/*
 * Copyright (C) 2008-2012 TrinityCore <http://www.trinitycore.org/>
 * Copyright (C) 2005-2009 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, see <http://www.gnu.org/licenses/>.
 */

#include "GuardAI.h"
#include "Errors.h"
#include "Player.h"
#include "ObjectAccessor.h"
#include "World.h"
#include "CreatureAIImpl.h"

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

    return PERMIT_BASE_NO;
}

GuardAI::GuardAI(Creature* creature) : ScriptedAI(creature), i_victimGuid(0), i_state(STATE_NORMAL), i_tracker(TIME_INTERVAL_LOOK)
{
}

bool GuardAI::CanSeeAlways(WorldObject const* obj)
{
    if (!obj->isType(TYPEMASK_UNIT))
        return false;

    std::list<HostileReference*> t_list = me->getThreatManager().getThreatList();
    for (std::list<HostileReference*>::const_iterator itr = t_list.begin(); itr!= t_list.end(); ++itr)
    {
        if (Unit* unit = Unit::GetUnit(*me, (*itr)->getUnitGuid()))
            if (unit == obj)
                return true;
    }

    return false;
}

void GuardAI::MoveInLineOfSight(Unit* unit)
{
    // Ignore Z for flying creatures
    if (!me->canFly() && me->GetDistanceZ(unit) > CREATURE_Z_ATTACK_RANGE)
        return;

    if (!me->getVictim() && me->IsValidAttackTarget(unit) &&
        (unit->IsHostileToPlayers() || me->IsHostileTo(unit)) &&
        unit->isInAccessiblePlaceFor(me))
    {
        float attackRadius = me->GetAttackDistance(unit);
        if (me->IsWithinDistInMap(unit, attackRadius))
        {
            //Need add code to let guard support player
            AttackStart(unit);
            //u->RemoveAurasByType(SPELL_AURA_MOD_STEALTH);
        }
    }
}

void GuardAI::EnterEvadeMode()
{
    if (!me->isAlive())
    {
        sLog->outStaticDebug("Creature stopped attacking because he is dead [guid=%u]", me->GetGUIDLow());
        me->GetMotionMaster()->MoveIdle();

        i_state = STATE_NORMAL;

        i_victimGuid = 0;
        me->CombatStop(true);
        me->DeleteThreatList();
        return;
    }

    Unit* victim = ObjectAccessor::GetUnit(*me, i_victimGuid);

    if (!victim)
    {
        sLog->outStaticDebug("Creature stopped attacking because victim does not exist [guid=%u]", me->GetGUIDLow());
    }
    else if (!victim ->isAlive())
    {
        sLog->outStaticDebug("Creature stopped attacking because victim is dead [guid=%u]", me->GetGUIDLow());
    }
    else if (victim ->HasStealthAura())
    {
        sLog->outStaticDebug("Creature stopped attacking because victim is using stealth [guid=%u]", me->GetGUIDLow());
    }
    else if (victim ->isInFlight())
    {
        sLog->outStaticDebug("Creature stopped attacking because victim is flying away [guid=%u]", me->GetGUIDLow());
    }
    else
    {
        sLog->outStaticDebug("Creature stopped attacking because victim outran him [guid=%u]", me->GetGUIDLow());
    }

    me->RemoveAllAuras();
    me->DeleteThreatList();
    i_victimGuid = 0;
    me->CombatStop(true);
    i_state = STATE_NORMAL;

    // Remove TargetedMovementGenerator from MotionMaster stack list, and add HomeMovementGenerator instead
    if (me->GetMotionMaster()->GetCurrentMovementGeneratorType() == TARGETED_MOTION_TYPE)
        me->GetMotionMaster()->MoveTargetedHome();
}

void GuardAI::UpdateAI(const uint32 /*diff*/)
{
    // update i_victimGuid if me->getVictim() !=0 and changed
    if (!UpdateVictim())
        return;

    Unit* const victim = me->getVictim();
    if (!victim)
        return;

    i_victimGuid = victim->GetGUID();

    if (me->isAttackReady())
    {
        if (me->IsWithinMeleeRange(victim))
        {
            me->AttackerStateUpdate(victim);
            me->resetAttackTimer();
        }
    }
}

void GuardAI::JustDied(Unit* killer)
{
    if (Player* player = killer->GetCharmerOrOwnerPlayerOrPlayerItself())
        me->SendZoneUnderAttackMessage(player);
}
