#include <gtest/gtest.h>

#include <XCEngine/UI/Runtime/UIScreenDocumentHost.h>
#include <XCEngine/UI/Runtime/UIScreenPlayer.h>

#include <chrono>
#include <filesystem>
#include <fstream>
#include <string>

namespace {

using XCEngine::UI::UIRect;
using XCEngine::UI::Runtime::UIScreenAsset;
using XCEngine::UI::Runtime::UIScreenFrameInput;
using XCEngine::UI::Runtime::UIScreenPlayer;
using XCEngine::UI::Runtime::UIDocumentScreenHost;

namespace fs = std::filesystem;

class TempFileScope {
public:
    TempFileScope(std::string stem, std::string extension, std::string contents) {
        const auto uniqueId = std::to_string(
            std::chrono::steady_clock::now().time_since_epoch().count());
        m_path = fs::temp_directory_path() / (std::move(stem) + "_" + uniqueId + std::move(extension));
        std::ofstream output(m_path, std::ios::binary | std::ios::trunc);
        output << contents;
    }

    ~TempFileScope() {
        std::error_code ec;
        fs::remove(m_path, ec);
    }

    const fs::path& Path() const {
        return m_path;
    }

private:
    fs::path m_path = {};
};

UIScreenAsset BuildScreenAsset(const fs::path& viewPath, const char* screenId) {
    UIScreenAsset screen = {};
    screen.screenId = screenId;
    screen.documentPath = viewPath.string();
    return screen;
}

UIScreenFrameInput BuildInputState(std::uint64_t frameIndex = 1u) {
    UIScreenFrameInput input = {};
    input.viewportRect = UIRect(0.0f, 0.0f, 960.0f, 720.0f);
    input.frameIndex = frameIndex;
    input.focused = true;
    return input;
}

} // namespace

TEST(UIRuntimeSplitterValidationTest, InvalidSplitterArityProducesExplicitFrameError) {
    TempFileScope viewFile(
        "xcui_runtime_invalid_splitter",
        ".xcui",
        "<View name=\"Invalid Splitter Test\">\n"
        "  <Column padding=\"16\" gap=\"10\">\n"
        "    <Splitter id=\"broken-splitter\" axis=\"horizontal\" splitRatio=\"0.5\">\n"
        "      <Card title=\"Only Child\" />\n"
        "    </Splitter>\n"
        "  </Column>\n"
        "</View>\n");

    UIDocumentScreenHost host = {};
    UIScreenPlayer player(host);

    ASSERT_TRUE(player.Load(BuildScreenAsset(viewFile.Path(), "runtime.invalid_splitter")));

    const auto& frame = player.Update(BuildInputState());
    EXPECT_FALSE(frame.errorMessage.empty());
    EXPECT_NE(frame.errorMessage.find("broken-splitter"), std::string::npos);
    EXPECT_NE(frame.errorMessage.find("exactly 2 child elements"), std::string::npos);
}