/**
    * Copyright 2009 Timothy Johnston 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.timjohnstondev.unitconverter.view;
  
  import java.awt.Color;
  import java.awt.Component;
  import java.awt.Dimension;
  import java.awt.GridLayout;
  import java.awt.event.KeyAdapter;
  import java.awt.event.KeyEvent;
  import java.math.BigDecimal;
  import java.util.ResourceBundle;
  import javax.swing.BorderFactory;
  import javax.swing.JLabel;
  import javax.swing.JPanel;
  import javax.swing.JTextField;
  import javax.swing.event.DocumentEvent;
  import javax.swing.event.DocumentListener;
  import com.timjohnstondev.unitconverter.controller.LogicController;
  
  /**
   * This panel contains all of the {@code JTextField}s for input, conversion factor and result display. All fields can be
   * copied from, but only the input field can take number input.
   */
  public class CalculationPanel extends JPanel implements Configuration
  {
    private LogicController logicController;
    private JLabel inputLabel;
    private JLabel conversionFactorLabel;
    private JLabel resultLabel;
    private JTextField input;
    private ConversionTextField conversionFactor;
    private JTextField result;
    private ResourceBundle resources;
  
    /**
     * Constructs a {@code CalculationPanel} and sets the layout and size of the panel and its contents.
     */
    public CalculationPanel()
    {
      setMaximumSize(new Dimension(500, 80));
      setLayout(new GridLayout(2, 3, 10, 5));
      setBorder(BorderFactory.createEmptyBorder(20, 10, 5, 10));
      logicController = new LogicController();
  
      resources = ResourceBundle.getBundle("com.timjohnstondev.unitconverter.view.View");
      inputLabel = new JLabel(resources.getString("CalculationPanel.inputLabel"));
      conversionFactorLabel = new JLabel(resources.getString("CalculationPanel.conversionFactorLabel"));
      resultLabel = new JLabel(resources.getString("CalculationPanel.resultLabel"));
      configureLabels();
  
      input = new JTextField();
      input.setDocument(new InputFilter(resources.getString("CalculationPanel.allowableCharacters")));
      conversionFactor = new ConversionTextField();
      result = new JTextField();
      addListeners();
  
      add(inputLabel);
      add(conversionFactorLabel);
      add(resultLabel);
      add(input);
      add(conversionFactor);
      add(result);
    }
  
    /**
     * Updates the conversion factor field and stores the exact number or formula because the display may limit the
     * characters to show.
     * 
     * @param conversion the conversion factor or formula
     */
    public final void setConversion(final String conversion)
    {
      conversionFactor.setConversion(conversion);
      final String text = logicController.getConversionFactor(conversion);
      conversionFactor.setText(text);
    }
  
    /**
     * Updates the result field if the input field has valid data and a conversion factor is selected.
     * 
     * @param molecularWeightCorrection the correction factor to adjust for molecular weight in mole to mass and mass to
     *          mole conversions
     */
    public final void updateCalculations(final BigDecimal molecularWeightCorrection)
    {
      final String conversion = conversionFactor.getConversion();
      final String resultText = logicController.getResult(input.getText(), conversion, molecularWeightCorrection);
      result.setText(resultText);
    }
  
   private void updateCalculations()
   {
     updateCalculations(BigDecimal.ONE);
   }
 
   /**
    * Clears out the text of the conversion factor and results displays by setting their text to {@code null}.
    */
   public final void clearFactor()
   {
     conversionFactor.setConversion(null);
     conversionFactor.setText(null);
     result.setText(null);
   }
 
   private void configureLabels()
   {
     final JLabel[] labels = {inputLabel, conversionFactorLabel, resultLabel};
     for (JLabel label : labels)
     {
       label.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 0));
     }
   }
 
   private void addListeners()
   {
     input.getDocument().addDocumentListener(new InputDocumentListener());
     conversionFactor.addKeyListener(new DoNothingKeyListener());
     result.addKeyListener(new DoNothingKeyListener());
   }
 
   private class InputDocumentListener implements DocumentListener
   {
     @Override
     public final void changedUpdate(final DocumentEvent e)
     {
       updateCalculations();
     }
 
     @Override
     public final void insertUpdate(final DocumentEvent e)
     {
       changedUpdate(e);
     }
 
     @Override
     public final void removeUpdate(final DocumentEvent e)
     {
       changedUpdate(e);
     }
   }
 
   private class DoNothingKeyListener extends KeyAdapter
   {
     @Override
     public final void keyPressed(final KeyEvent e)
     {
       if (e.getKeyCode() == KeyEvent.VK_V)
       {
         e.consume();
       }
     }
 
     @Override
     public final void keyTyped(final KeyEvent e)
     {
       e.consume();
     }
   }
 
   private class ConversionTextField extends JTextField
   {
     private String conversion;
 
     private void setConversion(final String newConversion)
     {
       conversion = newConversion;
     }
 
     private String getConversion()
     {
       return conversion;
     }
   }
 
   @Override
   public final void setBackgroundColor(final Color color)
   {
     setBackground(color);
     final Component[] children = getComponents();
     for (Component child : children)
     {
       if (child instanceof JLabel)
       {
         child.setBackground(color);
       }
       if (child instanceof JTextField)
       {
         child.setBackground(color.brighter());
       }
     }
   }
 
   @Override
   public final void setForegroundColor(final Color color)
   {
     setForeground(color);
     final Component[] children = getComponents();
     for (Component child : children)
     {
       child.setForeground(color);
     }
   }
 
   @Override
   public final void setFontSize(final float fontSize)
   {
     setFont(getFont().deriveFont(fontSize));
     final Component[] children = getComponents();
     for (Component child : children)
     {
       child.setFont(child.getFont().deriveFont(fontSize));
     }
   }
 }