/*
 * Copyright (c) Contributors to the Open 3D Engine Project.
 * For complete copyright and license terms please see the LICENSE at the root of this distribution.
 *
 * SPDX-License-Identifier: Apache-2.0 OR MIT
 *
 */

#include <AzCore/UnitTest/TestTypes.h>
#include <AzCore/UserSettings/UserSettingsComponent.h>
#include <AzFramework/Application/Application.h>
#include <AzFramework/Components/TransformComponent.h>
#include <AzFramework/Spawnable/SpawnableAssetHandler.h>
#include <AzFramework/Spawnable/SpawnableEntitiesManager.h>
#include <AzFramework/Spawnable/Script/SpawnableScriptAssetRef.h>
#include <AzFramework/Spawnable/Script/SpawnableScriptBus.h>
#include <AzFramework/Spawnable/Script/SpawnableScriptMediator.h>
#include <AzTest/AzTest.h>

namespace UnitTest
{    
    class SpawnableScriptMediatorTests
        : public LeakDetectionFixture
        , public AzFramework::Scripts::SpawnableScriptNotificationsBus::MultiHandler
    {
    public:
        using TicketToEntityIdsPair = AZStd::pair<AzFramework::EntitySpawnTicket, AZStd::vector<AZ::EntityId>>;
        constexpr static AZ::u64 EntityIdStartId = 40;

        AZStd::vector<TicketToEntityIdsPair> m_spawnedTicketAndEntitiesPairs ;

        void OnSpawn(AzFramework::EntitySpawnTicket spawnTicket, AZStd::vector<AZ::EntityId> entityList) override
        {
            m_spawnedTicketAndEntitiesPairs .push_back({ spawnTicket, AZStd::move(entityList) });
        }

        virtual void OnDespawn(AzFramework::EntitySpawnTicket spawnTicket) override
        {
            AZStd::erase_if(
                m_spawnedTicketAndEntitiesPairs ,
                [&spawnTicket](const TicketToEntityIdsPair& pair) -> bool
                {
                    return pair.first == spawnTicket;
                });
        }

        void SetUp() override
        {
            LeakDetectionFixture::SetUp();

            m_application = new AzFramework::Application();
            AZ::ComponentApplication::Descriptor descriptor;
            AZ::ComponentApplication::StartupParameters startupParameters;
            startupParameters.m_loadSettingsRegistry = false;
            m_application->Start(descriptor, startupParameters);

            // Without this, the user settings component would attempt to save on finalize/shutdown. Since the file is
            // shared across the whole engine, if multiple tests are run in parallel, the saving could cause a crash
            // in the unit tests.
            AZ::UserSettingsComponentRequestBus::Broadcast(&AZ::UserSettingsComponentRequests::DisableSaveOnFinalize);

            auto managerInterface = AzFramework::SpawnableEntitiesInterface::Get();
            m_manager = azrtti_cast<AzFramework::SpawnableEntitiesManager*>(managerInterface);
        }

        void TearDown() override
        {
            AzFramework::Scripts::SpawnableScriptNotificationsBus::MultiHandler::BusDisconnect();
            // One more tick on the spawnable entities manager in order to delete the ticket fully.
            m_manager->ProcessQueue(
                AzFramework::SpawnableEntitiesManager::CommandQueuePriority::High |
                AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
            
            m_spawnedTicketAndEntitiesPairs  = {};

            delete m_application;
            m_application = nullptr;

            LeakDetectionFixture::TearDown();
        }

        void WaitForResponse(AzFramework::Scripts::SpawnableScriptMediator& mediator)
        {
            m_manager->ProcessQueue(
                AzFramework::SpawnableEntitiesManager::CommandQueuePriority::High |
                AzFramework::SpawnableEntitiesManager::CommandQueuePriority::Regular);
            // force an additional tick on mediator to synchronize spawn callbacks and dispatch EBus notifications
            mediator.OnTick(0, AZ::ScriptTimePoint());
        }
        
        AzFramework::Scripts::SpawnableScriptAssetRef CreateSpawnable(size_t numElements)
        {
            AZ::Data::AssetId spawnableAssetId(AZ::Uuid::Create(), 0);
            auto spawnable = aznew AzFramework::Spawnable(spawnableAssetId, AZ::Data::AssetData::AssetStatus::Ready);
            AzFramework::Spawnable::EntityList& entities = spawnable->GetEntities();
            entities.reserve(numElements);
            for (size_t i = 0; i < numElements; ++i)
            {
                auto entry = AZStd::make_unique<AZ::Entity>();
                entry->SetId(AZ::EntityId(EntityIdStartId + i));
                AzFramework::TransformComponent* transformComponent = aznew AzFramework::TransformComponent();
                entry->AddComponent(transformComponent);
                entities.push_back(AZStd::move(entry));
            }
            auto spawnableAsset = AZ::Data::Asset<AzFramework::Spawnable>(spawnable, AZ::Data::AssetLoadBehavior::Default);
            AzFramework::Scripts::SpawnableScriptAssetRef spawnableScriptAssetRef;
            spawnableScriptAssetRef.SetAsset(spawnableAsset);
            return spawnableScriptAssetRef;
        }

    protected:
        AzFramework::SpawnableEntitiesManager* m_manager { nullptr };
        AzFramework::Application* m_application{ nullptr };
    };

    TEST_F(SpawnableScriptMediatorTests, CreateSpawnTicket_Works)
    {
        using namespace AzFramework::Scripts;
        auto spawnable = CreateSpawnable(1);
        SpawnableScriptMediator mediator;
        auto ticket = mediator.CreateSpawnTicket(spawnable);
        EXPECT_TRUE(ticket.IsValid());
    }

    TEST_F(SpawnableScriptMediatorTests, SpawnAndDespawn_Works)
    {
        using namespace AzFramework::Scripts;

        auto spawnable = CreateSpawnable(1);
        SpawnableScriptMediator mediator;
        const auto ticket = mediator.CreateSpawnTicket(spawnable);

        SpawnableScriptNotificationsBus::MultiHandler::BusConnect(ticket.GetId());

        mediator.Spawn(ticket);
        WaitForResponse(mediator);
        EXPECT_EQ(m_spawnedTicketAndEntitiesPairs .size(), 1);
        EXPECT_EQ(m_spawnedTicketAndEntitiesPairs [0].first, ticket);
        EXPECT_EQ(m_spawnedTicketAndEntitiesPairs [0].second.size(), 1);

        mediator.Despawn(ticket);
        WaitForResponse(mediator);

        EXPECT_TRUE(m_spawnedTicketAndEntitiesPairs .empty());
    }

    TEST_F(SpawnableScriptMediatorTests, SpawnMultipleAtOnce_Works)
    {
        using namespace AzFramework::Scripts;
        
        auto spawnable1 = CreateSpawnable(1);
        auto spawnable2 = CreateSpawnable(2);

        SpawnableScriptMediator mediator;

        auto ticket1 = mediator.CreateSpawnTicket(spawnable1);
        auto ticket2 = mediator.CreateSpawnTicket(spawnable2);

        SpawnableScriptNotificationsBus::MultiHandler::BusConnect(ticket1.GetId());
        SpawnableScriptNotificationsBus::MultiHandler::BusConnect(ticket2.GetId());

        mediator.Spawn(ticket1);
        mediator.Spawn(ticket2);
        WaitForResponse(mediator);

        auto it1 = AZStd::find_if(
            m_spawnedTicketAndEntitiesPairs .begin(), m_spawnedTicketAndEntitiesPairs .end(),
            [&ticket1](const TicketToEntityIdsPair& pair) -> bool
            {
                return pair.first == ticket1;
            });
        EXPECT_FALSE(it1 == m_spawnedTicketAndEntitiesPairs .end());
        EXPECT_EQ(it1->second.size(), 1);

        auto it2 = AZStd::find_if(
            m_spawnedTicketAndEntitiesPairs .begin(), m_spawnedTicketAndEntitiesPairs .end(),
            [&ticket2](const TicketToEntityIdsPair& pair) -> bool
            {
                return pair.first == ticket2;
            });
        EXPECT_FALSE(it2 == m_spawnedTicketAndEntitiesPairs .end());
        EXPECT_EQ(it2->second.size(), 2);

        mediator.Despawn(ticket1);
        mediator.Despawn(ticket2);
        WaitForResponse(mediator);

        EXPECT_TRUE(m_spawnedTicketAndEntitiesPairs .empty());
    }

    TEST_F(SpawnableScriptMediatorTests, SpawnAndParent_Works)
    {
        using namespace AzFramework::Scripts;

        auto spawnable = CreateSpawnable(1);
        SpawnableScriptMediator mediator;
        auto ticket = mediator.CreateSpawnTicket(spawnable);

        SpawnableScriptNotificationsBus::MultiHandler::BusConnect(ticket.GetId());

        AZ::EntityId parentId = AZ::Entity::MakeId();
        AZ::Entity parentEntity(parentId);
        AzFramework::TransformComponent parentTransformComponent;
        parentEntity.AddComponent(&parentTransformComponent);
        parentEntity.Init();
        parentEntity.ApplyEffectiveActiveState();

        mediator.SpawnAndParent(ticket, parentEntity.GetId());
        WaitForResponse(mediator);

        AZStd::vector<AZ::EntityId> descendantIds;
        AZ::TransformBus::EventResult(descendantIds, parentId, &AZ::TransformBus::Events::GetAllDescendants);
        EXPECT_EQ(descendantIds.size(), 1);
        EXPECT_EQ(m_spawnedTicketAndEntitiesPairs .size(), 1);
        EXPECT_EQ(m_spawnedTicketAndEntitiesPairs [0].second.size(), 1);
        EXPECT_EQ(descendantIds[0], m_spawnedTicketAndEntitiesPairs [0].second[0]);

        mediator.Despawn(ticket);
        WaitForResponse(mediator);

        // Wait for entities to actually be destroyed
        AZ::TickBus::ExecuteQueuedEvents();

        AZ::TransformBus::EventResult(descendantIds, parentId, &AZ::TransformBus::Events::GetAllDescendants);
        EXPECT_TRUE(descendantIds.empty());

        parentEntity.SetEntityActive(false);
        parentEntity.ApplyEffectiveActiveState();
    }

    TEST_F(SpawnableScriptMediatorTests, SpawnAndParentAndTransform_Works)
    {
        using namespace AzFramework::Scripts;

        auto spawnable = CreateSpawnable(1);
        SpawnableScriptMediator mediator;
        auto ticket = mediator.CreateSpawnTicket(spawnable);

        SpawnableScriptNotificationsBus::MultiHandler::BusConnect(ticket.GetId());

        AZ::EntityId parentId = AZ::Entity::MakeId();
        AZ::Entity parentEntity(parentId);
        AzFramework::TransformComponent parentTransformComponent;
        parentEntity.AddComponent(&parentTransformComponent);
        parentEntity.Init();
        parentEntity.Activate();

        AZ::Vector3 translation(5, 0, 0);
        AZ::Vector3 rotation(90, 0, 0);
        float scale = 2.0f;

        mediator.SpawnAndParentAndTransform(ticket, parentEntity.GetId(), translation, rotation, scale);
        WaitForResponse(mediator);

        AZStd::vector<AZ::EntityId> descendantIds;
        AZ::TransformBus::EventResult(descendantIds, parentId, &AZ::TransformBus::Events::GetAllDescendants);

        EXPECT_EQ(descendantIds.size(), 1);
        auto it = AZStd::find_if(
            m_spawnedTicketAndEntitiesPairs .begin(), m_spawnedTicketAndEntitiesPairs .end(),
            [&ticket](const TicketToEntityIdsPair& pair) -> bool
            {
                return pair.first.GetId() == ticket.GetId();
            });
        EXPECT_FALSE(it == m_spawnedTicketAndEntitiesPairs .end());
        EXPECT_FALSE(it->second.empty());

        AZ::EntityId entityId = it->second[0];
        AZ::Vector3 spawnedTranslation = {};
        AZ::Quaternion spawnedRotation = {};
        float spawnedScale;

        AZ::TransformBus::EventResult(spawnedTranslation, entityId, &AZ::TransformBus::Events::GetLocalTranslation);
        AZ::TransformBus::EventResult(spawnedRotation, entityId, &AZ::TransformBus::Events::GetLocalRotationQuaternion);
        AZ::TransformBus::EventResult(spawnedScale, entityId, &AZ::TransformBus::Events::GetLocalUniformScale);
        EXPECT_EQ(translation, spawnedTranslation);
        EXPECT_EQ(AZ::Quaternion::CreateFromEulerAnglesDegrees(rotation), spawnedRotation);
        EXPECT_EQ(scale, spawnedScale);

        mediator.Despawn(ticket);
        WaitForResponse(mediator);

        // Wait for entities to actually be destroyed
        AZ::TickBus::ExecuteQueuedEvents();
        
        AZ::TransformBus::EventResult(descendantIds, parentId, &AZ::TransformBus::Events::GetAllDescendants);
        EXPECT_TRUE(descendantIds.empty());

        parentEntity.Deactivate();
    }
} // namespace UnitTest