#include "Button.h"
#include <algorithm>

namespace UI {

Button::Button(const std::string& label, std::function<void()> onClick)
    : label(label), onClick(onClick) {
    focusable = true;
    padding = Thickness(12.0f, 6.0f);
    minSize = Size(80.0f, 32.0f);
    horizontalAlignment = HorizontalAlignment::Center;
}

void Button::SetLabel(const std::string& newLabel) {
    label = newLabel;
    MarkDirty(DirtyFlags::Layout | DirtyFlags::Render);
}

void Button::RefreshPrimitives() {
    bgRect = std::make_unique<Rectangle>(globalBounds.X, globalBounds.Y, globalBounds.Width, globalBounds.Height);
    Color drawColor = normalColor;
    if (pressed) {
        drawColor = activeColor;
    } else if (hovered) {
        drawColor = hoverColor;
    }
    bgRect->SetColor(drawColor.r, drawColor.g, drawColor.b, drawColor.a);
    previousColor = drawColor;

    UI::Size textSize = Text::Measure(label);
    float contentW = std::max(0.0f, globalBounds.Width - padding.HorizontalTotal());
    float contentH = std::max(0.0f, globalBounds.Height - padding.VerticalTotal());
    float textX = globalBounds.X + padding.Left + std::max(0.0f, (contentW - textSize.width) * 0.5f);
    float textY = globalBounds.Y + padding.Top + std::max(0.0f, (contentH - textSize.height) * 0.5f);
    labelText = std::make_unique<Text>(textX, textY, label);
}

void Button::Measure(Size /*availableSpace*/) {
    UI::Size textSize = Text::Measure(label);
    
    desiredSize.width = std::clamp(textSize.width + padding.HorizontalTotal() + margin.HorizontalTotal(), minSize.width, maxSize.width);
    desiredSize.height = std::clamp(textSize.height + padding.VerticalTotal() + margin.VerticalTotal(), minSize.height, maxSize.height);
}

void Button::Arrange(Rect finalBounds) {
    Rect oldGlobal = globalBounds;
    bool doWeRefreshMaybe = IsDirty(DirtyFlags::Render | DirtyFlags::Layout);
    Widget::Arrange(finalBounds);

    if (doWeRefreshMaybe || globalBounds != oldGlobal) {
        RefreshPrimitives();
    }
}


void Button::Draw() {
    if (!visible) return;

    if (!bgRect || IsDirty(DirtyFlags::Layout)) {
        RefreshPrimitives();
    }

    // Determine primitive color based on input interaction state  // TODO: needs dedup
    Color drawColor = normalColor;
    if (pressed) {
        drawColor = activeColor;
    } else if (hovered) {
        drawColor = hoverColor;
    }

    if (drawColor != previousColor) {
        bgRect->SetColor(drawColor.r, drawColor.g, drawColor.b, drawColor.a);
        previousColor = drawColor;
    }

    if (bgRect) {
        bgRect->Render();
    }
    if (labelText) {
        labelText->Render();
    }

    Widget::Draw();
}

bool Button::OnPointerStream(const std::shared_ptr<PointerStream>& stream) {
    if (!enabled || !visible) return false;

    const auto event = stream->PeekLatestInput();

    if (event.actDirection == PointerDirection::Down) {
        SetPressed(true);
        return true;
    } else if (event.actDirection == PointerDirection::Up) {
        if (pressed) {
            SetPressed(false);
            if (globalBounds.Contains(event.screenX, event.screenY)) {
                if (onClick) {
                    onClick();
                }
            }
            return true;
        }
    }
    return false;
}

}