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

    Copyright (C) 2007 by Robert Knight <robertknight@gmail.com>
    Copyright (C) 1997,1998 by Lars Doelle <lars.doelle@on-line.de>

    Rewritten for QT4 by e_k <e_k at users.sourceforge.net>, Copyright (C)2008

    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

#include <QStringList>
#include <QWidget>

#include "Emulation.h"
#include "History.h"
#include "ProcessInfo.h"

class KProcess;

namespace Konsole {

class Emulation;
class Pty;
class TerminalDisplay;
//class ZModemDialog;

/**
 * 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 Session : public QObject {
    Q_OBJECT

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.
     */
    Session(QObject* parent = nullptr);
    ~Session() override;

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

    /**
     * Sets the profile associated with this session.
     *
     * @param profileKey A key which can be used to obtain the current
     * profile settings from the SessionManager
     */
    void setProfileKey(const QString & profileKey);
    /**
     * Returns the profile key associated with this session.
     * This can be passed to the SessionManager to obtain the current
     * profile settings.
     */
    QString profileKey() 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 environment of this session as a list of strings like
     * VARIABLE=VALUE
     */
    QStringList environment() const;
    /**
     * Sets the environment for this session.
     * @p environment should be a list of strings like
     * VARIABLE=VALUE
     */
    void setEnvironment(const QStringList & environment);

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

    /**
     * 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;

    /**
     * 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
    };
    /**
     * Sets the format used by this session for tab titles.
     *
     * @param context The context whoose 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;


    /** 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 );

    /**
     * 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 & type);
    /**
     * Returns the type of history store used by this session.
     */
    const HistoryType & historyType() const;
    /**
     * Clears the history store used by this session.
     */
    void clearHistory();

    /**
     * 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.
     */
    void setMonitorActivity(bool);
    /** Returns true if monitoring for activity is enabled. */
    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()
     */
    void setMonitorSilence(bool);
    /**
     * Returns true if monitoring for inactivity (silence)
     * in the session is enabled.
     */
    bool isMonitorSilence()  const;
    /** See setMonitorSilence() */
    void setMonitorSilenceSeconds(int seconds);

    /**
     * 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 id 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 & id);
    /** 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
    };

    /** Sets the session's title for the specified @p role to @p title. */
    void setTitle(TitleRole role , const QString & title);
    /** Returns the session's title for the specified @p role. */
    QString title(TitleRole role) const;
    /** Convenience method used to read the name property.  Returns title(Session::NameRole). */
    QString nameTitle() const {
        return title(Session::NameRole);
    }

    /** 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;

    /** 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;

    /** Flag if the title/icon was changed by user/shell. */
    bool isTitleChanged() const;

    /** Specifies whether a utmp entry should be created for the pty used by this session. */
    void setAddToUtmp(bool);

    /** Sends the specified @p signal to the terminal process. */
    bool sendSignal(int signal);

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

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

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

    /**
     * Sends @p text to the current foreground terminal program.
     */
    void sendText(const QString & text) const;

    void sendKeyEvent(QKeyEvent* e) const;

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

    /**
     * Returns the name of the terminal's foreground process.
     */
    QString foregroundProcessName();

    /**
     * Returns the current working directory of the process.
     */
    QString currentDir();

    /** 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);

    /** Sets the text codec used by this session's terminal emulation. */
    void setCodec(QTextCodec * codec) const;

    /**
     * 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);
    /**
     * Returns true if the session has a dark background.
     * See setDarkBackground()
     */
    bool hasDarkBackground() const;

    /**
     * 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 &rz, const QString &dir, const QStringList &list);
//  void cancelZModem();
//  bool isZModemBusy() { return _zmodemBusy; }

    /**
     * Returns a pty slave file descriptor.
     * This can be used for display and control
     * a remote terminal.
     */
    int getPtySlaveFd() const;

public slots:

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

    /**
     * Starts the terminal session for "as is" PTY
     * (without the direction a data to internal terminal process).
     * It can be used for control or display a remote/external terminal.
     */
    void runEmptyPTY();

    /**
     * Closes the terminal session.  This sends a hangup signal
     * (SIGHUP) to the terminal process and causes the done(Session*)
     * signal to be emitted.
     */
    void close();

    /**
     * Changes the session title or other customizable aspects of the terminal
     * emulation display. For a list of what may be changed see the
     * Emulation::titleChanged() signal.
     */
    void setUserTitle( int, const QString & caption );

signals:

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

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

    /**
     * Emitted when output is received from the terminal process.
     */
    void receivedData( const QString & text );

    /** Emitted when the session's title has changed. */
    void titleChanged();

    /** Emitted when the session's profile has changed. */
    void profileChanged(const QString & profile);

    /**
     * Emitted when the activity state of this session changes.
     *
     * @param state The new state of the session.  This may be one
     * of NOTIFYNORMAL, NOTIFYSILENCE or NOTIFYACTIVITY
     */
    void stateChanged(int state);

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

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

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

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

    /** TODO: Document me. */
//  void zmodemDetected();

    /**
     * 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);

    /**
     * Broker for Emulation::cursorChanged() signal
     */
    void cursorChanged(Emulation::KeyboardCursorShape cursorShape, bool blinkingCursorEnabled);

    void silence();
    void activity();

private slots:
    void done(int);

//  void fireZModemDetected();

    void onReceiveBlock( const char * buffer, int len );
    void monitorTimerDone();

    void onViewSizeChange(int height, int width);
    void onEmulationSizeChange(QSize);

    void activityStateSet(int);

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

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

private:

    void updateTerminalSize();
    bool updateForegroundProcessInfo();
    WId windowId() const;

    int            _uniqueIdentifier;

    Pty     *_shellProcess;
    Emulation  *  _emulation;

    QList<TerminalDisplay *> _views;

    bool           _monitorActivity;
    bool           _monitorSilence;
    bool           _notifiedActivity;
    bool           _masterMode;
    bool           _autoClose;
    bool           _wantedClose;
    QTimer    *    _monitorTimer;

    int            _silenceSeconds;

    QString        _nameTitle;
    QString        _displayTitle;
    QString        _userTitle;

    QString        _localTabTitleFormat;
    QString        _remoteTabTitleFormat;

    QString        _iconName;
    QString        _iconText; // as set by: echo -en '\033]1;IconText\007
    bool           _isTitleChanged; ///< flag if the title/icon was changed by user
    bool           _addToUtmp;
    bool           _flowControl;
    bool           _fullScripting;

    QString        _program;
    QStringList    _arguments;

    QStringList    _environment;
    int            _sessionId;

    QString        _initialWorkingDir;

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

    // Color/Font Changes by ESC Sequences

    QColor         _modifiedBackground; // as set by: echo -en '\033]11;Color\007

    QString        _profileKey;

    bool _hasDarkBackground;

    ProcessInfo *_foregroundProcessInfo;
    int _foregroundPid;
    static int lastSessionId;
    int ptySlaveFd;
};

/**
 * Provides a group of sessions which is divided into master and slave sessions.
 * Activity in master sessions can be propagated to all sessions within the group.
 * The type of activity which is propagated and method of propagation is controlled
 * by the masterMode() flags.
 */
class SessionGroup : public QObject {
    Q_OBJECT

public:
    /** Constructs an empty session group. */
    SessionGroup();
    /** Destroys the session group and removes all connections between master and slave sessions. */
    ~SessionGroup() override;

    /** Adds a session to the group. */
    void addSession( Session * session );
    /** Removes a session from the group. */
    void removeSession( Session * session );

    /** Returns the list of sessions currently in the group. */
    QList<Session *> sessions() const;

    /**
     * Sets whether a particular session is a master within the group.
     * Changes or activity in the group's master sessions may be propagated
     * to all the sessions in the group, depending on the current masterMode()
     *
     * @param session The session whoose master status should be changed.
     * @param master True to make this session a master or false otherwise
     */
    void setMasterStatus( Session * session , bool master );
    /** Returns the master status of a session.  See setMasterStatus() */
    bool masterStatus( Session * session ) const;

    /**
     * This enum describes the options for propagating certain activity or
     * changes in the group's master sessions to all sessions in the group.
     */
    enum MasterMode {
        /**
         * Any input key presses in the master sessions are sent to all
         * sessions in the group.
         */
        CopyInputToAll = 1
    };

    /**
     * Specifies which activity in the group's master sessions is propagated
     * to all sessions in the group.
     *
     * @param mode A bitwise OR of MasterMode flags.
     */
    void setMasterMode( int mode );
    /**
     * Returns a bitwise OR of the active MasterMode flags for this group.
     * See setMasterMode()
     */
    int masterMode() const;

private:
    void connectPair(Session * master , Session * other) const;
    void disconnectPair(Session * master , Session * other) const;
    void connectAll(bool connect);
    QList<Session *> masters() const;

    // maps sessions to their master status
    QHash<Session *,bool> _sessions;

    int _masterMode;
};

}

#endif