/*
Copyright 2011-2016 Google Inc. All Rights Reserved.

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.security.zynamics.zylib.gui;

import javax.swing.JFormattedTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;

public class CDecFormatter extends JFormattedTextField.AbstractFormatter {
  private static final long serialVersionUID = 8368311921001233300L;

  private final DecFilter filter = new DecFilter();

  private final int m_maxChar;

  private final int m_minNumber;
  private final int m_maxNumber;

  public CDecFormatter() {
    this(Integer.MAX_VALUE);
  }

  public CDecFormatter(final int maxChar) {
    m_maxChar = maxChar;

    m_minNumber = -1;
    m_maxNumber = -1;
  }

  public CDecFormatter(final int maxChar, final int minNumber, final int maxNumber) {
    m_maxChar = maxChar;
    m_minNumber = minNumber;
    m_maxNumber = maxNumber;
  }

  private boolean isValid(final String string, final int selected) {
    if (((getFormattedTextField().getText().length() - selected) + string.length()) > m_maxChar) {
      invalidEdit();
      return false;
    }

    for (int i = 0; i < string.length(); i++) {
      final char ch = string.charAt(i);
      if (Character.digit(ch, 10) == -1) {
        invalidEdit();
        return false;
      }
    }

    if ((m_minNumber != -1) && (m_maxNumber != -1)) {
      final int value = Integer.parseInt(getFormattedTextField().getText() + string);
      if ((value < m_minNumber) || (value > m_maxNumber)) {
        invalidEdit();
        return false;
      }
    }

    return true;
  }

  @Override
  protected DocumentFilter getDocumentFilter() {
    return filter;
  }

  @Override
  public Object stringToValue(final String s) {
    return s.equals("") ? 0 : Long.parseLong(s);
  }

  @Override
  public String valueToString(final Object o) {
    if (o == null) {
      return null;
    }
    return Long.toString((Long) o);
  }

  private class DecFilter extends DocumentFilter {
    @Override
    public void insertString(final DocumentFilter.FilterBypass fb, final int offset,
        final String string, final AttributeSet attr) throws BadLocationException {
      if (isValid(string, 0)) {
        super.insertString(fb, offset, string, attr);
      }
    }

    @Override
    public void replace(final DocumentFilter.FilterBypass fb, final int offset, final int length,
        final String string, final AttributeSet attr) throws BadLocationException {
      if (isValid(string, length)) {
        super.replace(fb, offset, length, string, attr);
      }
    }
  }
}
