/*
 * Copyright (C) 2005-2011 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, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifndef MANGOS_TARGETEDMOVEMENTGENERATOR_H
#define MANGOS_TARGETEDMOVEMENTGENERATOR_H

#include "MovementGenerator.h"
#include "FollowerReference.h"
#include "Unit.h"

class MANGOS_DLL_SPEC TargetedMovementGeneratorBase
{
    public:
        TargetedMovementGeneratorBase(Unit &target) { i_target.link(&target, this); }
        void stopFollowing() { }
    protected:
        FollowerReference i_target;
};

template<class T, typename D>
class MANGOS_DLL_SPEC TargetedMovementGeneratorMedium
: public MovementGeneratorMedium< T, D >, public TargetedMovementGeneratorBase
{
    protected:
        TargetedMovementGeneratorMedium(Unit &target, float offset, float angle) :
            TargetedMovementGeneratorBase(target), i_offset(offset), i_angle(angle),
            i_recalculateTravel(false), i_targetReached(false), i_recheckDistance(0)
        {
        }
        ~TargetedMovementGeneratorMedium() {}

    public:
        bool Update(T &, const uint32 &);

        Unit* GetTarget() const { return i_target.getTarget(); }

        void unitSpeedChanged() { i_recalculateTravel=true; }
        void UpdateFinalDistance(float fDistance);

    protected:
        void _setTargetLocation(T &);

        ShortTimeTracker i_recheckDistance;
        float i_offset;
        float i_angle;
        bool i_recalculateTravel : 1;
        bool i_targetReached : 1;
};

template<class T>
class MANGOS_DLL_SPEC ChaseMovementGenerator : public TargetedMovementGeneratorMedium<T, ChaseMovementGenerator<T> >
{
    public:
        ChaseMovementGenerator(Unit &target)
            : TargetedMovementGeneratorMedium<T, ChaseMovementGenerator<T> >(target) {}
        ChaseMovementGenerator(Unit &target, float offset, float angle)
            : TargetedMovementGeneratorMedium<T, ChaseMovementGenerator<T> >(target, offset, angle) {}
        ~ChaseMovementGenerator() {}

        MovementGeneratorType GetMovementGeneratorType() const { return CHASE_MOTION_TYPE; }

        void Initialize(T &);
        void Finalize(T &);
        void Interrupt(T &);
        void Reset(T &);

        static void _clearUnitStateMove(T &u) { u.clearUnitState(UNIT_STAT_CHASE_MOVE); }
        static void _addUnitStateMove(T &u)  { u.addUnitState(UNIT_STAT_CHASE_MOVE); }
        bool EnableWalking() const { return false;}
        bool _lostTarget(T &u) const { return u.getVictim() != this->GetTarget(); }
        void _reachTarget(T &);
};

template<class T>
class MANGOS_DLL_SPEC FollowMovementGenerator : public TargetedMovementGeneratorMedium<T, FollowMovementGenerator<T> >
{
    public:
        FollowMovementGenerator(Unit &target)
            : TargetedMovementGeneratorMedium<T, FollowMovementGenerator<T> >(target){}
        FollowMovementGenerator(Unit &target, float offset, float angle)
            : TargetedMovementGeneratorMedium<T, FollowMovementGenerator<T> >(target, offset, angle) {}
        ~FollowMovementGenerator() {}

        MovementGeneratorType GetMovementGeneratorType() const { return FOLLOW_MOTION_TYPE; }

        void Initialize(T &);
        void Finalize(T &);
        void Interrupt(T &);
        void Reset(T &);

        static void _clearUnitStateMove(T &u) { u.clearUnitState(UNIT_STAT_FOLLOW_MOVE); }
        static void _addUnitStateMove(T &u)  { u.addUnitState(UNIT_STAT_FOLLOW_MOVE); }
        bool EnableWalking() const;
        bool _lostTarget(T &) const { return false; }
        void _reachTarget(T &) {}
    private:
        void _updateSpeed(T &u);
};

#endif