#pragma once

#include "Application.h"
#include "IComponentEditor.h"
#include "ScriptComponentEditorUtils.h"
#include "Core/IUndoManager.h"
#include "UI/UI.h"

#include <XCEngine/Scripting/ScriptComponent.h>
#include <XCEngine/Scripting/ScriptEngine.h>

#include <algorithm>
#include <array>
#include <cstdint>
#include <cstring>
#include <string>
#include <unordered_map>
#include <utility>
#include <vector>

namespace XCEngine {
namespace Editor {

class ScriptComponentEditor : public IComponentEditor {
public:
    const char* GetComponentTypeName() const override {
        return "ScriptComponent";
    }

    const char* GetDisplayName() const override {
        return "Script";
    }

    bool Render(::XCEngine::Components::Component* component, IUndoManager* undoManager) override {
        auto* scriptComponent = dynamic_cast<::XCEngine::Scripting::ScriptComponent*>(component);
        if (!scriptComponent) {
            return false;
        }

        bool changed = false;
        changed |= RenderScriptClassSelector(*scriptComponent, undoManager);

        ::XCEngine::Scripting::ScriptFieldModel model;
        if (!::XCEngine::Scripting::ScriptEngine::Get().TryGetScriptFieldModel(scriptComponent, model)) {
            UI::DrawHintText("Failed to query script field metadata.");
            return changed;
        }

        switch (model.classStatus) {
            case ::XCEngine::Scripting::ScriptFieldClassStatus::Unassigned:
                UI::DrawHintText("Assign a C# script to edit serialized fields.");
                return changed;
            case ::XCEngine::Scripting::ScriptFieldClassStatus::Missing:
                UI::DrawHintText("Assigned script class is not available in the loaded script assemblies.");
                break;
            case ::XCEngine::Scripting::ScriptFieldClassStatus::Available:
            default:
                break;
        }

        if (model.fields.empty()) {
            UI::DrawHintText(
                model.classStatus == ::XCEngine::Scripting::ScriptFieldClassStatus::Available
                    ? "Selected script exposes no supported public instance fields."
                    : "No serialized script fields are currently available.");
            return changed;
        }

        for (const ::XCEngine::Scripting::ScriptFieldSnapshot& field : model.fields) {
            changed |= RenderScriptField(*scriptComponent, model.classStatus, field, undoManager);
        }

        return changed;
    }

    bool CanAddTo(::XCEngine::Components::GameObject* gameObject) const override {
        return gameObject != nullptr;
    }

    const char* GetAddDisabledReason(::XCEngine::Components::GameObject* gameObject) const override {
        return gameObject ? nullptr : "Invalid";
    }

    bool CanRemove(::XCEngine::Components::Component* component) const override {
        return CanEdit(component);
    }

private:
    static constexpr size_t kStringBufferSize = 512;

    struct StringFieldEditState {
        std::array<char, kStringBufferSize> buffer{};
        std::string lastSyncedValue;
        bool initialized = false;
        bool editing = false;
    };

    bool RenderScriptClassSelector(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        IUndoManager* undoManager) {
        std::vector<::XCEngine::Scripting::ScriptClassDescriptor> scriptClasses;
        const bool hasLoadedClasses =
            ::XCEngine::Scripting::ScriptEngine::Get().TryGetAvailableScriptClasses(scriptClasses);

        const ::XCEngine::Scripting::ScriptClassDescriptor currentDescriptor{
            scriptComponent.GetAssemblyName(),
            scriptComponent.GetNamespaceName(),
            scriptComponent.GetClassName()
        };

        std::string currentLabel = "None";
        if (scriptComponent.HasScriptClass()) {
            const auto currentIt = std::find(scriptClasses.begin(), scriptClasses.end(), currentDescriptor);
            currentLabel = currentIt != scriptClasses.end()
                ? ScriptComponentEditorUtils::BuildScriptClassDisplayName(*currentIt)
                : ScriptComponentEditorUtils::BuildScriptClassDisplayName(scriptComponent) + " (Missing)";
        }

        bool changed = false;
        UI::DrawPropertyRow("Script", UI::InspectorPropertyLayout(), [&](const UI::PropertyLayoutMetrics& layout) {
            UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
            ImGui::SetNextItemWidth(layout.controlWidth);
            if (!ImGui::BeginCombo("##ScriptClass", currentLabel.c_str())) {
                return false;
            }

            if (ImGui::Selectable("None", !scriptComponent.HasScriptClass())) {
                changed |= ApplyScriptClassSelection(scriptComponent, nullptr, undoManager);
            }

            if (!scriptClasses.empty()) {
                ImGui::Separator();
            }

            for (const ::XCEngine::Scripting::ScriptClassDescriptor& descriptor : scriptClasses) {
                const bool selected = descriptor == currentDescriptor;
                const std::string label =
                    ScriptComponentEditorUtils::BuildScriptClassDisplayName(descriptor);
                if (ImGui::Selectable(label.c_str(), selected)) {
                    changed |= ApplyScriptClassSelection(scriptComponent, &descriptor, undoManager);
                }
                if (selected) {
                    ImGui::SetItemDefaultFocus();
                }
            }

            if (!hasLoadedClasses) {
                ImGui::Separator();
                ImGui::TextDisabled("No script assemblies are currently loaded.");
            }

            ImGui::EndCombo();
            return false;
        });

        if (!hasLoadedClasses) {
            const EditorScriptRuntimeStatus& runtimeStatus = Application::Get().GetScriptRuntimeStatus();
            const std::string hintText =
                ScriptComponentEditorUtils::BuildScriptRuntimeUnavailableHint(runtimeStatus);
            UI::DrawHintText(hintText.c_str());

            if (ScriptComponentEditorUtils::CanRebuildScriptAssemblies(runtimeStatus)) {
                if (UI::InspectorActionButton("Rebuild Scripts", ImVec2(120.0f, 0.0f))) {
                    Application::Get().RebuildScriptingAssemblies();
                }
            }

            if (ScriptComponentEditorUtils::CanReloadScriptRuntime(runtimeStatus)) {
                if (ScriptComponentEditorUtils::CanRebuildScriptAssemblies(runtimeStatus)) {
                    ImGui::SameLine();
                }
                if (UI::InspectorActionButton("Reload Scripts", ImVec2(120.0f, 0.0f))) {
                    Application::Get().ReloadScriptingRuntime();
                }
            }
        }

        return changed;
    }

    bool ApplyScriptClassSelection(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptClassDescriptor* descriptor,
        IUndoManager* undoManager) const {
        if (!descriptor) {
            if (!scriptComponent.HasScriptClass()) {
                return false;
            }

            if (undoManager) {
                undoManager->BeginInteractiveChange("Modify Script Component");
            }
            scriptComponent.ClearScriptClass();
            return true;
        }

        if (scriptComponent.GetAssemblyName() == descriptor->assemblyName &&
            scriptComponent.GetNamespaceName() == descriptor->namespaceName &&
            scriptComponent.GetClassName() == descriptor->className) {
            return false;
        }

        if (undoManager) {
            undoManager->BeginInteractiveChange("Modify Script Component");
        }
        scriptComponent.SetScriptClass(
            descriptor->assemblyName,
            descriptor->namespaceName,
            descriptor->className);
        return true;
    }

    bool RenderScriptField(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        ::XCEngine::Scripting::ScriptFieldClassStatus classStatus,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        IUndoManager* undoManager) {
        bool changed = false;
        const bool canEdit = ScriptComponentEditorUtils::CanEditScriptField(classStatus, field);

        if (canEdit) {
            changed |= RenderScriptFieldEditor(scriptComponent, field, undoManager);
        } else {
            RenderReadOnlyScriptField(field);
        }

        const std::string issueText = ScriptComponentEditorUtils::BuildScriptFieldIssueText(field);
        if (!issueText.empty()) {
            UI::DrawHintText(issueText.c_str());
        }

        if (ScriptComponentEditorUtils::CanClearScriptFieldOverride(field)) {
            ImGui::PushID((field.metadata.name + "##Reset").c_str());
            if (UI::InspectorActionButton("Reset", ImVec2(72.0f, 0.0f))) {
                changed |= ClearScriptFieldOverride(scriptComponent, field, undoManager);
            }
            ImGui::PopID();
        }

        return changed;
    }

    bool RenderScriptFieldEditor(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        IUndoManager* undoManager) {
        using namespace ::XCEngine::Scripting;

        switch (field.metadata.type) {
            case ScriptFieldType::Float: {
                float value = std::get<float>(field.value);
                const bool widgetChanged = UI::DrawPropertyFloat(field.metadata.name.c_str(), value, 0.1f);
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::Double: {
                double value = std::get<double>(field.value);
                const bool widgetChanged = UI::DrawPropertyRow(
                    field.metadata.name.c_str(),
                    UI::InspectorPropertyLayout(),
                    [&](const UI::PropertyLayoutMetrics& layout) {
                        UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
                        ImGui::SetNextItemWidth(layout.controlWidth);
                        return ImGui::InputDouble("##Value", &value, 0.0, 0.0, "%.3f");
                    });
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::Bool: {
                bool value = std::get<bool>(field.value);
                const bool widgetChanged = UI::DrawPropertyBool(field.metadata.name.c_str(), value);
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::Int32: {
                int value = std::get<int32_t>(field.value);
                const bool widgetChanged = UI::DrawPropertyInt(field.metadata.name.c_str(), value, 1);
                return widgetChanged &&
                    ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(static_cast<int32_t>(value)), undoManager);
            }
            case ScriptFieldType::UInt64: {
                uint64_t value = std::get<uint64_t>(field.value);
                const bool widgetChanged = UI::DrawPropertyRow(
                    field.metadata.name.c_str(),
                    UI::InspectorPropertyLayout(),
                    [&](const UI::PropertyLayoutMetrics& layout) {
                        UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
                        ImGui::SetNextItemWidth(layout.controlWidth);
                        return ImGui::InputScalar("##Value", ImGuiDataType_U64, &value);
                    });
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::String:
                return RenderStringScriptFieldEditor(scriptComponent, field, undoManager);
            case ScriptFieldType::Vector2: {
                ::XCEngine::Math::Vector2 value = std::get<::XCEngine::Math::Vector2>(field.value);
                const bool widgetChanged = UI::DrawPropertyVec2(field.metadata.name.c_str(), value, 0.0f, 0.1f);
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::Vector3: {
                ::XCEngine::Math::Vector3 value = std::get<::XCEngine::Math::Vector3>(field.value);
                const bool widgetChanged = UI::DrawPropertyVec3Input(field.metadata.name.c_str(), value, 0.1f);
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::Vector4: {
                ::XCEngine::Math::Vector4 value = std::get<::XCEngine::Math::Vector4>(field.value);
                const bool widgetChanged = UI::DrawPropertyRow(
                    field.metadata.name.c_str(),
                    UI::InspectorPropertyLayout(),
                    [&](const UI::PropertyLayoutMetrics& layout) {
                        UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
                        ImGui::SetNextItemWidth(layout.controlWidth);
                        return ImGui::DragFloat4("##Value", &value.x, 0.1f);
                    });
                return widgetChanged && ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(value), undoManager);
            }
            case ScriptFieldType::GameObject:
                return RenderGameObjectScriptFieldEditor(scriptComponent, field, undoManager);
            case ScriptFieldType::None:
            default:
                RenderReadOnlyScriptField(field);
                return false;
        }
    }

    bool RenderStringScriptFieldEditor(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        IUndoManager* undoManager) {
        StringFieldEditState& editState =
            m_stringFieldStates[scriptComponent.GetScriptComponentUUID()][field.metadata.name];
        const std::string currentValue = std::get<std::string>(field.value);

        if (!editState.initialized || (!editState.editing && editState.lastSyncedValue != currentValue)) {
            SyncStringFieldEditState(editState, currentValue);
        }

        bool isEditing = false;
        const bool widgetChanged = UI::DrawPropertyRow(
            field.metadata.name.c_str(),
            UI::InspectorPropertyLayout(),
            [&](const UI::PropertyLayoutMetrics& layout) {
                UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
                ImGui::SetNextItemWidth(layout.controlWidth);
                const bool changed = ImGui::InputText("##Value", editState.buffer.data(), editState.buffer.size());
                isEditing = ImGui::IsItemActive();
                return changed;
            });
        editState.editing = isEditing;

        if (!widgetChanged) {
            return false;
        }

        const std::string editedValue(editState.buffer.data());
        if (!ApplyScriptFieldWrite(
                scriptComponent,
                field,
                ::XCEngine::Scripting::ScriptFieldValue(editedValue),
                undoManager)) {
            SyncStringFieldEditState(editState, currentValue);
            return false;
        }

        editState.lastSyncedValue = editedValue;
        return true;
    }

    bool RenderGameObjectScriptFieldEditor(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        IUndoManager* undoManager) {
        using namespace ::XCEngine::Scripting;

        const GameObjectReference currentReference = std::get<GameObjectReference>(field.value);
        const auto& sceneRoots = Application::Get().GetEditorContext().GetSceneManager().GetRootEntities();
        const ::XCEngine::Components::GameObject::ID currentGameObjectId =
            ScriptComponentEditorUtils::FindGameObjectIdByUuid(sceneRoots, currentReference.gameObjectUUID);

        UI::ReferencePickerOptions pickerOptions;
        pickerOptions.popupTitle = "Select GameObject";
        pickerOptions.emptyHint = "None";
        pickerOptions.searchHint = "Search";
        pickerOptions.noSceneText = "No scene objects.";
        pickerOptions.showAssetsTab = false;
        pickerOptions.showSceneTab = true;

        GameObjectReference pendingReference = currentReference;
        const bool widgetChanged = UI::DrawPropertyRow(
            field.metadata.name.c_str(),
            UI::InspectorPropertyLayout(),
            [&](const UI::PropertyLayoutMetrics& layout) {
                UI::AlignPropertyControlVertically(layout, ImGui::GetFrameHeight());
                const UI::ReferencePickerInteraction interaction =
                    UI::DrawReferencePickerControl(
                        std::string(),
                        currentGameObjectId,
                        pickerOptions,
                        layout.controlWidth);

                if (interaction.clearRequested) {
                    pendingReference = GameObjectReference{};
                    return true;
                }

                if (interaction.assignedSceneObjectId == ::XCEngine::Components::GameObject::INVALID_ID ||
                    interaction.assignedSceneObjectId == currentGameObjectId) {
                    return false;
                }

                ::XCEngine::Components::GameObject* assignedGameObject =
                    Application::Get().GetEditorContext().GetSceneManager().GetEntity(interaction.assignedSceneObjectId);
                if (!assignedGameObject) {
                    return false;
                }

                pendingReference = GameObjectReference{assignedGameObject->GetUUID()};
                return true;
            });

        return widgetChanged &&
            ApplyScriptFieldWrite(scriptComponent, field, ScriptFieldValue(pendingReference), undoManager);
    }

    void RenderReadOnlyScriptField(const ::XCEngine::Scripting::ScriptFieldSnapshot& field) const {
        const std::string valueText = DescribeScriptFieldValue(field.metadata.type, field.value);
        UI::DrawPropertyRow(
            field.metadata.name.c_str(),
            UI::InspectorPropertyLayout(),
            [&](const UI::PropertyLayoutMetrics& layout) {
                UI::AlignPropertyControlVertically(layout, ImGui::GetTextLineHeight());
                ImGui::TextDisabled("%s", valueText.c_str());
                return false;
            });
    }

    bool ApplyScriptFieldWrite(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        const ::XCEngine::Scripting::ScriptFieldValue& value,
        IUndoManager* undoManager) const {
        std::vector<::XCEngine::Scripting::ScriptFieldWriteResult> results;
        if (undoManager) {
            undoManager->BeginInteractiveChange("Modify Script Field");
        }

        const bool applied = ::XCEngine::Scripting::ScriptEngine::Get().ApplyScriptFieldWrites(
            &scriptComponent,
            { ::XCEngine::Scripting::ScriptFieldWriteRequest{field.metadata.name, field.metadata.type, value} },
            results);

        if (!applied || results.empty() ||
            results.front().status != ::XCEngine::Scripting::ScriptFieldWriteStatus::Applied) {
            if (undoManager && undoManager->HasPendingInteractiveChange()) {
                undoManager->CancelInteractiveChange();
            }
            return false;
        }

        return true;
    }

    bool ClearScriptFieldOverride(
        ::XCEngine::Scripting::ScriptComponent& scriptComponent,
        const ::XCEngine::Scripting::ScriptFieldSnapshot& field,
        IUndoManager* undoManager) const {
        std::vector<::XCEngine::Scripting::ScriptFieldClearResult> results;
        if (undoManager) {
            undoManager->BeginInteractiveChange("Clear Script Field Override");
        }

        const bool cleared = ::XCEngine::Scripting::ScriptEngine::Get().ClearScriptFieldOverrides(
            &scriptComponent,
            { ::XCEngine::Scripting::ScriptFieldClearRequest{field.metadata.name} },
            results);

        if (!cleared || results.empty() ||
            results.front().status != ::XCEngine::Scripting::ScriptFieldClearStatus::Applied) {
            if (undoManager && undoManager->HasPendingInteractiveChange()) {
                undoManager->CancelInteractiveChange();
            }
            return false;
        }

        return true;
    }

    static void SyncStringFieldEditState(StringFieldEditState& editState, const std::string& value) {
        editState.buffer.fill('\0');
        const size_t copyLength = (std::min)(value.size(), editState.buffer.size() - 1);
        if (copyLength > 0) {
            std::memcpy(editState.buffer.data(), value.data(), copyLength);
        }
        editState.buffer[copyLength] = '\0';
        editState.lastSyncedValue = value;
        editState.initialized = true;
    }

    static std::string DescribeScriptFieldValue(
        ::XCEngine::Scripting::ScriptFieldType type,
        const ::XCEngine::Scripting::ScriptFieldValue& value) {
        if (type == ::XCEngine::Scripting::ScriptFieldType::GameObject) {
            const auto reference = std::get<::XCEngine::Scripting::GameObjectReference>(value);
            if (reference.gameObjectUUID == 0) {
                return "None";
            }

            return "GameObject (" + std::to_string(reference.gameObjectUUID) + ")";
        }

        return ::XCEngine::Scripting::SerializeScriptFieldValue(type, value);
    }

    std::unordered_map<uint64_t, std::unordered_map<std::string, StringFieldEditState>> m_stringFieldStates;
};

} // namespace Editor
} // namespace XCEngine