/*
 * This file is part of the TrinityCore Project. See AUTHORS file for Copyright information
 *
 * 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 TRINITYSERVER_MOVEPLINE_H
#define TRINITYSERVER_MOVEPLINE_H

#include "Spline.h"
#include "MoveSplineInitArgs.h"
#include <G3D/Vector3.h>

enum class AnimTier : uint8;

namespace WorldPackets
{
    namespace Movement
    {
        class CommonMovement;
        class MonsterMove;
    }
}

namespace Movement
{
    struct Location : public Vector3
    {
        Location() : orientation(0) { }
        Location(float x, float y, float z, float o) : Vector3(x, y, z), orientation(o) { }
        Location(Vector3 const& v) : Vector3(v), orientation(0) { }
        Location(Vector3 const& v, float o) : Vector3(v), orientation(o) { }

        float orientation;
    };

    // MoveSpline represents smooth catmullrom or linear curve and point that moves belong it
    // curve can be cyclic - in this case movement will be cyclic
    // point can have vertical acceleration motion component (used in fall, parabolic movement)
    class TC_GAME_API MoveSpline
    {
        friend class WorldPackets::Movement::CommonMovement;
        friend class WorldPackets::Movement::MonsterMove;

    public:
        typedef Spline<int32> MySpline;

        enum UpdateResult
        {
            Result_None         = 0x01,
            Result_Arrived      = 0x02,
            Result_NextCycle    = 0x04,
            Result_NextSegment  = 0x08
        };

    protected:
        MySpline        spline;

        FacingInfo      facing;

        uint32          m_Id;

        MoveSplineFlag  splineflags;

        int32           time_passed;
        // currently duration mods are unused, but its _currently_
        //float           duration_mod;
        //float           duration_mod_next;
        float           vertical_acceleration;
        float           initialOrientation;
        int32           effect_start_time;
        int32           point_Idx;
        int32           point_Idx_offset;
        float           velocity;
        Optional<SpellEffectExtraData> spell_effect_extra;
        Optional<TurnData> turn;
        Optional<AnimTierTransition> anim_tier;

        void init_spline(MoveSplineInitArgs const& args);

    protected:
        MySpline::ControlArray const& getPath() const { return spline.getPoints(); }
        Location computePosition(int32 time_point, int32 point_index) const;
        void computeParabolicElevation(int32 time_point, float& el) const;
        void computeFallElevation(int32 time_point, float& el) const;

        UpdateResult _updateState(int32& ms_time_diff);
        void reinit_spline_for_next_cycle();
        int32 next_timestamp() const { return spline.length(point_Idx + 1); }
        int32 segment_time_elapsed() const { return next_timestamp() - time_passed; }

    public:
        int32 timeRemaining() const { return Duration() - time_passed; }
        int32 timePassed() const { return time_passed; }
        int32 Duration() const { return spline.length(); }
        MySpline const& _Spline() const { return spline; }
        int32 _currentSplineIdx() const { return point_Idx; }
        float Velocity() const { return velocity; }
        void _Finalize();
        void _Interrupt() { splineflags.Done = true; }

    public:
        void Initialize(MoveSplineInitArgs const&);
        bool Initialized() const { return !spline.empty(); }

        MoveSpline();

        template<class UpdateHandler>
        void updateState(int32 difftime, UpdateHandler& handler)
        {
            ASSERT(Initialized());
            do
                handler(_updateState(difftime));
            while (difftime > 0);
        }

        void updateState(int32 difftime)
        {
            ASSERT(Initialized());
            do _updateState(difftime);
            while (difftime > 0);
        }

        Location ComputePosition() const;
        Location ComputePosition(int32 time_offset) const;

        uint32 GetId() const { return m_Id; }
        bool Finalized() const { return splineflags.Done; }
        bool isCyclic() const { return splineflags.Cyclic; }
        bool isFalling() const { return splineflags.Falling; }
        bool isTurning() const { return splineflags.Turning; }
        Vector3 const& FinalDestination() const { return Initialized() ? spline.getPoint(spline.last()) : Vector3::zero(); }
        Vector3 const& CurrentDestination() const { return Initialized() ? spline.getPoint(point_Idx + 1) : Vector3::zero(); }
        int32 currentPathIdx() const;

        Optional<AnimTier> GetAnimation() const { return anim_tier ? anim_tier->AnimTier : Optional<AnimTier>{}; }

        bool onTransport;
        bool splineIsFacingOnly;
        std::string ToString() const;
        bool HasStarted() const
        {
            return time_passed > 0;
        }
    };
}
#endif // TRINITYSERVER_MOVEPLINE_H