/**

  * Copyright 2010 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.osedu.org/licenses/ECL-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 org.kuali.student.common.ui.client.widgets.pagetable;

 import java.util.ArrayList;

 import java.util.Collections;

 import java.util.Comparator;

 import java.util.Iterator;

 import java.util.List;

 import org.kuali.student.common.dto.Idable;

 import org.kuali.student.common.ui.client.widgets.searchtable.ResultRow;

 import org.kuali.student.common.ui.client.widgets.searchtable.SearchColumnDefinition;

 import com.google.gwt.gen2.table.client.AbstractColumnDefinition;

 import com.google.gwt.gen2.table.client.CachedTableModel;

 import com.google.gwt.gen2.table.client.MutableTableModel;

 import com.google.gwt.gen2.table.client.TableModelHelper.Request;

 import com.google.gwt.gen2.table.client.TableModelHelper.Response;

 import com.google.gwt.gen2.table.client.TableModelHelper.SerializableResponse;

 /**

  * This is a description of what this class does - Gary Struthers don't forget to fill this in.

  *

  * @author Kuali Student Team (gstruthers@berkeley.edu)

  * @param <IsSerializiable>

  *

  */

 public class GenericTableModel<RowType> extends MutableTableModel<RowType> {

     private List<RowType> rowDTOs = null;

     private int fromIndex = 0;

     private int lastSortedColumn = -1;

     private int lastSortDirection = 1;

     private List<AbstractColumnDefinition<ResultRow, ?>> columnDefs;

     /**

      * A boolean indicating that we should throw an error.

      */

     private boolean errorMode = false;

     /**

      * A boolean indicating that we should return 0 rowDTOs in the response.

      */

     private boolean zeroMode = false;

     /**

      * This constructs an empty table model for the RowType

      *

      */

     public GenericTableModel() {

         super();

     }

     /**

      * This constructs a populated table model for the RowType

      *

      */

     public GenericTableModel(List<RowType>rows) {

         super();

         setRows(rows);

     }

     /**

      * This returns cached table model for the RowType

      *

      */

     public CachedTableModel<RowType>createCachedTableModel(int pageSize,int pages) {

         CachedTableModel<RowType>cachedTableModel = new CachedTableModel<RowType>(this);

         cachedTableModel.setPreCachedRowCount(pageSize);

         cachedTableModel.setPostCachedRowCount(pageSize);

         cachedTableModel.setRowCount(pageSize * pages);

         return cachedTableModel;

     }

     /**

      * This overridden method ...

      *

      * @see com.google.gwt.gen2.table.client.MutableTableModel#onRowInserted(int)

      */

     @Override

     protected boolean onRowInserted(int beforeRow) {

         return true;

     }

     /**

      * This overridden method ...

      *

      * @see com.google.gwt.gen2.table.client.MutableTableModel#onRowRemoved(int)

      */

     @Override

     protected boolean onRowRemoved(int row) {

         return true;

     }

     /**

      * This overridden method ...

      *

      * @see com.google.gwt.gen2.table.client.MutableTableModel#onSetRowValue(int, java.lang.Object)

      */

     @Override

     protected boolean onSetRowValue(int row, RowType rowValue) {

         return true;

     }

     /**

      * This overridden method handles only errorMode, zeroMode, and local dtos

      * Production code will need rpc to load server side dto's, that feature can be

      * added in a subclass and perhaps here if it can be done generically

      *

      * @see com.google.gwt.gen2.table.client.TableModel#requestRows(com.google.gwt.gen2.table.client.TableModelHelper.Request, com.google.gwt.gen2.table.client.TableModel.Callback)

      */

     @Override

     public void requestRows(final Request request, final Callback<RowType> callback) {

         if (errorMode) {

             // Return an error

             callback.onFailure(new Exception("An error has occured."));

         } else if (zeroMode) {

             // Return an empty result

             List<RowType> selectedRows = new ArrayList<RowType>(0);

             callback.onRowsReady(request, new SerializableResponse(selectedRows));//unchecked warning

         } else {

             callback.onRowsReady(request, new Response<RowType>() {

                 @SuppressWarnings("unchecked")

                 @Override

                 public Iterator<RowType> getRowValues() {

                     // Generate data locally

                     final int sortColumn = request.getColumnSortList().getPrimaryColumn();

                     final int sortDirection = (request.getColumnSortList().isPrimaryAscending() ? 1 : -1);

                     if (sortColumn>=0 && (sortColumn != lastSortedColumn || sortDirection != lastSortDirection)) {

                         SearchColumnDefinition rowDef = (SearchColumnDefinition) columnDefs.get(sortColumn);

                         final String sortColumKey = rowDef.getColumnKey();

                         Collections.sort((List<ResultRow>)rowDTOs, new Comparator<ResultRow>() {

                             @Override

                             public int compare(ResultRow o1, ResultRow o2) {

                                 return o1.getValue(sortColumKey).compareToIgnoreCase(o2.getValue(sortColumKey)) * sortDirection;

                             }});

                         lastSortedColumn = sortColumn;

                         lastSortDirection = sortDirection;

                     }

                     int numRows = request.getNumRows();

                     //fromIndex = request.getStartRow(); This disables column sort, bug?

                     if((fromIndex + numRows) >= rowDTOs.size()) {

                         fromIndex = 0;

                     }

                     int toIndex = fromIndex + numRows;

                     List<RowType> selectedRows = new ArrayList<RowType>(numRows);

                     for(int i = fromIndex; i < toIndex; i++) {

                         RowType e = rowDTOs.get(i);

                         selectedRows.add(e);

                     }

                     fromIndex = toIndex;

                     return new SerializableResponse(selectedRows).getRowValues();

                 }

             });

         }

     }

     /**

      * @param rowDTOs the rowDTOs to set

      */

     public void setRows(List<RowType> rows) {

             List<Idable> ids = (List<Idable>)rows;//Force ClassCast exception if list items aren't Idable

             this.rowDTOs = rows;

     }

     /**

      * This overridden method returns the static size the table

      *

      * @see com.google.gwt.gen2.table.client.TableModel#getRowCount()

      */

     @Override

     public int getRowCount() {

         // TODO return dynamic size when loading with RPC

         return rowDTOs.size();

     }

     /**

      * @return the errorMode

      */

     public boolean isErrorMode() {

         return errorMode;

     }

     /**

      * @param errorMode the errorMode to set

      */

     public void setErrorMode(boolean errorMode) {

         this.errorMode = errorMode;

     }

     /**

      * @return the zeroMode

      */

     public boolean isZeroMode() {

         return zeroMode;

     }

     /**

      * @param zeroMode the zeroMode to set

      */

     public void setZeroMode(boolean zeroMode) {

         this.zeroMode = zeroMode;

     }

     public void setColumnDefs(List<AbstractColumnDefinition<ResultRow, ?>> columnDefs) {

         this.columnDefs = columnDefs;

     }

 }