/*
 * Copyright (C) 2016+     AzerothCore <www.azerothcore.org>, released under GNU GPL v2 license, you may redistribute it and/or modify it under version 2 of the License, or (at your option), any later version.
 * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
 */

#include "MovementPacketBuilder.h"
#include "MoveSpline.h"
#include "MoveSplineInit.h"
#include "Opcodes.h"
#include "Transport.h"
#include "Unit.h"
#include "Vehicle.h"
#include "WorldPacket.h"

namespace Movement
{
    UnitMoveType SelectSpeedType(uint32 moveFlags)
    {
        if (moveFlags & MOVEMENTFLAG_FLYING)
        {
            if (moveFlags & MOVEMENTFLAG_BACKWARD /*&& speed_obj.flight >= speed_obj.flight_back*/)
                return MOVE_FLIGHT_BACK;
            else
                return MOVE_FLIGHT;
        }
        else if (moveFlags & MOVEMENTFLAG_SWIMMING)
        {
            if (moveFlags & MOVEMENTFLAG_BACKWARD /*&& speed_obj.swim >= speed_obj.swim_back*/)
                return MOVE_SWIM_BACK;
            else
                return MOVE_SWIM;
        }
        else if (moveFlags & MOVEMENTFLAG_WALKING)
        {
            //if (speed_obj.run > speed_obj.walk)
            return MOVE_WALK;
        }
        else if (moveFlags & MOVEMENTFLAG_BACKWARD /*&& speed_obj.run >= speed_obj.run_back*/)
            return MOVE_RUN_BACK;

        // Flying creatures use MOVEMENTFLAG_CAN_FLY or MOVEMENTFLAG_DISABLE_GRAVITY
        // Run speed is their default flight speed.
        return MOVE_RUN;
    }

    int32 MoveSplineInit::Launch()
    {
        MoveSpline& move_spline = *unit->movespline;

        bool transport = unit->HasUnitMovementFlag(MOVEMENTFLAG_ONTRANSPORT) && unit->GetTransGUID();
        Location real_position;
        // there is a big chance that current position is unknown if current state is not finalized, need compute it
        // this also allows CalculatePath spline position and update map position in much greater intervals
        // Don't compute for transport movement if the unit is in a motion between two transports
        if (!move_spline.Finalized() && move_spline.onTransport == transport)
            real_position = move_spline.ComputePosition();
        else
        {
            Position const* pos;
            if (!transport)
                pos = unit;
            else
                pos = &unit->m_movementInfo.transport.pos;

            real_position.x = pos->GetPositionX();
            real_position.y = pos->GetPositionY();
            real_position.z = pos->GetPositionZ();
            real_position.orientation = unit->GetOrientation();
        }

        // should i do the things that user should do? - no.
        if (args.path.empty())
            return 0;

        // corrent first vertex
        args.path[0] = real_position;
        args.initialOrientation = real_position.orientation;
        move_spline.onTransport = transport;

        uint32 moveFlags = unit->m_movementInfo.GetMovementFlags();
        moveFlags |= MOVEMENTFLAG_SPLINE_ENABLED;

        if (!args.flags.orientationInversed)
        {
            moveFlags = (moveFlags & ~(MOVEMENTFLAG_BACKWARD)) | MOVEMENTFLAG_FORWARD;
        }
        else
        {
            moveFlags = (moveFlags & ~(MOVEMENTFLAG_FORWARD)) | MOVEMENTFLAG_BACKWARD;
        }

        if (moveFlags & MOVEMENTFLAG_ROOT)
            moveFlags &= ~MOVEMENTFLAG_MASK_MOVING;

        if (!args.HasVelocity)
        {
            // If spline is initialized with SetWalk method it only means we need to select
            // walk move speed for it but not add walk flag to unit
            uint32 moveFlagsForSpeed = moveFlags;
            if (args.flags.walkmode)
                moveFlagsForSpeed |= MOVEMENTFLAG_WALKING;
            else
                moveFlagsForSpeed &= ~MOVEMENTFLAG_WALKING;

            args.velocity = unit->GetSpeed(SelectSpeedType(moveFlagsForSpeed));
            if (Creature* creature = unit->ToCreature())
                if (creature->HasSearchedAssistance())
                    args.velocity *= 0.66f;
        }

        // limit the speed in the same way the client does
        args.velocity = std::min(args.velocity, args.flags.catmullrom || args.flags.flying ? 50.0f : std::max(28.0f, unit->GetSpeed(MOVE_RUN) * 4.0f));

        if (!args.Validate(unit))
            return 0;

        unit->m_movementInfo.SetMovementFlags(moveFlags);
        move_spline.Initialize(args);

        WorldPacket data(SMSG_MONSTER_MOVE, 64);
        data.append(unit->GetPackGUID());
        if (transport)
        {
            data.SetOpcode(SMSG_MONSTER_MOVE_TRANSPORT);
            data.appendPackGUID(unit->GetTransGUID());
            data << int8(unit->GetTransSeat());
        }

        Movement::SplineBase::ControlArray* visualPoints = const_cast<Movement::SplineBase::ControlArray*>(move_spline._Spline().allocateVisualPoints());
        visualPoints->resize(move_spline._Spline().getPointCount());
        // Xinef: Apply hover in creature movement packet
        std::copy(move_spline._Spline().getPoints(false).begin(), move_spline._Spline().getPoints(false).end(), visualPoints->begin());

        PacketBuilder::WriteMonsterMove(move_spline, data);
        unit->SendMessageToSet(&data, true);

        return move_spline.Duration();
    }

    void MoveSplineInit::Stop()
    {
        MoveSpline& move_spline = *unit->movespline;

        // No need to stop if we are not moving
        if (move_spline.Finalized())
            return;

        bool transport = unit->HasUnitMovementFlag(MOVEMENTFLAG_ONTRANSPORT) && unit->GetTransGUID();
        Location loc;
        if (move_spline.onTransport == transport)
            loc = move_spline.ComputePosition();
        else
        {
            Position const* pos;
            if (!transport)
                pos = unit;
            else
                pos = &unit->m_movementInfo.transport.pos;

            loc.x = pos->GetPositionX();
            loc.y = pos->GetPositionY();
            loc.z = pos->GetPositionZ();
            loc.orientation = unit->GetOrientation();
        }

        args.flags = MoveSplineFlag::Done;
        unit->m_movementInfo.RemoveMovementFlag(MOVEMENTFLAG_FORWARD | MOVEMENTFLAG_BACKWARD | MOVEMENTFLAG_SPLINE_ENABLED);
        move_spline.onTransport = transport;
        move_spline.Initialize(args);

        WorldPacket data(SMSG_MONSTER_MOVE, 64);
        data.append(unit->GetPackGUID());
        if (transport)
        {
            data.SetOpcode(SMSG_MONSTER_MOVE_TRANSPORT);
            data.appendPackGUID(unit->GetTransGUID());
            data << int8(unit->GetTransSeat());
        }

        PacketBuilder::WriteStopMovement(loc, args.splineId, data);
        unit->SendMessageToSet(&data, true);
    }

    MoveSplineInit::MoveSplineInit(Unit* m) : unit(m)
    {
        args.splineId = splineIdGen.NewId();
        args.TransformForTransport = unit->HasUnitMovementFlag(MOVEMENTFLAG_ONTRANSPORT) && unit->GetTransGUID();
        // mix existing state into new
        args.flags.walkmode = unit->m_movementInfo.HasMovementFlag(MOVEMENTFLAG_WALKING);
        args.flags.flying = unit->m_movementInfo.HasMovementFlag((MovementFlags)(MOVEMENTFLAG_CAN_FLY | MOVEMENTFLAG_DISABLE_GRAVITY));
    }

    void MoveSplineInit::SetFacing(const Unit* target)
    {
        args.flags.EnableFacingTarget();
        args.facing.target = target->GetGUID();
    }

    void MoveSplineInit::SetFacing(float angle)
    {
        if (args.TransformForTransport)
        {
            if (Unit* vehicle = unit->GetVehicleBase())
                angle -= vehicle->GetOrientation();
            else if (Transport* transport = unit->GetTransport())
                angle -= transport->GetOrientation();
        }

        args.facing.angle = G3D::wrap(angle, 0.f, (float)G3D::twoPi());
        args.flags.EnableFacingAngle();
    }

    void MoveSplineInit::MoveTo(const Vector3& dest, bool generatePath, bool forceDestination)
    {
        if (generatePath)
        {
            PathGenerator path(unit);
            bool result = path.CalculatePath(dest.x, dest.y, dest.z, forceDestination);
            if (result && !(path.GetPathType() & PATHFIND_NOPATH))
            {
                MovebyPath(path.GetPath());
                return;
            }
        }

        args.path_Idx_offset = 0;
        args.path.resize(2);
        TransportPathTransform transform(unit, args.TransformForTransport);
        args.path[1] = transform(dest);
    }

    Vector3 TransportPathTransform::operator()(Vector3 input)
    {
        if (_transformForTransport)
            if (TransportBase* transport = _owner->GetDirectTransport())
                transport->CalculatePassengerOffset(input.x, input.y, input.z);

        return input;
    }
}