/*
 * Copyright (C) 2008-2017 TrinityCore <http://www.trinitycore.org/>
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */

#ifndef _EVENT_MAP_H_
#define _EVENT_MAP_H_

#include "Common.h"
#include "Duration.h"
#include "Util.h"

class TC_COMMON_API EventMap
{
    /**
    * Internal storage type.
    * Key: Time as uint32 when the event should occur.
    * Value: The event data as uint32.
    *
    * Structure of event data:
    * - Bit  0 - 15: Event Id.
    * - Bit 16 - 23: Group
    * - Bit 24 - 31: Phase
    * - Pattern: 0xPPGGEEEE
    */
    typedef std::multimap<uint32, uint32> EventStore;

public:
    EventMap() : _time(0), _phase(0), _lastEvent(0) { }

    /**
    * @name Reset
    * @brief Removes all scheduled events and resets time and phase.
    */
    void Reset();

    /**
    * @name Update
    * @brief Updates the timer of the event map.
    * @param time Value in ms to be added to time.
    */
    void Update(uint32 time)
    {
        _time += time;
    }

    /**
    * @name GetTimer
    * @return Current timer in ms value.
    */
    uint32 GetTimer() const
    {
        return _time;
    }

    /**
    * @name GetPhaseMask
    * @return Active phases as mask.
    */
    uint8 GetPhaseMask() const
    {
        return _phase;
    }

    /**
    * @name Empty
    * @return True, if there are no events scheduled.
    */
    bool Empty() const
    {
        return _eventMap.empty();
    }

    /**
    * @name SetPhase
    * @brief Sets the phase of the map (absolute).
    * @param phase Phase which should be set. Values: 1 - 8. 0 resets phase.
    */
    void SetPhase(uint8 phase);

    /**
    * @name AddPhase
    * @brief Activates the given phase (bitwise).
    * @param phase Phase which should be activated. Values: 1 - 8
    */
    void AddPhase(uint8 phase)
    {
        if (phase && phase <= 8)
            _phase |= uint8(1 << (phase - 1));
    }

    /**
    * @name RemovePhase
    * @brief Deactivates the given phase (bitwise).
    * @param phase Phase which should be deactivated. Values: 1 - 8.
    */
    void RemovePhase(uint8 phase)
    {
        if (phase && phase <= 8)
            _phase &= uint8(~(1 << (phase - 1)));
    }

    /**
    * @name ScheduleEvent
    * @brief Creates new event entry in map.
    * @param eventId The id of the new event.
    * @param time The time in milliseconds as std::chrono::duration until the event occurs.
    * @param group The group which the event is associated to. Has to be between 1 and 8. 0 means it has no group.
    * @param phase The phase in which the event can occur. Has to be between 1 and 8. 0 means it can occur in all phases.
    */
    void ScheduleEvent(uint32 eventId, Milliseconds const& time, uint32 group = 0, uint8 phase = 0)
    {
        ScheduleEvent(eventId, uint32(time.count()), group, phase);
    }

    /**
    * @name ScheduleEvent
    * @brief Creates new event entry in map.
    * @param eventId The id of the new event.
    * @param time The time in milliseconds until the event occurs.
    * @param group The group which the event is associated to. Has to be between 1 and 8. 0 means it has no group.
    * @param phase The phase in which the event can occur. Has to be between 1 and 8. 0 means it can occur in all phases.
    */
    void ScheduleEvent(uint32 eventId, uint32 time, uint32 group = 0, uint8 phase = 0);

    /**
    * @name RescheduleEvent
    * @brief Cancels the given event and reschedules it.
    * @param eventId The id of the event.
    * @param time The time in milliseconds as std::chrono::duration until the event occurs.
    * @param group The group which the event is associated to. Has to be between 1 and 8. 0 means it has no group.
    * @param phase The phase in which the event can occur. Has to be between 1 and 8. 0 means it can occur in all phases.
    */
    void RescheduleEvent(uint32 eventId, Milliseconds const& time, uint32 group = 0, uint8 phase = 0)
    {
        RescheduleEvent(eventId, uint32(time.count()), group, phase);
    }

    /**
    * @name RescheduleEvent
    * @brief Cancels the given event and reschedules it.
    * @param eventId The id of the event.
    * @param time The time in milliseconds until the event occurs.
    * @param group The group which the event is associated to. Has to be between 1 and 8. 0 means it has no group.
    * @param phase The phase in which the event can occur. Has to be between 1 and 8. 0 means it can occur in all phases.
    */
    void RescheduleEvent(uint32 eventId, uint32 time, uint32 group = 0, uint8 phase = 0)
    {
        CancelEvent(eventId);
        ScheduleEvent(eventId, time, group, phase);
    }

    /**
    * @name RepeatEvent
    * @brief Repeats the mostly recently executed event.
    * @param time Time until in milliseconds as std::chrono::duration the event occurs.
    */
    void Repeat(Milliseconds const& time)
    {
        Repeat(uint32(time.count()));
    }

    /**
    * @name RepeatEvent
    * @brief Repeats the mostly recently executed event.
    * @param time Time until the event occurs.
    */
    void Repeat(uint32 time)
    {
        _eventMap.insert(EventStore::value_type(_time + time, _lastEvent));
    }

    /**
    * @name RepeatEvent
    * @brief Repeats the mostly recently executed event.
    * @param minTime Minimum time as std::chrono::duration until the event occurs.
    * @param maxTime Maximum time as std::chrono::duration until the event occurs.
    */
    void Repeat(Milliseconds const& minTime, Milliseconds const& maxTime)
    {
        Repeat(uint32(minTime.count()), uint32(maxTime.count()));
    }

    /**
    * @name RepeatEvent
    * @brief Repeats the mostly recently executed event, Equivalent to Repeat(urand(minTime, maxTime).
    * @param minTime Minimum time until the event occurs.
    * @param maxTime Maximum time until the event occurs.
    */
    void Repeat(uint32 minTime, uint32 maxTime)
    {
        Repeat(urand(minTime, maxTime));
    }

    /**
    * @name ExecuteEvent
    * @brief Returns the next event to execute and removes it from map.
    * @return Id of the event to execute.
    */
    uint32 ExecuteEvent();

    /**
    * @name DelayEvents
    * @brief Delays all events in the map. If delay is greater than or equal internal timer, delay will be 0.
    * @param delay Amount of delay in ms as std::chrono::duration.
    */
    void DelayEvents(Milliseconds const& delay)
    {
        DelayEvents(uint32(delay.count()));
    }

    /**
    * @name DelayEvents
    * @brief Delays all events in the map. If delay is greater than or equal internal timer, delay will be 0.
    * @param delay Amount of delay.
    */
    void DelayEvents(uint32 delay)
    {
        _time = delay < _time ? _time - delay : 0;
    }

    /**
    * @name DelayEvents
    * @brief Delay all events of the same group.
    * @param delay Amount of delay in ms as std::chrono::duration.
    * @param group Group of the events.
    */
    void DelayEvents(Milliseconds const& delay, uint32 group)
    {
        DelayEvents(uint32(delay.count()), group);
    }

    /**
    * @name DelayEvents
    * @brief Delay all events of the same group.
    * @param delay Amount of delay.
    * @param group Group of the events.
    */
    void DelayEvents(uint32 delay, uint32 group);

    /**
    * @name CancelEvent
    * @brief Cancels all events of the specified id.
    * @param eventId Event id to cancel.
    */
    void CancelEvent(uint32 eventId);

    /**
    * @name CancelEventGroup
    * @brief Cancel events belonging to specified group.
    * @param group Group to cancel.
    */
    void CancelEventGroup(uint32 group);

    /**
    * @name GetNextEventTime
    * @brief Returns closest occurence of specified event.
    * @param eventId Wanted event id.
    * @return Time of found event.
    */
    uint32 GetNextEventTime(uint32 eventId) const;

    /**
    * @name GetNextEventTime
    * @return Time of next event.
    */
    uint32 GetNextEventTime() const
    {
        return Empty() ? 0 : _eventMap.begin()->first;
    }

    /**
    * @name IsInPhase
    * @brief Returns whether event map is in specified phase or not.
    * @param phase Wanted phase.
    * @return True, if phase of event map contains specified phase.
    */
    bool IsInPhase(uint8 phase) const
    {
        return phase <= 8 && (!phase || _phase & (1 << (phase - 1)));
    }

    /**
    * @name GetTimeUntilEvent
    * @brief Returns time in milliseconds until next event.
    * @param eventId of the event.
    * @return Time of next event.
    */
    uint32 GetTimeUntilEvent(uint32 eventId) const;

private:
    /**
    * @name _time
    * @brief Internal timer.
    *
    * This does not represent the real date/time value.
    * It's more like a stopwatch: It can run, it can be stopped,
    * it can be resetted and so on. Events occur when this timer
    * has reached their time value. Its value is changed in the
    * Update method.
    */
    uint32 _time;

    /**
    * @name _phase
    * @brief Phase mask of the event map.
    *
    * Contains the phases the event map is in. Multiple
    * phases from 1 to 8 can be set with SetPhase or
    * AddPhase. RemovePhase deactives a phase.
    */
    uint8 _phase;

    /**
    * @name _eventMap
    * @brief Internal event storage map. Contains the scheduled events.
    *
    * See typedef at the beginning of the class for more
    * details.
    */
    EventStore _eventMap;

    /**
    * @name _lastEvent
    * @brief Stores information on the most recently executed event
    */
    uint32 _lastEvent;
};

#endif // _EVENT_MAP_H_