#include <gtest/gtest.h>

#include "Core/EditorContext.h"
#include "Core/EditorEvents.h"
#include "Core/PlaySessionController.h"
#include "Commands/EntityCommands.h"

#include <XCEngine/Core/Math/Vector3.h>
#include <XCEngine/Input/InputManager.h>

namespace XCEngine::Editor {
namespace {

GameViewInputFrameEvent CreateGameViewInputFrame(
    bool focused,
    bool hovered,
    std::initializer_list<XCEngine::Input::KeyCode> keys = {},
    std::initializer_list<XCEngine::Input::MouseButton> mouseButtons = {},
    XCEngine::Math::Vector2 mousePosition = XCEngine::Math::Vector2::Zero(),
    XCEngine::Math::Vector2 mouseDelta = XCEngine::Math::Vector2::Zero(),
    float mouseWheel = 0.0f) {
    GameViewInputFrameEvent event = {};
    event.focused = focused;
    event.hovered = hovered;
    event.mousePosition = mousePosition;
    event.mouseDelta = mouseDelta;
    event.mouseWheel = mouseWheel;

    for (const XCEngine::Input::KeyCode key : keys) {
        const size_t index = static_cast<size_t>(key);
        if (index < event.keyDown.size()) {
            event.keyDown[index] = true;
        }
    }

    for (const XCEngine::Input::MouseButton button : mouseButtons) {
        const size_t index = static_cast<size_t>(button);
        if (index < event.mouseButtonDown.size()) {
            event.mouseButtonDown[index] = true;
        }
    }

    return event;
}

class PlaySessionControllerTest : public ::testing::Test {
protected:
    void SetUp() override {
        XCEngine::Input::InputManager::Get().Shutdown();
        m_context.GetSceneManager().NewScene("Play Session Scene");
    }

    void TearDown() override {
        m_controller.Detach(m_context);
        XCEngine::Input::InputManager::Get().Shutdown();
    }

    EditorContext m_context;
    PlaySessionController m_controller;
};

TEST_F(PlaySessionControllerTest, StartPlayClonesCurrentSceneAndStopRestoresEditorScene) {
    auto* editorEntity = m_context.GetSceneManager().CreateEntity("Persistent");
    ASSERT_NE(editorEntity, nullptr);
    const uint64_t editorEntityId = editorEntity->GetID();
    editorEntity->GetTransform()->SetLocalPosition(Math::Vector3(1.0f, 2.0f, 3.0f));

    int startedCount = 0;
    int stoppedCount = 0;
    const uint64_t startedSubscription = m_context.GetEventBus().Subscribe<PlayModeStartedEvent>(
        [&](const PlayModeStartedEvent&) {
            ++startedCount;
        });
    const uint64_t stoppedSubscription = m_context.GetEventBus().Subscribe<PlayModeStoppedEvent>(
        [&](const PlayModeStoppedEvent&) {
            ++stoppedCount;
        });

    ASSERT_TRUE(m_controller.StartPlay(m_context));
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Play);
    EXPECT_EQ(startedCount, 1);

    auto* runtimeEntity = m_context.GetSceneManager().GetEntity(editorEntityId);
    ASSERT_NE(runtimeEntity, nullptr);
    runtimeEntity->GetTransform()->SetLocalPosition(Math::Vector3(8.0f, 9.0f, 10.0f));
    auto* runtimeOnlyEntity = m_context.GetSceneManager().CreateEntity("RuntimeOnly");
    ASSERT_NE(runtimeOnlyEntity, nullptr);
    const uint64_t runtimeOnlyId = runtimeOnlyEntity->GetID();

    ASSERT_TRUE(m_controller.StopPlay(m_context));
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Edit);
    EXPECT_EQ(stoppedCount, 1);

    auto* restoredEntity = m_context.GetSceneManager().GetEntity(editorEntityId);
    ASSERT_NE(restoredEntity, nullptr);
    EXPECT_EQ(m_context.GetSceneManager().GetEntity(runtimeOnlyId), nullptr);

    const Math::Vector3 restoredPosition = restoredEntity->GetTransform()->GetLocalPosition();
    EXPECT_NEAR(restoredPosition.x, 1.0f, 1e-4f);
    EXPECT_NEAR(restoredPosition.y, 2.0f, 1e-4f);
    EXPECT_NEAR(restoredPosition.z, 3.0f, 1e-4f);

    m_context.GetEventBus().Unsubscribe<PlayModeStartedEvent>(startedSubscription);
    m_context.GetEventBus().Unsubscribe<PlayModeStoppedEvent>(stoppedSubscription);
}

TEST_F(PlaySessionControllerTest, StartAndStopRequestsRouteThroughEventBus) {
    auto* editorEntity = m_context.GetSceneManager().CreateEntity("Persistent");
    ASSERT_NE(editorEntity, nullptr);

    m_controller.Attach(m_context);

    m_context.GetEventBus().Publish(PlayModeStartRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Play);

    m_context.GetEventBus().Publish(PlayModeStopRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Edit);

    m_controller.Detach(m_context);
}

TEST_F(PlaySessionControllerTest, PauseResumeAndStepRequestsDrivePlayStateMachine) {
    auto* editorEntity = m_context.GetSceneManager().CreateEntity("Persistent");
    ASSERT_NE(editorEntity, nullptr);

    int pausedCount = 0;
    int resumedCount = 0;
    const uint64_t pausedSubscription = m_context.GetEventBus().Subscribe<PlayModePausedEvent>(
        [&](const PlayModePausedEvent&) {
            ++pausedCount;
        });
    const uint64_t resumedSubscription = m_context.GetEventBus().Subscribe<PlayModeResumedEvent>(
        [&](const PlayModeResumedEvent&) {
            ++resumedCount;
        });

    m_controller.Attach(m_context);

    m_context.GetEventBus().Publish(PlayModeStartRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Play);

    m_context.GetEventBus().Publish(PlayModePauseRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Paused);
    EXPECT_EQ(pausedCount, 1);

    m_context.GetEventBus().Publish(PlayModeStepRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Paused);
    EXPECT_EQ(pausedCount, 1);
    EXPECT_EQ(resumedCount, 0);

    m_context.GetEventBus().Publish(PlayModeResumeRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Play);
    EXPECT_EQ(resumedCount, 1);

    m_context.GetEventBus().Publish(PlayModeStopRequestedEvent{});
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Edit);

    m_controller.Detach(m_context);
    m_context.GetEventBus().Unsubscribe<PlayModePausedEvent>(pausedSubscription);
    m_context.GetEventBus().Unsubscribe<PlayModeResumedEvent>(resumedSubscription);
}

TEST_F(PlaySessionControllerTest, GameViewInputFramesDoNotAffectInputManagerOutsidePlayMode) {
    m_controller.Attach(m_context);

    m_context.GetEventBus().Publish(CreateGameViewInputFrame(
        true,
        true,
        {XCEngine::Input::KeyCode::A},
        {XCEngine::Input::MouseButton::Left},
        XCEngine::Math::Vector2(120.0f, 48.0f),
        XCEngine::Math::Vector2(3.0f, -2.0f),
        1.0f));

    m_controller.Update(m_context, 0.016f);

    auto& inputManager = XCEngine::Input::InputManager::Get();
    EXPECT_FALSE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::A));
    EXPECT_FALSE(inputManager.IsMouseButtonDown(XCEngine::Input::MouseButton::Left));
    EXPECT_EQ(inputManager.GetMousePosition(), XCEngine::Math::Vector2::Zero());
    EXPECT_FLOAT_EQ(inputManager.GetMouseScrollDelta(), 0.0f);

    m_controller.Detach(m_context);
}

TEST_F(PlaySessionControllerTest, GameViewInputFramesDriveAndReleaseRuntimeInputDuringPlayMode) {
    auto* editorEntity = m_context.GetSceneManager().CreateEntity("Persistent");
    ASSERT_NE(editorEntity, nullptr);

    m_controller.Attach(m_context);
    ASSERT_TRUE(m_controller.StartPlay(m_context));

    m_context.GetEventBus().Publish(CreateGameViewInputFrame(
        true,
        true,
        {XCEngine::Input::KeyCode::A, XCEngine::Input::KeyCode::Space},
        {XCEngine::Input::MouseButton::Left},
        XCEngine::Math::Vector2(120.0f, 48.0f),
        XCEngine::Math::Vector2(3.0f, -2.0f),
        1.0f));

    m_controller.Update(m_context, 0.016f);

    auto& inputManager = XCEngine::Input::InputManager::Get();
    EXPECT_TRUE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::A));
    EXPECT_TRUE(inputManager.IsKeyPressed(XCEngine::Input::KeyCode::A));
    EXPECT_TRUE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::Space));
    EXPECT_TRUE(inputManager.IsMouseButtonDown(XCEngine::Input::MouseButton::Left));
    EXPECT_TRUE(inputManager.IsMouseButtonClicked(XCEngine::Input::MouseButton::Left));
    EXPECT_EQ(inputManager.GetMousePosition(), XCEngine::Math::Vector2(120.0f, 48.0f));
    EXPECT_EQ(inputManager.GetMouseDelta(), XCEngine::Math::Vector2(3.0f, -2.0f));
    EXPECT_FLOAT_EQ(inputManager.GetMouseScrollDelta(), 1.0f);

    m_context.GetEventBus().Publish(CreateGameViewInputFrame(
        true,
        true,
        {XCEngine::Input::KeyCode::A, XCEngine::Input::KeyCode::Space},
        {XCEngine::Input::MouseButton::Left},
        XCEngine::Math::Vector2(120.0f, 48.0f)));

    m_controller.Update(m_context, 0.016f);

    EXPECT_TRUE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::A));
    EXPECT_FALSE(inputManager.IsKeyPressed(XCEngine::Input::KeyCode::A));
    EXPECT_TRUE(inputManager.IsMouseButtonDown(XCEngine::Input::MouseButton::Left));
    EXPECT_FALSE(inputManager.IsMouseButtonClicked(XCEngine::Input::MouseButton::Left));
    EXPECT_EQ(inputManager.GetMouseDelta(), XCEngine::Math::Vector2::Zero());
    EXPECT_FLOAT_EQ(inputManager.GetMouseScrollDelta(), 0.0f);

    m_context.GetEventBus().Publish(GameViewInputFrameEvent{});
    m_controller.Update(m_context, 0.016f);

    EXPECT_FALSE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::A));
    EXPECT_FALSE(inputManager.IsKeyDown(XCEngine::Input::KeyCode::Space));
    EXPECT_FALSE(inputManager.IsMouseButtonDown(XCEngine::Input::MouseButton::Left));

    m_controller.Detach(m_context);
}

TEST_F(PlaySessionControllerTest, RuntimeSceneUndoRedoRebindsPlaySessionBeforeStop) {
    auto* editorEntity = m_context.GetSceneManager().CreateEntity("Persistent");
    ASSERT_NE(editorEntity, nullptr);
    const uint64_t editorEntityId = editorEntity->GetID();

    ASSERT_TRUE(m_controller.StartPlay(m_context));
    ASSERT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Play);

    const auto* runtimeSceneBeforeUndo = m_context.GetSceneManager().GetScene();
    ASSERT_NE(runtimeSceneBeforeUndo, nullptr);
    ASSERT_EQ(m_controller.GetRuntimeScene(), runtimeSceneBeforeUndo);

    auto* runtimeEntity = Commands::CreateEmptyEntity(m_context, nullptr, "Create Runtime Entity", "RuntimeOnly");
    ASSERT_NE(runtimeEntity, nullptr);
    const uint64_t runtimeEntityId = runtimeEntity->GetID();
    ASSERT_EQ(m_controller.GetRuntimeScene(), m_context.GetSceneManager().GetScene());

    m_context.GetUndoManager().Undo();
    const auto* runtimeSceneAfterUndo = m_context.GetSceneManager().GetScene();
    ASSERT_NE(runtimeSceneAfterUndo, nullptr);
    EXPECT_NE(runtimeSceneAfterUndo, runtimeSceneBeforeUndo);
    EXPECT_EQ(m_controller.GetRuntimeScene(), runtimeSceneAfterUndo);
    EXPECT_EQ(m_context.GetSceneManager().GetEntity(runtimeEntityId), nullptr);

    m_context.GetUndoManager().Redo();
    const auto* runtimeSceneAfterRedo = m_context.GetSceneManager().GetScene();
    ASSERT_NE(runtimeSceneAfterRedo, nullptr);
    EXPECT_NE(runtimeSceneAfterRedo, runtimeSceneAfterUndo);
    EXPECT_EQ(m_controller.GetRuntimeScene(), runtimeSceneAfterRedo);
    EXPECT_NE(m_context.GetSceneManager().GetEntity(runtimeEntityId), nullptr);

    ASSERT_TRUE(m_controller.StopPlay(m_context));
    EXPECT_EQ(m_context.GetRuntimeMode(), EditorRuntimeMode::Edit);
    ASSERT_NE(m_context.GetSceneManager().GetEntity(editorEntityId), nullptr);
    EXPECT_EQ(m_context.GetSceneManager().GetEntity(runtimeEntityId), nullptr);
}

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