
 
     @Override
     public MetisViewerEntry getParent() {
         return theParent;
     }
 
     /**
      * Get unique name.
      *
      * @return the name
      */
     public String getUniqueName() {
         return theUniqueName;
     }
 
     @Override
     public String getDisplayName() {
         return theDisplayName;
     }
 
     /**
      * Get id.
      *
      * @return the id
      */
     public int getId() {
         return theId;
     }
 
     @Override
     public Object getObject() {
         return theObject;
     }
 
     @Override
     public String toString() {
         return theDisplayName;
     }
 
     /**
      * Get child iterator.
      *
      * @return the iterator
      */
     public Iterator<MetisViewerEntry> childIterator() {
         return theChildList == null
                 ? Collections.emptyIterator()
                 : theChildList.iterator();
     }
 
     /**
      * Add child.
      *
      * @param pChild the child to add
      */
     private void addChild(final MetisViewerEntryImpl pChild) {
         if (theChildList == null) {
             theChildList = new ArrayList<>();
         }
         theChildList.add(pChild);
     }
 
     @Override
     public boolean isVisible() {
         return isVisible;
     }
 
     @Override
     public void setVisible(final boolean pVisible) {
         /* If this is a change in status */
         if (isVisible != pVisible) {
             /* Change status and report it */
             isVisible = pVisible;
             theManager.fireEvent(MetisViewerEvent.VISIBILITY, this);
         }
     }
 
     @Override
     public void setFocus() {
         theManager.setFocus(this);
     }
 
     @Override
     public void setFocus(final String pName) {
         /* Loop through the children */
         for (MetisViewerEntry myEntry : theChildList) {
             /* If we match the object */
             if (pName.equals(myEntry.getDisplayName())) {
                 /* Set the focus and return */
                 myEntry.setFocus();
                 return;
             }
         }
     }
 
     @Override
     public void setObject(final Object pObject) {
         /* Set the new object */
         setTheObject(pObject);
 
         /* Notify regarding the data change */
         theManager.fireEvent(MetisViewerEvent.VALUE, this);
     }
 
     /**
      * Set the tree object referred to by the entry.
      *
      * @param pObject the new object
      */
     public void setTreeObject(final Object pObject) {
         /* Set the new object */
         setTheObject(pObject);
 
         /* Create child elements if required */
         if (pObject instanceof MetisFieldItem myItem) {
             createChildElements(myItem);
         }
 
         /* Notify regarding the data change */
         theManager.fireEvent(MetisViewerEvent.VALUE, this);
     }
 
     /**
      * Set the object referred to by the entry.
      *
      * @param pObject the new object
      */
     private void setTheObject(final Object pObject) {
         /* Set the new object */
         theObject = pObject;
 
         /* Clear the childList */
         if (theChildList != null) {
             theChildList.clear();
         }
     }
 
     /**
      * Create child elements.
      *
      * @param pItem the item
      */
     private void createChildElements(final MetisFieldItem pItem) {
         /* Loop through the fields */
         final Iterator<MetisFieldDef> myIterator = pItem.getDataFieldSet().fieldIterator();
         while (myIterator.hasNext()) {
             final MetisFieldDef myField = myIterator.next();
 
             /* Obtain the value */
             final Object myValue = myField.getFieldValue(pItem);
             boolean addChild = false;
 
             /* Determine whether to add the child */
             if (myValue instanceof List) {
                 addChild = !((List<?>) myValue).isEmpty();
             } else if (myValue instanceof MetisDataList) {
                 addChild = !((MetisDataList<?>) myValue).isEmpty();
             } else if (myValue instanceof Map) {
                 addChild = !((Map<?, ?>) myValue).isEmpty();
             } else if (myValue instanceof MetisDataMap) {
                 addChild = !((MetisDataMap<?, ?>) myValue).isEmpty();
             }
 
             /* If we should add the child */
             if (addChild) {
                 /* Create it */
                 final MetisViewerEntry myChild = theManager.newEntry(this, myField.getFieldId().getId());
                 myChild.setObject(myValue);
             }
         }
     }
 
     @Override
     public boolean equals(final Object pThat) {
         /* Handle trivial cases */
         if (this == pThat) {
             return true;
         }
         if (pThat == null) {
             return false;
         }
 
         /* Check class */
         if (!(pThat instanceof MetisViewerEntryImpl myThat)) {
             return false;
         }
 
         /* Must have same id */
         return theId == myThat.theId;
     }
 
     @Override
     public int hashCode() {
         return theId;
     }
 }