/*
    SPDX-FileCopyrightText: 1997 Stephan Kulow <coolo@kde.org>
    SPDX-FileCopyrightText: 2019 Alexander Potashev <aspotashev@gmail.com>

    SPDX-License-Identifier: GPL-2.0-or-later
*/

#ifndef KTIMETRACKER_TASK_H
#define KTIMETRACKER_TASK_H

#include <QDateTime>
#include <QList>

#include <KCalendarCore/Todo>

#include "base/desktoplist.h" // Required b/c DesktopList is a typedef not a class.
#include "model/tasksmodelitem.h"

class TimeTrackerStorage;
class ProjectModel;
class EventsModel;

/** \brief A class representing a task
 *
 * A "Task" object stores information about a task such as it's name,
 * total and session times.
 *
 * It can log when the task is started, stopped or deleted.
 *
 * If a task is associated with some desktop's activity it can remember that
 * too.
 *
 * It can also contain subtasks - these are managed using the
 * QListViewItem class.
 */
class Task : public TasksModelItem
{
public:
    enum {
        SortRole = Qt::UserRole,
    };

    Task(const QString &taskname,
         const QString &taskdescription,
         int64_t minutes,
         int64_t sessionTime,
         const DesktopList &desktops,
         ProjectModel *projectModel,
         Task *parentTask);
    Task(const KCalendarCore::Todo::Ptr &todo, ProjectModel *projectModel);

    /* destructor */
    ~Task() override;

    Task *parentTask() const
    {
        return dynamic_cast<Task *>(TasksModelItem::parent());
    }

    /** Return unique iCalendar Todo ID for this task. */
    QString uid() const;

    /**
     * Deliver the depth of a task, i.e. how many tasks are supertasks to it.
     * A toplevel task has the depth 0.
     */
    int depth();

    void delete_recursive();

    /** cut Task out of parent Task or the TaskView */
    void cut();

    /** cut Task out of parent Task or the TaskView and into the
     *  destination Task */
    void move(TasksModelItem *destination);

    /** insert Task into the destination Task */
    void paste(TasksModelItem *destination);

    //@{ timing related functions

    /**
     * Change task time.  Adds minutes to both total time and session time by adding an event.
     *
     *  @param minutes        minutes to add to - may be negative
     *  @param storage        Pointer to TimeTrackerStorage instance.
     *                        If zero, don't save changes.
     */
    void changeTime(int64_t minutes, EventsModel *eventsModel);

    /**
     * Add minutes to time and session time by adding an event, and write to storage.
     *
     *  @param minutesSession   minutes to add to task session time
     *  @param minutes          minutes to add to task time
     *  @param storage          Pointer to TimeTrackerStorage instance.
     *                          If zero, don't save changes.
     */
    void changeTimes(int64_t minutesSession, int64_t minutes, EventsModel *eventsModel);

    /** adds minutes to total and session time by adding an event
     *
     *  @param minutesSession   minutes to add to task total session time
     *  @param minutes          minutes to add to task total time
     */
    void changeTotalTimes(int64_t minutesSession, int64_t minutes);

    /** Adds minutes to the time of the task and the total time of its supertasks. This does not add an event.
     *
     *  @param minutes          minutes to add to the time
     */
    void addTime(int64_t minutes);

    /** Adds minutes to the total time of the task and its supertasks. This does not add an event.
     *
     *  @param minutes          minutes to add to the time
     */
    void addTotalTime(int64_t minutes);

    /** Adds minutes to the task's session time and its supertasks' total session time. This does not add an event.
     *
     *  @param minutes          minutes to add to the session time
     */
    void addSessionTime(int64_t minutes);

    /** Adds minutes to the task's and its supertasks' total session time. This does not add an event.
     *
     *  @param minutes          minutes to add to the session time
     */
    void addTotalSessionTime(int64_t minutes);

    /** Sets the time (not session time). This does not add an event.
     *
     *  @param minutes          minutes to set time to
     *
     */
    QString setTime(int64_t minutes);

    /** Sets the total time, does not change the parent's total time.
      This means the parent's total time can run out of sync.
      */
    void setTotalTime(int64_t minutes)
    {
        m_totalTime = minutes;
    }

    /** Sets the total session time, does not change the parent's total session time.
      This means the parent's total session time can run out of sync.
      */
    void setTotalSessionTime(int64_t minutes)
    {
        m_totalSessionTime = minutes;
    }

    /** A recursive function to calculate the total time/session time of a task. */
    void recalculateTotalTimesSubtree();

    /** Sets the session time.
     * Set the session time without changing totalTime nor sessionTime.
     * Do not change the parent's totalTime.
     * Do not add an event.
     * See also: changeTimes(long, long) and resetTimes
     *
     *  @param minutes          minutes to set session time to
     *
     */
    QString setSessionTime(int64_t minutes);

    /**
     * Reset all times to 0 and adjust parent task's totalTiMes.
     */
    void resetTimes();

    /** @return time in minutes */
    int64_t time() const
    {
        return m_time;
    }
    /** @return total time in minutes */
    int64_t totalTime() const
    {
        return m_totalTime;
    }
    int64_t sessionTime() const
    {
        return m_sessionTime;
    }
    int64_t totalSessionTime() const
    {
        return m_totalSessionTime;
    }
    QDateTime sessionStartTiMe() const;

    /**
     * Return time the task was started.
     */
    QDateTime startTime() const;

    /** sets session time to zero. */
    void startNewSession();
    //@}

    //@{ desktop related functions

    void setDesktopList(const DesktopList &desktopList);
    DesktopList desktops() const;

    QString getDesktopStr() const;
    //@}

    //@{ name related functions

    /** sets the name of the task
     *  @param name    a pointer to the name. A deep copy will be made.
     */
    void setName(const QString &name);

    /** sets the description of the task */
    void setDescription(const QString &description);

    /** returns the name of this task.
     *  @return a pointer to the name.
     */
    QString name() const;

    /** returns the description of this task.
     * @return a pointer to the description.
     */
    QString description() const;

    /**
     * Returns that task name, prefixed by parent tree up to root.
     *
     * Task names are separated by a forward slash:  /
     */
    QString fullName() const;
    //@}

    /** Update the display of the task (all columns) in the UI. */
    void update();

    //@{ the state of a Task - stopped, running

    /** starts or stops a task
     * @param on   True or false for starting or stopping a task
     * @param when Time when the task was started or stopped. Normally
     *             QDateTime::currentDateTime, but if calendar has
     *             been changed by another program and being reloaded
     *             the task is set to running with another start date
     */
    void setRunning(bool on, const QDateTime &when = QDateTime::currentDateTime());

    /**
     * Resume the running state of a task.
     * This is the same as setrunning, but the storage is not modified.
     */
    void resumeRunning();

    /** return the state of a task - if it's running or not
     *  @return         true or false depending on whether the task is running
     */
    bool isRunning() const;
    //@}

    /**
     *  Parses an incidence. This is needed e.g. when you create a task out of a todo.
     *  You read the todo, extract its custom properties (like session time)
     *  and use these data to initialize the task.
     */
    bool parseIncidence(const KCalendarCore::Incidence::Ptr &,
                        QString &sessionStartTiMe,
                        QString &name,
                        QString &description,
                        DesktopList &desktops,
                        int &percent_complete,
                        int &priority);

    /**
     *  Load the todo passed in with this tasks info.
     */
    KCalendarCore::Todo::Ptr asTodo(const KCalendarCore::Todo::Ptr &todo) const;

    /** tells you whether this task is the root of the task tree */
    bool isRoot() const
    {
        return !parentTask();
    }

    /** This task and all its descendant tasks. */
    QList<Task *> selfAndDescendants() const;

    /** remove Task with all it's children
     * Removes task as well as all event history for this task.
     */
    bool remove();

    /**
     * Update percent complete for this task.
     *
     * Tasks that are complete (i.e., percent = 100) do not show up in
     * taskview.  If percent NULL, set to zero.  If greater than 100, set to
     * 100.  If less than zero, set to zero.
     */
    void setPercentComplete(int percent);

    int percentComplete() const;

    /**
     * Update priority for this task.
     *
     * Priority is allowed from 0 to 9. 0 unspecified, 1 highest and 9 lowest.
     */
    void setPriority(int priority);

    int priority() const;

    /** Return true if task is complete (percent complete equals 100).  */
    bool isComplete();

    QVariant data(int column, int role) const override;

protected:
    void changeParentTotalTimes(int64_t minutesSession, int64_t minutes);

private:
    /** initialize a task */
    void init(const QString &taskname,
              const QString &taskdescription,
              int64_t minutes,
              int64_t sessionTime,
              const QString &sessionStartTiMe,
              const DesktopList &desktops,
              int percent_complete,
              int priority);

    bool m_isRunning;

    /** The iCal unique ID of the Todo for this task. */
    QString m_uid;

    int m_percentComplete;

    /** task name */
    QString m_name;

    /** task description */
    QString m_description;

    /** Last time this task was started. */
    QDateTime m_lastStart;

    /** totals of the whole subtree including self */
    int64_t m_totalTime;
    int64_t m_totalSessionTime;

    /** times spend on the task itself */
    int64_t m_time;
    int64_t m_sessionTime;

    /** time when the session was started */
    QDateTime m_sessionStartTime;

    DesktopList m_desktops;

    /** Priority of the task. */
    int m_priority;

    ProjectModel *m_projectModel;
};

#endif // KTIMETRACKER_TASK_H
