/* This file is part of the KDE libraries
   Copyright (C) 2000 David Faure <faure@kde.org>
   Copyright (C) 2000 Dawit Alemayehu <adawit@kde.org>
   Copyright (C) 2007 Olivier Goffart <ogoffart at kde.org>

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License version 2 as published by the Free Software Foundation.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; see the file COPYING.LIB.  If
   not, write to the Free Software Foundation, Inc., 51 Franklin Street,
   Fifth Floor, Boston, MA 02110-1301, USA.
*/

#ifndef KPASSWORDDIALOG_H
#define KPASSWORDDIALOG_H

#include <QDialog>
#include <QDialogButtonBox>
#include <QFlags>

#include <kwidgetsaddons_export.h>

/**
 * @class KPasswordDialog kpassworddialog.h KPasswordDialog
 *
 * A dialog for requesting a password and optionaly a login from the end user.
 *
 * \section usage Usage Example
 *
 * Requesting a simple password, asynchronous
 *
 * \code
 *  KPasswordDialog *dlg = new KPasswordDialog( parent );
 *  dlg->setPrompt(i18n("Enter a password"));
 *  connect( dlg, SIGNAL( gotPassword( const QString& , bool ) )  , this, SLOT( setPassword( const QString &) ) );
 *  connect( dlg, SIGNAL( rejected() )  , this, SLOT( slotCancel() ) );
 *  dlg->show();
 * \endcode
 *
 * Requesting a login and a password, synchronous
 *
 * \code
 *  KPasswordDialog dlg(parent, KPasswordDialog::ShowUsernameLine);
 *  dlg.setPrompt(i18n("Enter a login and a password"));
 *  if( !dlg.exec() )
 *      return; //the user canceled
 *  use( dlg.username() , dlg.password() );
 * \endcode
 *
 * \image html kpassworddialog.png "KPasswordDialog"
 *
 * @short dialog for requesting login and password from the end user
 */
class KWIDGETSADDONS_EXPORT KPasswordDialog : public QDialog
{
    Q_OBJECT

public:

    enum KPasswordDialogFlag {
        NoFlags = 0x00,
        /**
         * If this flag is set, the "keep this password" checkbox will been shown,
         * otherwise, it will not be shown and keepPassword will have no effect
         */
        ShowKeepPassword = 0x01,
        /**
         * If this flag is set, there will be an additional line to let the user enter his login.
         * otherwise, only the password line will be shown.
         */
        ShowUsernameLine = 0x02,
        /**
         * If this flag is set, the login lineedit will be in read only mode.
         */
        UsernameReadOnly = 0x04,
        /**
         * If this flag is set, the Anonymous Login checkbox will be displayed
         * @since 4.1
         */
        ShowAnonymousLoginCheckBox = 0x08,
        /**
         * If this flag is set, there will be an additional line to let the user enter the domain.
         * @since 4.1
         */
        ShowDomainLine = 0x10,
        /**
         * If this flag is set, the domain lineedit will be in read only mode.
         * @since 4.1
         */
        DomainReadOnly = 0x20
    };
    Q_DECLARE_FLAGS(KPasswordDialogFlags, KPasswordDialogFlag)

    enum ErrorType {
        UnknownError = 0,

        /**
         * A problem with the user name as entered
         **/
        UsernameError,

        /**
         * Incorrect password
         */
        PasswordError,

        /**
         * Error preventing further attempts, will result in disabling most of the interface
         */
        FatalError,

        /**
         * A problem with the domain as entered
         * @since 4.1
         **/
        DomainError
    };

    /**
     * create a password dialog
     *
     * @param parent the parent widget
     * @param flags a set of KPasswordDialogFlag flags
     */
    explicit KPasswordDialog(QWidget *parent = nullptr,
                             const KPasswordDialogFlags &flags = KPasswordDialog::NoFlags);

    /**
     * Destructor
     */
    ~KPasswordDialog() override;

    /**
     * Sets the prompt to show to the user.
     * @param prompt        instructional text to be shown.
     */
    void setPrompt(const QString &prompt);

    /**
     * Returns the prompt
     */
    QString prompt() const;

    /**
     * set an image that appears next to the prompt.
     */
    void setPixmap(const QPixmap &);
    /**
     *
     */
    QPixmap pixmap() const;

    /**
     * Adds a comment line to the dialog.
     *
     * This function allows you to add one additional comment
     * line to this widget.  Calling this function after a
     * comment has already been added will not have any effect.
     *
     * @param label       label for comment (ex:"Command:")
     * @param comment     the actual comment text.
     */
    void addCommentLine(const QString &label, const QString &comment);

    /**
     * Shows an error message in the dialog box. Prevents having to show a dialog-on-a-dialog.
     *
     * @param message the error message to show
     */
    void showErrorMessage(const QString &message, const ErrorType type = PasswordError);

    /**
     * Returns the password entered by the user.
     * @return the password
     */
    QString password() const;

    /**
     * set the default username.
     */
    void setUsername(const QString &);

    /**
     * Returns the username entered by the user.
     * @return the user name
     */
    QString username() const;

    /**
     * set the default domain.
     * @since 4.1
     */
    void setDomain(const QString &);

    /**
     * Returns the domain entered by the user.
     * @return the domain name
     * @since 4.1
     */
    QString domain() const;

    /**
     * set anonymous mode (all other fields will be grayed out)
     * @since 4.1
     */
    void setAnonymousMode(bool anonymous);

    /**
     * @return anonymous mode has been selected.
     * @since 4.1
     */
    bool anonymousMode() const;

    /**
     * Determines whether supplied authorization should
     * persist even after the application has been closed.
     *
     * this is set with the check password checkbox is the ShowKeepCheckBox flag
     * is set in the constructor, if it is not set, this function return false
     *
     * @return true to keep the password
     */
    bool keepPassword() const;

    /**
     * Check or uncheck the "keep password" checkbox.
     * This can be used to check it before showing the dialog, to tell
     * the user that the password is stored already (e.g. in the wallet).
     * enableKeep must have been set to true in the constructor.
     *
     * has only effect if ShowKeepCheckBox is set in the constructor
     */
    void setKeepPassword(bool b);

    /**
     * Sets the username field read-only and sets the
     * focus to the password field.
     *
     * this can also be set by passing UsernameReadOnly as flag in the constructor
     *
     * @param readOnly true to set the user field to read-only
     */
    void setUsernameReadOnly(bool readOnly);

    /**
     * Presets the password.
     * If the password is not empty, the ability to show the password will not be available.
     * @param password the password to set
     */
    void setPassword(const QString &password);

    /**
     * Presets a number of login+password pairs that the user can choose from.
     * The passwords can be empty if you simply want to offer usernames to choose from.
     *
     * This require the flag ShowUnernameLine to be set in the constructoe, and not the flag UsernameReadOnly
     * @param knownLogins map of known logins: the keys are usernames, the values are passwords.
     */
    void setKnownLogins(const QMap<QString, QString> &knownLogins);

    /**
     * @internal
     */
    void accept() override;

    /**
     * Returns the button box used in the dialog.
     * This can be used to add new buttons.
     *
     * @return the button box
     *
     * @since 5.0
     */
    QDialogButtonBox *buttonBox() const;

Q_SIGNALS:
    /**
     * emitted when the dialog has been accepted
     * @param password  the entered password
     * @param keep true if the "remember password" checkbox was checked, false otherwise.  false if ShowKeepPassword was not set in the constructor
     */
    void gotPassword(const QString &password, bool keep);

    /**
     * emitted when the dialog has been accepted, and ShowUsernameLine was set on the constructor
     * @param username the entered username
     * @param password  the entered password
     * @param keep true if the "remember password" checkbox was checked, false otherwise.  false if ShowKeepPassword was not set in the constructor
     */
    void gotUsernameAndPassword(const QString &username, const QString &password, bool keep);

protected:
    /**
     * Virtual function that can be overridden to provide password
     * checking in derived classes. It should return @p true if the
     * password is valid, @p false otherwise.
     */
    virtual bool checkPassword();

private:
    Q_PRIVATE_SLOT(d, void actuallyAccept())
    Q_PRIVATE_SLOT(d, void activated(const QString &userName))
    Q_PRIVATE_SLOT(d, void updateFields())

private:
    class KPasswordDialogPrivate;
    friend class KPasswordDialogPrivate;
    KPasswordDialogPrivate *const d;

    Q_DISABLE_COPY(KPasswordDialog)
};

Q_DECLARE_OPERATORS_FOR_FLAGS(KPasswordDialog::KPasswordDialogFlags)

#endif
