#include "Actions/ActionRouting.h"
#include "Actions/ProjectActionRouter.h"
#include "Commands/ProjectCommands.h"
#include "ProjectPanel.h"
#include "Core/IEditorContext.h"
#include "Core/IProjectManager.h"
#include "Core/AssetItem.h"
#include "UI/UI.h"

#include <algorithm>
#include <cctype>
#include <imgui.h>

namespace XCEngine {
namespace Editor {

namespace {

constexpr float kProjectToolbarHeight = 26.0f;
constexpr float kProjectToolbarPaddingY = 3.0f;

template <typename Fn>
void QueueDeferredAction(std::function<void()>& pendingAction, Fn&& fn) {
    if (!pendingAction) {
        pendingAction = std::forward<Fn>(fn);
    }
}

void DrawProjectFolderTreePrefix(const UI::TreeNodePrefixContext& context) {
    if (!context.drawList) {
        return;
    }

    const float width = context.max.x - context.min.x;
    const float height = context.max.y - context.min.y;
    const float iconExtent = UI::NavigationTreeIconSize();
    const float minX = context.min.x + (width - iconExtent) * 0.5f;
    const float minY = context.min.y + (height - iconExtent) * 0.5f;
    UI::DrawAssetIcon(
        context.drawList,
        ImVec2(minX, minY),
        ImVec2(minX + iconExtent, minY + iconExtent),
        UI::AssetIconKind::Folder);
}

UI::AssetIconKind ResolveProjectAssetIconKind(const AssetItemPtr& item) {
    if (!item) {
        return UI::AssetIconKind::File;
    }

    if (item->isFolder) {
        return UI::AssetIconKind::Folder;
    }

    if (item->type == "Scene") {
        return UI::AssetIconKind::Scene;
    }

    return UI::AssetIconKind::File;
}

std::string GetProjectAssetDisplayName(const AssetItemPtr& item) {
    if (!item) {
        return {};
    }

    if (item->isFolder) {
        return item->name;
    }

    const size_t extensionPos = item->name.find_last_of('.');
    if (extensionPos == std::string::npos || extensionPos == 0) {
        return item->name;
    }

    return item->name.substr(0, extensionPos);
}

UI::AssetTileOptions MakeProjectAssetTileOptions() {
    UI::AssetTileOptions options;
    options.drawIdleFrame = false;
    options.drawSelectionBorder = false;
    options.iconOffset = UI::ProjectAssetTileIconOffset();
    options.iconSize = UI::ProjectAssetTileIconSize();

    return options;
}

} // namespace

ProjectPanel::ProjectPanel() : Panel("Project") {
}

void ProjectPanel::Initialize(const std::string& projectPath) {
    m_context->GetProjectManager().Initialize(projectPath);
}

void ProjectPanel::BeginAssetDragDropFrame() {
    m_assetDragDropState.Reset();
    if (const char* draggedPath = Actions::GetDraggedProjectAssetPath()) {
        m_assetDragDropState.dragging = true;
        m_assetDragDropState.sourcePath = draggedPath;
    }
}

void ProjectPanel::RegisterFolderDropTarget(IProjectManager& manager, const AssetItemPtr& folder) {
    if (!m_assetDragDropState.dragging || !folder || !folder->isFolder || !ImGui::BeginDragDropTarget()) {
        return;
    }

    const ImGuiPayload* payload = ImGui::GetDragDropPayload();
    if (!payload || !payload->IsDataType(Actions::ProjectAssetPayloadType())) {
        ImGui::EndDragDropTarget();
        return;
    }

    m_assetDragDropState.hoveredTarget = true;
    const bool canDrop = Commands::CanMoveAssetToFolder(manager, m_assetDragDropState.sourcePath, folder);
    if (canDrop) {
        m_assetDragDropState.hoveredValidTarget = true;
        if (const ImGuiPayload* accepted = ImGui::AcceptDragDropPayload(
                Actions::ProjectAssetPayloadType(),
                ImGuiDragDropFlags_AcceptNoDrawDefaultRect))
        {
            if (accepted->Delivery) {
                m_assetDragDropState.deliveredSourcePath = m_assetDragDropState.sourcePath;
                m_assetDragDropState.deliveredTarget = folder;
            }
        }
    }

    ImGui::EndDragDropTarget();
}

void ProjectPanel::FinalizeAssetDragDrop(IProjectManager& manager) {
    if (m_assetDragDropState.dragging) {
        ImGui::SetMouseCursor(
            m_assetDragDropState.hoveredValidTarget ? ImGuiMouseCursor_Arrow : ImGuiMouseCursor_NotAllowed);
    }

    if (!m_assetDragDropState.deliveredSourcePath.empty() && m_assetDragDropState.deliveredTarget) {
        Commands::MoveAssetToFolder(
            manager,
            m_assetDragDropState.deliveredSourcePath,
            m_assetDragDropState.deliveredTarget);
    }
}

void ProjectPanel::BeginRename(const AssetItemPtr& item) {
    if (!item) {
        CancelRename();
        return;
    }

    m_renameState.Begin(item->fullPath, GetProjectAssetDisplayName(item).c_str());
}

bool ProjectPanel::CommitRename(IProjectManager& manager) {
    if (!m_renameState.IsActive()) {
        return false;
    }

    const std::string sourcePath = m_renameState.Item();
    std::string currentDisplayName;
    for (const auto& item : manager.GetCurrentItems()) {
        if (item && item->fullPath == sourcePath) {
            currentDisplayName = GetProjectAssetDisplayName(item);
            break;
        }
    }

    if (!currentDisplayName.empty() && currentDisplayName == m_renameState.Buffer()) {
        CancelRename();
        return true;
    }

    if (!Commands::RenameAsset(manager, sourcePath, m_renameState.Buffer())) {
        return false;
    }

    CancelRename();
    return true;
}

void ProjectPanel::CancelRename() {
    m_renameState.Cancel();
}

void ProjectPanel::Render() {
    UI::PanelWindowScope panel(m_name.c_str());
    if (!panel.IsOpen()) {
        return;
    }

    Actions::ObserveFocusedActionRoute(*m_context, EditorActionRoute::Project);

    auto& manager = m_context->GetProjectManager();
    BeginAssetDragDropFrame();
    m_deferredContextAction = {};
    RenderToolbar();

    ImGui::PushStyleColor(ImGuiCol_ChildBg, UI::ProjectBrowserSurfaceColor());
    UI::PanelContentScope content("ProjectContent", ImVec2(0.0f, 0.0f));
    if (!content.IsOpen()) {
        ImGui::PopStyleColor();
        return;
    }

    const float totalHeight = ImGui::GetContentRegionAvail().y;
    const float splitterWidth = UI::PanelSplitterHitThickness();
    const float availableWidth = ImGui::GetContentRegionAvail().x;
    const float clampedNavigationWidth = std::clamp(
        m_navigationWidth,
        UI::ProjectNavigationMinWidth(),
        (std::max)(UI::ProjectNavigationMinWidth(), availableWidth - UI::ProjectBrowserMinWidth() - splitterWidth));
    m_navigationWidth = clampedNavigationWidth;

    RenderFolderTreePane(manager);
    ImGui::SameLine(0.0f, 0.0f);
    const UI::SplitterResult splitter = UI::DrawSplitter("##ProjectPaneSplitter", UI::SplitterAxis::Vertical, totalHeight);
    if (splitter.active) {
        m_navigationWidth += splitter.delta;
    }
    ImGui::SameLine(0.0f, 0.0f);
    RenderBrowserPane(manager);

    FinalizeAssetDragDrop(manager);
    ImGui::PopStyleColor();

    if (m_deferredContextAction) {
        auto deferredAction = std::move(m_deferredContextAction);
        m_deferredContextAction = {};
        deferredAction();
    }
}

void ProjectPanel::RenderToolbar() {
    UI::PanelToolbarScope toolbar(
        "ProjectToolbar",
        kProjectToolbarHeight,
        ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse,
        true,
        ImVec2(UI::ToolbarPadding().x, kProjectToolbarPaddingY),
        UI::ToolbarItemSpacing(),
        UI::ProjectPanelToolbarBackgroundColor());
    if (!toolbar.IsOpen()) {
        return;
    }

    ImGui::PushStyleVar(ImGuiStyleVar_CellPadding, ImVec2(0.0f, 0.0f));
    if (ImGui::BeginTable("##ProjectToolbarLayout", 2, ImGuiTableFlags_NoSavedSettings | ImGuiTableFlags_SizingStretchProp)) {
        ImGui::TableSetupColumn("##Spacer", ImGuiTableColumnFlags_WidthStretch);
        ImGui::TableSetupColumn("##Search", ImGuiTableColumnFlags_WidthFixed, 220.0f);

        ImGui::TableNextRow();

        ImGui::TableNextColumn();

        ImGui::TableNextColumn();
        UI::ToolbarSearchField("##Search", "Search assets", m_searchBuffer, sizeof(m_searchBuffer));

        ImGui::EndTable();
    }
    ImGui::PopStyleVar();
}

void ProjectPanel::RenderFolderTreePane(IProjectManager& manager) {
    auto* managerPtr = &manager;
    ImGui::PushStyleColor(ImGuiCol_ChildBg, UI::ProjectNavigationPaneBackgroundColor());
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, UI::ProjectNavigationPanePadding());
    const bool open = ImGui::BeginChild("ProjectFolderTree", ImVec2(m_navigationWidth, 0.0f), false);
    ImGui::PopStyleVar();
    ImGui::PopStyleColor();
    if (!open) {
        ImGui::EndChild();
        return;
    }

    const AssetItemPtr rootFolder = manager.GetRootFolder();
    const AssetItemPtr currentFolder = manager.GetCurrentFolder();
    const std::string currentFolderPath = currentFolder ? currentFolder->fullPath : std::string();
    UI::ResetTreeLayout();
    if (rootFolder) {
        RenderFolderTreeNode(manager, rootFolder, currentFolderPath);
    } else {
        UI::DrawEmptyState("No Assets Folder");
    }

    if (UI::BeginContextMenuForWindow("##ProjectFolderTreeContext")) {
        Actions::DrawMenuAction(Actions::MakeCreateFolderAction(), [&]() {
            QueueDeferredAction(m_deferredContextAction, [this, managerPtr]() {
                if (AssetItemPtr createdFolder = Commands::CreateFolder(*managerPtr, "New Folder")) {
                    BeginRename(createdFolder);
                }
            });
        });
        UI::EndContextMenu();
    }

    ImGui::EndChild();
}

void ProjectPanel::RenderFolderTreeNode(
    IProjectManager& manager,
    const AssetItemPtr& folder,
    const std::string& currentFolderPath) {
    if (!folder || !folder->isFolder) {
        return;
    }

    bool hasChildFolders = false;
    for (const auto& child : folder->children) {
        if (child && child->isFolder) {
            hasChildFolders = true;
            break;
        }
    }

    UI::TreeNodeDefinition nodeDefinition;
    nodeDefinition.options.selected = folder->fullPath == currentFolderPath;
    nodeDefinition.options.leaf = !hasChildFolders;
    nodeDefinition.options.defaultOpen = IsCurrentTreeBranch(currentFolderPath, folder->fullPath);
    nodeDefinition.persistenceKey = folder->fullPath;
    nodeDefinition.style = UI::ProjectFolderTreeStyle();
    nodeDefinition.prefix.width = UI::NavigationTreePrefixWidth();
    nodeDefinition.prefix.draw = DrawProjectFolderTreePrefix;
    nodeDefinition.callbacks.onInteraction = [this, &manager, folder](const UI::TreeNodeResult& node) {
        if (node.clicked) {
            manager.NavigateToFolder(folder);
        }

    };

    const UI::TreeNodeResult node = UI::DrawTreeNode(
        &m_folderTreeState,
        (void*)folder.get(),
        folder->name.c_str(),
        nodeDefinition);

    RegisterFolderDropTarget(manager, folder);

    if (node.open) {
        for (const auto& child : folder->children) {
            if (!child || !child->isFolder) {
                continue;
            }
            RenderFolderTreeNode(manager, child, currentFolderPath);
        }
        UI::EndTreeNode();
    }
}

void ProjectPanel::RenderBrowserPane(IProjectManager& manager) {
    auto* managerPtr = &manager;
    ImGui::PushStyleColor(ImGuiCol_ChildBg, UI::ProjectBrowserPaneBackgroundColor());
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(0.0f, 0.0f));
    const bool open = ImGui::BeginChild("ProjectBrowser", ImVec2(0.0f, 0.0f), false);
    ImGui::PopStyleVar();
    ImGui::PopStyleColor();
    if (!open) {
        ImGui::EndChild();
        return;
    }

    std::vector<AssetItemPtr> visibleItems;
    const auto& items = manager.GetCurrentItems();
    const UI::SearchQuery searchQuery(m_searchBuffer);
    if (m_renameState.IsActive() && manager.FindCurrentItemIndex(m_renameState.Item()) < 0) {
        CancelRename();
    }
    visibleItems.reserve(items.size());
    for (const auto& item : items) {
        if ((m_renameState.IsActive() && item && item->fullPath == m_renameState.Item()) || MatchesSearch(item, searchQuery)) {
            visibleItems.push_back(item);
        }
    }

    RenderBrowserHeader(manager);

    ImGui::PushStyleColor(ImGuiCol_ChildBg, UI::ProjectBrowserPaneBackgroundColor());
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, UI::ProjectBrowserPanePadding());
    ImGui::PushStyleVar(ImGuiStyleVar_ItemSpacing, UI::AssetGridSpacing());
    const bool bodyOpen = ImGui::BeginChild(
        "ProjectBrowserBody",
        ImVec2(0.0f, 0.0f),
        ImGuiChildFlags_AlwaysUseWindowPadding);
    ImGui::PopStyleVar(2);
    ImGui::PopStyleColor();
    if (!bodyOpen) {
        ImGui::EndChild();
        ImGui::EndChild();
        return;
    }

    const float tileWidth = UI::AssetTileSize().x;
    const float tileHeight = UI::AssetTileSize().y;
    const float spacing = UI::AssetGridSpacing().x;
    const float rowSpacing = UI::AssetGridSpacing().y;
    const float panelWidth = ImGui::GetContentRegionAvail().x;
    int columns = static_cast<int>((panelWidth + spacing) / (tileWidth + spacing));
    if (columns < 1) {
        columns = 1;
    }

    AssetItemPtr pendingSelection;
    AssetItemPtr pendingOpenTarget;
    const std::string selectedItemPath = manager.GetSelectedItemPath();
    const ImVec2 gridOrigin = ImGui::GetCursorPos();
    for (int visibleIndex = 0; visibleIndex < static_cast<int>(visibleItems.size()); ++visibleIndex) {
        const int column = visibleIndex % columns;
        const int row = visibleIndex / columns;
        ImGui::SetCursorPos(ImVec2(
            gridOrigin.x + column * (tileWidth + spacing),
            gridOrigin.y + row * (tileHeight + rowSpacing)));

        const AssetItemPtr& item = visibleItems[visibleIndex];
        const AssetItemInteraction interaction = RenderAssetItem(item, selectedItemPath == item->fullPath);
        if (interaction.clicked) {
            pendingSelection = item;
        }
        if (interaction.openRequested) {
            pendingOpenTarget = item;
            break;
        }
        if (m_deferredContextAction) {
            break;
        }
    }

    if (!visibleItems.empty()) {
        const int rowCount = (static_cast<int>(visibleItems.size()) + columns - 1) / columns;
        ImGui::SetCursorPosY(gridOrigin.y + rowCount * tileHeight + (rowCount - 1) * rowSpacing);
    }

    if (visibleItems.empty() && !searchQuery.Empty()) {
        UI::DrawEmptyState(
            "No Search Results",
            "No assets match the current search");
    }

    if (!m_deferredContextAction) {
        Actions::HandleProjectBackgroundPrimaryClick(manager, m_renameState);
        if (pendingSelection) {
            manager.SetSelectedItem(pendingSelection);
        }
        if (pendingOpenTarget) {
            Actions::OpenProjectAsset(*m_context, pendingOpenTarget);
        }
    }

    if (UI::BeginContextMenuForWindow("##ProjectBrowserContext")) {
        Actions::DrawMenuAction(Actions::MakeCreateFolderAction(), [&]() {
            QueueDeferredAction(m_deferredContextAction, [this, managerPtr]() {
                if (AssetItemPtr createdFolder = Commands::CreateFolder(*managerPtr, "New Folder")) {
                    BeginRename(createdFolder);
                }
            });
        });
        if (manager.CanNavigateBack()) {
            Actions::DrawMenuSeparator();
            Actions::DrawMenuAction(Actions::MakeNavigateBackAction(true), [&]() {
                QueueDeferredAction(m_deferredContextAction, [managerPtr]() {
                    managerPtr->NavigateBack();
                });
            });
        }
        UI::EndContextMenu();
    }

    ImGui::EndChild();
    ImGui::EndChild();
}

void ProjectPanel::RenderBrowserHeader(IProjectManager& manager) {
    auto* managerPtr = &manager;
    ImGui::PushStyleColor(ImGuiCol_ChildBg, UI::ProjectBrowserHeaderBackgroundColor());
    ImGui::PushStyleVar(ImGuiStyleVar_WindowPadding, ImVec2(10.0f, 5.0f));
    const bool open = ImGui::BeginChild(
        "ProjectBrowserHeader",
        ImVec2(0.0f, UI::ProjectBrowserHeaderHeight()),
        false,
        ImGuiWindowFlags_NoScrollbar | ImGuiWindowFlags_NoScrollWithMouse);
    ImGui::PopStyleVar();
    ImGui::PopStyleColor();
    if (!open) {
        ImGui::EndChild();
        return;
    }

    const float rowHeight = UI::BreadcrumbItemHeight();
    const float startY = ImGui::GetCursorPosY();
    const float availableHeight = ImGui::GetContentRegionAvail().y;
    if (availableHeight > rowHeight) {
        ImGui::SetCursorPosY(startY + (availableHeight - rowHeight) * 0.5f - 1.0f);
    }

    UI::DrawToolbarBreadcrumbs(
        "Assets",
        manager.GetPathDepth(),
        [&](size_t index) { return manager.GetPathName(index); },
        [&](size_t index) {
            QueueDeferredAction(m_deferredContextAction, [managerPtr, index]() {
                managerPtr->NavigateToIndex(index);
            });
        });

    ImDrawList* drawList = ImGui::GetWindowDrawList();
    const ImVec2 windowMin = ImGui::GetWindowPos();
    const ImVec2 windowMax(windowMin.x + ImGui::GetWindowSize().x, windowMin.y + ImGui::GetWindowSize().y);
    UI::DrawHorizontalDivider(drawList, windowMin.x, windowMax.x, windowMax.y - 0.5f);

    ImGui::EndChild();
}

ProjectPanel::AssetItemInteraction ProjectPanel::RenderAssetItem(const AssetItemPtr& item, bool isSelected) {
    AssetItemInteraction interaction;

    ImGui::PushID(item ? item->fullPath.c_str() : "ProjectItem");
    const bool isRenaming = item && m_renameState.IsEditing(item->fullPath);
    const bool isDraggingThisItem = !isRenaming && Actions::IsProjectAssetBeingDragged(item);
    const UI::AssetIconKind iconKind = ResolveProjectAssetIconKind(item);
    const std::string displayName = GetProjectAssetDisplayName(item);
    UI::AssetTileOptions tileOptions = MakeProjectAssetTileOptions();
    tileOptions.drawLabel = !isRenaming;

    const UI::AssetTileResult tile = UI::DrawAssetTile(
        displayName.c_str(),
        isSelected,
        isDraggingThisItem,
        [&](ImDrawList* drawList, const ImVec2& iconMin, const ImVec2& iconMax) {
            if (item && item->canUseImagePreview &&
                UI::DrawTextureAssetPreview(
                    drawList,
                    iconMin,
                    iconMax,
                    item->fullPath,
                    m_context ? m_context->GetProjectPath() : std::string())) {
                return;
            }
            UI::DrawAssetIcon(drawList, iconMin, iconMax, iconKind);
        },
        tileOptions);
    const bool secondaryClicked = !isRenaming && ImGui::IsItemClicked(ImGuiMouseButton_Right);

    if (isRenaming) {
        const float renameWidth = tile.labelMax.x - tile.labelMin.x;
        const float renameOffsetY = (std::max)(0.0f, (tile.labelMax.y - tile.labelMin.y - UI::InlineRenameFieldHeight()) * 0.5f);
        const UI::InlineRenameFieldResult renameField = UI::DrawInlineRenameFieldAt(
            "##Rename",
            ImVec2(tile.labelMin.x, tile.labelMin.y + renameOffsetY),
            m_renameState.Buffer(),
            m_renameState.BufferSize(),
            renameWidth,
            m_renameState.ConsumeFocusRequest());

        if (renameField.cancelRequested) {
            CancelRename();
        } else if (renameField.submitted || renameField.deactivated) {
            CommitRename(m_context->GetProjectManager());
        }
    } else {
        if (tile.clicked) {
            interaction.clicked = true;
        }
        if (secondaryClicked && item) {
            m_context->GetProjectManager().SetSelectedItem(item);
        }

        RegisterFolderDropTarget(m_context->GetProjectManager(), item);
        Actions::BeginProjectAssetDrag(item, iconKind);

        if (UI::BeginContextMenuForLastItem("##ProjectItemContext")) {
            Actions::DrawMenuAction(Actions::MakeOpenAssetAction(Commands::CanOpenAsset(item)), [&]() {
                QueueDeferredAction(m_deferredContextAction, [this, item]() {
                    Actions::OpenProjectAsset(*m_context, item);
                });
            });
            Actions::DrawMenuAction(Actions::MakeAction("Rename", nullptr, false, item != nullptr), [&]() {
                QueueDeferredAction(m_deferredContextAction, [this, item]() {
                    BeginRename(item);
                });
            });
            Actions::DrawMenuAction(Actions::MakeDeleteAssetAction(item != nullptr), [&]() {
                QueueDeferredAction(m_deferredContextAction, [this, item]() {
                    Commands::DeleteAsset(m_context->GetProjectManager(), item);
                });
            });
            UI::EndContextMenu();
        }

        if (tile.openRequested) {
            interaction.openRequested = true;
        }
    }

    ImGui::PopID();
    return interaction;
}

bool ProjectPanel::MatchesSearch(const AssetItemPtr& item, const UI::SearchQuery& searchQuery) {
    if (!item) {
        return false;
    }
    if (searchQuery.Empty()) {
        return true;
    }

    return searchQuery.Matches(item->name);
}

bool ProjectPanel::IsCurrentTreeBranch(const std::string& currentFolderPath, const std::string& folderPath) {
    if (currentFolderPath.empty() || folderPath.empty()) {
        return false;
    }
    if (currentFolderPath == folderPath) {
        return true;
    }

    const std::string withForwardSlash = folderPath + "/";
    const std::string withBackwardSlash = folderPath + "\\";
    return currentFolderPath.rfind(withForwardSlash, 0) == 0 || currentFolderPath.rfind(withBackwardSlash, 0) == 0;
}

}
}