#include <XCEditor/Fields/UIEditorBoolField.h>
#include <XCEditor/Widgets/UIEditorFieldRowLayout.h>
#include <XCEditor/Widgets/UIEditorTextLayout.h>

#include <algorithm>

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

namespace {

float ClampNonNegative(float value) {
    return (std::max)(0.0f, value);
}

bool ContainsPoint(const ::XCEngine::UI::UIRect& rect, const ::XCEngine::UI::UIPoint& point) {
    return point.x >= rect.x &&
        point.x <= rect.x + rect.width &&
        point.y >= rect.y &&
        point.y <= rect.y + rect.height;
}

void AppendCheckMark(
    ::XCEngine::UI::UIDrawList& drawList,
    const ::XCEngine::UI::UIRect& rect,
    const ::XCEngine::UI::UIColor& color) {
    const float size = (std::min)(rect.width, rect.height);
    const float pad = (std::max)(size * 0.22f, 2.0f);
    const ::XCEngine::UI::UIPoint a(rect.x + pad, rect.y + size * 0.56f);
    const ::XCEngine::UI::UIPoint b(rect.x + size * 0.44f, rect.y + size - pad);
    const ::XCEngine::UI::UIPoint c(rect.x + size - pad, rect.y + pad);
    drawList.AddLine(a, b, color, 2.0f);
    drawList.AddLine(b, c, color, 2.0f);
}

} // namespace

UIEditorBoolFieldLayout BuildUIEditorBoolFieldLayout(
    const ::XCEngine::UI::UIRect& bounds,
    const UIEditorBoolFieldSpec&,
    const UIEditorBoolFieldMetrics& metrics) {
    const UIEditorFieldRowLayout hostLayout = BuildUIEditorFieldRowLayout(
        bounds,
        metrics.checkboxSize,
        UIEditorFieldRowLayoutMetrics {
            metrics.rowHeight,
            metrics.horizontalPadding,
            metrics.labelControlGap,
            metrics.controlColumnStart,
            metrics.controlMinWidth,
            metrics.controlTrailingInset,
            0.0f,
        });

    UIEditorBoolFieldLayout layout = {};
    layout.bounds = hostLayout.bounds;
    layout.labelRect = hostLayout.labelRect;
    layout.controlRect = hostLayout.controlRect;
    layout.checkboxRect = ::XCEngine::UI::UIRect(
        layout.controlRect.x,
        layout.bounds.y + ClampNonNegative((layout.bounds.height - metrics.checkboxSize) * 0.5f),
        metrics.checkboxSize,
        metrics.checkboxSize);
    layout.checkmarkRect = layout.checkboxRect;
    return layout;
}

UIEditorBoolFieldHitTarget HitTestUIEditorBoolField(
    const UIEditorBoolFieldLayout& layout,
    const ::XCEngine::UI::UIPoint& point) {
    if (!ContainsPoint(layout.bounds, point)) {
        return {};
    }

    if (ContainsPoint(layout.controlRect, point)) {
        return { UIEditorBoolFieldHitTargetKind::Checkbox };
    }

    return { UIEditorBoolFieldHitTargetKind::Row };
}

void AppendUIEditorBoolFieldBackground(
    ::XCEngine::UI::UIDrawList& drawList,
    const UIEditorBoolFieldLayout& layout,
    const UIEditorBoolFieldSpec& spec,
    const UIEditorBoolFieldState& state,
    const UIEditorBoolFieldPalette& palette,
    const UIEditorBoolFieldMetrics& metrics) {
    const bool checkboxHovered = state.hoveredTarget == UIEditorBoolFieldHitTargetKind::Checkbox;
    const ::XCEngine::UI::UIColor checkboxColor =
        spec.readOnly
            ? palette.checkboxReadOnlyColor
            : (checkboxHovered ? palette.checkboxHoverColor : palette.checkboxColor);
    drawList.AddFilledRect(layout.checkboxRect, checkboxColor, metrics.checkboxRounding);
    drawList.AddRectOutline(
        layout.checkboxRect,
        palette.checkboxBorderColor,
        metrics.borderThickness,
        metrics.checkboxRounding);
}

void AppendUIEditorBoolFieldForeground(
    ::XCEngine::UI::UIDrawList& drawList,
    const UIEditorBoolFieldLayout& layout,
    const UIEditorBoolFieldSpec& spec,
    const UIEditorBoolFieldPalette& palette,
    const UIEditorBoolFieldMetrics& metrics) {
    drawList.PushClipRect(ResolveUIEditorTextClipRect(layout.labelRect, metrics.labelFontSize));
    drawList.AddText(
        ::XCEngine::UI::UIPoint(
            layout.labelRect.x,
            ResolveUIEditorTextTop(layout.labelRect, metrics.labelFontSize, metrics.labelTextInsetY)),
        spec.label,
        palette.labelColor,
        metrics.labelFontSize);
    drawList.PopClipRect();

    if (spec.value) {
        AppendCheckMark(drawList, layout.checkmarkRect, palette.checkboxMarkColor);
    }
}

void AppendUIEditorBoolField(
    ::XCEngine::UI::UIDrawList& drawList,
    const ::XCEngine::UI::UIRect& bounds,
    const UIEditorBoolFieldSpec& spec,
    const UIEditorBoolFieldState& state,
    const UIEditorBoolFieldPalette& palette,
    const UIEditorBoolFieldMetrics& metrics) {
    const UIEditorBoolFieldLayout layout = BuildUIEditorBoolFieldLayout(bounds, spec, metrics);
    AppendUIEditorBoolFieldBackground(drawList, layout, spec, state, palette, metrics);
    AppendUIEditorBoolFieldForeground(drawList, layout, spec, palette, metrics);
}

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