/*
 * Copyright 2011 Google Inc.
 * 
 * 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 com.google.gwt.sample.showcase.client.content.cell;

import com.google.gwt.cell.client.CheckboxCell;
import com.google.gwt.cell.client.EditTextCell;
import com.google.gwt.cell.client.FieldUpdater;
import com.google.gwt.cell.client.NumberCell;
import com.google.gwt.cell.client.SelectionCell;
import com.google.gwt.cell.client.TextCell;
import com.google.gwt.core.client.GWT;
import com.google.gwt.core.client.RunAsyncCallback;
import com.google.gwt.dom.client.Style.Unit;
import com.google.gwt.i18n.client.Constants;
import com.google.gwt.safehtml.shared.SafeHtmlUtils;
import com.google.gwt.sample.showcase.client.ContentWidget;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseData;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseRaw;
import com.google.gwt.sample.showcase.client.ShowcaseAnnotations.ShowcaseSource;
import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.Category;
import com.google.gwt.sample.showcase.client.content.cell.ContactDatabase.ContactInfo;
import com.google.gwt.uibinder.client.UiBinder;
import com.google.gwt.uibinder.client.UiField;
import com.google.gwt.user.cellview.client.Column;
import com.google.gwt.user.cellview.client.ColumnSortEvent.ListHandler;
import com.google.gwt.user.cellview.client.DataGrid;
import com.google.gwt.user.cellview.client.Header;
import com.google.gwt.user.cellview.client.SafeHtmlHeader;
import com.google.gwt.user.cellview.client.SimplePager;
import com.google.gwt.user.cellview.client.SimplePager.TextLocation;
import com.google.gwt.user.client.rpc.AsyncCallback;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.Widget;
import com.google.gwt.view.client.DefaultSelectionEventManager;
import com.google.gwt.view.client.MultiSelectionModel;
import com.google.gwt.view.client.SelectionModel;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

/**
 * Example file.
 */
@ShowcaseRaw({"ContactDatabase.java", "CwDataGrid.ui.xml"})
public class CwDataGrid extends ContentWidget {

  /**
   * The UiBinder interface used by this example.
   */
  @ShowcaseSource
  interface Binder extends UiBinder<Widget, CwDataGrid> {
  }

  /**
   * The constants used in this Content Widget.
   */
  @ShowcaseSource
  public static interface CwConstants extends Constants {
    String cwDataGridColumnAddress();

    String cwDataGridColumnAge();

    String cwDataGridColumnCategory();

    String cwDataGridColumnFirstName();

    String cwDataGridColumnLastName();

    String cwDataGridDescription();

    String cwDataGridEmpty();

    String cwDataGridName();
  }

  /**
   * The main DataGrid.
   */
  @ShowcaseData
  @UiField(provided = true)
  DataGrid<ContactInfo> dataGrid;

  /**
   * The pager used to change the range of data.
   */
  @ShowcaseData
  @UiField(provided = true)
  SimplePager pager;

  /**
   * An instance of the constants.
   */
  @ShowcaseData
  private final CwConstants constants;

  /**
   * Constructor.
   * 
   * @param constants the constants
   */
  public CwDataGrid(CwConstants constants) {
    super(constants.cwDataGridName(), constants.cwDataGridDescription(), false,
        "ContactDatabase.java", "CwDataGrid.ui.xml");
    this.constants = constants;
  }

  @Override
  public boolean hasMargins() {
    return false;
  }

  @Override
  public boolean hasScrollableContent() {
    return false;
  }

  /**
   * Initialize this example.
   */
  @ShowcaseSource
  @Override
  public Widget onInitialize() {
    // Create a DataGrid.

    // Set a key provider that provides a unique key for each contact. If key is
    // used to identify contacts when fields (such as the name and address)
    // change.
    dataGrid = new DataGrid<ContactInfo>(ContactDatabase.ContactInfo.KEY_PROVIDER);
    dataGrid.setWidth("100%");

    // Set the message to display when the table is empty.
    dataGrid.setEmptyTableWidget(new Label(constants.cwDataGridEmpty()));

    // Attach a column sort handler to the ListDataProvider to sort the list.
    ListHandler<ContactInfo> sortHandler =
        new ListHandler<ContactInfo>(ContactDatabase.get().getDataProvider().getList());
    dataGrid.addColumnSortHandler(sortHandler);

    // Create a Pager to control the table.
    SimplePager.Resources pagerResources = GWT.create(SimplePager.Resources.class);
    pager = new SimplePager(TextLocation.CENTER, pagerResources, false, 0, true);
    pager.setDisplay(dataGrid);

    // Add a selection model so we can select cells.
    final SelectionModel<ContactInfo> selectionModel =
        new MultiSelectionModel<ContactInfo>(ContactDatabase.ContactInfo.KEY_PROVIDER);
    dataGrid.setSelectionModel(selectionModel, DefaultSelectionEventManager
        .<ContactInfo> createCheckboxManager());

    // Initialize the columns.
    initTableColumns(selectionModel, sortHandler);

    // Add the CellList to the adapter in the database.
    ContactDatabase.get().addDataDisplay(dataGrid);

    // Create the UiBinder.
    Binder uiBinder = GWT.create(Binder.class);
    return uiBinder.createAndBindUi(this);
  }

  @Override
  protected void asyncOnInitialize(final AsyncCallback<Widget> callback) {
    GWT.runAsync(CwDataGrid.class, new RunAsyncCallback() {

      public void onFailure(Throwable caught) {
        callback.onFailure(caught);
      }

      public void onSuccess() {
        callback.onSuccess(onInitialize());
      }
    });
  }

  /**
   * Add the columns to the table.
   */
  @ShowcaseSource
  private void initTableColumns(final SelectionModel<ContactInfo> selectionModel,
      ListHandler<ContactInfo> sortHandler) {
    // Checkbox column. This table will uses a checkbox column for selection.
    // Alternatively, you can call dataGrid.setSelectionEnabled(true) to enable
    // mouse selection.
    Column<ContactInfo, Boolean> checkColumn =
        new Column<ContactInfo, Boolean>(new CheckboxCell(true, false)) {
          @Override
          public Boolean getValue(ContactInfo object) {
            // Get the value from the selection model.
            return selectionModel.isSelected(object);
          }
        };
    dataGrid.addColumn(checkColumn, SafeHtmlUtils.fromSafeConstant("<br/>"));
    dataGrid.setColumnWidth(checkColumn, 40, Unit.PX);

    // First name.
    Column<ContactInfo, String> firstNameColumn =
        new Column<ContactInfo, String>(new EditTextCell()) {
          @Override
          public String getValue(ContactInfo object) {
            return object.getFirstName();
          }
        };
    firstNameColumn.setSortable(true);
    sortHandler.setComparator(firstNameColumn, new Comparator<ContactInfo>() {
      public int compare(ContactInfo o1, ContactInfo o2) {
        return o1.getFirstName().compareTo(o2.getFirstName());
      }
    });
    dataGrid.addColumn(firstNameColumn, constants.cwDataGridColumnFirstName());
    firstNameColumn.setFieldUpdater(new FieldUpdater<ContactInfo, String>() {
      public void update(int index, ContactInfo object, String value) {
        // Called when the user changes the value.
        object.setFirstName(value);
        ContactDatabase.get().refreshDisplays();
      }
    });
    dataGrid.setColumnWidth(firstNameColumn, 20, Unit.PCT);

    // Last name.
    Column<ContactInfo, String> lastNameColumn =
        new Column<ContactInfo, String>(new EditTextCell()) {
          @Override
          public String getValue(ContactInfo object) {
            return object.getLastName();
          }
        };
    lastNameColumn.setSortable(true);
    sortHandler.setComparator(lastNameColumn, new Comparator<ContactInfo>() {
      public int compare(ContactInfo o1, ContactInfo o2) {
        return o1.getLastName().compareTo(o2.getLastName());
      }
    });
    dataGrid.addColumn(lastNameColumn, constants.cwDataGridColumnLastName());
    lastNameColumn.setFieldUpdater(new FieldUpdater<ContactInfo, String>() {
      public void update(int index, ContactInfo object, String value) {
        // Called when the user changes the value.
        object.setLastName(value);
        ContactDatabase.get().refreshDisplays();
      }
    });
    dataGrid.setColumnWidth(lastNameColumn, 20, Unit.PCT);

    // Age.
    Column<ContactInfo, Number> ageColumn = new Column<ContactInfo, Number>(new NumberCell()) {
      @Override
      public Number getValue(ContactInfo object) {
        return object.getAge();
      }
    };
    lastNameColumn.setSortable(true);
    sortHandler.setComparator(ageColumn, new Comparator<ContactInfo>() {
      public int compare(ContactInfo o1, ContactInfo o2) {
        return o1.getBirthday().compareTo(o2.getBirthday());
      }
    });
    Header<String> ageFooter = new Header<String>(new TextCell()) {
      @Override
      public String getValue() {
        List<ContactInfo> items = dataGrid.getVisibleItems();
        if (items.size() == 0) {
          return "";
        } else {
          int totalAge = 0;
          for (ContactInfo item : items) {
            totalAge += item.getAge();
          }
          return "Avg: " + totalAge / items.size();
        }
      }
    };
    dataGrid.addColumn(ageColumn, new SafeHtmlHeader(SafeHtmlUtils.fromSafeConstant(constants
        .cwDataGridColumnAge())), ageFooter);
    dataGrid.setColumnWidth(ageColumn, 7, Unit.EM);

    // Category.
    final Category[] categories = ContactDatabase.get().queryCategories();
    List<String> categoryNames = new ArrayList<String>();
    for (Category category : categories) {
      categoryNames.add(category.getDisplayName());
    }
    SelectionCell categoryCell = new SelectionCell(categoryNames);
    Column<ContactInfo, String> categoryColumn = new Column<ContactInfo, String>(categoryCell) {
      @Override
      public String getValue(ContactInfo object) {
        return object.getCategory().getDisplayName();
      }
    };
    dataGrid.addColumn(categoryColumn, constants.cwDataGridColumnCategory());
    categoryColumn.setFieldUpdater(new FieldUpdater<ContactInfo, String>() {
      public void update(int index, ContactInfo object, String value) {
        for (Category category : categories) {
          if (category.getDisplayName().equals(value)) {
            object.setCategory(category);
          }
        }
        ContactDatabase.get().refreshDisplays();
      }
    });
    dataGrid.setColumnWidth(categoryColumn, 130, Unit.PX);

    // Address.
    Column<ContactInfo, String> addressColumn = new Column<ContactInfo, String>(new TextCell()) {
      @Override
      public String getValue(ContactInfo object) {
        return object.getAddress();
      }
    };
    addressColumn.setSortable(true);
    sortHandler.setComparator(addressColumn, new Comparator<ContactInfo>() {
      public int compare(ContactInfo o1, ContactInfo o2) {
        return o1.getAddress().compareTo(o2.getAddress());
      }
    });
    dataGrid.addColumn(addressColumn, constants.cwDataGridColumnAddress());
    dataGrid.setColumnWidth(addressColumn, 60, Unit.PCT);
  }
}