/**
    * 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.hadoop.hbase.hbtop.screen.mode;
  
  import java.util.List;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.hbase.hbtop.mode.Mode;
  import org.apache.hadoop.hbase.hbtop.screen.AbstractScreenView;
  import org.apache.hadoop.hbase.hbtop.screen.Screen;
  import org.apache.hadoop.hbase.hbtop.screen.ScreenView;
  import org.apache.hadoop.hbase.hbtop.terminal.KeyPress;
  import org.apache.hadoop.hbase.hbtop.terminal.Terminal;
  import org.apache.hadoop.hbase.hbtop.terminal.TerminalPrinter;
  
  /**
   * The screen where we can choose the {@link Mode} in the top screen.
   */
  @InterfaceAudience.Private
  public class ModeScreenView extends AbstractScreenView {
  
    private static final int SCREEN_DESCRIPTION_START_ROW = 0;
    private static final int MODE_START_ROW = 4;
  
    private final ModeScreenPresenter modeScreenPresenter;
  
    public ModeScreenView(Screen screen, Terminal terminal, Mode currentMode,
      ModeScreenPresenter.ResultListener resultListener, ScreenView nextScreenView) {
      super(screen, terminal);
      this.modeScreenPresenter = new ModeScreenPresenter(this, currentMode, resultListener,
        nextScreenView);
    }
  
    @Override
    public void init() {
      modeScreenPresenter.init();
    }
  
    @Override
    public ScreenView handleKeyPress(KeyPress keyPress) {
      switch (keyPress.getType()) {
        case Escape:
          return modeScreenPresenter.transitionToNextScreen(false);
  
        case Enter:
          return modeScreenPresenter.transitionToNextScreen(true);
  
        case ArrowUp:
          modeScreenPresenter.arrowUp();
          return this;
  
        case ArrowDown:
          modeScreenPresenter.arrowDown();
          return this;
  
        case PageUp:
        case Home:
          modeScreenPresenter.pageUp();
          return this;
  
        case PageDown:
        case End:
          modeScreenPresenter.pageDown();
          return this;
  
        default:
          // Do nothing
          break;
      }
  
      if (keyPress.getType() != KeyPress.Type.Character) {
        return this;
      }
  
      assert keyPress.getCharacter() != null;
      switch (keyPress.getCharacter()) {
        case 'q':
          return modeScreenPresenter.transitionToNextScreen(false);
  
        default:
          // Do nothing
          break;
      }
  
      return this;
   }
 
   public void showModeScreen(Mode currentMode, List<Mode> modes, int currentPosition,
     int modeHeaderMaxLength, int modeDescriptionMaxLength) {
     showScreenDescription(currentMode);
 
     for (int i = 0; i < modes.size(); i++) {
       showMode(i, modes.get(i), i == currentPosition,
         modeHeaderMaxLength, modeDescriptionMaxLength);
     }
   }
 
   private void showScreenDescription(Mode currentMode) {
     TerminalPrinter printer = getTerminalPrinter(SCREEN_DESCRIPTION_START_ROW);
     printer.startBold().print("Mode Management").stopBold().endOfLine();
     printer.print("Current mode: ")
       .startBold().print(currentMode.getHeader()).stopBold().endOfLine();
     printer.print("Select mode followed by <Enter>").endOfLine();
   }
 
   public void showMode(int pos, Mode mode, boolean selected, int modeHeaderMaxLength,
     int modeDescriptionMaxLength) {
 
     String modeHeader = String.format("%-" + modeHeaderMaxLength + "s", mode.getHeader());
     String modeDescription = String.format("%-" + modeDescriptionMaxLength + "s",
       mode.getDescription());
 
     int row = MODE_START_ROW + pos;
     TerminalPrinter printer = getTerminalPrinter(row);
     if (selected) {
       printer.startHighlight().print(modeHeader).stopHighlight()
         .printFormat(" = %s", modeDescription).endOfLine();
     } else {
       printer.printFormat("%s = %s", modeHeader, modeDescription).endOfLine();
     }
   }
 }