#include <gtest/gtest.h>

#include <XCEngine/Components/CameraComponent.h>
#include <XCEngine/Components/GameObject.h>
#include <XCEngine/Components/MeshFilterComponent.h>
#include <XCEngine/Components/MeshRendererComponent.h>
#include <XCEngine/Core/Asset/IResource.h>
#include <XCEngine/Core/Math/Vector3.h>
#include <XCEngine/Rendering/RenderSceneExtractor.h>
#include <XCEngine/Scene/Scene.h>
#include <XCEngine/Resources/Mesh/Mesh.h>

using namespace XCEngine::Components;
using namespace XCEngine::Math;
using namespace XCEngine::Rendering;
using namespace XCEngine::Resources;

namespace {

Mesh* CreateTestMesh(const char* path) {
    auto* mesh = new Mesh();
    IResource::ConstructParams params = {};
    params.name = "TestMesh";
    params.path = path;
    params.guid = ResourceGUID::Generate(path);
    mesh->Initialize(params);
    return mesh;
}

TEST(RenderSceneExtractor_Test, SelectsHighestDepthPrimaryCameraAndVisibleObjects) {
    Scene scene("RenderScene");

    GameObject* cameraObjectA = scene.CreateGameObject("CameraA");
    auto* cameraA = cameraObjectA->AddComponent<CameraComponent>();
    cameraA->SetPrimary(true);
    cameraA->SetDepth(0.0f);

    GameObject* cameraObjectB = scene.CreateGameObject("CameraB");
    auto* cameraB = cameraObjectB->AddComponent<CameraComponent>();
    cameraB->SetPrimary(true);
    cameraB->SetDepth(5.0f);
    cameraObjectB->GetTransform()->SetLocalPosition(Vector3(2.0f, 3.0f, 4.0f));

    GameObject* visibleObject = scene.CreateGameObject("VisibleQuad");
    visibleObject->GetTransform()->SetLocalPosition(Vector3(1.0f, 2.0f, 3.0f));
    auto* meshFilter = visibleObject->AddComponent<MeshFilterComponent>();
    visibleObject->AddComponent<MeshRendererComponent>();
    Mesh* visibleMesh = CreateTestMesh("Meshes/visible.mesh");
    meshFilter->SetMesh(visibleMesh);

    GameObject* hiddenObject = scene.CreateGameObject("HiddenQuad");
    hiddenObject->SetActive(false);
    auto* hiddenMeshFilter = hiddenObject->AddComponent<MeshFilterComponent>();
    hiddenObject->AddComponent<MeshRendererComponent>();
    Mesh* hiddenMesh = CreateTestMesh("Meshes/hidden.mesh");
    hiddenMeshFilter->SetMesh(hiddenMesh);

    RenderSceneExtractor extractor;
    const RenderSceneData sceneData = extractor.Extract(scene, nullptr, 1280, 720);

    ASSERT_TRUE(sceneData.HasCamera());
    EXPECT_EQ(sceneData.camera, cameraB);
    EXPECT_EQ(sceneData.cameraData.viewportWidth, 1280u);
    EXPECT_EQ(sceneData.cameraData.viewportHeight, 720u);
    EXPECT_EQ(sceneData.cameraData.worldPosition, Vector3(2.0f, 3.0f, 4.0f));

    ASSERT_EQ(sceneData.visibleObjects.size(), 1u);
    EXPECT_EQ(sceneData.visibleObjects[0].gameObject, visibleObject);
    EXPECT_EQ(sceneData.visibleObjects[0].mesh, visibleMesh);
    EXPECT_EQ(sceneData.visibleObjects[0].localToWorld.GetTranslation(), Vector3(1.0f, 2.0f, 3.0f));

    meshFilter->ClearMesh();
    hiddenMeshFilter->ClearMesh();
    delete visibleMesh;
    delete hiddenMesh;
}

TEST(RenderSceneExtractor_Test, OverrideCameraTakesPriority) {
    Scene scene("OverrideScene");

    GameObject* primaryObject = scene.CreateGameObject("PrimaryCamera");
    auto* primaryCamera = primaryObject->AddComponent<CameraComponent>();
    primaryCamera->SetPrimary(true);
    primaryCamera->SetDepth(10.0f);

    GameObject* overrideObject = scene.CreateGameObject("OverrideCamera");
    auto* overrideCamera = overrideObject->AddComponent<CameraComponent>();
    overrideCamera->SetPrimary(false);
    overrideCamera->SetDepth(-1.0f);

    RenderSceneExtractor extractor;
    const RenderSceneData sceneData = extractor.Extract(scene, overrideCamera, 640, 480);

    ASSERT_TRUE(sceneData.HasCamera());
    EXPECT_EQ(sceneData.camera, overrideCamera);
    EXPECT_NE(sceneData.camera, primaryCamera);
    EXPECT_EQ(sceneData.cameraData.viewportWidth, 640u);
    EXPECT_EQ(sceneData.cameraData.viewportHeight, 480u);
}

} // namespace