text: #include "askpassphrasedialog.h"
  #include "ui_askpassphrasedialog.h"
  
  #include "guiconstants.h"
  #include "walletmodel.h"
  
  #include <QMessageBox>
  #include <QPushButton>
  #include <QKeyEvent>
  
  extern bool fWalletUnlockStakingOnly;
  
  AskPassphraseDialog::AskPassphraseDialog(Mode mode, QWidget *parent) :
      QDialog(parent),
      ui(new Ui::AskPassphraseDialog),
      mode(mode),
      model(0),
      fCapsLock(false)
  {
      ui->setupUi(this);
      ui->passEdit1->setMaxLength(MAX_PASSPHRASE_SIZE);
      ui->passEdit2->setMaxLength(MAX_PASSPHRASE_SIZE);
      ui->passEdit3->setMaxLength(MAX_PASSPHRASE_SIZE);
      
      // Setup Caps Lock detection.
      ui->passEdit1->installEventFilter(this);
      ui->passEdit2->installEventFilter(this);
      ui->passEdit3->installEventFilter(this);
  
      switch(mode)
      {
          case Encrypt: // Ask passphrase x2
              ui->passLabel1->hide();
              ui->passEdit1->hide();
              ui->warningLabel->setText(tr("Enter the new passphrase to the wallet.<br/>Please use a passphrase of <b>10 or more random characters</b>, or <b>eight or more words</b>."));
              setWindowTitle(tr("Encrypt wallet"));
              break;
          case UnlockStaking:
              ui->stakingCheckBox->setChecked(true);
              ui->stakingCheckBox->show();
              // fallthru
          case Unlock: // Ask passphrase
              ui->warningLabel->setText(tr("This operation needs your wallet passphrase to unlock the wallet."));
              ui->passLabel2->hide();
              ui->passEdit2->hide();
              ui->passLabel3->hide();
              ui->passEdit3->hide();
              setWindowTitle(tr("Unlock wallet"));
              break;
          case Decrypt:   // Ask passphrase
              ui->warningLabel->setText(tr("This operation needs your wallet passphrase to decrypt the wallet."));
              ui->passLabel2->hide();
              ui->passEdit2->hide();
              ui->passLabel3->hide();
              ui->passEdit3->hide();
              setWindowTitle(tr("Decrypt wallet"));
              break;
          case ChangePass: // Ask old passphrase + new passphrase x2
              setWindowTitle(tr("Change passphrase"));
              ui->warningLabel->setText(tr("Enter the old and new passphrase to the wallet."));
              break;
      }
  
      textChanged();
      connect(ui->passEdit1, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
      connect(ui->passEdit2, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
      connect(ui->passEdit3, SIGNAL(textChanged(QString)), this, SLOT(textChanged()));
  }
  
  AskPassphraseDialog::~AskPassphraseDialog()
  {
      // Attempt to overwrite text so that they do not linger around in memory
      ui->passEdit1->setText(QString(" ").repeated(ui->passEdit1->text().size()));
      ui->passEdit2->setText(QString(" ").repeated(ui->passEdit2->text().size()));
      ui->passEdit3->setText(QString(" ").repeated(ui->passEdit3->text().size()));
      delete ui;
  }
  
  void AskPassphraseDialog::setModel(WalletModel *model)
  {
      this->model = model;
  }
  
  void AskPassphraseDialog::accept()
  {
      SecureString oldpass, newpass1, newpass2;
      if(!model)
          return;
      oldpass.reserve(MAX_PASSPHRASE_SIZE);
      newpass1.reserve(MAX_PASSPHRASE_SIZE);
      newpass2.reserve(MAX_PASSPHRASE_SIZE);
      // TODO: get rid of this .c_str() by implementing SecureString::operator=(std::string)
      // Alternately, find a way to make this input mlock()'d to begin with.
      oldpass.assign(ui->passEdit1->text().toStdString().c_str());
      newpass1.assign(ui->passEdit2->text().toStdString().c_str());
      newpass2.assign(ui->passEdit3->text().toStdString().c_str());
  
      switch(mode)
      {
      case Encrypt: {
          if(newpass1.empty() || newpass2.empty())
          {
              // Cannot encrypt with empty passphrase
              break;
          }
          QMessageBox::StandardButton retval = QMessageBox::question(this, tr("Confirm wallet encryption"),
                   tr("Warning: If you encrypt your wallet and lose your passphrase, you will <b>LOSE ALL OF YOUR COINS</b>!") + "<br><br>" + tr("Are you sure you wish to encrypt your wallet?"),
                   QMessageBox::Yes|QMessageBox::Cancel,
                   QMessageBox::Cancel);
          if(retval == QMessageBox::Yes)
          {
              if(newpass1 == newpass2)
              {
                  if(model->setWalletEncrypted(true, newpass1))
                  {
                      QMessageBox::warning(this, tr("Wallet encrypted"),
                                           "<qt>" + 
                                           tr("Qibuck will close now to finish the encryption process. "
                                           "Remember that encrypting your wallet cannot fully protect "
                                           "your coins from being stolen by malware infecting your computer.") + 
                                           "<br><br><b>" + 
                                           tr("IMPORTANT: Any previous backups you have made of your wallet file "
                                           "should be replaced with the newly generated, encrypted wallet file. "
                                           "For security reasons, previous backups of the unencrypted wallet file "
                                           "will become useless as soon as you start using the new, encrypted wallet.") + 
                                           "</b></qt>");
                      QApplication::quit();
                  }
                  else
                  {
                      QMessageBox::critical(this, tr("Wallet encryption failed"),
                                           tr("Wallet encryption failed due to an internal error. Your wallet was not encrypted."));
                  }
                  QDialog::accept(); // Success
              }
              else
              {
                  QMessageBox::critical(this, tr("Wallet encryption failed"),
                                       tr("The supplied passphrases do not match."));
              }
          }
          else
          {
              QDialog::reject(); // Cancelled
          }
          } break;
      case UnlockStaking:
      case Unlock:
          if(!model->setWalletLocked(false, oldpass))
          {
              QMessageBox::critical(this, tr("Wallet unlock failed"),
                                    tr("The passphrase entered for the wallet decryption was incorrect."));
          }
          else
          {
              fWalletUnlockStakingOnly = ui->stakingCheckBox->isChecked();
              QDialog::accept(); // Success
          }
          break;
      case Decrypt:
          if(!model->setWalletEncrypted(false, oldpass))
          {
              QMessageBox::critical(this, tr("Wallet decryption failed"),
                                    tr("The passphrase entered for the wallet decryption was incorrect."));
          }
          else
          {
              QDialog::accept(); // Success
          }
          break;
      case ChangePass:
          if(newpass1 == newpass2)
          {
              if(model->changePassphrase(oldpass, newpass1))
              {
                  QMessageBox::information(this, tr("Wallet encrypted"),
                                       tr("Wallet passphrase was successfully changed."));
                  QDialog::accept(); // Success
              }
              else
              {
                  QMessageBox::critical(this, tr("Wallet encryption failed"),
                                       tr("The passphrase entered for the wallet decryption was incorrect."));
              }
          }
          else
          {
              QMessageBox::critical(this, tr("Wallet encryption failed"),
                                   tr("The supplied passphrases do not match."));
          }
          break;
      }
  }
  
  void AskPassphraseDialog::textChanged()
  {
      // Validate input, set Ok button to enabled when acceptable
      bool acceptable = false;
      switch(mode)
      {
      case Encrypt: // New passphrase x2
          acceptable = !ui->passEdit2->text().isEmpty() && !ui->passEdit3->text().isEmpty();
          break;
      case UnlockStaking:
      case Unlock: // Old passphrase x1
      case Decrypt:
          acceptable = !ui->passEdit1->text().isEmpty();
          break;
      case ChangePass: // Old passphrase x1, new passphrase x2
          acceptable = !ui->passEdit1->text().isEmpty() && !ui->passEdit2->text().isEmpty() && !ui->passEdit3->text().isEmpty();
          break;
      }
      ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(acceptable);
  }
  
  bool AskPassphraseDialog::event(QEvent *event)
  {
      // Detect Caps Lock key press.
      if (event->type() == QEvent::KeyPress) {
          QKeyEvent *ke = static_cast<QKeyEvent *>(event);
          if (ke->key() == Qt::Key_CapsLock) {
              fCapsLock = !fCapsLock;
          }
          if (fCapsLock) {
              ui->capsLabel->setText(tr("Warning: The Caps Lock key is on!"));
          } else {
              ui->capsLabel->clear();
          }
      }
      return QWidget::event(event);
  }
  
  bool AskPassphraseDialog::eventFilter(QObject *object, QEvent *event)
  {
      /* Detect Caps Lock.
       * There is no good OS-independent way to check a key state in Qt, but we
       * can detect Caps Lock by checking for the following condition:
       * Shift key is down and the result is a lower case character, or
       * Shift key is not down and the result is an upper case character.
       */
      if (event->type() == QEvent::KeyPress) {
          QKeyEvent *ke = static_cast<QKeyEvent *>(event);
          QString str = ke->text();
          if (str.length() != 0) {
              const QChar *psz = str.unicode();
              bool fShift = (ke->modifiers() & Qt::ShiftModifier) != 0;
              if ((fShift && psz->isLower()) || (!fShift && psz->isUpper())) {
                  fCapsLock = true;
                  ui->capsLabel->setText(tr("Warning: The Caps Lock key is on!"));
              } else if (psz->isLetter()) {
                  fCapsLock = false;
                  ui->capsLabel->clear();
              }
          }
      }
      return QDialog::eventFilter(object, event);
  }
  