/*
    * 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.oceanus.base.OceanusException;
  import io.github.tonywasher.joceanus.oceanus.decimal.OceanusDecimal;
  import io.github.tonywasher.joceanus.oceanus.format.OceanusDataFormatter;
  import io.github.tonywasher.joceanus.oceanus.profile.OceanusProfile;
  import io.github.tonywasher.joceanus.metis.data.MetisDataDelta;
  import io.github.tonywasher.joceanus.metis.data.MetisDataFieldValue;
  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 io.github.tonywasher.joceanus.metis.field.MetisFieldItem.MetisFieldSetDef;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem.MetisFieldVersionedDef;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldValidation;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldVersionHistory;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldVersionedItem;
  
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  
  /**
   * Data Viewer Formatter.
   */
  public class MetisViewerFormatter {
      /**
       * Items per page.
       */
      protected static final int ITEMS_PER_PAGE = 50;
  
      /**
       * The index column.
       */
      private static final String COLUMN_INDEX = "Index";
  
      /**
       * The field column.
       */
      private static final String COLUMN_FIELD = MetisViewerResource.VIEWER_COLUMN_FIELD.getValue();
  
      /**
       * The key column.
       */
      private static final String COLUMN_KEY = MetisViewerResource.VIEWER_COLUMN_KEY.getValue();
  
      /**
       * The value column.
       */
      private static final String COLUMN_VALUE = MetisViewerResource.VIEWER_COLUMN_VALUE.getValue();
  
      /**
       * List Table.
       */
      private static final String TABLE_LIST = "List";
  
      /**
       * Map Table.
       */
      private static final String TABLE_MAP = MetisViewerResource.VIEWER_TABLE_MAP.getValue();
  
      /**
       * Stack Trace table.
       */
      private static final String TABLE_STACKTRACE = MetisViewerResource.VIEWER_TABLE_STACKTRACE.getValue();
  
      /**
       * The HTML Builder.
       */
      private final MetisViewerBuilder theBuilder;
  
      /**
       * Constructor.
       *
       * @param pFormatter the data formatter
       * @throws OceanusException on error
       */
      protected MetisViewerFormatter(final OceanusDataFormatter pFormatter) throws OceanusException {
          theBuilder = new MetisViewerBuilder(pFormatter);
      }
  
      /**
      * Build HTML table describing Object.
      *
      * @param pPage the viewer page
      */
     protected void formatPage(final MetisViewerPage pPage) {
         /* Reset the document */
         theBuilder.resetDocument(pPage);
 
         /* Switch on the Mode */
         switch (pPage.getMode()) {
             case CONTENTS:
                 formatHTMLObject(pPage.getObject());
                 break;
             case SUMMARY:
                 formatHTMLCollection(pPage.getObject(), pPage.getItemNo());
                 break;
             case ITEMS:
                 formatHTMLItem(pPage.getObject(), pPage.getItemNo());
                 break;
             default:
                 break;
         }
 
         /* Format the document */
         theBuilder.formatDocument();
     }
 
     /**
      * Build HTML table.
      *
      * @param pObject the object
      */
     private void formatHTMLObject(final Object pObject) {
         /* handle DataDifference */
         final Object myObject = pObject instanceof MetisDataDelta myDelta
                 ? myDelta.getObject()
                 : pObject;
 
         /* If we are FieldItem */
         if (myObject instanceof MetisFieldItem myField) {
             formatHTMLEosFieldItem(myField);
 
             /* If we are Stack Trace */
         } else if (myObject instanceof StackTraceElement[] myStack) {
             formatHTMLStackTrace(myStack);
 
             /* If we are TethysProfile */
         } else if (myObject instanceof OceanusProfile myProfile) {
             formatHTMLEosFieldItem(new MetisViewerProfileWrapper(myProfile));
 
             /* If we are Throwable */
         } else if (myObject instanceof Throwable myThrow) {
             formatHTMLEosFieldItem(new MetisViewerExceptionWrapper(myThrow));
 
             /* else handle unsupported list item */
         } else {
             formatHTMLUnknown(myObject);
         }
     }
 
     /**
      * Build HTML collection.
      *
      * @param pObject the object
      * @param pStart  the start index for the section
      */
     private void formatHTMLCollection(final Object pObject,
                                       final int pStart) {
         /* handle DataDifference */
         Object myObject = pObject instanceof MetisDataDelta myDelta
                 ? myDelta.getObject()
                 : pObject;
 
         /* handle embedded objects */
         if (myObject instanceof MetisDataList<?> myList) {
             myObject = myList.getUnderlyingList();
         } else if (myObject instanceof MetisDataMap<?, ?> myMap) {
             myObject = myMap.getUnderlyingMap();
         }
 
         /* If we are List */
         if (myObject instanceof List<?> myList) {
             formatHTMLListSection(myList, pStart);
 
             /* If we are Map */
         } else if (myObject instanceof Map<?, ?> myMap) {
             formatHTMLMapSection(myMap, pStart);
         }
     }
 
     /**
      * Build HTML item.
      *
      * @param pObject the object
      * @param pIndex  index of the item
      */
     private void formatHTMLItem(final Object pObject,
                                 final int pIndex) {
         /* handle DataDifference */
         Object myObject = pObject instanceof MetisDataDelta myDelta
                 ? myDelta.getObject()
                 : pObject;
 
         /* handle embedded objects */
         if (myObject instanceof MetisDataList<?> myList) {
             myObject = myList.getUnderlyingList();
         }
 
         /* If we are List */
         if (myObject instanceof List<?> myList) {
             formatHTMLListItem(myList, pIndex);
         }
     }
 
     /**
      * Build HTML table describing DataEosFieldItem.
      *
      * @param pItem the item
      */
     private void formatHTMLEosFieldItem(final MetisFieldItem pItem) {
         /* Access details */
         final MetisFieldSetDef myFields = pItem.getDataFieldSet();
         final boolean isVersioned = pItem instanceof MetisFieldVersionedItem;
         final MetisFieldVersionedItem myItem = isVersioned
                 ? (MetisFieldVersionedItem) pItem
                 : null;
 
         /* Initialise the document */
         theBuilder.newTitle(myFields.getName());
         theBuilder.newTable();
         theBuilder.newTitleCell(COLUMN_FIELD);
         theBuilder.newTitleCell(COLUMN_VALUE);
 
         /* Loop through the fields */
         final Iterator<MetisFieldDef> myIterator = myFields.fieldIterator();
         while (myIterator.hasNext()) {
             /* Access Field */
             final MetisFieldDef myField = myIterator.next();
 
             /* Access the value */
             final Object myValue = myField.isCalculated()
                     ? MetisDataFieldValue.SKIP
                     : myField.getFieldValue(pItem);
 
             /* Skip value if required */
             if (skipValue(myValue)) {
                 continue;
             }
 
             /* Start the field */
             theBuilder.newTableRow();
             theBuilder.newDataCell(myField.getFieldId().getId());
             if (myItem != null
                     && myField instanceof MetisFieldVersionedDef
                     && myItem.fieldChanged(myField).isDifferent()) {
                 theBuilder.newDataCell(myValue, true);
             } else {
                 theBuilder.newDataCell(myValue);
             }
         }
     }
 
     /**
      * Should we skip the value.
      *
      * @param pValue the value
      * @return true/false
      */
     private static boolean skipValue(final Object pValue) {
         /* Access the value */
         Object myValue = pValue;
 
         /* Skip empty lists */
         if (myValue instanceof MetisDataList<?> myList) {
             myValue = myList.getUnderlyingList();
         }
         if (myValue instanceof List<?> myList) {
             return myList.isEmpty();
         }
 
         /* Skip empty maps */
         if (myValue instanceof MetisDataMap<?, ?> myMap) {
             myValue = myMap.getUnderlyingMap();
         }
         if (myValue instanceof Map<?, ?> myMap) {
             return myMap.isEmpty();
         }
 
         /* Skip empty history/errors */
         if (myValue instanceof MetisFieldVersionHistory myHistory) {
             return !myHistory.hasHistory();
         }
         if (myValue instanceof MetisFieldValidation myValid) {
             return !myValid.hasErrors();
         }
 
         /* Skip zero decimals */
         if (myValue instanceof OceanusDecimal myDecimal) {
             return myDecimal.isZero();
         }
         if (myValue instanceof Number myNumber) {
             return myNumber.longValue() == 0;
         }
 
         /* Skip false */
         if (myValue instanceof Boolean myBool) {
             return !myBool;
         }
 
         /* Skip value if required */
         return myValue == null
                 || MetisDataFieldValue.SKIP.equals(myValue);
     }
 
     /**
      * Build HTML table describing list item.
      *
      * @param pList  the list
      * @param pIndex the index of the item
      */
     private void formatHTMLListItem(final List<?> pList,
                                     final int pIndex) {
         /* Obtain the object */
         final Object myObject = pList.get(pIndex - 1);
 
         /* Format the object */
         formatHTMLObject(myObject);
     }
 
     /**
      * Build HTML table describing list section.
      *
      * @param pList  the list
      * @param pStart the start index for the section
      */
     private void formatHTMLListSection(final List<?> pList,
                                        final int pStart) {
         /* Initialise the document */
         theBuilder.newTitle(TABLE_LIST);
         theBuilder.newTable();
         theBuilder.newTitleCell(COLUMN_INDEX);
         theBuilder.newTitleCell(COLUMN_VALUE);
 
         /* If there are items in the list */
         if (!pList.isEmpty()) {
             /* Calculate start point */
             final int myStart = (pStart - 1) * ITEMS_PER_PAGE;
 
             /* Create iterator at start */
             final Iterator<?> myIterator = pList.listIterator(myStart);
 
             /* Loop up to the limit */
             int myCount = ITEMS_PER_PAGE;
             int myIndex = myStart + 1;
             while (myIterator.hasNext()
                     && myCount-- > 0) {
                 /* Access the key and value */
                 final Object myObject = myIterator.next();
 
                 /* Format the row */
                 theBuilder.newTableRow();
                 theBuilder.newDataCell(myIndex++);
                 theBuilder.newDataCell(myObject);
             }
         }
     }
 
     /**
      * Build HTML table describing map section.
      *
      * @param pMap   the map
      * @param pStart the start index for the section
      */
     private void formatHTMLMapSection(final Map<?, ?> pMap,
                                       final int pStart) {
 
         /* Initialise the document */
         theBuilder.newTitle(TABLE_MAP);
         theBuilder.newTable();
         theBuilder.newTitleCell(COLUMN_INDEX);
         theBuilder.newTitleCell(COLUMN_KEY);
         theBuilder.newTitleCell(COLUMN_VALUE);
 
         /* If there are items in the list */
         if (!pMap.isEmpty()) {
             /* Calculate start point */
             int myCount = (pStart - 1) * ITEMS_PER_PAGE;
             int myIndex = myCount + 1;
 
             /* Create iterator and shift to start */
             final Iterator<?> myIterator = pMap.entrySet().iterator();
             if (myCount > 0) {
                 /* Skip leading entries */
                 while (myIterator.hasNext()
                         && myCount-- > 0) {
                     myIterator.next();
                 }
             }
 
             /* Loop up to the limit */
             myCount = ITEMS_PER_PAGE;
             while (myIterator.hasNext()
                     && (myCount-- > 0)) {
                 /* Access the key and value */
                 final Entry<?, ?> myEntry = (Entry<?, ?>) myIterator.next();
 
                 /* Format the row */
                 theBuilder.newTableRow();
                 theBuilder.newDataCell(myIndex++);
                 theBuilder.newDataCell(myEntry.getKey());
                 theBuilder.newDataCell(myEntry.getValue());
             }
         }
     }
 
     /**
      * Build HTML table describing stack.
      *
      * @param pStack the stack to describe
      */
     private void formatHTMLStackTrace(final StackTraceElement[] pStack) {
         /* Initialise the document */
         theBuilder.newTitle(TABLE_STACKTRACE);
         theBuilder.newTable();
         theBuilder.newTitleCell(TABLE_STACKTRACE);
 
         /* Loop through the elements */
         for (StackTraceElement st : pStack) {
             /* Format the row */
             theBuilder.newTableRow();
             theBuilder.newDataCell(st.toString());
         }
     }
 
     /**
      * Build HTML table describing unknown object.
      *
      * @param pObject the object to describe
      */
     private void formatHTMLUnknown(final Object pObject) {
         /* Initialise the document */
         theBuilder.newTitle("Unknown");
         theBuilder.newTable();
         theBuilder.newTitleCell(COLUMN_FIELD);
         theBuilder.newTitleCell(COLUMN_VALUE);
 
         /* Describe the class */
         theBuilder.newTableRow();
         theBuilder.newDataCell("Class");
         theBuilder.newDataCell(pObject != null
                 ? pObject.getClass()
                 : null);
 
         /* Describe the object */
         theBuilder.newTableRow();
         theBuilder.newDataCell("Value");
         theBuilder.newDataCell(pObject);
     }
 }