/*
    * 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.field;
  
  import io.github.tonywasher.joceanus.oceanus.format.OceanusDataFormatter;
  import io.github.tonywasher.joceanus.metis.data.MetisDataDifference;
  import io.github.tonywasher.joceanus.metis.data.MetisDataEditState;
  import io.github.tonywasher.joceanus.metis.data.MetisDataItem.MetisDataDeletableItem;
  import io.github.tonywasher.joceanus.metis.data.MetisDataItem.MetisDataFieldId;
  import io.github.tonywasher.joceanus.metis.data.MetisDataResource;
  import io.github.tonywasher.joceanus.metis.data.MetisDataState;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem.MetisFieldTableItem;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldItem.MetisFieldUpdatableItem;
  import io.github.tonywasher.joceanus.metis.field.MetisFieldValidation.MetisFieldError;
  
  /**
   * Data Version Control.
   */
  public abstract class MetisFieldVersionedItem
          implements MetisFieldTableItem, MetisDataDeletableItem, MetisFieldUpdatableItem {
      /**
       * Report fields.
       */
      private static final MetisFieldVersionedSet<MetisFieldVersionedItem> FIELD_DEFS = MetisFieldVersionedSet.newVersionedFieldSet(MetisFieldVersionedItem.class);
  
      /*
       * FieldIds.
       */
      static {
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_ID, MetisFieldVersionedItem::getIndexedId);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_ITEMTYPE, MetisFieldVersionedItem::getItemType);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_VERSION, MetisFieldVersionedItem::getVersion);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_DELETED, MetisFieldVersionedItem::isDeleted);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_STATE, MetisFieldVersionedItem::getState);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_EDITSTATE, MetisFieldVersionedItem::getEditState);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_HISTORY, MetisFieldVersionedItem::getValuesHistory);
          FIELD_DEFS.declareLocalField(MetisDataResource.DATA_ERRORS, MetisFieldVersionedItem::getValidation);
      }
  
      /**
       * The history of values for this object.
       */
      private final MetisFieldVersionHistory theHistory;
  
      /**
       * The Item Validation.
       */
      private final MetisFieldValidation theValidation;
  
      /**
       * The id.
       */
      private Integer theId;
  
      /**
       * The itemType.
       */
      private MetisFieldItemType theItemType;
  
      /**
       * The editState.
       */
      private MetisDataEditState theEditState;
  
      /**
       * Constructor.
       */
      protected MetisFieldVersionedItem() {
          /* Allocate the history */
          final MetisFieldVersionValues myValues = newVersionValues();
          theHistory = new MetisFieldVersionHistory(myValues);
  
          /* Allocate the validation */
          theValidation = new MetisFieldValidation();
          theEditState = MetisDataEditState.CLEAN;
      }
  
      /**
       * Constructor.
       *
       * @param pValues the initial values
       */
      protected MetisFieldVersionedItem(final MetisFieldVersionValues pValues) {
          /* Allocate the history */
          theHistory = new MetisFieldVersionHistory(pValues);
 
         /* Allocate the validation */
         theValidation = new MetisFieldValidation();
     }
 
     /**
      * Obtain new version values.
      *
      * @return new values
      */
     protected MetisFieldVersionValues newVersionValues() {
         return new MetisFieldVersionValues(this);
     }
 
     @Override
     public Integer getIndexedId() {
         return theId;
     }
 
     /**
      * Set Id.
      *
      * @param pId the Id
      */
     public void setIndexedId(final Integer pId) {
         theId = pId;
     }
 
     /**
      * Obtain the itemType.
      *
      * @return the item type
      */
     public MetisFieldItemType getItemType() {
         return theItemType;
     }
 
     /**
      * Set ItemType.
      *
      * @param pItemType the itemType
      */
     public void setItemType(final MetisFieldItemType pItemType) {
         theItemType = pItemType;
     }
 
     /**
      * Obtain the State of item.
      *
      * @return the state
      */
     public MetisDataState getState() {
         return determineState();
     }
 
     /**
      * Obtain the editState of item.
      *
      * @return the editState
      */
     public MetisDataEditState getEditState() {
         return theEditState;
     }
 
     @Override
     public MetisFieldVersionHistory getValuesHistory() {
         return theHistory;
     }
 
     /**
      * Obtain the Validation.
      *
      * @return the validation
      */
     public MetisFieldValidation getValidation() {
         return theValidation;
     }
 
     @Override
     public MetisFieldVersionValues getValues() {
         return theHistory.getValueSet();
     }
 
     @Override
     public MetisFieldVersionValues getOriginalValues() {
         return theHistory.getOriginalValues();
     }
 
     /**
      * Obtain the Version of item.
      *
      * @return the version
      */
     public Integer getVersion() {
         return getValues().getVersion();
     }
 
     /**
      * Obtain the original Version of item.
      *
      * @return the version
      */
     public Integer getOriginalVersion() {
         return getOriginalValues().getVersion();
     }
 
     @Override
     public boolean isDeleted() {
         return getValues().isDeletion();
     }
 
     @Override
     public void setDeleted(final boolean pFlag) {
         /* If the state has changed */
         if (pFlag != isDeleted()) {
             /* Push history and set flag */
             pushHistory();
             getValues().setDeletion(pFlag);
         }
     }
 
     @Override
     public MetisFieldSetDef getDataFieldSet() {
         return FIELD_DEFS;
     }
 
     @Override
     public String formatObject(final OceanusDataFormatter pFormatter) {
         return FIELD_DEFS.getName();
     }
 
     /**
      * Set the Edit State.
      *
      * @param pState the Edit Status
      */
     protected void setEditState(final MetisDataEditState pState) {
         theEditState = pState;
     }
 
     /**
      * Determine whether the item has Errors.
      *
      * @return <code>true/false</code>
      */
     public boolean hasErrors() {
         return theEditState == MetisDataEditState.ERROR;
     }
 
     /**
      * Determine whether the item has Changes.
      *
      * @return <code>true/false</code>
      */
     public boolean hasChanges() {
         return theEditState != MetisDataEditState.CLEAN;
     }
 
     /**
      * Determine whether the item is Valid.
      *
      * @return <code>true/false</code>
      */
     public boolean isValid() {
         return theEditState == MetisDataEditState.CLEAN
                 || theEditState == MetisDataEditState.VALID;
     }
 
     @Override
     public boolean hasErrors(final MetisDataFieldId pFieldId) {
         return pFieldId != null
                 && theValidation.hasErrors(pFieldId);
     }
 
     /**
      * Add an error for this item.
      *
      * @param pError   the error text
      * @param pFieldId the associated field
      */
     public void addError(final String pError,
                          final MetisDataFieldId pFieldId) {
         /* Set edit state and add the error */
         theEditState = MetisDataEditState.ERROR;
         theValidation.addError(pError, pFieldId);
     }
 
     /**
      * Clear all errors for this item.
      */
     public void clearErrors() {
         theEditState = getValues().getVersion() > 0
                 ? MetisDataEditState.DIRTY
                 : MetisDataEditState.CLEAN;
         theValidation.clearErrors();
     }
 
     /**
      * Get the first error element for an item.
      *
      * @return the first error (or <code>null</code>)
      */
     public MetisFieldError getFirstError() {
         return theValidation.getFirst();
     }
 
     @Override
     public String getFieldErrors(final MetisDataFieldId pField) {
         return pField != null
                 ? theValidation.getFieldErrors(pField)
                 : null;
     }
 
     @Override
     public String getFieldErrors(final MetisDataFieldId[] pFields) {
         final MetisFieldSetDef myFieldSet = getDataFieldSet();
         final MetisFieldDef[] myFields = new MetisFieldDef[pFields.length];
         for (int i = 0; i < pFields.length; i++) {
             myFields[i] = myFieldSet.getField(pFields[i]);
         }
         return theValidation.getFieldErrors(myFields);
     }
 
     /**
      * Initialise the current values.
      *
      * @param pValues the current values
      */
     public void setValues(final MetisFieldVersionValues pValues) {
         theHistory.setValues(pValues);
         adjustState();
     }
 
     @Override
     public void pushHistory() {
         final int myVersion = getNextVersion();
         theHistory.pushHistory(myVersion);
     }
 
     /**
      * Push history to a specific version.
      *
      * @param pVersion the version
      */
     public void pushHistory(final int pVersion) {
         theHistory.pushHistory(pVersion);
     }
 
     @Override
     public void popHistory() {
         theHistory.popTheHistory();
     }
 
     /**
      * popItem from the history if equal to current.
      *
      * @return was a change made
      */
     public boolean maybePopHistory() {
         return theHistory.maybePopHistory();
     }
 
     /**
      * Is there any history.
      *
      * @return whether there are entries in the history list
      */
     public boolean hasHistory() {
         return theHistory.hasHistory();
     }
 
     /**
      * Clear history.
      */
     public void clearHistory() {
         theHistory.clearHistory();
         adjustState();
     }
 
     /**
      * Reset history.
      */
     public void resetHistory() {
         theHistory.resetHistory();
         adjustState();
     }
 
     /**
      * Set history explicitly.
      *
      * @param pBase the base item
      */
     public void setHistory(final MetisFieldVersionValues pBase) {
         theHistory.setHistory(pBase);
         adjustState();
     }
 
     @Override
     public boolean checkForHistory() {
         return theHistory.maybePopHistory();
     }
 
     /**
      * Condense history.
      *
      * @param pNewVersion the new maximum version
      */
     public void condenseHistory(final int pNewVersion) {
         theHistory.condenseHistory(pNewVersion);
     }
 
     /**
      * Rewind item to the required version.
      *
      * @param pVersion the version to rewind to
      */
     public void rewindToVersion(final int pVersion) {
         /* Loop while version is too high */
         while (getValues().getVersion() > pVersion) {
             /* Pop history */
             getValuesHistory().popTheHistory();
         }
     }
 
     /**
      * Determines whether a particular field has changed.
      *
      * @param pField the field
      * @return the difference
      */
     public MetisDataDifference fieldChanged(final MetisDataFieldId pField) {
         final MetisFieldDef myField = getDataFieldSet().getField(pField);
         return theHistory.fieldChanged(myField);
     }
 
     /**
      * Determines whether a particular field has changed.
      *
      * @param pField the field
      * @return the difference
      */
     public MetisDataDifference fieldChanged(final MetisFieldDef pField) {
         return theHistory.fieldChanged(pField);
     }
 
     /**
      * Adjust State of item.
      */
     public void adjustState() {
         theEditState = determineEditState();
     }
 
     /**
      * Determine dataState of item.
      *
      * @return the dataState
      */
     private MetisDataState determineState() {
         final MetisFieldVersionValues myCurr = getValues();
         final MetisFieldVersionValues myOriginal = getOriginalValues();
 
         /* If we are a new element */
         if (myOriginal.getVersion() > 0) {
             /* Return status */
             return myCurr.isDeletion()
                     ? MetisDataState.DELNEW
                     : MetisDataState.NEW;
         }
 
         /* If we have no changes we are CLEAN */
         if (myCurr.getVersion() == 0) {
             return MetisDataState.CLEAN;
         }
 
         /* If we are deleted return so */
         if (myCurr.isDeletion()) {
             return MetisDataState.DELETED;
         }
 
         /* We must have changed */
         return MetisDataState.CHANGED;
     }
 
     /**
      * Determine editState of item.
      *
      * @return the editState
      */
     private MetisDataEditState determineEditState() {
         /* If we have errors */
         if (theValidation.hasErrors()) {
             /* Return status */
             return MetisDataEditState.ERROR;
         }
 
         /* If we have no changes we are CLEAN */
         return getVersion() == 0
                 ? MetisDataEditState.CLEAN
                 : MetisDataEditState.DIRTY;
     }
 
     /**
      * Obtain a versioned field.
      *
      * @param pId the field id
      * @return the versioned field
      */
     public MetisFieldVersionedDef getVersionedField(final MetisDataFieldId pId) {
         final MetisFieldDef myField = getDataFieldSet().getField(pId);
         return myField instanceof MetisFieldVersionedDef myVersioned
                 ? myVersioned
                 : null;
     }
 }