/*
 * Copyright (C) 2005,2006,2007 MaNGOS <http://www.mangosproject.org/>
 *
 * 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 "PetAI.h"
#include "Errors.h"
#include "Pet.h"
#include "Player.h"
#include "TargetedMovementGenerator.h"
#include "Database/DBCStores.h"
#include "Spell.h"
#include "ObjectAccessor.h"
#include "ObjectMgr.h"
#include "Creature.h"
#include "World.h"

int PetAI::Permissible(const Creature *creature)
{
    if( creature->isPet())
        return PERMIT_BASE_SPECIAL;

    return PERMIT_BASE_NO;
}

PetAI::PetAI(Creature &c) : i_pet(c), i_victimGuid(0), i_tracker(TIME_INTERVAL_LOOK)
{
    m_AllySet.clear();
    UpdateAllies();
}

void PetAI::MoveInLineOfSight(Unit *who)
{
    if( i_pet.GetCharmInfo() )
    {
        //Planning something to get Rid of all Z check like that will be great since it wrong, GS 
        if( i_pet.GetDistanceZ(who) > CREATURE_Z_ATTACK_RANGE ) 
            return;

        if( !i_pet.GetUInt64Value(UNIT_FIELD_TARGET) )
        {
            if( i_pet.GetCharmInfo()->HasReactState(REACT_AGGRESSIVE))
            {
                if( i_pet.IsWithinDistInMap(who,RANGE_AUTO_ASSIST_PET ) && i_pet.IsFriendlyTo(who) )
                {
                    if(!i_pet.IsWithinLOSInMap(who))
                        return;

                    //TODO: make it with IsInCombat() + Take target from AttackerList.
                    if(!who->getAttackers().empty())
                    {   
                        Unit* victimTarget = *(who->getAttackers().begin());
                        if( i_pet.IsHostileTo(victimTarget) && (Unit::getHpPercent(victimTarget) < 100 || Unit::getHpPercent(who) < 100) 
                            && i_pet.IsWithinDistInMap(victimTarget, 46.0f) ) //Just a safe distance.
                            AttackStart( victimTarget );
                    }
                }
                return;
            }

            if((i_pet.GetCharmInfo()->HasReactState(REACT_DEFENSIVE) && Unit::getHpPercent(who) < 100))
            {
                if( i_pet.IsWithinDistInMap(who,RANGE_AUTO_ASSIST_PET ) && i_pet.IsFriendlyTo(who) )
                {
                    if(!i_pet.IsWithinLOSInMap(who))
                        return;

                    //TODO: make it with IsInCombat() + Take target from AttackerList.
                    if(!who->getAttackers().empty())
                    {   
                        Unit* victimTarget = *(who->getAttackers().begin());
                        if( i_pet.IsHostileTo(victimTarget) && i_pet.IsWithinDistInMap(victimTarget, 46.0f)) //Just a safe distance.
                            AttackStart( victimTarget );
                    }
                }
            }
        }
    }
}

void PetAI::AttackStart(Unit *unit)
{
    if( !unit || i_pet.isPet() && ((Pet&)i_pet).getPetType()==MINI_PET )
        return;

    if( unit->isTargetableForAttack() )
    {
        if ( i_pet.Attack(unit) )
        {
            i_pet.AddThreat(unit, 0.0f);
            i_pet.resetAttackTimer();
            if(i_pet.GetCharmInfo()->HasCommandState(COMMAND_FOLLOW))
                AIMotionTarget(unit,FOLLOW_RANGE_MELEE);

            return;
        }else if( i_pet.getVictim() == unit && i_pet.GetCharmInfo()->HasCommandState(COMMAND_FOLLOW) ) //HackWay... Cause Attack() will return false if same attacker.
            AIMotionTarget(unit,FOLLOW_RANGE_MELEE);    
    }
}

void PetAI::EnterEvadeMode()
{
    i_pet.DeleteThreatList();
    i_pet.AttackStop();
    i_pet.ClearInCombat(false);
}

bool PetAI::IsVisible(Unit *pl) const
{
    return _isVisible(pl);
}

bool PetAI::_needToStop() const
{
    if(!i_pet.getVictim() || !i_pet.isAlive())
        return true;

    // This is needed for charmed creatures, as once their target was reset other effects can trigger threat
    if(i_pet.isCharmed() && i_pet.getVictim() == i_pet.GetCharmer())
        return true;

    return !i_pet.getVictim()->isTargetableForAttack();
}

void PetAI::_stopAttack()
{
    EnterEvadeMode();
}

void PetAI::UpdateAI(const uint32 diff)
{
    Unit* owner = i_pet.GetCharmerOrOwner();
    if(!owner)
        return;

	// update i_victimGuid if i_pet.getVictim() !=0 and changed
    if(!i_pet.getVictim() && !i_pet.GetCharmInfo()->HasReactState(REACT_PASSIVE))
    {
        
        Unit* ownerAttacker = owner->getAttackerForHelper();
        if(ownerAttacker)
        {

            if(i_pet.GetCharmInfo()->HasReactState(REACT_AGGRESSIVE) && (Unit::getHpPercent(ownerAttacker) < 100 || Unit::getHpPercent(owner) < 100))
                AttackStart(ownerAttacker);
            else if(Unit::getHpPercent(owner) < 100)
                AttackStart(ownerAttacker);
        }
    }

    if(m_updateAlliesTimer <= diff)
        // UpdateAllies self set update timer
        UpdateAllies();
    else
        m_updateAlliesTimer -= diff;
    
    if( !i_pet.GetCharmInfo()->HasReactState(REACT_PASSIVE) && !_needToStop() )
    {
        if( i_pet.isAttackReady() && i_pet.IsWithinDistInMap(i_pet.getVictim(), i_pet.GetFloatValue(UNIT_FIELD_COMBATREACH)) )
        {
            i_pet.AttackerStateUpdate(i_pet.getVictim());
            i_pet.resetAttackTimer();
            i_pet.SelectHostilTarget();
        }
    }
    if( i_pet.isInCombat() && _needToStop() )
    {
        _stopAttack();
        return;
    }
    //Autocast
    HM_NAMESPACE::hash_map<uint32, Unit*> targetMap;
    targetMap.clear();
    SpellCastTargets NULLtargets;

    for (uint8 i = 0; i < i_pet.GetPetAutoSpellSize(); i++)
    {
        SpellEntry const *spellInfo;
        uint32 spellID = i_pet.GePetAutoSpellOnPos(i);
        if (!spellID || !(spellInfo = sSpellStore.LookupEntry(spellID)))
            continue;

        Spell *spell = new Spell(&i_pet, spellInfo, false, 0);

        if(!IsPositiveSpell(spellInfo->Id) && i_pet.getVictim() && !_needToStop() /*&& !i_pet.hasUnitState(UNIT_STAT_FOLLOW)*/ && spell->CanAutoCast(i_pet.getVictim()))
            targetMap[spellID] = i_pet.getVictim();
        else
        {
            spell->m_targets = NULLtargets;
            for(std::set<uint64>::iterator tar = m_AllySet.begin(); tar != m_AllySet.end(); ++tar)
            {
                Unit* Target = ObjectAccessor::Instance().GetUnit(i_pet,*tar);

                //only buff targets that are in combat, unless the spell can only be cast while out of combat
                if(!Target || (!Target->isInCombat() && !IsNonCombatSpell(spellID)))
                    continue;
                if(spell->CanAutoCast(Target))
                    targetMap[spellID] = Target;
            }
        }

        delete spell;
    }

    //found units to cast on to
    if(!targetMap.empty())
    {
        uint32 index = urand(1, targetMap.size());
        HM_NAMESPACE::hash_map<uint32, Unit*>::iterator itr;
        uint32 i;
        for(itr = targetMap.begin(), i = 1; i < index; ++itr, ++i);

        SpellEntry const *spellInfo = sSpellStore.LookupEntry(itr->first);

        Spell *spell = new Spell(&i_pet, spellInfo, false, 0);

        SpellCastTargets targets;
        targets.setUnitTarget( itr->second );

        if(!i_pet.HasInArc(M_PI, itr->second))
        {
            i_pet.SetInFront(itr->second);
            if( itr->second->GetTypeId() == TYPEID_PLAYER )
                i_pet.SendUpdateToPlayer( (Player*)itr->second );

            if(owner && owner->GetTypeId() == TYPEID_PLAYER)
                i_pet.SendUpdateToPlayer( (Player*)owner );
        }

        i_pet.AddCreatureSpellCooldown(itr->first);
        if(i_pet.isPet())
            ((Pet*)&i_pet)->CheckLearning(itr->first);

        spell->prepare(&targets);
    }
    targetMap.clear();
    
    //if(i_pet.getVictim())
}

bool PetAI::_isVisible(Unit *u) const
{
    //return false;                                           //( ((Creature*)&i_pet)->GetDistanceSq(u) * 1.0<= sWorld.getConfig(CONFIG_SIGHT_GUARDER) && !u->m_stealth && u->isAlive());
    return i_pet.GetDistanceSq(u) < sWorld.getConfig(CONFIG_SIGHT_GUARDER)
        && u->isVisibleForOrDetect(&i_pet,true);
}

void PetAI::UpdateAllies()
{
    Unit* owner = i_pet.GetCharmerOrOwner();
    Group *pGroup = NULL;

    m_updateAlliesTimer = 10000;                            //update friendly targets every 10 seconds, lesser checks increase performance

    if(!owner)
        return;
    else if(owner->GetTypeId() == TYPEID_PLAYER)
        pGroup = ((Player*)owner)->GetGroup();

    //only pet and owner/not in group->ok
    if(m_AllySet.size() == 2 && !pGroup)
        return;
    //owner is in group; group members filled in already (no raid -> subgroupcount = whole count)
    if(pGroup && !pGroup->isRaidGroup() && m_AllySet.size() == (pGroup->GetMembersCount() + 2))
        return;

    m_AllySet.clear();
    m_AllySet.insert(i_pet.GetGUID());
    if(pGroup)                                              //add group
    {
        for(GroupReference *itr = pGroup->GetFirstMember(); itr != NULL; itr = itr->next())
        {
            Player* Target = itr->getSource();
            if(!Target || !pGroup->SameSubGroup((Player*)owner, Target))
                continue;

            if(Target->GetGUID() == owner->GetGUID())
                continue;

            m_AllySet.insert(Target->GetGUID());
        }
    }
    else                                                    //remove group
        m_AllySet.insert(owner->GetGUID());
}

void PetAI::AIMotionTarget(Unit* target, float offSet)
{
    bool exist = false;
    MotionMaster* creatureMM = i_pet.GetMotionMaster();

    if(!target /*&& creatureMM->top()->GetMovementGeneratorType() == TARGETED_MOTION_TYPE*/)
    {
        //creatureMM->MovementExpired();
        return;    
    }
    //Here is wrong... TODO fix angle... but in fact i wan MV for Follower and One for Attacker.
    float angle = NULL;
    if( !i_pet.IsHostileTo(target) )
    {
        angle = target->GetOrientation()*2.0f;
    }

    if(creatureMM->top()->GetMovementGeneratorType() == TARGETED_MOTION_TYPE)
    {
        TargetedMovementGenerator<Creature>* targetMV = static_cast<TargetedMovementGenerator<Creature>*> (creatureMM->top());
        if( targetMV && targetMV->GetTarget() )
        {
            if( targetMV->GetTarget()->GetGUID() != target->GetGUID() )
            {
                creatureMM->MovementExpired(false);
                creatureMM->Mutate(new TargetedMovementGenerator<Creature>(*target,offSet,angle));
            }
            else if(targetMV->GetOffSet() != offSet)
                targetMV->SetOffSet(offSet);
        }
    }
    else
    { 
        i_pet.GetMotionMaster()->Mutate(new TargetedMovementGenerator<Creature>(*target,offSet,angle));
    }
}

/*void PetAI::AttackedBy(Unit *attacker)
{
    //when attacked, fight back in case 1)no victim already AND 2)not set to passive AND 3)not set to stay, unless can it can reach attacker with melee attack anyway
    if(!i_pet.getVictim() && i_pet.GetCharmInfo() && !i_pet.GetCharmInfo()->HasReactState(REACT_PASSIVE) &&
        (!i_pet.GetCharmInfo()->HasCommandState(COMMAND_STAY) || i_pet.canReachWithAttack(attacker)))
        AttackStart(attacker);
}
*/