/*
 * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 *
 * 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 TRINITY_MOTIONMASTER_H
#define TRINITY_MOTIONMASTER_H

#include "Common.h"
#include <vector>
#include "SharedDefines.h"
#include "Object.h"

class MovementGenerator;
class Unit;
class PathGenerator;

// Creature Entry ID used for waypoints show, visible only for GMs
#define VISUAL_WAYPOINT 1

// values 0 ... MAX_DB_MOTION_TYPE-1 used in DB
enum MovementGeneratorType
{
    IDLE_MOTION_TYPE      = 0,                              // IdleMovementGenerator.h
    RANDOM_MOTION_TYPE    = 1,                              // RandomMovementGenerator.h
    WAYPOINT_MOTION_TYPE  = 2,                              // WaypointMovementGenerator.h
    MAX_DB_MOTION_TYPE    = 3,                              // *** this and below motion types can't be set in DB.
    ANIMAL_RANDOM_MOTION_TYPE = MAX_DB_MOTION_TYPE,         // AnimalRandomMovementGenerator.h
    CONFUSED_MOTION_TYPE  = 4,                              // ConfusedMovementGenerator.h
    CHASE_MOTION_TYPE     = 5,                              // TargetedMovementGenerator.h
    HOME_MOTION_TYPE      = 6,                              // HomeMovementGenerator.h
    FLIGHT_MOTION_TYPE    = 7,                              // WaypointMovementGenerator.h
    POINT_MOTION_TYPE     = 8,                              // PointMovementGenerator.h
    FLEEING_MOTION_TYPE   = 9,                              // FleeingMovementGenerator.h
    DISTRACT_MOTION_TYPE  = 10,                             // IdleMovementGenerator.h
    ASSISTANCE_MOTION_TYPE= 11,                             // PointMovementGenerator.h (first part of flee for assistance)
    ASSISTANCE_DISTRACT_MOTION_TYPE = 12,                   // IdleMovementGenerator.h (second part of flee for assistance)
    TIMED_FLEEING_MOTION_TYPE = 13,                         // FleeingMovementGenerator.h (alt.second part of flee for assistance)
    FOLLOW_MOTION_TYPE    = 14,
    ROTATE_MOTION_TYPE    = 15,
    EFFECT_MOTION_TYPE    = 16,
    NULL_MOTION_TYPE      = 17
};

enum MovementSlot
{
    MOTION_SLOT_IDLE,
    MOTION_SLOT_ACTIVE,
    MOTION_SLOT_CONTROLLED,
    MAX_MOTION_SLOT
};

enum MMCleanFlag
{
    MMCF_NONE   = 0,
    MMCF_UPDATE = 1, // Clear or Expire called from update
    MMCF_RESET  = 2  // Flag if need top()->Reset()
};

enum RotateDirection
{
    ROTATE_DIRECTION_LEFT,
    ROTATE_DIRECTION_RIGHT
};

// assume it is 25 yard per 0.6 second
#define SPEED_CHARGE    42.0f

class TC_GAME_API MotionMaster //: private std::stack<MovementGenerator *>
{
    private:
        //typedef std::stack<MovementGenerator *> Impl;
        typedef MovementGenerator* _Ty;

        void pop()
        {
            if (empty())
                return;

            Impl[_top] = NULL;
            while (!empty() && !top())
                --_top;
        }
        void push(_Ty _Val) { ++_top; Impl[_top] = _Val; }

        bool needInitTop() const
        {
            if (empty())
                return false;
            return _needInit[_top];
        }
        void InitTop();
    public:

        explicit MotionMaster(Unit* unit) : _expList(NULL), _top(-1), _owner(unit), _cleanFlag(MMCF_NONE)
        {
            for (uint8 i = 0; i < MAX_MOTION_SLOT; ++i)
            {
                Impl[i] = NULL;
                _needInit[i] = true;
            }
        }
        ~MotionMaster();

        void Initialize();
        void InitDefault();

        bool empty() const { return (_top < 0); }
        int size() const { return _top + 1; }
        _Ty top() const
        {
            ASSERT(!empty());
            return Impl[_top];
        }
        _Ty GetMotionSlot(int slot) const
        {
            ASSERT(slot >= 0);
            return Impl[slot];
        }

        void DirectDelete(_Ty curr);
        void DelayedDelete(_Ty curr);

        void UpdateMotion(uint32 diff);
        void Clear(bool reset = true)
        {
            if (_cleanFlag & MMCF_UPDATE)
            {
                if (reset)
                    _cleanFlag |= MMCF_RESET;
                else
                    _cleanFlag &= ~MMCF_RESET;
                DelayedClean();
            }
            else
                DirectClean(reset);
        }
        void MovementExpired(bool reset = true)
        {
            if (_cleanFlag & MMCF_UPDATE)
            {
                if (reset)
                    _cleanFlag |= MMCF_RESET;
                else
                    _cleanFlag &= ~MMCF_RESET;
                DelayedExpire();
            }
            else
                DirectExpire(reset);
        }

        void MoveIdle();
        void MoveTargetedHome();
        void MoveRandom(float spawndist = 0.0f);
        void MoveFollow(Unit* target, float dist, float angle, MovementSlot slot = MOTION_SLOT_ACTIVE);
        void MoveChase(Unit* target, float dist = 0.0f, float angle = 0.0f);
        void MoveConfused();
        void MoveFleeing(Unit* enemy, uint32 time = 0);
        void MovePoint(uint32 id, Position const& pos, bool generatePath = true)
            { MovePoint(id, pos.m_positionX, pos.m_positionY, pos.m_positionZ, generatePath); }
        void MovePoint(uint32 id, float x, float y, float z, bool generatePath = true);

        /*  Makes the unit move toward the target until it is at a certain distance from it. The unit then stops.
            Only works in 2D.
            This method doesn't account for any movement done by the target. in other words, it only works if the target is stationary.
        */
        void MoveCloserAndStop(uint32 id, Unit* target, float distance);

        // These two movement types should only be used with creatures having landing/takeoff animations
        void MoveLand(uint32 id, Position const& pos);
        void MoveTakeoff(uint32 id, Position const& pos);

        void MoveCharge(float x, float y, float z, float speed = SPEED_CHARGE, uint32 id = EVENT_CHARGE, bool generatePath = false);
        void MoveCharge(PathGenerator const& path, float speed = SPEED_CHARGE);
        void MoveKnockbackFrom(float srcX, float srcY, float speedXY, float speedZ);
        void MoveJumpTo(float angle, float speedXY, float speedZ);
        void MoveJump(Position const& pos, float speedXY, float speedZ, uint32 id = EVENT_JUMP, bool hasOrientation = false)
        {
            MoveJump(pos.GetPositionX(), pos.GetPositionY(), pos.GetPositionZ(), pos.GetOrientation(), speedXY, speedZ, id, hasOrientation);
        }
        void MoveJump(float x, float y, float z, float o, float speedXY, float speedZ, uint32 id = EVENT_JUMP, bool hasOrientation = false);
        void MoveCirclePath(float x, float y, float z, float radius, bool clockwise, uint8 stepCount);
        void MoveSmoothPath(uint32 pointId, G3D::Vector3 const* pathPoints, size_t pathSize, bool walk);
        void MoveFall(uint32 id = 0);

        void MoveSeekAssistance(float x, float y, float z);
        void MoveSeekAssistanceDistract(uint32 timer);
        void MoveTaxiFlight(uint32 path, uint32 pathnode);
        void MoveDistract(uint32 time);
        void MovePath(uint32 path_id, bool repeatable);
        void MoveRotate(uint32 time, RotateDirection direction);

        MovementGeneratorType GetCurrentMovementGeneratorType() const;
        MovementGeneratorType GetMotionSlotType(int slot) const;

        void propagateSpeedChange();

        bool GetDestination(float &x, float &y, float &z);
    private:
        void Mutate(MovementGenerator *m, MovementSlot slot);                  // use Move* functions instead

        void DirectClean(bool reset);
        void DelayedClean();

        void DirectExpire(bool reset);
        void DelayedExpire();

        typedef std::vector<_Ty> ExpireList;
        ExpireList* _expList;
        _Ty Impl[MAX_MOTION_SLOT];
        int _top;
        Unit* _owner;
        bool _needInit[MAX_MOTION_SLOT];
        uint8 _cleanFlag;
};
#endif
