#include <XCEditor/Widgets/UIEditorBoolField.h>

#include <algorithm>

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

namespace {

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;
}

} // namespace

UIEditorBoolFieldLayout BuildUIEditorBoolFieldLayout(
    const ::XCEngine::UI::UIRect& bounds,
    const UIEditorBoolFieldSpec& spec,
    const UIEditorBoolFieldMetrics& metrics) {
    UIEditorBoolFieldLayout layout = {};
    layout.bounds = bounds;

    const float controlX = (std::min)(
        bounds.x + bounds.width - metrics.horizontalPadding - metrics.toggleWidth,
        bounds.x + metrics.controlColumnStart);
    const float labelWidth = (std::max)(
        0.0f,
        controlX - bounds.x - metrics.horizontalPadding - metrics.labelControlGap);
    layout.labelRect = ::XCEngine::UI::UIRect(
        bounds.x + metrics.horizontalPadding,
        bounds.y,
        labelWidth,
        bounds.height);
    layout.toggleRect = ::XCEngine::UI::UIRect(
        controlX,
        bounds.y + (std::max)(0.0f, (bounds.height - metrics.toggleHeight) * 0.5f),
        metrics.toggleWidth,
        metrics.toggleHeight);

    const float knobSize = (std::max)(0.0f, layout.toggleRect.height - metrics.toggleKnobInset * 2.0f);
    const float knobX = spec.value
        ? layout.toggleRect.x + layout.toggleRect.width - metrics.toggleKnobInset - knobSize
        : layout.toggleRect.x + metrics.toggleKnobInset;
    layout.knobRect = ::XCEngine::UI::UIRect(
        knobX,
        layout.toggleRect.y + metrics.toggleKnobInset,
        knobSize,
        knobSize);
    return layout;
}

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

    if (ContainsPoint(layout.toggleRect, point)) {
        return { UIEditorBoolFieldHitTargetKind::Toggle };
    }

    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 hovered = state.hoveredTarget != UIEditorBoolFieldHitTargetKind::None;
    const ::XCEngine::UI::UIColor rowColor =
        state.active ? palette.rowActiveColor :
        (hovered ? palette.rowHoverColor : palette.surfaceColor);
    drawList.AddFilledRect(layout.bounds, rowColor, metrics.cornerRounding);
    drawList.AddRectOutline(
        layout.bounds,
        state.focused ? palette.focusedBorderColor : palette.borderColor,
        state.focused ? metrics.focusedBorderThickness : metrics.borderThickness,
        metrics.cornerRounding);

    const ::XCEngine::UI::UIColor toggleColor =
        spec.readOnly ? palette.toggleReadOnlyColor :
        (spec.value ? palette.toggleOnColor : palette.toggleOffColor);
    drawList.AddFilledRect(layout.toggleRect, toggleColor, layout.toggleRect.height * 0.5f);
    drawList.AddRectOutline(
        layout.toggleRect,
        palette.toggleBorderColor,
        metrics.borderThickness,
        layout.toggleRect.height * 0.5f);
    drawList.AddFilledRect(layout.knobRect, palette.knobColor, layout.knobRect.height * 0.5f);
}

void AppendUIEditorBoolFieldForeground(
    ::XCEngine::UI::UIDrawList& drawList,
    const UIEditorBoolFieldLayout& layout,
    const UIEditorBoolFieldSpec& spec,
    const UIEditorBoolFieldPalette& palette,
    const UIEditorBoolFieldMetrics& metrics) {
    drawList.PushClipRect(layout.labelRect);
    drawList.AddText(
        ::XCEngine::UI::UIPoint(layout.labelRect.x, layout.labelRect.y + metrics.textInsetY),
        spec.label,
        palette.labelColor,
        12.0f);
    drawList.PopClipRect();

    drawList.AddText(
        ::XCEngine::UI::UIPoint(
            layout.toggleRect.x - 42.0f,
            layout.bounds.y + metrics.textInsetY),
        spec.value ? "On" : "Off",
        palette.valueColor,
        12.0f);
}

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