#include <gtest/gtest.h>

#include "panels/ViewportPanelContent.h"

#include <imgui.h>

namespace {

class ImGuiContextScope {
public:
    ImGuiContextScope() {
        IMGUI_CHECKVERSION();
        ImGui::CreateContext();
    }

    ~ImGuiContextScope() {
        ImGui::DestroyContext();
    }
};

void BeginTestFrame() {
    ImGuiIO& io = ImGui::GetIO();
    io.DisplaySize = ImVec2(640.0f, 480.0f);
    io.DeltaTime = 1.0f / 60.0f;
    unsigned char* fontPixels = nullptr;
    int fontWidth = 0;
    int fontHeight = 0;
    io.Fonts->GetTexDataAsRGBA32(&fontPixels, &fontWidth, &fontHeight);
    io.Fonts->SetTexID(static_cast<ImTextureID>(1));
    ImGui::GetStyle().WindowPadding = ImVec2(0.0f, 0.0f);

    ImGui::NewFrame();
    ImGui::SetNextWindowPos(ImVec2(0.0f, 0.0f));
    ImGui::SetNextWindowSize(ImVec2(320.0f, 240.0f));
    ASSERT_TRUE(ImGui::Begin(
        "ViewportPanelContentTestWindow",
        nullptr,
        ImGuiWindowFlags_NoResize |
            ImGuiWindowFlags_NoMove |
            ImGuiWindowFlags_NoTitleBar |
            ImGuiWindowFlags_NoCollapse |
            ImGuiWindowFlags_NoSavedSettings));
}

void EndTestFrame() {
    ImGui::End();
    ImGui::EndFrame();
}

} // namespace

TEST(ViewportPanelContentTest, AllowOverlapDefaultItemClickMissesMiddleClickOnFirstFrame) {
    ImGuiContextScope contextScope;
    ImGuiIO& io = ImGui::GetIO();

    BeginTestFrame();
    EndTestFrame();

    io.MousePos = ImVec2(32.0f, 32.0f);
    io.MouseDown[ImGuiMouseButton_Middle] = true;
    BeginTestFrame();

    ImGui::SetCursorScreenPos(ImVec2(16.0f, 16.0f));

    ImGui::SetNextItemAllowOverlap();
    ImGui::InvisibleButton(
        "##ViewportOverlapProbe",
        ImVec2(120.0f, 90.0f),
        ImGuiButtonFlags_MouseButtonMiddle);

    EXPECT_FALSE(ImGui::IsItemHovered());
    EXPECT_FALSE(ImGui::IsItemClicked(ImGuiMouseButton_Middle));
    EXPECT_TRUE(ImGui::IsItemHovered(ImGuiHoveredFlags_AllowWhenOverlappedByItem));

    EndTestFrame();
}

TEST(ViewportPanelContentTest, InteractionSurfaceCapturesMiddleClickOnFirstHoveredFrame) {
    ImGuiContextScope contextScope;
    ImGuiIO& io = ImGui::GetIO();

    BeginTestFrame();
    EndTestFrame();

    io.MousePos = ImVec2(32.0f, 32.0f);
    io.MouseDown[ImGuiMouseButton_Middle] = true;
    BeginTestFrame();

    ImGui::SetCursorScreenPos(ImVec2(16.0f, 16.0f));

    XCEngine::Editor::ViewportPanelContentResult result = {};
    XCEngine::Editor::RenderViewportInteractionSurface(
        result,
        XCEngine::Editor::EditorViewportKind::Scene,
        ImVec2(120.0f, 90.0f));

    EXPECT_TRUE(result.hovered);
    EXPECT_TRUE(result.clickedMiddle);
    EXPECT_FALSE(result.clickedLeft);
    EXPECT_FALSE(result.clickedRight);

    EndTestFrame();
}