#include <gtest/gtest.h>

#include "Scripting/EditorScriptAssemblyBuilder.h"

#ifdef XCENGINE_ENABLE_MONO_SCRIPTING
#include <XCEngine/Scripting/Mono/MonoScriptRuntime.h>
#endif

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

namespace XCEngine::Editor::Scripting {
namespace {

class EditorScriptAssemblyBuilderTest : public ::testing::Test {
protected:
    static void WriteTextFile(const std::filesystem::path& path, const std::string& content) {
        std::ofstream output(path, std::ios::out | std::ios::trunc);
        ASSERT_TRUE(output.is_open());
        output << content;
        output.close();
        ASSERT_TRUE(output.good());
    }

    void SetUp() override {
        const auto stamp = std::chrono::steady_clock::now().time_since_epoch().count();
        m_projectRoot = std::filesystem::temp_directory_path() / ("xc_script_builder_" + std::to_string(stamp));
        std::filesystem::create_directories(m_projectRoot / "Assets" / "Scripts");
    }

    void TearDown() override {
        std::error_code ec;
        std::filesystem::remove_all(m_projectRoot, ec);
    }

    std::filesystem::path m_projectRoot;
};

TEST_F(EditorScriptAssemblyBuilderTest, RebuildsProjectScriptAssembliesIntoLibraryDirectory) {
    const std::filesystem::path scriptPath = m_projectRoot / "Assets" / "Scripts" / "BuilderProbe.cs";
    WriteTextFile(
        scriptPath,
        "using XCEngine;\n"
        "namespace BuilderTests {\n"
        "    public sealed class BuilderProbe : MonoBehaviour {\n"
        "        public float Speed = 4.0f;\n"
        "    }\n"
        "}\n");

    const EditorScriptAssemblyBuildResult result =
        EditorScriptAssemblyBuilder::RebuildProjectAssemblies(m_projectRoot.string());
    ASSERT_TRUE(result.succeeded) << result.message;

    EXPECT_TRUE(std::filesystem::exists(m_projectRoot / "Library" / "ScriptAssemblies" / "XCEngine.ScriptCore.dll"));
    EXPECT_TRUE(std::filesystem::exists(m_projectRoot / "Library" / "ScriptAssemblies" / "GameScripts.dll"));
    EXPECT_TRUE(std::filesystem::exists(m_projectRoot / "Library" / "ScriptAssemblies" / "mscorlib.dll"));
}

#ifdef XCENGINE_ENABLE_MONO_SCRIPTING
TEST_F(EditorScriptAssemblyBuilderTest, RebuildFailsWhileLoadedAssemblyIsStillHeldByMonoRuntime) {
    const std::filesystem::path initialScriptPath = m_projectRoot / "Assets" / "Scripts" / "BuilderProbe.cs";
    WriteTextFile(
        initialScriptPath,
        "using XCEngine;\n"
        "namespace BuilderTests {\n"
        "    public sealed class BuilderProbe : MonoBehaviour {\n"
        "        public float Speed = 4.0f;\n"
        "    }\n"
        "}\n");

    EditorScriptAssemblyBuildResult result =
        EditorScriptAssemblyBuilder::RebuildProjectAssemblies(m_projectRoot.string());
    ASSERT_TRUE(result.succeeded) << result.message;

    XCEngine::Scripting::MonoScriptRuntime::Settings settings;
    settings.assemblyDirectory = m_projectRoot / "Library" / "ScriptAssemblies";
    settings.corlibDirectory = settings.assemblyDirectory;
    settings.coreAssemblyPath = settings.assemblyDirectory / "XCEngine.ScriptCore.dll";
    settings.appAssemblyPath = settings.assemblyDirectory / "GameScripts.dll";

    auto runtime = std::make_unique<XCEngine::Scripting::MonoScriptRuntime>(settings);
    ASSERT_TRUE(runtime->Initialize()) << runtime->GetLastError();

    const std::filesystem::path addedScriptPath = m_projectRoot / "Assets" / "Scripts" / "TickLogProbe.cs";
    WriteTextFile(
        addedScriptPath,
        "using XCEngine;\n"
        "namespace BuilderTests {\n"
        "    public sealed class TickLogProbe : MonoBehaviour {\n"
        "        public int TickCount;\n"
        "    }\n"
        "}\n");

    result = EditorScriptAssemblyBuilder::RebuildProjectAssemblies(m_projectRoot.string());
    EXPECT_FALSE(result.succeeded);

    runtime.reset();

    result = EditorScriptAssemblyBuilder::RebuildProjectAssemblies(m_projectRoot.string());
    ASSERT_TRUE(result.succeeded) << result.message;

    runtime = std::make_unique<XCEngine::Scripting::MonoScriptRuntime>(settings);
    ASSERT_TRUE(runtime->Initialize()) << runtime->GetLastError();
    EXPECT_TRUE(runtime->IsClassAvailable("GameScripts", "BuilderTests", "BuilderProbe"));
    EXPECT_TRUE(runtime->IsClassAvailable("GameScripts", "BuilderTests", "TickLogProbe"));
}
#endif

} // namespace
} // namespace XCEngine::Editor::Scripting