#include "aipursue.hpp"

#include <components/esm3/aisequence.hpp>

#include "../mwbase/environment.hpp"
#include "../mwbase/mechanicsmanager.hpp"
#include "../mwbase/windowmanager.hpp"
#include "../mwbase/world.hpp"

#include "../mwworld/class.hpp"

#include "actorutil.hpp"
#include "creaturestats.hpp"

namespace MWMechanics
{

    AiPursue::AiPursue(const MWWorld::Ptr& actor)
    {
        mTargetActorId = actor.getClass().getCreatureStats(actor).getActorId();
    }

    AiPursue::AiPursue(const ESM::AiSequence::AiPursue* pursue)
    {
        mTargetActorId = pursue->mTargetActorId;
    }

    bool AiPursue::execute(
        const MWWorld::Ptr& actor, CharacterController& characterController, AiState& state, float duration)
    {
        if (actor.getClass().getCreatureStats(actor).isDead())
            return true;

        const MWWorld::Ptr target
            = MWBase::Environment::get().getWorld()->searchPtrViaActorId(mTargetActorId); // The target to follow

        // Stop if the target doesn't exist
        // Really we should be checking whether the target is currently registered with the MechanicsManager
        if (target == MWWorld::Ptr() || !target.getRefData().getCount() || !target.getRefData().isEnabled())
            return true;

        if (isTargetMagicallyHidden(target)
            && !MWBase::Environment::get().getMechanicsManager()->awarenessCheck(target, actor))
            return false;

        if (target.getClass().getCreatureStats(target).isDead())
            return true;

        actor.getClass().getCreatureStats(actor).setDrawState(DrawState::Nothing);

        // Set the target destination
        const osg::Vec3f dest = target.getRefData().getPosition().asVec3();
        const osg::Vec3f actorPos = actor.getRefData().getPosition().asVec3();

        const float pathTolerance = 100.f;

        // check the true distance in case the target is far away in Z-direction
        bool reached = pathTo(actor, dest, duration, pathTolerance, (actorPos - dest).length(), PathType::Partial)
            && std::abs(dest.z() - actorPos.z()) < pathTolerance;

        if (reached)
        {
            if (!MWBase::Environment::get().getWorld()->getLOS(target, actor))
                return false;
            MWBase::Environment::get().getWindowManager()->pushGuiMode(
                MWGui::GM_Dialogue, actor); // Arrest player when reached
            return true;
        }

        actor.getClass().getCreatureStats(actor).setMovementFlag(
            MWMechanics::CreatureStats::Flag_Run, true); // Make NPC run

        return false;
    }

    MWWorld::Ptr AiPursue::getTarget() const
    {
        if (!mCachedTarget.isEmpty())
        {
            if (mCachedTarget.getRefData().isDeleted() || !mCachedTarget.getRefData().isEnabled())
                mCachedTarget = MWWorld::Ptr();
            else
                return mCachedTarget;
        }
        mCachedTarget = MWBase::Environment::get().getWorld()->searchPtrViaActorId(mTargetActorId);
        return mCachedTarget;
    }

    void AiPursue::writeState(ESM::AiSequence::AiSequence& sequence) const
    {
        auto pursue = std::make_unique<ESM::AiSequence::AiPursue>();
        pursue->mTargetActorId = mTargetActorId;

        ESM::AiSequence::AiPackageContainer package;
        package.mType = ESM::AiSequence::Ai_Pursue;
        package.mPackage = std::move(pursue);
        sequence.mPackages.push_back(std::move(package));
    }

} // namespace MWMechanics