/*
 * Copyright (C) 2005-2011 MaNGOS <http://getmangos.com/>
 * Copyright (C) 2009-2011 MaNGOSZero <https://github.com/mangos/zero>
 * Copyright (C) 2011-2016 Nostalrius <https://nostalrius.org>
 * Copyright (C) 2016-2017 Elysium Project <https://github.com/elysium-project>
 *
 * 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 "GuardAI.h"
#include "Creature.h"
#include "Player.h"

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

    return PERMIT_BASE_NO;
}

GuardAI::GuardAI(Creature *c) : CreatureAI(c)
{
}

// Returns whether the Unit is currently attacking other players or friendly npcs.
bool GuardAI::IsAttackingPlayerOrFriendly(const Unit* pWho) const
{
    if (pWho->IsPvPContested())
        return true;

    if (Unit* pVictim = pWho->getVictim())
    {
        if (m_creature->IsFriendlyTo(pVictim) || pVictim->isTaxi())
            return true;
    }

    return false;
}

void GuardAI::MoveInLineOfSight(Unit *pWho)
{
    if (m_creature->getVictim())
        return;

    // Ignore Z for flying creatures
    if (!m_creature->CanFly() && pWho->IsCreature() && m_creature->GetDistanceZ(pWho) > CREATURE_Z_ATTACK_RANGE)
        return;

    float attackRadius = m_creature->GetAttackDistance(pWho);

    bool isAttackingFriend = false;

    if (pWho->IsPlayer() && !m_creature->IsFriendlyTo(pWho))
    {
        // Assignment, not a typo.
        if (isAttackingFriend = IsAttackingPlayerOrFriendly(pWho))
            if ((attackRadius < 30.0f))
                attackRadius = 30.0f;
    }

    if (!m_creature->IsWithinDistInMap(pWho, attackRadius))
        return;

    if (m_creature->CanInitiateAttack() && pWho->isTargetableForAttack() &&
       (pWho->IsHostileToPlayers() || m_creature->IsHostileTo(pWho) || isAttackingFriend) &&
        pWho->isInAccessablePlaceFor(m_creature) && m_creature->IsWithinLOSInMap(pWho))
    {
        AttackStart(pWho);
    }
}

void GuardAI::EnterCombat(Unit *)
{
    m_creature->CallForHelp(30.0f);
}

void GuardAI::UpdateAI(const uint32 uiDiff)
{
    if (!m_creature->SelectHostileTarget() || !m_creature->getVictim())
        return;

    if (!m_CreatureSpells.empty())
        DoSpellsListCasts(uiDiff);

    DoMeleeAttackIfReady();
}

void GuardAI::AttackStart(Unit *pWho)
{
    if (!pWho)
        return;

    if (m_creature->Attack(pWho, m_bMeleeAttack))
    {
        m_creature->AddThreat(pWho);
        m_creature->SetInCombatWith(pWho);
        pWho->SetInCombatWith(m_creature);

        if (m_bCombatMovement)
            m_creature->GetMotionMaster()->MoveChase(pWho);
    }
}

void GuardAI::JustDied(Unit *pKiller)
{
    if (Player* pPlayerKiller = pKiller->GetCharmerOrOwnerPlayerOrPlayerItself())
        m_creature->SendZoneUnderAttackMessage(pPlayerKiller);
}