/*
    * Copyright 2008 The Kuali Foundation
    * 
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
    * 
   * 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 org.kuali.ole.sys.document.validation.impl;
  
  import org.kuali.ole.sys.OLEConstants;
  import org.kuali.ole.sys.OLEKeyConstants;
  import org.kuali.ole.sys.context.SpringContext;
  import org.kuali.ole.sys.document.AccountingDocument;
  import org.kuali.ole.sys.document.validation.GenericValidation;
  import org.kuali.ole.sys.document.validation.event.AttributedDocumentEvent;
  import org.kuali.ole.sys.document.validation.event.AttributedSaveDocumentEvent;
  import org.kuali.rice.core.api.util.type.KualiDecimal;
  import org.kuali.rice.core.web.format.CurrencyFormatter;
  import org.kuali.rice.kew.api.exception.WorkflowException;
  import org.kuali.rice.krad.service.DocumentService;
  import org.kuali.rice.krad.util.GlobalVariables;
  
  /**
   * A validation, used on accounting document approval, that accounting line totals are unchanged
   */
  public class AccountingLineGroupTotalsUnchangedValidation extends GenericValidation {
      private AccountingDocument accountingDocumentForValidation;
      
      /**
       * Checks that the source and total amounts on the current version of the accounting document
       * are equal to the persisted source and total totals.
       * <strong>Expects a document to be sent in as the first parameter</strong>
       * @see org.kuali.ole.sys.document.validation.GenericValidation#validate(java.lang.Object[])
       */
      public boolean validate(AttributedDocumentEvent event) {
          AccountingDocument persistedDocument = null;
          
          if (event instanceof AttributedSaveDocumentEvent && !accountingDocumentForValidation.getDocumentHeader().getWorkflowDocument().isEnroute()) {
              return true; // only check save document events if the document is enroute
          }
  
          persistedDocument = retrievePersistedDocument(accountingDocumentForValidation);
  
          boolean isUnchanged = true;
          if (persistedDocument == null) {
              handleNonExistentDocumentWhenApproving(accountingDocumentForValidation);
          }
          else {
              // retrieve the persisted totals
              KualiDecimal persistedSourceLineTotal = persistedDocument.getSourceTotal();
              KualiDecimal persistedTargetLineTotal = persistedDocument.getTargetTotal();
  
              // retrieve the updated totals
              KualiDecimal currentSourceLineTotal = accountingDocumentForValidation.getSourceTotal();
              KualiDecimal currentTargetLineTotal = accountingDocumentForValidation.getTargetTotal();
  
              // make sure that totals have remained unchanged, if not, recognize that, and
              // generate appropriate error messages
              if (currentSourceLineTotal.compareTo(persistedSourceLineTotal) != 0) {
                  isUnchanged = false;
  
                  // build out error message
                  buildTotalChangeErrorMessage(OLEConstants.SOURCE_ACCOUNTING_LINE_ERRORS, persistedSourceLineTotal, currentSourceLineTotal);
              }
  
              if (currentTargetLineTotal.compareTo(persistedTargetLineTotal) != 0) {
                  isUnchanged = false;
  
                  // build out error message
                  buildTotalChangeErrorMessage(OLEConstants.TARGET_ACCOUNTING_LINE_ERRORS, persistedTargetLineTotal, currentTargetLineTotal);
              }
          }
  
          return isUnchanged;
      }
  
      /**
       * attempt to retrieve the document from the DB for comparison
       * 
       * @param accountingDocument
       * @return AccountingDocument
       */
      protected AccountingDocument retrievePersistedDocument(AccountingDocument accountingDocument) {
          AccountingDocument persistedDocument = null;
  
          try {
              persistedDocument = (AccountingDocument) SpringContext.getBean(DocumentService.class).getByDocumentHeaderId(accountingDocument.getDocumentNumber());
          }
          catch (WorkflowException we) {
              handleNonExistentDocumentWhenApproving(accountingDocument);
          }
 
         return persistedDocument;
     }
     
     /**
      * This method builds out the error message for when totals have changed.
      * 
      * @param propertyName
      * @param persistedSourceLineTotal
      * @param currentSourceLineTotal
      */
     protected void buildTotalChangeErrorMessage(String propertyName, KualiDecimal persistedSourceLineTotal, KualiDecimal currentSourceLineTotal) {
         String persistedTotal = (String) new CurrencyFormatter().format(persistedSourceLineTotal);
         String currentTotal = (String) new CurrencyFormatter().format(currentSourceLineTotal);
         GlobalVariables.getMessageMap().putError(propertyName, OLEKeyConstants.ERROR_DOCUMENT_SINGLE_ACCOUNTING_LINE_SECTION_TOTAL_CHANGED, new String[] { persistedTotal, currentTotal });
     }
 
     /**
      * Handles the case when a non existent document is attempted to be retrieve and that if it's in an initiated state, it's ok.
      * 
      * @param accountingDocument
      */
     protected final void handleNonExistentDocumentWhenApproving(AccountingDocument accountingDocument) {
         // check to make sure this isn't an initiated document being blanket approved
         if (!accountingDocument.getDocumentHeader().getWorkflowDocument().isInitiated()) {
             throw new IllegalStateException("Document " + accountingDocument.getDocumentNumber() + " is not a valid document that currently exists in the system.");
         }
     }
 
     /**
      * Gets the accountingDocumentForValidation attribute. 
      * @return Returns the accountingDocumentForValidation.
      */
     public AccountingDocument getAccountingDocumentForValidation() {
         return accountingDocumentForValidation;
     }
 
     /**
      * Sets the accountingDocumentForValidation attribute value.
      * @param accountingDocumentForValidation The accountingDocumentForValidation to set.
      */
     public void setAccountingDocumentForValidation(AccountingDocument accountingDocumentForValidation) {
         this.accountingDocumentForValidation = accountingDocumentForValidation;
     }
 }