/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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 org.apache.myfaces.custom.newspaper;
  
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.component.html.HtmlDataTable;
  import javax.faces.context.ResponseWriter;
  import javax.faces.component.UIColumn;
  import javax.faces.component.UIData;
  import org.apache.myfaces.shared_tomahawk.renderkit.JSFAttr;
  import org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HTML;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlRendererUtils;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlTableRendererBase;
  import org.apache.myfaces.shared_tomahawk.util.ArrayUtils;
  import org.apache.myfaces.shared_tomahawk.util.StringUtils;
  
  import java.io.IOException;
  import java.util.Iterator;
  import java.util.List;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /**
   * Renderer for a table in multiple balanced columns.
   *
   * @JSFRenderer
   *   renderKitId = "HTML_BASIC" 
   *   family = "javax.faces.Data"
   *   type = "org.apache.myfaces.HtmlNewspaperTable"
   *
   * @author <a href="mailto:jesse@odel.on.ca">Jesse Wilson</a>
   */
  public class HtmlNewspaperTableRenderer
          extends HtmlTableRendererBase
  {
      private static final Log log = LogFactory.getLog(HtmlNewspaperTableRenderer.class);
  
      public void encodeBegin(FacesContext facesContext, UIComponent uiComponent) throws IOException {
          RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
          ResponseWriter writer = facesContext.getResponseWriter();
          HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
          
          // write out the table start tag
          HtmlRendererUtils.writePrettyLineSeparator(facesContext);
          writer.startElement(HTML.TABLE_ELEM, newspaperTable);
          writer.writeAttribute(HTML.ID_ATTR, newspaperTable.getClientId(facesContext), null);
          HtmlRendererUtils.renderHTMLAttributes(writer, newspaperTable, HTML.TABLE_PASSTHROUGH_ATTRIBUTES);
  
          // render the header
          renderFacet(facesContext, writer, newspaperTable, true);
      }
      
      public void encodeChildren(FacesContext facesContext, UIComponent uiComponent) throws IOException {
          RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
          ResponseWriter writer = facesContext.getResponseWriter();
          HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
          
          // begin the table
          HtmlRendererUtils.writePrettyLineSeparator(facesContext);
          writer.startElement(HTML.TBODY_ELEM, newspaperTable);
          
          // get the CSS styles
          Styles styles = getStyles(newspaperTable);
  
          // count the number of actual rows
          int first = newspaperTable.getFirst();
          int rows = newspaperTable.getRows();
          int rowCount = newspaperTable.getRowCount();
          if(rows <= 0) {
              rows = rowCount - first;
          }
          int last = first + rows;
          if(last > rowCount) last = rowCount;
          
          // the number of slices to break the table up into */
          int newspaperColumns = newspaperTable.getNewspaperColumns();
          int newspaperRows;
          if((last - first) % newspaperColumns == 0) newspaperRows = (last - first) / newspaperColumns;
          else newspaperRows = ((last - first) / newspaperColumns) + 1;
  
          // walk through the newspaper rows
         for(int nr = 0; nr < newspaperRows; nr++) {
 
             // write the row start
             HtmlRendererUtils.writePrettyLineSeparator(facesContext);
             writer.startElement(HTML.TR_ELEM, newspaperTable);
             if(styles.hasRowStyle()) {
                 String rowStyle = styles.getRowStyle(nr);
                 writer.writeAttribute(HTML.CLASS_ATTR, rowStyle, null);
             }
 
             // walk through the newspaper columns
             for(int nc = 0; nc < newspaperColumns; nc++) {
 
                 // the current row in the 'real' table
                 int currentRow = nc * newspaperRows + nr + first;
                 
                 // if this row is not to be rendered
                 if(currentRow >= last) continue;
 
                 // bail if any row does not exist
                 newspaperTable.setRowIndex(currentRow);
                 if(!newspaperTable.isRowAvailable()) {
                     log.error("Row is not available. Rowindex = " + currentRow);
                     return;
                 }
     
                 // write each cell
                 List children = newspaperTable.getChildren();
                 for(int j = 0; j < newspaperTable.getChildCount(); j++) {
                     // skip this child if its not a rendered column 
                     UIComponent child = (UIComponent)children.get(j);
                     if(!(child instanceof UIColumn)) continue;
                     if(!child.isRendered()) continue;
                     // draw the element's cell
                     writer.startElement(HTML.TD_ELEM, newspaperTable);
                     if(styles.hasColumnStyle()) writer.writeAttribute(HTML.CLASS_ATTR, styles.getColumnStyle(nc * newspaperTable.getChildCount() + j), null);
                     RendererUtils.renderChild(facesContext, child);
                     writer.endElement(HTML.TD_ELEM);
                 }
 
                 // draw the spacer facet
                 if(nc < newspaperColumns - 1) renderSpacerCell(facesContext, writer, newspaperTable);
             }
             // write the row end
             writer.endElement(HTML.TR_ELEM);
         }
         
         // write the end of the table's body
         writer.endElement(HTML.TBODY_ELEM);
     }
     
     /** 
      * Fetch the number of columns to divide the table into.
      */
     private int getNewspaperColumns() {
         return 3;
     }
 
     public void encodeEnd(FacesContext facesContext, UIComponent uiComponent) throws IOException {
         RendererUtils.checkParamValidity(facesContext, uiComponent, UIData.class);
         ResponseWriter writer = facesContext.getResponseWriter();
         HtmlNewspaperTable newspaperTable = (HtmlNewspaperTable)uiComponent;
         
         // render the footer
         renderFacet(facesContext, writer, newspaperTable, false);
         
         // write out the table end tag
         writer.endElement(HTML.TABLE_ELEM);
         HtmlRendererUtils.writePrettyLineSeparator(facesContext);
     }
 
     
     /**
      * Count the number of columns in the speicifed Newspaper table..
      */
     private int countColumns(HtmlNewspaperTable newspaperTable) {
         int columnCount = 0;
         for(Iterator it = newspaperTable.getChildren().iterator(); it.hasNext(); ) {
             UIComponent uiComponent = (UIComponent)it.next();
             if (uiComponent instanceof UIColumn && ((UIColumn)uiComponent).isRendered()) {
                 columnCount++;
             }
         }
         return columnCount;
     }
     
     /**
      * Tests if the specified facet exists for the specified newspaper table.
      */
     private boolean hasFacet(HtmlNewspaperTable newspaperTable, boolean header) {
         for(Iterator it = newspaperTable.getChildren().iterator(); it.hasNext(); ) {
             // get the column
             UIComponent uiComponent = (UIComponent)it.next();
             if(!(uiComponent instanceof UIColumn)) continue;
             UIColumn column = (UIColumn)uiComponent;
             if(!column.isRendered()) continue;
             
             // test the facet
             if(header && ((UIColumn)uiComponent).getHeader() != null) return true;
             if(!header && ((UIColumn)uiComponent).getFooter() != null) return true;
         }
         return false;
     }
 
     /**
      * Render table headers and footers.
      */
     private void renderFacet(FacesContext facesContext, ResponseWriter writer, HtmlNewspaperTable newspaperTable, boolean header) throws IOException {
         int columnCount = countColumns(newspaperTable);
         boolean hasColumnFacet = hasFacet(newspaperTable, header);
         UIComponent facet = header ? newspaperTable.getHeader() : newspaperTable.getFooter();
         
         // quit if there's nothing to draw
         if(facet == null && !hasColumnFacet) return;
         
         // start the row block
         HtmlRendererUtils.writePrettyLineSeparator(facesContext);
         String elemName = header ? HTML.THEAD_ELEM : HTML.TFOOT_ELEM;
         writer.startElement(elemName, newspaperTable);
         
         // fetch the style
         String styleClass;
         if(header) styleClass = getHeaderClass(newspaperTable);
         else styleClass = getFooterClass(newspaperTable);
         
         // write the header row and column headers
         if(header) {
             if (facet != null) renderTableHeaderOrFooterRow(facesContext, writer, newspaperTable, facet, styleClass, HTML.TD_ELEM, columnCount);
             if (hasColumnFacet) renderColumnHeaderOrFooterRow(facesContext, writer, newspaperTable, styleClass, header);
         // write the footer row and column footers
         } else {
             if (hasColumnFacet) renderColumnHeaderOrFooterRow(facesContext, writer, newspaperTable, styleClass, header);
             if (facet != null) renderTableHeaderOrFooterRow(facesContext, writer, newspaperTable, facet, styleClass, HTML.TD_ELEM, columnCount);
         }
         
         // end the row block
         writer.endElement(elemName);
     }
     
     /**
      * Renders the table header or footer row. This is one giant cell that spans
      * the entire table header or footer.
      */
     private void renderTableHeaderOrFooterRow(FacesContext facesContext, ResponseWriter writer,
         HtmlNewspaperTable newspaperTable, UIComponent facet, String styleClass, String colElementName, int tableColumns)
         throws IOException {
 
         // start the row
         HtmlRendererUtils.writePrettyLineSeparator(facesContext);
         writer.startElement(HTML.TR_ELEM, newspaperTable);
         writer.startElement(colElementName, newspaperTable);
         if(styleClass != null) writer.writeAttribute(HTML.CLASS_ATTR, styleClass, null);
         if(colElementName.equals(HTML.TH_ELEM)) writer.writeAttribute(HTML.SCOPE_ATTR, HTML.SCOPE_COLGROUP_VALUE, null);
 
         // span all the table's columns
         int totalColumns = newspaperTable.getNewspaperColumns() * tableColumns;
         if(newspaperTable.getSpacer() != null) totalColumns = totalColumns + getNewspaperColumns() - 1;
         writer.writeAttribute(HTML.COLSPAN_ATTR, new Integer(totalColumns), null);
 
         // write the actual cell contents
         if(facet != null) RendererUtils.renderChild(facesContext, facet);
         
         // finish
         writer.endElement(colElementName);
         writer.endElement(HTML.TR_ELEM);
     }
 
 
     /**
      * Renders the column header or footer row.
      */
     private void renderColumnHeaderOrFooterRow(FacesContext facesContext,
         ResponseWriter writer, HtmlNewspaperTable newspaperTable, String styleClass, boolean header)
         throws IOException {
 
         HtmlRendererUtils.writePrettyLineSeparator(facesContext);
         writer.startElement(HTML.TR_ELEM, newspaperTable);
         int newspaperColumns = newspaperTable.getNewspaperColumns();
         for(int nc = 0; nc < newspaperColumns; nc++) {
             for(Iterator it = newspaperTable.getChildren().iterator(); it.hasNext(); ) {
                 UIComponent uiComponent = (UIComponent)it.next();
                 if(!(uiComponent instanceof UIColumn)) continue;
                 UIColumn column = (UIColumn)uiComponent;
                 if(!column.isRendered()) continue;
                 // get the component to render
                 UIComponent facet = null;
                 if(header) facet = column.getHeader();
                 else facet = column.getFooter();
                 // do the rendering of the cells
                 renderColumnHeaderOrFooterCell(facesContext, writer, column, styleClass, facet);
             }
 
             // draw the spacer facet
             if(nc < newspaperColumns - 1) renderSpacerCell(facesContext, writer, newspaperTable);
         }
         writer.endElement(HTML.TR_ELEM);
     }
 
     /**
      * Renders a cell in the column header or footer.
      */
     private void renderColumnHeaderOrFooterCell(FacesContext facesContext, ResponseWriter writer,
         UIColumn uiColumn, String styleClass, UIComponent facet) throws IOException {
 
         writer.startElement(HTML.TH_ELEM, uiColumn);
         if(styleClass != null) writer.writeAttribute(HTML.CLASS_ATTR, styleClass, null);
         if(facet != null) RendererUtils.renderChild(facesContext, facet);
         writer.endElement(HTML.TH_ELEM);
     }
     
     /**
      * Renders a spacer between adjacent newspaper columns.
      */
     private void renderSpacerCell(FacesContext facesContext, ResponseWriter writer,
         HtmlNewspaperTable newspaperTable) throws IOException {
         if(newspaperTable.getSpacer() == null) return;
         
         writer.startElement(HTML.TD_ELEM, newspaperTable);
         RendererUtils.renderChild(facesContext, newspaperTable.getSpacer());
         writer.endElement(HTML.TD_ELEM);
     }
 
     /**
      * Gets the style class for the table header.
      */
     private static String getHeaderClass(HtmlNewspaperTable newspaperTable) {
         if(newspaperTable instanceof HtmlDataTable) {
             return ((HtmlDataTable)newspaperTable).getHeaderClass();
         } else {
             return (String)newspaperTable.getAttributes().get(JSFAttr.HEADER_CLASS_ATTR);
         }
     }
     /**
      * Gets the style class for the table footer.
      */
     private static String getFooterClass(HtmlNewspaperTable newspaperTable) {
         if(newspaperTable instanceof HtmlDataTable) {
             return ((HtmlDataTable)newspaperTable).getFooterClass();
         } else {
             return (String)newspaperTable.getAttributes().get(JSFAttr.FOOTER_CLASS_ATTR);
         }
     }
 
     /**
      * Gets styles for the specified component.
      */
     public static Styles getStyles(HtmlNewspaperTable newspaperTable) {
         String rowClasses;
         String columnClasses;
         if(newspaperTable instanceof HtmlDataTable) {
             rowClasses = ((HtmlDataTable)newspaperTable).getRowClasses();
             columnClasses = ((HtmlDataTable)newspaperTable).getColumnClasses();
         } else {
             rowClasses = (String)newspaperTable.getAttributes().get(JSFAttr.ROW_CLASSES_ATTR);
             columnClasses = (String)newspaperTable.getAttributes().get(JSFAttr.COLUMN_CLASSES_ATTR);
         }
         return new Styles(rowClasses, columnClasses);
     }
 
     /**
      * Class manages the styles from String lists.
      */
     private static class Styles {
 
         private String[] _columnStyle;
         private String[] _rowStyle;
 
         Styles(String rowStyles, String columnStyles) {
             _rowStyle = (rowStyles == null)
                 ? ArrayUtils.EMPTY_STRING_ARRAY
                 : StringUtils.trim(
                     StringUtils.splitShortString(rowStyles, ','));
             _columnStyle = (columnStyles == null)
                 ? ArrayUtils.EMPTY_STRING_ARRAY
                 : StringUtils.trim(
                     StringUtils.splitShortString(columnStyles, ','));
         }
 
         public String getRowStyle(int idx) {
             if(!hasRowStyle()) {
                 return null;
             }
             return _rowStyle[idx % _rowStyle.length];
         }
 
         public String getColumnStyle(int idx) {
             if(!hasColumnStyle()) {
                 return null;
             }
             return _columnStyle[idx % _columnStyle.length];
         }
 
         public boolean hasRowStyle() {
             return _rowStyle.length > 0;
         }
 
         public boolean hasColumnStyle() {
             return _columnStyle.length > 0;
         }
     }
 }