#include <gtest/gtest.h>

#include <XCEngine/Components/CameraComponent.h>
#include <XCEngine/Rendering/Planning/SceneRenderRequestUtils.h>
#include <XCEngine/Scene/Scene.h>

#include <vector>

using namespace XCEngine::Components;
using namespace XCEngine::Rendering;

namespace {

RenderContext CreateValidContext() {
    RenderContext context;
    context.device = reinterpret_cast<XCEngine::RHI::RHIDevice*>(1);
    context.commandList = reinterpret_cast<XCEngine::RHI::RHICommandList*>(1);
    context.commandQueue = reinterpret_cast<XCEngine::RHI::RHICommandQueue*>(1);
    return context;
}

} // namespace

TEST(SceneRenderRequestUtils_Test, RejectsNullDisabledAndInactiveCameras) {
    Scene scene("SceneRenderRequestUtilsUsableCameraScene");

    GameObject* activeObject = scene.CreateGameObject("ActiveCamera");
    auto* activeCamera = activeObject->AddComponent<CameraComponent>();

    GameObject* disabledObject = scene.CreateGameObject("DisabledCamera");
    auto* disabledCamera = disabledObject->AddComponent<CameraComponent>();
    disabledCamera->SetEnabled(false);

    GameObject* inactiveObject = scene.CreateGameObject("InactiveCamera");
    auto* inactiveCamera = inactiveObject->AddComponent<CameraComponent>();
    inactiveObject->SetActive(false);

    EXPECT_FALSE(SceneRenderRequestUtils::IsUsableCamera(nullptr));
    EXPECT_TRUE(SceneRenderRequestUtils::IsUsableCamera(activeCamera));
    EXPECT_FALSE(SceneRenderRequestUtils::IsUsableCamera(disabledCamera));
    EXPECT_FALSE(SceneRenderRequestUtils::IsUsableCamera(inactiveCamera));
}

TEST(SceneRenderRequestUtils_Test, SortsSceneCamerasByStackDepthAndKeepsStableTieOrder) {
    Scene scene("SceneRenderRequestUtilsSortSceneCameras");

    GameObject* lateBaseObject = scene.CreateGameObject("LateBase");
    auto* lateBase = lateBaseObject->AddComponent<CameraComponent>();
    lateBase->SetDepth(10.0f);
    lateBase->SetStackType(CameraStackType::Base);

    GameObject* firstTieObject = scene.CreateGameObject("FirstTie");
    auto* firstTie = firstTieObject->AddComponent<CameraComponent>();
    firstTie->SetDepth(2.0f);
    firstTie->SetStackType(CameraStackType::Base);

    GameObject* secondTieObject = scene.CreateGameObject("SecondTie");
    auto* secondTie = secondTieObject->AddComponent<CameraComponent>();
    secondTie->SetDepth(2.0f);
    secondTie->SetStackType(CameraStackType::Base);

    GameObject* overlayObject = scene.CreateGameObject("Overlay");
    auto* overlay = overlayObject->AddComponent<CameraComponent>();
    overlay->SetDepth(-50.0f);
    overlay->SetStackType(CameraStackType::Overlay);

    std::vector<CameraComponent*> cameras = { overlay, lateBase, secondTie, firstTie };
    SceneRenderRequestUtils::SortSceneCamerasForRendering(cameras);

    ASSERT_EQ(cameras.size(), 4u);
    EXPECT_EQ(cameras[0], secondTie);
    EXPECT_EQ(cameras[1], firstTie);
    EXPECT_EQ(cameras[2], lateBase);
    EXPECT_EQ(cameras[3], overlay);
}

TEST(SceneRenderRequestUtils_Test, SortsRequestsByPriorityAndKeepsStableTieOrder) {
    Scene scene("SceneRenderRequestUtilsSortRequests");

    GameObject* firstObject = scene.CreateGameObject("First");
    auto* firstCamera = firstObject->AddComponent<CameraComponent>();

    GameObject* secondObject = scene.CreateGameObject("Second");
    auto* secondCamera = secondObject->AddComponent<CameraComponent>();

    CameraRenderRequest overlayRequest;
    overlayRequest.scene = &scene;
    overlayRequest.camera = secondCamera;
    overlayRequest.context = CreateValidContext();
    overlayRequest.surface = RenderSurface(320, 180);
    overlayRequest.cameraDepth = 100.0f;
    overlayRequest.cameraStackOrder = 1;

    CameraRenderRequest secondTieRequest = overlayRequest;
    secondTieRequest.camera = secondCamera;
    secondTieRequest.cameraDepth = 5.0f;
    secondTieRequest.cameraStackOrder = 0;

    CameraRenderRequest firstTieRequest = overlayRequest;
    firstTieRequest.camera = firstCamera;
    firstTieRequest.cameraDepth = 5.0f;
    firstTieRequest.cameraStackOrder = 0;

    std::vector<CameraRenderRequest> requests = { overlayRequest, secondTieRequest, firstTieRequest };
    SceneRenderRequestUtils::SortCameraRenderRequests(requests);

    ASSERT_EQ(requests.size(), 3u);
    EXPECT_EQ(requests[0].camera, secondCamera);
    EXPECT_EQ(requests[1].camera, firstCamera);
    EXPECT_EQ(requests[2].camera, secondCamera);
    EXPECT_EQ(requests[2].cameraStackOrder, 1u);
}

TEST(SceneRenderRequestUtils_Test, ResolvesClearFlagsForExplicitAndAutoModes) {
    Scene scene("SceneRenderRequestUtilsClearFlags");

    GameObject* baseObject = scene.CreateGameObject("Base");
    auto* baseCamera = baseObject->AddComponent<CameraComponent>();
    baseCamera->SetStackType(CameraStackType::Base);

    GameObject* overlayObject = scene.CreateGameObject("Overlay");
    auto* overlayCamera = overlayObject->AddComponent<CameraComponent>();
    overlayCamera->SetStackType(CameraStackType::Overlay);

    baseCamera->SetClearMode(CameraClearMode::ColorAndDepth);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*baseCamera, 0u, 0u),
        RenderClearFlags::All);

    baseCamera->SetClearMode(CameraClearMode::DepthOnly);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*baseCamera, 0u, 0u),
        RenderClearFlags::Depth);

    baseCamera->SetClearMode(CameraClearMode::None);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*baseCamera, 0u, 0u),
        RenderClearFlags::None);

    baseCamera->SetClearMode(CameraClearMode::Auto);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*baseCamera, 0u, 0u),
        RenderClearFlags::All);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*baseCamera, 1u, 1u),
        RenderClearFlags::Depth);

    overlayCamera->SetClearMode(CameraClearMode::Auto);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*overlayCamera, 0u, 0u),
        RenderClearFlags::All);
    EXPECT_EQ(
        SceneRenderRequestUtils::ResolveClearFlags(*overlayCamera, 0u, 1u),
        RenderClearFlags::Depth);
}

TEST(SceneRenderRequestUtils_Test, ComposesCameraViewportWithinNestedSurfaceRenderArea) {
    Scene scene("SceneRenderRequestUtilsViewport");

    GameObject* cameraObject = scene.CreateGameObject("Camera");
    auto* camera = cameraObject->AddComponent<CameraComponent>();
    camera->SetViewportRect(XCEngine::Math::Rect(0.25f, 0.1f, 0.5f, 0.4f));

    RenderSurface surface(800, 600);
    surface.SetRenderArea(XCEngine::Math::RectInt(100, 50, 400, 300));

    const XCEngine::Math::RectInt renderArea =
        SceneRenderRequestUtils::ResolveCameraRenderArea(*camera, surface);
    EXPECT_EQ(renderArea.x, 200);
    EXPECT_EQ(renderArea.y, 80);
    EXPECT_EQ(renderArea.width, 200);
    EXPECT_EQ(renderArea.height, 120);
}

TEST(SceneRenderRequestUtils_Test, BuildsRequestMetadataAndRejectsZeroSizedRenderAreas) {
    Scene scene("SceneRenderRequestUtilsBuildRequest");

    GameObject* cameraObject = scene.CreateGameObject("Camera");
    auto* camera = cameraObject->AddComponent<CameraComponent>();
    camera->SetDepth(3.0f);
    camera->SetStackType(CameraStackType::Overlay);
    camera->SetClearMode(CameraClearMode::Auto);
    camera->SetViewportRect(XCEngine::Math::Rect(0.25f, 0.5f, 0.5f, 0.25f));

    CameraRenderRequest request;
    ASSERT_TRUE(SceneRenderRequestUtils::BuildCameraRenderRequest(
        scene,
        *camera,
        CreateValidContext(),
        RenderSurface(800, 600),
        1u,
        1u,
        request));
    EXPECT_EQ(request.scene, &scene);
    EXPECT_EQ(request.camera, camera);
    EXPECT_FLOAT_EQ(request.cameraDepth, 3.0f);
    EXPECT_EQ(request.cameraStackOrder, 1u);
    EXPECT_EQ(request.clearFlags, RenderClearFlags::Depth);
    EXPECT_EQ(request.surface.GetRenderArea().x, 200);
    EXPECT_EQ(request.surface.GetRenderArea().y, 300);
    EXPECT_EQ(request.surface.GetRenderArea().width, 400);
    EXPECT_EQ(request.surface.GetRenderArea().height, 150);

    camera->SetViewportRect(XCEngine::Math::Rect(0.5f, 0.5f, 0.0f, 1.0f));
    EXPECT_FALSE(SceneRenderRequestUtils::BuildCameraRenderRequest(
        scene,
        *camera,
        CreateValidContext(),
        RenderSurface(800, 600),
        0u,
        0u,
        request));
}