/*
* All or portions of this file Copyright (c) Amazon.com, Inc. or its affiliates or
* its licensors.
*
* For complete copyright and license terms please see the LICENSE at the root of this
* distribution (the "License"). All use of this software is governed by the License,
* or, if provided, by the license below or the license accompanying this file. Do not
* remove or modify any license notices. This file is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
*
*/

#include "LmbrCentral_precompiled.h"
#include "CompoundShapeComponent.h"
#include <AzCore/Math/Transform.h>
#include "Cry_GeoOverlap.h"


namespace LmbrCentral
{
    void CompoundShapeComponent::Reflect(AZ::ReflectContext* context)
    {
        CompoundShapeConfiguration::Reflect(context);

        auto serializeContext = azrtti_cast<AZ::SerializeContext*>(context);
        if (serializeContext)
        {
            serializeContext->Class<CompoundShapeComponent, AZ::Component>()
                ->Version(1)
                ->Field("Configuration", &CompoundShapeComponent::m_configuration)
                ;
        }
    }

    void CompoundShapeComponent::Activate()
    {
        for (const AZ::EntityId& childEntity : m_configuration.GetChildEntities())
        {
            AZ::EntityBus::MultiHandler::BusConnect(childEntity);
        }

        ShapeComponentRequestsBus::Handler::BusConnect(GetEntityId());
        CompoundShapeComponentRequestsBus::Handler::BusConnect(GetEntityId());
    }

    void CompoundShapeComponent::Deactivate()
    {
        AZ::EntityBus::MultiHandler::BusDisconnect();
        CompoundShapeComponentRequestsBus::Handler::BusDisconnect();
        ShapeComponentRequestsBus::Handler::BusDisconnect();
        ShapeComponentNotificationsBus::MultiHandler::BusDisconnect();
    }

    //////////////////////////////////////////////////////////////////////////

    AZ::Aabb CompoundShapeComponent::GetEncompassingAabb()
    {
        AZ::Aabb finalAabb = AZ::Aabb::CreateNull();

        for (AZ::EntityId childEntity : m_configuration.GetChildEntities())
        {
            AZ::Aabb childAabb = AZ::Aabb::CreateNull();
            EBUS_EVENT_ID_RESULT(childAabb, childEntity, ShapeComponentRequestsBus, GetEncompassingAabb);
            if (childAabb.IsValid())
            {
                finalAabb.AddAabb(childAabb);
            }
        }
        return finalAabb;
    }

    bool CompoundShapeComponent::IsPointInside(const AZ::Vector3& point)
    {
        bool result = false;
        for (AZ::EntityId childEntity : m_configuration.GetChildEntities())
        {
            EBUS_EVENT_ID_RESULT(result, childEntity, ShapeComponentRequestsBus, IsPointInside, point);
            if (result)
            {
                break;
            }
        }
        return result;
    }

    float CompoundShapeComponent::DistanceSquaredFromPoint(const AZ::Vector3& point)
    {
        float smallestDistanceSquared = FLT_MAX;
        for (AZ::EntityId childEntity : m_configuration.GetChildEntities())
        {
            float currentDistanceSquared = FLT_MAX;
            EBUS_EVENT_ID_RESULT(currentDistanceSquared, childEntity, ShapeComponentRequestsBus, DistanceSquaredFromPoint, point);
            if (currentDistanceSquared < smallestDistanceSquared)
            {
                smallestDistanceSquared = currentDistanceSquared;
            }
        }
        return smallestDistanceSquared;
    }

    bool CompoundShapeComponent::IntersectRay(const AZ::Vector3& src, const AZ::Vector3& dir, AZ::VectorFloat& distance)
    {
        bool intersection = false;
        for (AZ::EntityId childEntity : m_configuration.GetChildEntities())
        {
            ShapeComponentRequestsBus::EventResult(intersection, childEntity, &ShapeComponentRequests::IntersectRay, src, dir, distance);
            if (intersection)
            {
                return true;
            }
        }

        return false;
    }

    void CompoundShapeComponent::OnEntityActivated(const AZ::EntityId& id)
    {
        m_currentlyActiveChildren++;
        ShapeComponentNotificationsBus::MultiHandler::BusConnect(id);
        
        if (ShapeComponentRequestsBus::Handler::BusIsConnected() && CompoundShapeComponentRequestsBus::Handler::BusIsConnected())
        {
            EBUS_EVENT_ID(GetEntityId(), ShapeComponentNotificationsBus, OnShapeChanged, ShapeComponentNotifications::ShapeChangeReasons::ShapeChanged);
        }
    }

    void CompoundShapeComponent::OnEntityDeactivated(const AZ::EntityId& id)
    {
        m_currentlyActiveChildren--;
        ShapeComponentNotificationsBus::MultiHandler::BusDisconnect(id);
        EBUS_EVENT_ID(GetEntityId(), ShapeComponentNotificationsBus, OnShapeChanged, ShapeComponentNotifications::ShapeChangeReasons::ShapeChanged);
    }

    void CompoundShapeComponent::OnShapeChanged(ShapeComponentNotifications::ShapeChangeReasons changeReason)
    {
        if (changeReason == ShapeComponentNotifications::ShapeChangeReasons::ShapeChanged)
        {
            EBUS_EVENT_ID(GetEntityId(), ShapeComponentNotificationsBus, OnShapeChanged, ShapeComponentNotifications::ShapeChangeReasons::ShapeChanged);
        }
        else if (changeReason == ShapeComponentNotifications::ShapeChangeReasons::TransformChanged)
        {
            // If there are multiple shapes in a compound shape, then moving one of them changes the overall compound shape, otherwise the transform change is bubbled up directly
            EBUS_EVENT_ID(GetEntityId(), ShapeComponentNotificationsBus, OnShapeChanged, (m_currentlyActiveChildren > 1) ? ShapeComponentNotifications::ShapeChangeReasons::ShapeChanged
                          : ShapeComponentNotifications::ShapeChangeReasons::TransformChanged);
        }
    }

    //////////////////////////////////////////////////////////////////////////
} // namespace LmbrCentral