/*
 * Copyright (C) 2005-2010 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
 */

#include "Creature.h"
#include "CreatureAI.h"
#include "MapManager.h"
#include "FleeingMovementGenerator.h"
#include "DestinationHolderImp.h"
#include "ObjectAccessor.h"

#define MIN_QUIET_DISTANCE 28.0f
#define MAX_QUIET_DISTANCE 43.0f

template<class T>
void
FleeingMovementGenerator<T>::_setTargetLocation(T &owner)
{
    if( !&owner )
        return;

    if( owner.hasUnitState(UNIT_STAT_ROOT | UNIT_STAT_STUNNED | UNIT_STAT_DIED) )
        return;

    if(!_setMoveData(owner))
        return;

    float x, y, z;
    if(!_getPoint(owner, x, y, z))
        return;

    owner.addUnitState(UNIT_STAT_FLEEING);
    Traveller<T> traveller(owner);
    i_destinationHolder.SetDestination(traveller, x, y, z);
}

template<class T>
bool
FleeingMovementGenerator<T>::_getPoint(T &owner, float &x, float &y, float &z)
{
    if(!&owner)
        return false;

    x = owner.GetPositionX();
    y = owner.GetPositionY();
    z = owner.GetPositionZ();

    float temp_x, temp_y, angle;
    const Map * _map = owner.GetBaseMap();
    //primitive path-finding
    for(uint8 i = 0; i < 18; ++i)
    {
        if(i_only_forward && i > 2)
            break;

        float distance = 5.0f;

        switch(i)
        {
            case 0:
                angle = i_cur_angle;
                break;
            case 1:
                angle = i_cur_angle;
                distance /= 2;
                break;
            case 2:
                angle = i_cur_angle;
                distance /= 4;
                break;
            case 3:
                angle = i_cur_angle + M_PI/4.0f;
                break;
            case 4:
                angle = i_cur_angle - M_PI/4.0f;
                break;
            case 5:
                angle = i_cur_angle + M_PI/4.0f;
                distance /= 2;
                break;
            case 6:
                angle = i_cur_angle - M_PI/4.0f;
                distance /= 2;
                break;
            case 7:
                angle = i_cur_angle + M_PI/2.0f;
                break;
            case 8:
                angle = i_cur_angle - M_PI/2.0f;
                break;
            case 9:
                angle = i_cur_angle + M_PI/2.0f;
                distance /= 2;
                break;
            case 10:
                angle = i_cur_angle - M_PI/2.0f;
                distance /= 2;
                break;
            case 11:
                angle = i_cur_angle + M_PI/4.0f;
                distance /= 4;
                break;
            case 12:
                angle = i_cur_angle - M_PI/4.0f;
                distance /= 4;
                break;
            case 13:
                angle = i_cur_angle + M_PI/2.0f;
                distance /= 4;
                break;
            case 14:
                angle = i_cur_angle - M_PI/2.0f;
                distance /= 4;
                break;
            case 15:
                angle = i_cur_angle + M_PI*3/4.0f;
                distance /= 2;
                break;
            case 16:
                angle = i_cur_angle - M_PI*3/4.0f;
                distance /= 2;
                break;
            case 17:
                angle = i_cur_angle + M_PI;
                distance /= 2;
                break;
        }
        temp_x = x + distance * cos(angle);
        temp_y = y + distance * sin(angle);
        MaNGOS::NormalizeMapCoord(temp_x);
        MaNGOS::NormalizeMapCoord(temp_y);
        if( owner.IsWithinLOS(temp_x,temp_y,z))
        {
            bool is_water_now = _map->IsInWater(x,y,z);

            if(is_water_now && _map->IsInWater(temp_x,temp_y,z))
            {
                x = temp_x;
                y = temp_y;
                return true;
            }
            float new_z = _map->GetHeight(temp_x,temp_y,z,true);

            if(new_z <= INVALID_HEIGHT)
                continue;

            bool is_water_next = _map->IsInWater(temp_x,temp_y,new_z);

            if((is_water_now && !is_water_next && !is_land_ok) || (!is_water_now && is_water_next && !is_water_ok))
                continue;

            if( !(new_z - z) || distance / fabs(new_z - z) > 1.0f)
            {
                float new_z_left = _map->GetHeight(temp_x + 1.0f*cos(angle+M_PI/2),temp_y + 1.0f*sin(angle+M_PI/2),z,true);
                float new_z_right = _map->GetHeight(temp_x + 1.0f*cos(angle-M_PI/2),temp_y + 1.0f*sin(angle-M_PI/2),z,true);
                if(fabs(new_z_left - new_z) < 1.2f && fabs(new_z_right - new_z) < 1.2f)
                {
                    x = temp_x;
                    y = temp_y;
                    z = new_z;
                    return true;
                }
            }
        }
    }
    i_to_distance_from_caster = 0.0f;
    i_nextCheckTime.Reset( urand(500,1000) );
    return false;
}

template<class T>
bool
FleeingMovementGenerator<T>::_setMoveData(T &owner)
{
    float cur_dist_xyz = owner.GetDistance(i_caster_x, i_caster_y, i_caster_z);

    if(i_to_distance_from_caster > 0.0f)
    {
        if((i_last_distance_from_caster > i_to_distance_from_caster && cur_dist_xyz < i_to_distance_from_caster)   ||
                                                            // if we reach lower distance
           (i_last_distance_from_caster > i_to_distance_from_caster && cur_dist_xyz > i_last_distance_from_caster) ||
                                                            // if we can't be close
           (i_last_distance_from_caster < i_to_distance_from_caster && cur_dist_xyz > i_to_distance_from_caster)   ||
                                                            // if we reach bigger distance
           (cur_dist_xyz > MAX_QUIET_DISTANCE) ||           // if we are too far
           (i_last_distance_from_caster > MIN_QUIET_DISTANCE && cur_dist_xyz < MIN_QUIET_DISTANCE) )
                                                            // if we leave 'quiet zone'
        {
            // we are very far or too close, stopping
            i_to_distance_from_caster = 0.0f;
            i_nextCheckTime.Reset( urand(500,1000) );
            return false;
        }
        else
        {
            // now we are running, continue
            i_last_distance_from_caster = cur_dist_xyz;
            return true;
        }
    }

    float cur_dist;
    float angle_to_caster;

    Unit * fright = ObjectAccessor::GetUnit(owner, i_frightGUID);

    if(fright)
    {
        cur_dist = fright->GetDistance(&owner);
        if(cur_dist < cur_dist_xyz)
        {
            i_caster_x = fright->GetPositionX();
            i_caster_y = fright->GetPositionY();
            i_caster_z = fright->GetPositionZ();
            angle_to_caster = fright->GetAngle(&owner);
        }
        else
        {
            cur_dist = cur_dist_xyz;
            angle_to_caster = owner.GetAngle(i_caster_x, i_caster_y) + M_PI;
        }
    }
    else
    {
        cur_dist = cur_dist_xyz;
        angle_to_caster = owner.GetAngle(i_caster_x, i_caster_y) + M_PI;
    }

    // if we too close may use 'path-finding' else just stop
    i_only_forward = cur_dist >= MIN_QUIET_DISTANCE/3;

    //get angle and 'distance from caster' to run
    float angle;

    if(i_cur_angle == 0.0f && i_last_distance_from_caster == 0.0f) //just started, first time
    {
        angle = rand_norm()*(1.0f - cur_dist/MIN_QUIET_DISTANCE) * M_PI/3 + rand_norm()*M_PI*2/3;
        i_to_distance_from_caster = MIN_QUIET_DISTANCE;
        i_only_forward = true;
    }
    else if(cur_dist < MIN_QUIET_DISTANCE)
    {
        angle = M_PI/6 + rand_norm()*M_PI*2/3;
        i_to_distance_from_caster = cur_dist*2/3 + rand_norm()*(MIN_QUIET_DISTANCE - cur_dist*2/3);
    }
    else if(cur_dist > MAX_QUIET_DISTANCE)
    {
        angle = rand_norm()*M_PI/3 + M_PI*2/3;
        i_to_distance_from_caster = MIN_QUIET_DISTANCE + 2.5f + rand_norm()*(MAX_QUIET_DISTANCE - MIN_QUIET_DISTANCE - 2.5f);
    }
    else
    {
        angle = rand_norm()*M_PI;
        i_to_distance_from_caster = MIN_QUIET_DISTANCE + 2.5f + rand_norm()*(MAX_QUIET_DISTANCE - MIN_QUIET_DISTANCE - 2.5f);
    }

    int8 sign = rand_norm() > 0.5f ? 1 : -1;
    i_cur_angle = sign*angle + angle_to_caster;

    // current distance
    i_last_distance_from_caster = cur_dist;

    return true;
}

template<class T>
void
FleeingMovementGenerator<T>::Initialize(T &owner)
{
    if(!&owner)
        return;

    _Init(owner);

    if(Unit * fright = ObjectAccessor::GetUnit(owner, i_frightGUID))
    {
        i_caster_x = fright->GetPositionX();
        i_caster_y = fright->GetPositionY();
        i_caster_z = fright->GetPositionZ();
    }
    else
    {
        i_caster_x = owner.GetPositionX();
        i_caster_y = owner.GetPositionY();
        i_caster_z = owner.GetPositionZ();
    }

    i_only_forward = true;
    i_cur_angle = 0.0f;
    i_last_distance_from_caster = 0.0f;
    i_to_distance_from_caster = 0.0f;
    _setTargetLocation(owner);
}

template<>
void
FleeingMovementGenerator<Creature>::_Init(Creature &owner)
{
    if(!&owner)
        return;

    owner.RemoveMonsterMoveFlag(MONSTER_MOVE_WALK);
    owner.SetTargetGUID(0);
    is_water_ok = owner.canSwim();
    is_land_ok  = owner.canWalk();
}

template<>
void
FleeingMovementGenerator<Player>::_Init(Player &)
{
    is_water_ok = true;
    is_land_ok  = true;
}

template<>
void FleeingMovementGenerator<Player>::Finalize(Player &owner)
{
    owner.clearUnitState(UNIT_STAT_FLEEING);
}

template<>
void FleeingMovementGenerator<Creature>::Finalize(Creature &owner)
{
    owner.AddMonsterMoveFlag(MONSTER_MOVE_WALK);
    owner.clearUnitState(UNIT_STAT_FLEEING);
}

template<class T>
void
FleeingMovementGenerator<T>::Reset(T &owner)
{
    Initialize(owner);
}

template<class T>
bool
FleeingMovementGenerator<T>::Update(T &owner, const uint32 & time_diff)
{
    if( !&owner || !owner.isAlive() )
        return false;
    if( owner.hasUnitState(UNIT_STAT_ROOT | UNIT_STAT_STUNNED | UNIT_STAT_DIED) )
        return true;

    Traveller<T> traveller(owner);

    i_nextCheckTime.Update(time_diff);

    if( (owner.IsStopped() && !i_destinationHolder.HasArrived()) || !i_destinationHolder.HasDestination() )
    {
        _setTargetLocation(owner);
        return true;
    }

    if (i_destinationHolder.UpdateTraveller(traveller, time_diff, false))
    {
        i_destinationHolder.ResetUpdate(50);
        if(i_nextCheckTime.Passed() && i_destinationHolder.HasArrived())
        {
            _setTargetLocation(owner);
            return true;
        }
    }
    return true;
}

template void FleeingMovementGenerator<Player>::Initialize(Player &);
template void FleeingMovementGenerator<Creature>::Initialize(Creature &);
template bool FleeingMovementGenerator<Player>::_setMoveData(Player &);
template bool FleeingMovementGenerator<Creature>::_setMoveData(Creature &);
template bool FleeingMovementGenerator<Player>::_getPoint(Player &, float &, float &, float &);
template bool FleeingMovementGenerator<Creature>::_getPoint(Creature &, float &, float &, float &);
template void FleeingMovementGenerator<Player>::_setTargetLocation(Player &);
template void FleeingMovementGenerator<Creature>::_setTargetLocation(Creature &);
template void FleeingMovementGenerator<Player>::Reset(Player &);
template void FleeingMovementGenerator<Creature>::Reset(Creature &);
template bool FleeingMovementGenerator<Player>::Update(Player &, const uint32 &);
template bool FleeingMovementGenerator<Creature>::Update(Creature &, const uint32 &);

void TimedFleeingMovementGenerator::Finalize(Unit &owner)
{
    owner.clearUnitState(UNIT_STAT_FLEEING);
    if (Unit* victim = owner.getVictim())
    {
        if (owner.isAlive())
        {
            owner.AttackStop(true);
            ((Creature*)&owner)->AI()->AttackStart(victim);
        }
    }
}

bool TimedFleeingMovementGenerator::Update(Unit & owner, const uint32 & time_diff)
{
    if( !owner.isAlive() )
        return false;

    if( owner.hasUnitState(UNIT_STAT_ROOT | UNIT_STAT_STUNNED | UNIT_STAT_DIED) )
        return true;

    i_totalFleeTime.Update(time_diff);
    if (i_totalFleeTime.Passed())
        return false;

    // This calls grant-parent Update method hiden by FleeingMovementGenerator::Update(Creature &, const uint32 &) version
    // This is done instead of casting Unit& to Creature& and call parent method, then we can use Unit directly
    return MovementGeneratorMedium< Creature, FleeingMovementGenerator<Creature> >::Update(owner, time_diff);
}
