#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 {

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

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

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();
    RenderToolbar();

    UI::PanelContentScope content("ProjectContent", ImVec2(0.0f, 0.0f));
    if (!content.IsOpen()) {
        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);

    Actions::DrawProjectCreateFolderDialog(*m_context, m_createFolderDialog);
}

void ProjectPanel::RenderToolbar() {
    UI::PanelToolbarScope toolbar("ProjectToolbar", UI::ProjectPanelToolbarHeight());
    if (!toolbar.IsOpen()) {
        return;
    }

    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();
    }
}

void ProjectPanel::RenderFolderTreePane(IProjectManager& 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();
    if (rootFolder) {
        RenderFolderTreeNode(manager, rootFolder, currentFolderPath);
    } else {
        UI::DrawEmptyState("No Assets Folder");
    }

    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::TreeNodeOptions nodeOptions;
    nodeOptions.selected = folder->fullPath == currentFolderPath;
    nodeOptions.leaf = !hasChildFolders;
    nodeOptions.defaultOpen = IsCurrentTreeBranch(currentFolderPath, folder->fullPath);

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

    if (node.clicked) {
        manager.NavigateToFolder(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) {
    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 std::string search = m_searchBuffer;
    visibleItems.reserve(items.size());
    for (const auto& item : items) {
        if (MatchesSearch(item, search)) {
            visibleItems.push_back(item);
        }
    }

    RenderBrowserHeader(manager);

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

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

    AssetItemPtr pendingSelection;
    AssetItemPtr pendingContextTarget;
    AssetItemPtr pendingOpenTarget;
    AssetItemPtr pendingMoveTarget;
    std::string pendingMoveSourcePath;

    const std::string selectedItemPath = manager.GetSelectedItemPath();
    for (int visibleIndex = 0; visibleIndex < static_cast<int>(visibleItems.size()); ++visibleIndex) {
        if (visibleIndex > 0 && visibleIndex % columns != 0) {
            ImGui::SameLine();
        }

        const AssetItemPtr& item = visibleItems[visibleIndex];
        const AssetItemInteraction interaction = RenderAssetItem(item, selectedItemPath == item->fullPath);
        if (interaction.clicked) {
            pendingSelection = item;
        }
        if (interaction.contextRequested) {
            pendingContextTarget = item;
        }
        if (!interaction.droppedSourcePath.empty()) {
            pendingMoveSourcePath = interaction.droppedSourcePath;
            pendingMoveTarget = item;
            break;
        }
        if (interaction.openRequested) {
            pendingOpenTarget = item;
            break;
        }
    }

    if (visibleItems.empty()) {
        UI::DrawEmptyState(
            search.empty() ? "No Assets" : "No Search Results",
            search.empty() ? "Current folder is empty" : "No assets match the current search");
    }

    Actions::HandleProjectBackgroundPrimaryClick(manager);
    if (pendingSelection) {
        manager.SetSelectedItem(pendingSelection);
    }
    if (pendingContextTarget) {
        Actions::HandleProjectItemContextRequest(manager, pendingContextTarget, m_itemContextMenu);
    }
    if (!pendingMoveSourcePath.empty() && pendingMoveTarget) {
        Commands::MoveAssetToFolder(manager, pendingMoveSourcePath, pendingMoveTarget);
    }
    if (pendingOpenTarget) {
        Actions::OpenProjectAsset(*m_context, pendingOpenTarget);
    }
    Actions::DrawProjectItemContextPopup(*m_context, m_itemContextMenu);
    Actions::RequestProjectEmptyContextPopup(m_emptyContextMenu);
    Actions::DrawProjectEmptyContextPopup(m_emptyContextMenu, m_createFolderDialog);

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

void ProjectPanel::RenderBrowserHeader(IProjectManager& 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;
    }

    if (ImGui::BeginTable("##ProjectBrowserHeaderLayout", 1, ImGuiTableFlags_NoSavedSettings | ImGuiTableFlags_SizingStretchProp | ImGuiTableFlags_NoPadOuterX)) {
        ImGui::TableNextRow();
        ImGui::TableNextColumn();
        UI::DrawToolbarBreadcrumbs(
            "Assets",
            manager.GetPathDepth(),
            [&](size_t index) { return manager.GetPathName(index); },
            [&](size_t index) { manager.NavigateToIndex(index); });
        ImGui::EndTable();
    }

    ImDrawList* drawList = ImGui::GetWindowDrawList();
    const ImVec2 min = ImGui::GetWindowPos();
    const ImVec2 max(min.x + ImGui::GetWindowSize().x, min.y + ImGui::GetWindowSize().y);
    UI::DrawHorizontalDivider(drawList, min.x, max.x, max.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 isDraggingThisItem = Actions::IsProjectAssetBeingDragged(item);
    const UI::AssetIconKind iconKind = item->isFolder ? UI::AssetIconKind::Folder : UI::AssetIconKind::File;

    const UI::AssetTileResult tile = UI::DrawAssetTile(
        item->name.c_str(),
        isSelected,
        isDraggingThisItem,
        [&](ImDrawList* drawList, const ImVec2& iconMin, const ImVec2& iconMax) {
            UI::DrawAssetIcon(drawList, iconMin, iconMax, iconKind);
                });

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

    if (tile.contextRequested) {
        interaction.contextRequested = true;
    }
    
    interaction.droppedSourcePath = Actions::AcceptProjectAssetDropPayload(item);
    Actions::BeginProjectAssetDrag(item, iconKind);
    
    if (tile.openRequested) {
        interaction.openRequested = true;
    }
    
    ImGui::PopID();
    return interaction;
}

bool ProjectPanel::MatchesSearch(const AssetItemPtr& item, const std::string& search) {
    if (!item) {
        return false;
    }
    if (search.empty()) {
        return true;
    }

    auto toLower = [](unsigned char c) {
        return static_cast<char>(std::tolower(c));
    };

    std::string itemName = item->name;
    std::string searchText = search;
    std::transform(itemName.begin(), itemName.end(), itemName.begin(), toLower);
    std::transform(searchText.begin(), searchText.end(), searchText.begin(), toLower);
    return itemName.find(searchText) != std::string::npos;
}

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;
}

}
}