text: // Copyright (c) 2011-2014 The Bitcoin developers
  // Copyright (c) 2014-2015 The Dash developers
  // Copyright (c) 2015-2018 The SEOCOIN developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "askpassphrasedialog.h"
  #include "ui_askpassphrasedialog.h"
  
  #include "guiconstants.h"
  #include "guiutil.h"
  #include "walletmodel.h"
  
  #include "allocators.h"
  
  #include <QKeyEvent>
  #include <QMessageBox>
  #include <QPushButton>
  #include <QWidget>
  
  AskPassphraseDialog::AskPassphraseDialog(Mode mode, QWidget* parent, WalletModel* model, Context context) : QDialog(parent, Qt::WindowSystemMenuHint | Qt::WindowTitleHint | Qt::WindowCloseButtonHint),
                                                                                                              ui(new Ui::AskPassphraseDialog),
                                                                                                              mode(mode),
                                                                                                              model(model),
                                                                                                              context(context),
                                                                                                              fCapsLock(false)
  {
      ui->setupUi(this);
      this->setStyleSheet(GUIUtil::loadStyleSheet());
  
      ui->passEdit1->setMinimumSize(ui->passEdit1->sizeHint());
      ui->passEdit2->setMinimumSize(ui->passEdit2->sizeHint());
      ui->passEdit3->setMinimumSize(ui->passEdit3->sizeHint());
  
      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);
  
      this->model = model;
  
      switch (mode) {
      case Mode::Encrypt: // Ask passphrase x2
          ui->warningLabel->setText(tr("Enter the new passphrase to the wallet.<br/>Please use a passphrase of <b>ten or more random characters</b>, or <b>eight or more words</b>."));
          ui->passLabel1->hide();
          ui->passEdit1->hide();
          setWindowTitle(tr("Encrypt wallet"));
          break;
      case Mode::UnlockAnonymize:
          ui->anonymizationCheckBox->show();
      case Mode::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 Mode::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 Mode::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;
      }
  
      // Set checkbox "For anonymization, automint, and staking only" depending on from where we were called
      if (context == Context::Unlock_Menu || context == Context::Mint_zSEO || context == Context::BIP_38) {
          ui->anonymizationCheckBox->setChecked(true);
      }
      else {
          ui->anonymizationCheckBox->setChecked(false);
      }
  
      // It doesn't make sense to show the checkbox for sending SEO because you wouldn't check it anyway.
      if (context == Context::Send_SEO || context == Context::Send_zSEO) {
          ui->anonymizationCheckBox->hide();
      }
  
      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::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 Mode::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 SEO</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("SEOCOIN will close now to finish the encryption process. "
                                 "Remember that encrypting your wallet cannot fully protect "
                                 "your SEOs 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 Mode::UnlockAnonymize:
      case Mode::Unlock:
          if (!model->setWalletLocked(false, oldpass, ui->anonymizationCheckBox->isChecked())) {
              QMessageBox::critical(this, tr("Wallet unlock failed"),
                  tr("The passphrase entered for the wallet decryption was incorrect."));
          } else {
              QDialog::accept(); // Success
          }
          break;
      case Mode::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 Mode::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 Mode::Encrypt: // New passphrase x2
          acceptable = !ui->passEdit2->text().isEmpty() && !ui->passEdit3->text().isEmpty();
          break;
      case Mode::UnlockAnonymize: // Old passphrase x1
      case Mode::Unlock:          // Old passphrase x1
      case Mode::Decrypt:
          acceptable = !ui->passEdit1->text().isEmpty();
          break;
      case Mode::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 >= 'a' && *psz <= 'z') || (!fShift && *psz >= 'A' && *psz <= 'Z')) {
                  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);
  }
  