#include "BorderlessWindowChrome.h"

#include <algorithm>

namespace XCEngine::UI::Editor::Host {

namespace {

using ::XCEngine::UI::UIPoint;
using ::XCEngine::UI::UIRect;

bool IsPointInsideRect(const UIRect& rect, const UIPoint& point) {
    return rect.width > 0.0f &&
        rect.height > 0.0f &&
        point.x >= rect.x &&
        point.x <= rect.x + rect.width &&
        point.y >= rect.y &&
        point.y <= rect.y + rect.height;
}

} // namespace

BorderlessWindowChromeLayout BuildBorderlessWindowChromeLayout(
    const UIRect& titleBarRect,
    float leadingOccupiedRight,
    const BorderlessWindowChromeMetrics& metrics) {
    BorderlessWindowChromeLayout layout = {};
    layout.titleBarRect = titleBarRect;
    if (titleBarRect.width <= 0.0f || titleBarRect.height <= 0.0f) {
        return layout;
    }

    const float buttonWidth = (std::max)(metrics.buttonWidth, 0.0f);
    const float buttonX3 = titleBarRect.x + titleBarRect.width - metrics.buttonInsetX - buttonWidth;
    const float buttonX2 = buttonX3 - buttonWidth;
    const float buttonX1 = buttonX2 - buttonWidth;

    layout.minimizeButtonRect = UIRect(buttonX1, titleBarRect.y, buttonWidth, titleBarRect.height);
    layout.maximizeRestoreButtonRect = UIRect(buttonX2, titleBarRect.y, buttonWidth, titleBarRect.height);
    layout.closeButtonRect = UIRect(buttonX3, titleBarRect.y, buttonWidth, titleBarRect.height);

    const float dragLeft =
        (std::max)(titleBarRect.x, leadingOccupiedRight + metrics.dragPaddingLeft);
    const float dragRight =
        (std::max)(dragLeft, layout.minimizeButtonRect.x - metrics.dragPaddingRight);
    layout.dragRect = UIRect(
        dragLeft,
        titleBarRect.y,
        (std::max)(0.0f, dragRight - dragLeft),
        titleBarRect.height);
    return layout;
}

BorderlessWindowChromeHitTarget HitTestBorderlessWindowChrome(
    const BorderlessWindowChromeLayout& layout,
    const UIPoint& point) {
    if (IsPointInsideRect(layout.closeButtonRect, point)) {
        return BorderlessWindowChromeHitTarget::CloseButton;
    }
    if (IsPointInsideRect(layout.maximizeRestoreButtonRect, point)) {
        return BorderlessWindowChromeHitTarget::MaximizeRestoreButton;
    }
    if (IsPointInsideRect(layout.minimizeButtonRect, point)) {
        return BorderlessWindowChromeHitTarget::MinimizeButton;
    }
    if (IsPointInsideRect(layout.dragRect, point)) {
        return BorderlessWindowChromeHitTarget::DragRegion;
    }
    return BorderlessWindowChromeHitTarget::None;
}

} // namespace XCEngine::UI::Editor::Host