/*
    This file is part of Konsole, an X terminal.

    Copyright 2007-2008 by Robert Knight <robertknight@gmail.com>
    Copyright 1997,1998 by Lars Doelle <lars.doelle@on-line.de>
    Copyright 2009 by Thomas Dreibholz <dreibh@iem.uni-due.de>

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program 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 General Public License for more details.

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

#ifndef SESSION_H
#define SESSION_H

// Qt
#include <QStringList>
#include <QHash>
#include <QUuid>
#include <QSize>
#include <QProcess>
#include <QWidget>
#include <QUrl>

// Konsole
#include "konsoleprivate_export.h"
#include "config-konsole.h"
#include "Shortcut_p.h"

class QColor;

class KConfigGroup;
class KProcess;

namespace Konsole {
class Emulation;
class Pty;
class ProcessInfo;
class TerminalDisplay;
class ZModemDialog;
class HistoryType;

/**
 * Represents a terminal session consisting of a pseudo-teletype and a terminal emulation.
 * The pseudo-teletype (or PTY) handles I/O between the terminal process and Konsole.
 * The terminal emulation ( Emulation and subclasses ) processes the output stream from the
 * PTY and produces a character image which is then shown on views connected to the session.
 *
 * Each Session can be connected to one or more views by using the addView() method.
 * The attached views can then display output from the program running in the terminal
 * or send input to the program in the terminal in the form of keypresses and mouse
 * activity.
 */
class KONSOLEPRIVATE_EXPORT Session : public QObject
{
    Q_OBJECT
    Q_CLASSINFO("D-Bus Interface", "org.kde.konsole.Session")

public:
    Q_PROPERTY(QString name READ nameTitle)
    Q_PROPERTY(int processId READ processId)
    Q_PROPERTY(QString keyBindings READ keyBindings WRITE setKeyBindings)
    Q_PROPERTY(QSize size READ size WRITE setSize)

    /**
     * Constructs a new session.
     *
     * To start the terminal process, call the run() method,
     * after specifying the program and arguments
     * using setProgram() and setArguments()
     *
     * If no program or arguments are specified explicitly, the Session
     * falls back to using the program specified in the SHELL environment
     * variable.
     */
    explicit Session(QObject *parent = nullptr);
    ~Session() override;

    /**
     * Connect to an existing terminal.  When a new Session() is constructed it
     * automatically searches for and opens a new teletype.  If you want to
     * use an existing teletype (given its file descriptor) call this after
     * constructing the session.
     *
     * Calling openTeletype() while a session is running has no effect.
     *
     * @param fd The file descriptor of the pseudo-teletype master (See KPtyProcess::KPtyProcess())
     * @param runShell When true, runs the teletype in a shell session environment.
     * When false, the session is not run, so that the KPtyProcess can be standalone.
     */
    void openTeletype(int fd, bool runShell);

    /**
     * Returns true if the session is currently running.  This will be true
     * after run() has been called successfully.
     */
    bool isRunning() const;

    /**
     * Returns true if the tab holding this session is currently selected
     * and Konsole is the foreground window.
     */
    bool hasFocus() const;

    /**
     * Adds a new view for this session.
     *
     * The viewing widget will display the output from the terminal and
     * input from the viewing widget (key presses, mouse activity etc.)
     * will be sent to the terminal.
     *
     * Views can be removed using removeView().  The session is automatically
     * closed when the last view is removed.
     */
    void addView(TerminalDisplay *widget);
    /**
     * Removes a view from this session.  When the last view is removed,
     * the session will be closed automatically.
     *
     * @p widget will no longer display output from or send input
     * to the terminal
     */
    void removeView(TerminalDisplay *widget);

    /**
     * Returns the views connected to this session
     */
    QList<TerminalDisplay *> views() const;

    /**
     * Returns the terminal emulation instance being used to encode / decode
     * characters to / from the process.
     */
    Emulation *emulation() const;

    /** Returns the unique ID for this session. */
    int sessionId() const;

    /**
     * This enum describes the contexts for which separate
     * tab title formats may be specified.
     */
    enum TabTitleContext {
        /** Default tab title format */
        LocalTabTitle,
        /**
         * Tab title format used session currently contains
         * a connection to a remote computer (via SSH)
         */
        RemoteTabTitle
    };

    /**
     * Returns true if the session currently contains a connection to a
     * remote computer.  It currently supports ssh.
     */
    bool isRemote();

    /**
     * Sets the format used by this session for tab titles.
     *
     * @param context The context whose format should be set.
     * @param format The tab title format.  This may be a mixture
     * of plain text and dynamic elements denoted by a '%' character
     * followed by a letter.  (eg. %d for directory).  The dynamic
     * elements available depend on the @p context
     */
    void setTabTitleFormat(TabTitleContext context, const QString &format);
    /** Returns the format used by this session for tab titles. */
    QString tabTitleFormat(TabTitleContext context) const;

    /**
     * Sets the color user by this session for tab.
     * 
     * @param color The background color for the tab.
     */
    void setColor(const QColor &color);
    /** Returns the color used by this session for tab. */
    QColor color() const;

    /**
     * Returns true if the tab title has been changed by the user via the
     * rename-tab dialog.
     */
    bool isTabTitleSetByUser() const;

    /**
     * Returns true if the tab color has been changed by the user via the
     * rename-tab dialog.
     */
    bool isTabColorSetByUser() const;

    /** Returns the arguments passed to the shell process when run() is called. */
    QStringList arguments() const;
    /** Returns the program name of the shell process started when run() is called. */
    QString program() const;

    /**
     * Sets the command line arguments which the session's program will be passed when
     * run() is called.
     */
    void setArguments(const QStringList &arguments);
    /** Sets the program to be executed when run() is called. */
    void setProgram(const QString &program);

    /** Returns the session's current working directory. */
    QString initialWorkingDirectory()
    {
        return _initialWorkingDir;
    }

    /**
     * Sets the initial working directory for the session when it is run
     * This has no effect once the session has been started.
     */
    void setInitialWorkingDirectory(const QString &dir);

    /**
     * Returns the current directory of the foreground process in the session
     */
    QString currentWorkingDirectory();

    /**
     * Sets the type of history store used by this session.
     * Lines of output produced by the terminal are added
     * to the history store.  The type of history store
     * used affects the number of lines which can be
     * remembered before they are lost and the storage
     * (in memory, on-disk etc.) used.
     */
    void setHistoryType(const HistoryType &hType);
    /**
     * Returns the type of history store used by this session.
     */
    const HistoryType &historyType() const;
    /**
     * Clears the history store used by this session.
     */
    void clearHistory();

    /**
     * Sets the key bindings used by this session.  The bindings
     * specify how input key sequences are translated into
     * the character stream which is sent to the terminal.
     *
     * @param name The name of the key bindings to use.  The
     * names of available key bindings can be determined using the
     * KeyboardTranslatorManager class.
     */
    void setKeyBindings(const QString &name);
    /** Returns the name of the key bindings used by this session. */
    QString keyBindings() const;

    /**
     * This enum describes the available title roles.
     */
    enum TitleRole {
        /** The name of the session. */
        NameRole,
        /** The title of the session which is displayed in tabs etc. */
        DisplayedTitleRole
    };

    /**
     * Return the session title set by the user (ie. the program running
     * in the terminal), or an empty string if the user has not set a custom title
     */
    QString userTitle() const;

    /** Convenience method used to read the name property.  Returns title(Session::NameRole). */
    QString nameTitle() const
    {
        return title(Session::NameRole);
    }

    /** Returns a title generated from tab format and process information. */
    QString getDynamicTitle();

    /** Sets the name of the icon associated with this session. */
    void setIconName(const QString &iconName);
    /** Returns the name of the icon associated with this session. */
    QString iconName() const;

    /** Return URL for the session. */
    QUrl getUrl();

    /** Sets the text of the icon associated with this session. */
    void setIconText(const QString &iconText);
    /** Returns the text of the icon associated with this session. */
    QString iconText() const;

    /** Sets the session's title for the specified @p role to @p title. */
    void setTitle(TitleRole role, const QString &newTitle);

    /** Returns the session's title for the specified @p role. */
    QString title(TitleRole role) const;

    /**
     * Specifies whether a utmp entry should be created for the pty used by this session.
     * If true, KPty::login() is called when the session is started.
     */
    void setAddToUtmp(bool);

    /**
     * Specifies whether to close the session automatically when the terminal
     * process terminates.
     */
    void setAutoClose(bool close);

    /** See setAutoClose() */
    bool autoClose() const;

    /** Returns true if the user has started a program in the session. */
    bool isForegroundProcessActive();

    /** Returns the name of the current foreground process. */
    QString foregroundProcessName();

    /** Returns the terminal session's window size in lines and columns. */
    QSize size();
    /**
     * Emits a request to resize the session to accommodate
     * the specified window size.
     *
     * @param size The size in lines and columns to request.
     */
    void setSize(const QSize &size);

    QSize preferredSize() const;

    void setPreferredSize(const QSize &size);

    /**
     * Sets whether the session has a dark background or not.  The session
     * uses this information to set the COLORFGBG variable in the process's
     * environment, which allows the programs running in the terminal to determine
     * whether the background is light or dark and use appropriate colors by default.
     *
     * This has no effect once the session is running.
     */
    void setDarkBackground(bool darkBackground);

    /**
     * Attempts to get the shell program to redraw the current display area.
     * This can be used after clearing the screen, for example, to get the
     * shell to redraw the prompt line.
     */
    void refresh();

    void startZModem(const QString &zmodem, const QString &dir, const QStringList &list);
    void cancelZModem();
    bool isZModemBusy()
    {
        return _zmodemBusy;
    }
    void setZModemBusy(bool busy)
    {
        _zmodemBusy = busy;
    }

    /**
      * Possible values of the @p what parameter for setSessionAttribute().
      * See the "Operating System Commands" section at:
      * https://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h3-Operating-System-Commands
      */
    enum SessionAttributes {
        IconNameAndWindowTitle = 0,
        IconName = 1,
        WindowTitle = 2,
        CurrentDirectory = 7,         // From VTE (supposedly 6 was for dir, 7 for file, but whatever)
        TextColor = 10,
        BackgroundColor = 11,
        SessionName = 30,             // Non-standard
        SessionIcon = 32,             // Non-standard
        ProfileChange = 50            // this clashes with Xterm's font change command
    };

    // Sets the text codec used by this sessions terminal emulation.
    void setCodec(QTextCodec *codec);

    // session management
    void saveSession(KConfigGroup &group);
    void restoreSession(KConfigGroup &group);

    void sendSignal(int signal);

    void reportColor(SessionAttributes r, const QColor &c);
    void reportForegroundColor(const QColor &c);
    void reportBackgroundColor(const QColor &c);

    bool isReadOnly() const;
    void setReadOnly(bool readOnly);

    // Returns true if the current screen is the secondary/alternate one
    // or false if it's the primary/normal buffer
    bool isPrimaryScreen();
    void tabTitleSetByUser(bool set);
    void tabColorSetByUser(bool set);

    enum Notification {
        NoNotification = 0,
        Activity = 1,
        Silence = 2,
        Bell = 4,
    };
    Q_DECLARE_FLAGS(Notifications, Notification)

    /** Returns active notifications. */
    Notifications activeNotifications() const { return _activeNotifications; }

public Q_SLOTS:

    /**
     * Starts the terminal session.
     *
     * This creates the terminal process and connects the teletype to it.
     */
    void run();

    /**
     * Returns the environment of this session as a list of strings like
     * VARIABLE=VALUE
     */
    Q_SCRIPTABLE QStringList environment() const;

    /**
     * Sets the environment for this session.
     * @p environment should be a list of strings like
     * VARIABLE=VALUE
     */
    Q_SCRIPTABLE void setEnvironment(const QStringList &environment);

    /**
     * Adds one entry for the environment of this session
     * @p entry should be like VARIABLE=VALUE
     */
    void addEnvironmentEntry(const QString &entry);

    /**
     * Closes the terminal session. It kills the terminal process by calling
     * closeInNormalWay() and, optionally, closeInForceWay().
     */
    //Q_SCRIPTABLE void close(); // This cause the menu issues bko 185466
    void close();

    /**
     * Kill the terminal process in normal way. This sends a hangup signal
     * (SIGHUP) to the terminal process and causes the finished() signal to
     * be emitted. If the process does not respond to the SIGHUP signal then
     * the terminal connection (the pty) is closed and Konsole waits for the
     * process to exit. This method works most of the time, but fails with some
     * programs which respond to SIGHUP signal in special way, such as autossh
     * and irssi.
     */
    bool closeInNormalWay();

    /**
     * kill terminal process in force way. This send a SIGKILL signal to the
     * terminal process. It should be called only after closeInNormalWay() has
     * failed. Take it as last resort.
     */
    bool closeInForceWay();

    /**
     * Changes one of certain session attributes in the terminal emulation
     * display. For a list of what may be changed see the
     * Emulation::sessionAttributeChanged() signal.
     *
     * @param what The session attribute being changed, it is one of the
     * SessionAttributes enum
     * @param caption The text part of the terminal command
     */
    void setSessionAttribute(int what, const QString &caption);

    /**
     * Enables monitoring for activity in the session.
     * This will cause notifySessionState() to be emitted
     * with the NOTIFYACTIVITY state flag when output is
     * received from the terminal.
     */
    Q_SCRIPTABLE void setMonitorActivity(bool);

    /** Returns true if monitoring for activity is enabled. */
    Q_SCRIPTABLE bool isMonitorActivity() const;

    /**
     * Enables monitoring for silence in the session.
     * This will cause notifySessionState() to be emitted
     * with the NOTIFYSILENCE state flag when output is not
     * received from the terminal for a certain period of
     * time, specified with setMonitorSilenceSeconds()
     */
    Q_SCRIPTABLE void setMonitorSilence(bool);

    /**
     * Returns true if monitoring for inactivity (silence)
     * in the session is enabled.
     */
    Q_SCRIPTABLE bool isMonitorSilence() const;

    /** See setMonitorSilence() */
    Q_SCRIPTABLE void setMonitorSilenceSeconds(int seconds);

    /**
     * Sets whether flow control is enabled for this terminal
     * session.
     */
    Q_SCRIPTABLE void setFlowControlEnabled(bool enabled);

    /** Returns whether flow control is enabled for this terminal session. */
    Q_SCRIPTABLE bool flowControlEnabled() const;

    /**
     * @param text to send to the current foreground terminal program.
     * @param eol send this after @p text
     */
    void sendTextToTerminal(const QString &text, const QChar &eol = QChar()) const;

#if defined(REMOVE_SENDTEXT_RUNCOMMAND_DBUS_METHODS)
    void sendText(const QString &text) const;
#else
    Q_SCRIPTABLE void sendText(const QString &text) const;
#endif

    /**
     * Sends @p command to the current foreground terminal program.
     */
#if defined(REMOVE_SENDTEXT_RUNCOMMAND_DBUS_METHODS)
    void runCommand(const QString &command) const;
#else
    Q_SCRIPTABLE void runCommand(const QString &command) const;
#endif

    /**
     * Sends a mouse event of type @p eventType emitted by button
     * @p buttons on @p column/@p line to the current foreground
     * terminal program
     */
    Q_SCRIPTABLE void sendMouseEvent(int buttons, int column, int line, int eventType);

    /**
    * Returns the process id of the terminal process.
    * This is the id used by the system API to refer to the process.
    */
    Q_SCRIPTABLE int processId() const;

    /**
     * Returns the process id of the terminal's foreground process.
     * This is initially the same as processId() but can change
     * as the user starts other programs inside the terminal.
     */
    Q_SCRIPTABLE int foregroundProcessId();

    /** Sets the text codec used by this sessions terminal emulation.
      * Overloaded to accept a QByteArray for convenience since DBus
      * does not accept QTextCodec directly.
      */
    Q_SCRIPTABLE bool setCodec(const QByteArray &name);

    /** Returns the codec used to decode incoming characters in this
     * terminal emulation
     */
    Q_SCRIPTABLE QByteArray codec();

    /** Sets the session's title for the specified @p role to @p title.
     *  This is an overloaded member function for setTitle(TitleRole, QString)
     *  provided for convenience since enum data types may not be
     *  exported directly through DBus
     */
    Q_SCRIPTABLE void setTitle(int role, const QString &title);

    /** Returns the session's title for the specified @p role.
     * This is an overloaded member function for  setTitle(TitleRole)
     * provided for convenience since enum data types may not be
     * exported directly through DBus
     */
    Q_SCRIPTABLE QString title(int role) const;

    /** Returns the "friendly" version of the QUuid of this session.
    * This is a QUuid with the braces and dashes removed, so it cannot be
    * used to construct a new QUuid. The same text appears in the
    * SHELL_SESSION_ID environment variable.
    */
    Q_SCRIPTABLE QString shellSessionId() const;

    /** Sets the session's tab title format for the specified @p context to @p format.
     *  This is an overloaded member function for setTabTitleFormat(TabTitleContext, QString)
     *  provided for convenience since enum data types may not be
     *  exported directly through DBus
     */
    Q_SCRIPTABLE void setTabTitleFormat(int context, const QString &format);

    /** Returns the session's tab title format for the specified @p context.
     * This is an overloaded member function for tabTitleFormat(TitleRole)
     * provided for convenience since enum data types may not be
     * exported directly through DBus
     */
    Q_SCRIPTABLE QString tabTitleFormat(int context) const;

    /**
     * Sets the history capacity of this session.
     *
     * @param lines The history capacity in unit of lines. Its value can be:
     * <ul>
     * <li> positive integer  -  fixed size history</li>
     * <li> 0 -  no history</li>
     * <li> negative integer -  unlimited history</li>
     * </ul>
     */
    Q_SCRIPTABLE void setHistorySize(int lines);

    /**
     * Returns the history capacity of this session.
     */
    Q_SCRIPTABLE int historySize() const;

    /**
     * Sets the current session's profile
     */
    Q_SCRIPTABLE void setProfile(const QString &profileName);

    /**
     * Returns the current session's profile name
     */
    Q_SCRIPTABLE QString profile();

Q_SIGNALS:

    /** Emitted when the terminal process starts. */
    void started();

    /**
     * Emitted when the terminal process exits.
     */
    void finished();

    /**
     * Emitted when one of certain session attributes has been changed.
     * See setSessionAttribute().
     */
    void sessionAttributeChanged();

    /** Emitted when the session gets locked / unlocked. */
    void readOnlyChanged();

    /**
     * Emitted when the current working directory of this session changes.
     *
     * @param dir The new current working directory of the session.
     */
    void currentDirectoryChanged(const QString &dir);

    /**
     * Emitted when the session text encoding changes.
     */
    void sessionCodecChanged(QTextCodec *codec);

    /** Emitted when a bell event occurs in the session. */
    void bellRequest(const QString &message);

    /** Emitted when @p notification state changed to @p enabled */
    void notificationsChanged(Notification notification, bool enabled);

    /**
     * Requests that the background color of views on this session
     * should be changed.
     */
    void changeBackgroundColorRequest(const QColor &);
    /**
     * Requests that the text color of views on this session should
     * be changed to @p color.
     */
    void changeForegroundColorRequest(const QColor &);

    /** TODO: Document me. */
    void openUrlRequest(const QString &url);

    /**
     * Emitted when the request for data transmission through ZModem
     * protocol is detected.
     */
    void zmodemDownloadDetected();
    void zmodemUploadDetected();

    /**
     * Emitted when the terminal process requests a change
     * in the size of the terminal window.
     *
     * @param size The requested window size in terms of lines and columns.
     */
    void resizeRequest(const QSize &size);

    /**
     * Emitted when a profile change command is received from the terminal.
     *
     * @param text The text of the command.  This is a string of the form
     * "PropertyName=Value;PropertyName=Value ..."
     */
    void profileChangeCommandReceived(const QString &text);

    /**
     * Emitted when the flow control state changes.
     *
     * @param enabled True if flow control is enabled or false otherwise.
     */
    void flowControlEnabledChanged(bool enabled);

    /**
     * Emitted when the active screen is switched, to indicate whether the primary
     * screen is in use.
     *
     * This signal serves as a relayer of Emulation::priamyScreenInUse(bool),
     * making it usable for higher level component.
     */
    void primaryScreenInUse(bool use);

    /**
     * Emitted when the text selection is changed.
     *
     * This signal serves as a relayer of Emulation::selectedText(QString),
     * making it usable for higher level component.
     */
    void selectionChanged(const QString &text);

    /**
     * Emitted when foreground request ("\033]10;?\a") terminal code received.
     * Terminal is expected send "\033]10;rgb:RRRR/GGGG/BBBB\a" response.
     */
    void getForegroundColor();

    /**
     * Emitted when background request ("\033]11;?\a") terminal code received.
     * Terminal is expected send "\033]11;rgb:RRRR/GGGG/BBBB\a" response.
     *
     * Originally implemented to support vim's background detection feature
     * (without explictly setting 'bg=dark' within local/remote vimrc)
     */
    void getBackgroundColor();

private Q_SLOTS:
    void done(int, QProcess::ExitStatus);

    void fireZModemDownloadDetected();
    void fireZModemUploadDetected();

    void onReceiveBlock(const char *buf, int len);
    void silenceTimerDone();
    void activityTimerDone();
    void resetNotifications();

    void onViewSizeChange(int height, int width);

    //automatically detach views from sessions when view is destroyed
    void viewDestroyed(QObject *view);

    void zmodemReadStatus();
    void zmodemReadAndSendBlock();
    void zmodemReceiveBlock(const char *data, int len);
    void zmodemFinished();

    void updateFlowControlState(bool suspended);
    void updateWindowSize(int lines, int columns);

    // Relays the signal from Emulation and sets _isPrimaryScreen
    void onPrimaryScreenInUse(bool use);

    void sessionAttributeRequest(int id);

    /**
     * Requests that the color the text for any tabs associated with
     * this session should be changed;
     *
     * TODO: Document what the parameter does
     */
    void changeTabTextColor(int);

private:
    Q_DISABLE_COPY(Session)

    // checks that the binary 'program' is available and can be executed
    // returns the binary name if available or an empty string otherwise
    static QString checkProgram(const QString &program);

    void updateTerminalSize();
    WId windowId() const;
    bool kill(int signal);
    // print a warning message in the terminal.  This is used
    // if the program fails to start, or if the shell exits in
    // an unsuccessful manner
    void terminalWarning(const QString &message);
    ProcessInfo *getProcessInfo();
    void updateSessionProcessInfo();
    bool updateForegroundProcessInfo();
    void updateWorkingDirectory();

    QString validDirectory(const QString &dir) const;

    QUuid _uniqueIdentifier;            // SHELL_SESSION_ID

    Pty *_shellProcess;
    Emulation *_emulation;

    QList<TerminalDisplay *> _views;

    // monitor activity & silence
    bool _monitorActivity;
    bool _monitorSilence;
    bool _notifiedActivity;
    int _silenceSeconds;
    QTimer *_silenceTimer;
    QTimer *_activityTimer;

    void setPendingNotification(Notification notification, bool enable = true);
    void handleActivity();

    Notifications _activeNotifications;

    bool _autoClose;
    bool _closePerUserRequest;

    QString _nameTitle;
    QString _displayTitle;
    QString _userTitle;

    QString _localTabTitleFormat;
    QString _remoteTabTitleFormat;
    QColor _tabColor;

    bool _tabTitleSetByUser;
    bool _tabColorSetByUser;

    QString _iconName;
    QString _iconText;        // not actually used
    bool _addToUtmp;
    bool _flowControlEnabled;

    QString _program;
    QStringList _arguments;

    QStringList _environment;
    int _sessionId;

    QString _initialWorkingDir;
    QString _currentWorkingDir;
    QUrl _reportedWorkingUrl;

    ProcessInfo *_sessionProcessInfo;
    ProcessInfo *_foregroundProcessInfo;
    int _foregroundPid;

    // ZModem
    bool _zmodemBusy;
    KProcess *_zmodemProc;
    ZModemDialog *_zmodemProgress;

    bool _hasDarkBackground;

    QSize _preferredSize;

    bool _readOnly;
    static int lastSessionId;

    bool _isPrimaryScreen;
};

}

#endif
