/**
    * Copyright 2005-2013 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.rice.krad.uif.layout;
  
  import java.util.ArrayList;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.krad.datadictionary.parse.BeanTag;
  import org.kuali.rice.krad.datadictionary.parse.BeanTagAttribute;
  import org.kuali.rice.krad.datadictionary.parse.BeanTags;
  import org.kuali.rice.krad.uif.component.Component;
  import org.kuali.rice.krad.uif.container.Container;
  import org.kuali.rice.krad.util.KRADUtils;
  
  /**
   * Css Grid Layout manager is a layout manager which creates div "rows" and "cells" to replicate a
   * table look by using div elements for its items. Items are added into rows based on their colSpan
   * setting, while each row has a max size of 12 columns. By default, if colSpan is not set on an
   * item, that item will take a full row.
   */
  @BeanTags({@BeanTag(name = "cssGridLayout-bean", parent = "Uif-CssGridLayoutBase"),
          @BeanTag(name = "fixedCssGridLayout-bean", parent = "Uif-FixedCssGridLayout"),
          @BeanTag(name = "fluidCssGridLayout-bean", parent = "Uif-FluidCssGridLayout")})
  public class CssGridLayoutManager extends LayoutManagerBase {
      private static final long serialVersionUID = 1830635073147703757L;
  
      private static final int NUMBER_OF_COLUMNS = 12;
      private static final String BOOTSTRAP_SPAN_PREFIX = "col-md-";
  
      private Map<String, String> conditionalRowCssClasses;
      private String rowLayoutCssClass;
      private int defaultItemColSpan;
  
      // non-settable
      protected List<List<Component>> rows;
      protected List<String> rowCssClassAttributes;
      protected List<String> cellCssClassAttributes;
  
      public CssGridLayoutManager() {
          rows = new ArrayList<List<Component>>();
          conditionalRowCssClasses = new HashMap<String, String>();
          cellCssClassAttributes = new ArrayList<String>();
          rowCssClassAttributes = new ArrayList<String>();
      }
  
      /**
       * CssGridLayoutManager's performFinalize method calculates and separates the items into rows
       * based on their colSpan settings and the defaultItemColSpan setting
       * 
       * @see Component#performFinalize(org.kuali.rice.krad.uif.view.View, Object,
       *      org.kuali.rice.krad.uif.component.Component)
       */
      @Override
      public void performFinalize(Object model, Component component) {
          super.performFinalize(model, component);
          
          Container container = (Container) component;
  
          int rowSpaceLeft = NUMBER_OF_COLUMNS;
          int rowIndex = 0;
          boolean isOdd = true;
          List<Component> currentRow = new ArrayList<Component>();
          for (Component item : container.getItems()) {
              if (item == null) {
                  continue;
              }
              isOdd = rowIndex % 2 == 0;
  
              // set colSpan to default setting (12 is the default)
              int colSpan = this.defaultItemColSpan;
  
              // if the item's set colSpan is greater than 1 set it to that number; 1 is the default colSpan for Component
              if (item.getColSpan() > 1 && item.getColSpan() <= NUMBER_OF_COLUMNS) {
                  colSpan = item.getColSpan();
              }
  
              // determine "cell" div css
              List<String> cellCssClasses = item.getCellCssClasses();
              if (cellCssClasses == null) {
                  item.setCellCssClasses(cellCssClasses = new ArrayList<String>());
              }
              cellCssClasses.add(0, BOOTSTRAP_SPAN_PREFIX + colSpan);
              cellCssClassAttributes.add(getCellStyleClassesAsString(cellCssClasses));
 
             // calculate space left in row
             rowSpaceLeft = rowSpaceLeft - colSpan;
 
             if (rowSpaceLeft > 0) {
                 // space is left, just add item to row
                 currentRow.add(item);
             } else if (rowSpaceLeft < 0) {
                 // went over, add item to next new row
                 rows.add(new ArrayList<Component>(currentRow));
                 currentRow = new ArrayList<Component>();
                 currentRow.add(item);
 
                 // determine "row" div css
                 String rowCss = rowLayoutCssClass + " " + KRADUtils.generateRowCssClassString(conditionalRowCssClasses,
                         rowIndex, isOdd, null, null);
                 rowCssClassAttributes.add(rowCss);
 
                 rowIndex++;
                 rowSpaceLeft = NUMBER_OF_COLUMNS - colSpan;
             } else if (rowSpaceLeft == 0) {
                 // last item in row, create new row
                 currentRow.add(item);
                 rows.add(new ArrayList<Component>(currentRow));
                 currentRow = new ArrayList<Component>();
 
                 // determine "row" div css
                 String rowCss = rowLayoutCssClass + " " + KRADUtils.generateRowCssClassString(conditionalRowCssClasses,
                         rowIndex, isOdd, null, null);
                 rowCssClassAttributes.add(rowCss);
 
                 rowIndex++;
                 rowSpaceLeft = NUMBER_OF_COLUMNS;
             }
         }
 
         isOdd = rowIndex % 2 == 0;
         // add the last row if it wasn't full (but has items)
         if (!currentRow.isEmpty()) {
             // determine "row" div css
             String rowCss = rowLayoutCssClass + " " + KRADUtils.generateRowCssClassString(conditionalRowCssClasses,
                     rowIndex, isOdd, null, null);
             rowCssClassAttributes.add(rowCss);
 
             rows.add(currentRow);
         }
     }
 
     /**
      * Builds the HTML class attribute string by combining the cellStyleClasses list with a space
      * delimiter
      * 
      * @return class attribute string
      */
     private String getCellStyleClassesAsString(List<String> cellCssClasses) {
         if (cellCssClasses != null) {
             return StringUtils.join(cellCssClasses, " ");
         }
 
         return "";
     }
 
     /**
      * Get the rows (which are a list of components each)
      * 
      * @return the List of Lists of Components which represents rows for this layout
      */
     public List<List<Component>> getRows() {
         return rows;
     }
 
     /**
      * List of css class HTML attribute values ordered by index of row
      * 
      * @return the list of css class HTML attributes for rows
      */
     public List<String> getRowCssClassAttributes() {
         return rowCssClassAttributes;
     }
 
     /**
      * List of css class HTML attribute values ordered by the order in which the cell appears
      * 
      * @return the list of css class HTML attributes for cells
      */
     public List<String> getCellCssClassAttributes() {
         return cellCssClassAttributes;
     }
 
     /**
      * The default cell colSpan to use for this layout (max setting, and the bean default, is 12)
      *
      * @return int representing the default colSpan for cells in this layout
      */
     @BeanTagAttribute(name = "defaultItemColSpan")
     public int getDefaultItemColSpan() {
         return defaultItemColSpan;
     }
 
     /**
      * Set the default colSpan for this layout's items
      * 
      * @param defaultItemColSpan
      */
     public void setDefaultItemColSpan(int defaultItemColSpan) {
         this.defaultItemColSpan = defaultItemColSpan;
     }
 
     /**
      * The row css classes for the rows of this layout
      * 
      * <p>
      * To set a css class on all rows, use "all" as a key. To set a class for even rows, use "even"
      * as a key, for odd rows, use "odd". Use a one-based index to target a specific row by index.
      * </p>
      * 
      * @return a map which represents the css classes of the rows of this layout
      */
     @BeanTagAttribute(name = "conditionalRowCssClasses", type = BeanTagAttribute.AttributeType.MAPVALUE)
     public Map<String, String> getConditionalRowCssClasses() {
         return conditionalRowCssClasses;
     }
 
     /**
      * Set conditionalRowCssClasses
      * 
      * @param conditionalRowCssClasses
      */
     public void setConditionalRowCssClasses(Map<String, String> conditionalRowCssClasses) {
         this.conditionalRowCssClasses = conditionalRowCssClasses;
     }
 
     /**
      * The layout css class used by the framework to represent the row as a row visually (currently
      * using a bootstrap class), which should not be manually reset in most situations
      * 
      * @return the css structure class for the rows of this layout
      */
     @BeanTagAttribute(name = "rowLayoutCssClass")
     public String getRowLayoutCssClass() {
         return rowLayoutCssClass;
     }
 
     /**
      * Set the rowLayoutCssClass
      * 
      * @param rowLayoutCssClass
      */
     public void setRowLayoutCssClass(String rowLayoutCssClass) {
         this.rowLayoutCssClass = rowLayoutCssClass;
     }
 
     /**
      * @see org.kuali.rice.krad.datadictionary.DictionaryBeanBase#copyProperties(Object)
      */
     @Override
     protected <T> void copyProperties(T component) {
         super.copyProperties(component);
 
         CssGridLayoutManager cssGridLayoutManagerCopy = (CssGridLayoutManager) component;
 
         if (this.rowLayoutCssClass != null) {
             cssGridLayoutManagerCopy.setRowLayoutCssClass(this.rowLayoutCssClass);
         }
 
         cssGridLayoutManagerCopy.setDefaultItemColSpan(this.defaultItemColSpan);
 
         if (this.conditionalRowCssClasses != null) {
             cssGridLayoutManagerCopy.setConditionalRowCssClasses(new HashMap<String, String>(
                     this.conditionalRowCssClasses));
         }
 
         if (this.cellCssClassAttributes != null) {
             cssGridLayoutManagerCopy.cellCssClassAttributes = new ArrayList<String>(this.cellCssClassAttributes);
         }
 
         if (this.rowCssClassAttributes != null) {
             cssGridLayoutManagerCopy.rowCssClassAttributes = new ArrayList<String>(this.rowCssClassAttributes);
         }
 
         if (this.rows != null) {
             cssGridLayoutManagerCopy.rows = new ArrayList<List<Component>>();
             for (List<Component> row : this.rows) {
                 List<Component> rowCopy = new ArrayList<Component>();
 
                 if (row == null) {
                     cssGridLayoutManagerCopy.rows.add(row);
                     continue;
                 }
 
                 for (Component cellComp : row) {
                     if (cellComp == null) {
                         rowCopy.add(cellComp);
                         continue;
                     }
                     rowCopy.add((Component) cellComp.copy());
                 }
 
                 cssGridLayoutManagerCopy.rows.add(rowCopy);
             }
         }
     }
 }