/*
 * 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.
 */

#include "EnemyPlayerValue.h"

#include "Playerbots.h"
#include "ServerFacade.h"
#include "Vehicle.h"

bool NearestEnemyPlayersValue::AcceptUnit(Unit* unit)
{
    bool inCannon = botAI->IsInVehicle(false, true);
    Player* enemy = dynamic_cast<Player*>(unit);
    if (enemy && botAI->IsOpposing(enemy) && enemy->IsPvP() &&
        !sPlayerbotAIConfig->IsPvpProhibited(enemy->GetZoneId(), enemy->GetAreaId()) &&
        !enemy->HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NON_ATTACKABLE | UNIT_FLAG_NON_ATTACKABLE_2) &&
        ((inCannon || !enemy->HasFlag(UNIT_FIELD_FLAGS, UNIT_FLAG_NOT_SELECTABLE))) &&
        /*!enemy->HasStealthAura() && !enemy->HasInvisibilityAura()*/ enemy->CanSeeOrDetect(bot) &&
        !(enemy->HasSpiritOfRedemptionAura()))
        return true;

    return false;
}

Unit* EnemyPlayerValue::Calculate()
{
    bool controllingCannon = false;
    bool controllingVehicle = false;
    if (Vehicle* vehicle = bot->GetVehicle())
    {
        VehicleSeatEntry const* seat = vehicle->GetSeatForPassenger(bot);
        if (!seat || !seat->CanControl())  // not in control of vehicle so cant attack anyone
            return nullptr;
        VehicleEntry const* vi = vehicle->GetVehicleInfo();
        if (vi && vi->m_flags & VEHICLE_FLAG_FIXED_POSITION)
            controllingCannon = true;
        else
            controllingVehicle = true;
    }

    // 1. Check units we are currently in combat with.
    std::vector<Unit*> targets;
    Unit* pVictim = bot->GetVictim();
    HostileReference* pReference = bot->getHostileRefMgr().getFirst();
    while (pReference)
    {
        ThreatMgr* threatMgr = pReference->GetSource();
        if (Unit* pTarget = threatMgr->GetOwner())
        {
            if (pTarget != pVictim && pTarget->IsPlayer() && pTarget->CanSeeOrDetect(bot) &&
                bot->IsWithinDist(pTarget, VISIBILITY_DISTANCE_NORMAL))
            {
                if (bot->GetTeamId() == TEAM_HORDE)
                {
                    if (pTarget->HasAura(23333))
                        return pTarget;
                }
                else
                {
                    if (pTarget->HasAura(23335))
                        return pTarget;
                }

                targets.push_back(pTarget);
            }
        }

        pReference = pReference->next();
    }

    if (!targets.empty())
    {
        std::sort(targets.begin(), targets.end(),
                  [&](Unit const* pUnit1, Unit const* pUnit2)
                  { return bot->GetDistance(pUnit1) < bot->GetDistance(pUnit2); });

        return *targets.begin();
    }

    // 2. Find enemy player in range.

    GuidVector players = AI_VALUE(GuidVector, "nearest enemy players");
    float const maxAggroDistance = GetMaxAttackDistance();
    for (const auto& gTarget : players)
    {
        Unit* pUnit = botAI->GetUnit(gTarget);
        if (!pUnit)
            continue;

        Player* pTarget = dynamic_cast<Player*>(pUnit);
        if (!pTarget)
            continue;

        if (pTarget == pVictim)
            continue;

        if (bot->GetTeamId() == TEAM_HORDE)
        {
            if (pTarget->HasAura(23333))
                return pTarget;
        }
        else
        {
            if (pTarget->HasAura(23335))
                return pTarget;
        }

        // Aggro weak enemies from further away.
        // If controlling mobile vehicle only agro close enemies (otherwise will never reach objective)
        uint32 const aggroDistance = controllingVehicle                                               ? 5.0f
                                     : (controllingCannon || bot->GetHealth() > pTarget->GetHealth()) ? maxAggroDistance
                                                                                                      : 20.0f;
        if (!bot->IsWithinDist(pTarget, aggroDistance))
            continue;

        if (bot->IsWithinLOSInMap(pTarget) &&
            (controllingCannon || (fabs(bot->GetPositionZ() - pTarget->GetPositionZ()) < 30.0f)))
            return pTarget;
    }

    // 3. Check party attackers.

    if (Group* pGroup = bot->GetGroup())
    {
        for (GroupReference* itr = pGroup->GetFirstMember(); itr != nullptr; itr = itr->next())
        {
            if (Unit* pMember = itr->GetSource())
            {
                if (pMember == bot)
                    continue;

                if (sServerFacade->GetDistance2d(bot, pMember) > 30.0f)
                    continue;

                if (Unit* pAttacker = pMember->getAttackerForHelper())
                    if (pAttacker->IsPlayer() && bot->IsWithinDist(pAttacker, maxAggroDistance * 2.0f) &&
                        bot->IsWithinLOSInMap(pAttacker) && pAttacker != pVictim && pAttacker->CanSeeOrDetect(bot))
                        return pAttacker;
            }
        }
    }

    return nullptr;
}

float EnemyPlayerValue::GetMaxAttackDistance()
{
    if (!bot->GetBattleground())
        return 60.0f;

    Battleground* bg = bot->GetBattleground();
    if (!bg)
        return 40.0f;

    BattlegroundTypeId bgType = bg->GetBgTypeID();
    if (bgType == BATTLEGROUND_RB)
        bgType = bg->GetBgTypeID(true);

    if (bgType == BATTLEGROUND_IC)
    {
        if (botAI->IsInVehicle(false, true))
            return 120.0f;
    }

    return 40.0f;
}