#include <XCEditor/Docking/UIEditorDockHost.h>

#include <algorithm>
#include <utility>

namespace XCEngine::UI::Editor::Widgets {

namespace {

using ::XCEngine::UI::UIColor;
using ::XCEngine::UI::UIDrawList;

bool UsesExternalBodyPresentation(
    const UIEditorDockHostForegroundOptions& options,
    std::string_view panelId) {
    return std::find(
               options.externalBodyPanelIds.begin(),
               options.externalBodyPanelIds.end(),
               panelId) != options.externalBodyPanelIds.end();
}

UIColor ResolveSplitterColor(
    const UIEditorDockHostSplitterLayout& splitter,
    const UIEditorDockHostPalette& palette) {
    if (splitter.active) {
        return palette.splitterActiveColor;
    }

    if (splitter.hovered) {
        return palette.splitterHoveredColor;
    }

    return palette.splitterColor;
}

} // namespace

void AppendUIEditorDockHostBackground(
    UIDrawList& drawList,
    const UIEditorDockHostLayout& layout,
    const UIEditorDockHostPalette& palette,
    const UIEditorDockHostMetrics& metrics) {
    for (const UIEditorDockHostTabStackLayout& tabStack : layout.tabStacks) {
        std::vector<UIEditorTabStripItem> tabItems = {};
        tabItems.reserve(tabStack.items.size());
        for (const UIEditorDockHostTabItemLayout& item : tabStack.items) {
            UIEditorTabStripItem tabItem = {};
            tabItem.tabId = item.panelId;
            tabItem.title = item.title;
            tabItem.closable = item.closable;
            tabItems.push_back(std::move(tabItem));
        }

        AppendUIEditorTabStripBackground(
            drawList,
            tabStack.tabStripLayout,
            tabStack.tabStripState,
            palette.tabStripPalette,
            metrics.tabStripMetrics);
    }

    for (const UIEditorDockHostSplitterLayout& splitter : layout.splitters) {
        drawList.AddFilledRect(
            splitter.splitterLayout.handleRect,
            ResolveSplitterColor(splitter, palette),
            metrics.splitterHandleRounding);
    }
}

void AppendUIEditorDockHostForeground(
    UIDrawList& drawList,
    const UIEditorDockHostLayout& layout,
    const UIEditorDockHostForegroundOptions& options,
    const UIEditorDockHostPalette& palette,
    const UIEditorDockHostMetrics& metrics) {
    for (const UIEditorDockHostTabStackLayout& tabStack : layout.tabStacks) {
        std::vector<UIEditorTabStripItem> tabItems = {};
        tabItems.reserve(tabStack.items.size());
        for (const UIEditorDockHostTabItemLayout& item : tabStack.items) {
            UIEditorTabStripItem tabItem = {};
            tabItem.tabId = item.panelId;
            tabItem.title = item.title;
            tabItem.closable = item.closable;
            tabItems.push_back(std::move(tabItem));
        }

        AppendUIEditorTabStripForeground(
            drawList,
            tabStack.tabStripLayout,
            tabItems,
            tabStack.tabStripState,
            palette.tabStripPalette,
            metrics.tabStripMetrics);

        if (UsesExternalBodyPresentation(options, tabStack.selectedPanelId)) {
            continue;
        }
    }

    if (layout.dropPreview.visible) {
        drawList.AddFilledRect(
            layout.dropPreview.previewRect,
            palette.dropPreviewFillColor);
        drawList.AddRectOutline(
            layout.dropPreview.previewRect,
            palette.dropPreviewBorderColor,
            1.0f);
    }
}

void AppendUIEditorDockHostForeground(
    UIDrawList& drawList,
    const UIEditorDockHostLayout& layout,
    const UIEditorDockHostPalette& palette,
    const UIEditorDockHostMetrics& metrics) {
    AppendUIEditorDockHostForeground(
        drawList,
        layout,
        UIEditorDockHostForegroundOptions{},
        palette,
        metrics);
}

void AppendUIEditorDockHost(
    UIDrawList& drawList,
    const ::XCEngine::UI::UIRect& bounds,
    const UIEditorPanelRegistry& panelRegistry,
    const UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    const UIEditorDockHostState& state,
    const UIEditorDockHostForegroundOptions& foregroundOptions,
    const UIEditorDockHostPalette& palette,
    const UIEditorDockHostMetrics& metrics) {
    const UIEditorDockHostLayout layout =
        BuildUIEditorDockHostLayout(bounds, panelRegistry, workspace, session, state, metrics);
    AppendUIEditorDockHostBackground(drawList, layout, palette, metrics);
    AppendUIEditorDockHostForeground(drawList, layout, foregroundOptions, palette, metrics);
}

void AppendUIEditorDockHost(
    UIDrawList& drawList,
    const ::XCEngine::UI::UIRect& bounds,
    const UIEditorPanelRegistry& panelRegistry,
    const UIEditorWorkspaceModel& workspace,
    const UIEditorWorkspaceSession& session,
    const UIEditorDockHostState& state,
    const UIEditorDockHostPalette& palette,
    const UIEditorDockHostMetrics& metrics) {
    AppendUIEditorDockHost(
        drawList,
        bounds,
        panelRegistry,
        workspace,
        session,
        state,
        UIEditorDockHostForegroundOptions{},
        palette,
        metrics);
}

} // namespace XCEngine::UI::Editor::Widgets