private static final Set<Character> SIMILAR = new HashSet<>(Arrays.asList(
 '0','O','o','1','l','I','|','5','S','2','Z','8','B'
));
private static final SecureRandom RNG = new SecureRandom();
// UI components
private JTextField outputField;
private JSlider lengthSlider;
private JCheckBox lowerBox, upperBox, digitBox, symbolBox, excludeSimilarBox, requireEachBox;
private JLabel entropyLabel, strengthLabel;
public PasswordGeneratorGUI() {
 super("🔐 Générateur de mots de passe");
 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
 setSize(500, 300);
 setLayout(new BorderLayout(10,10));
 // Top output
 JPanel top = new JPanel(new BorderLayout(5,5));
 outputField = new JTextField();
 outputField.setFont(new Font("Monospaced", Font.PLAIN, 16));
 top.add(outputField, BorderLayout.CENTER);
 JButton copyBtn = new JButton("Copier");
 copyBtn.addActionListener(e -> copyToClipboard());
 top.add(copyBtn, BorderLayout.EAST);
 add(top, BorderLayout.NORTH);
 // Center controls
 JPanel center = new JPanel();
 center.setLayout(new GridLayout(0,2));
 lowerBox = new JCheckBox("Minuscules (a-z)", true);
 upperBox = new JCheckBox("Majuscules (A-Z)", true);
 digitBox = new JCheckBox("Chiffres (0-9)", true);
 symbolBox = new JCheckBox("Symboles (!@#...)", true);
 excludeSimilarBox = new JCheckBox("Exclure caractères ambigus (0,O,1,l...)", true);
 requireEachBox = new JCheckBox("Exiger ≥1 caractère de chaque catégorie", true);
 center.add(lowerBox);
 center.add(upperBox);
 center.add(digitBox);
 center.add(symbolBox);
 center.add(excludeSimilarBox);
 center.add(requireEachBox);
 add(center, BorderLayout.CENTER);
 // Bottom panel
 JPanel bottom = new JPanel(new BorderLayout(5,5));
 lengthSlider = new JSlider(8, 64, 16);
 lengthSlider.setMajorTickSpacing(14);
 lengthSlider.setMinorTickSpacing(2);
 lengthSlider.setPaintTicks(true);
 lengthSlider.setPaintLabels(true);
 bottom.add(new JLabel("Longueur :"), BorderLayout.WEST);
 bottom.add(lengthSlider, BorderLayout.CENTER);
 JButton genBtn = new JButton("Générer");
 genBtn.addActionListener(e -> generatePassword());
 bottom.add(genBtn, BorderLayout.EAST);
 add(bottom, BorderLayout.SOUTH);
 // Status panel
 JPanel status = new JPanel(new GridLayout(2,1));
 entropyLabel = new JLabel("Entropie : -- bits");
 strengthLabel = new JLabel("Robustesse : --");
 status.add(entropyLabel);
 status.add(strengthLabel);
 add(status, BorderLayout.WEST);
 setLocationRelativeTo(null); // center window
 setVisible(true);
}
private void copyToClipboard() {
 String text = outputField.getText();
 if (text.isEmpty()) return;
 Toolkit.getDefaultToolkit()
 .getSystemClipboard()
 .setContents(new StringSelection(text), null);
 JOptionPane.showMessageDialog(this, "Mot de passe copié !");
}
private void generatePassword() {
 int length = lengthSlider.getValue();
 java.util.List<String> sets = new ArrayList<>();
 if (lowerBox.isSelected()) sets.add(LOWER);
 if (upperBox.isSelected()) sets.add(UPPER);
 if (digitBox.isSelected()) sets.add(DIGIT);
 if (symbolBox.isSelected()) sets.add(SYMBOL);
 String pool = combineAndFilter(sets, excludeSimilarBox.isSelected());
 if (pool.isEmpty()) {
 JOptionPane.showMessageDialog(this, "Aucun jeu de caractères disponible !");
 return;
 }
 String pwd = requireEachBox.isSelected()
 ? generateWithRequirement(length, sets, pool, excludeSimilarBox.isSelected())
 : randomFromPool(pool, length);
 outputField.setText(pwd);
 // update entropy
 int uniqueChars = (int) pool.chars().distinct().count();
 double entropyBits = length * (Math.log(uniqueChars)/Math.log(2));
 String strength = strengthLabel(entropyBits);
 entropyLabel.setText(String.format("Entropie : ~%.0f bits", entropyBits));
 strengthLabel.setText("Robustesse : " + strength);
}
private String combineAndFilter(java.util.List<String> sets, boolean excludeSimilar) {
 StringBuilder sb = new StringBuilder();
 for (String s : sets) sb.append(s);
 StringBuilder out = new StringBuilder();
 for (char c : sb.toString().toCharArray()) {
 if (excludeSimilar && SIMILAR.contains(c)) continue;
 out.append(c);
 }
 return out.toString();
}
private String generateWithRequirement(int length, java.util.List<String> sets, String pool, boolean excludeSimilar) {
 java.util.List<Character> chars = new ArrayList<>();
 for (String s : sets) {
 String filtered = combineAndFilter(Collections.singletonList(s), excludeSimilar);
 if (!filtered.isEmpty()) {
 chars.add(filtered.charAt(RNG.nextInt(filtered.length())));
 }
 }
 for (int i = chars.size(); i < length; i++) {
 chars.add(pool.charAt(RNG.nextInt(pool.length())));
 }
 // shuffle
 Collections.shuffle(chars, RNG);
 StringBuilder sb = new StringBuilder();
 for (char c : chars) sb.append(c);
 return sb.toString();
}
private String randomFromPool(String pool, int length) {
 StringBuilder sb = new StringBuilder(length);
 for (int i = 0; i < length; i++) {
 sb.append(pool.charAt(RNG.nextInt(pool.length())));
 }
 return sb.toString();
}
private String strengthLabel(double bits) {
 if (bits < 28) return "Très faible";
 if (bits < 36) return "Faible";
 if (bits < 60) return "Correct";
 if (bits < 128) return "Fort";
 return "Très fort";
}
public static void main(String[] args) {
 SwingUtilities.invokeLater(PasswordGeneratorGUI::new);
}