package d2ui

// RenderPriority determines in which order ui elements are drawn.
// The higher the number the later an element is drawn.
type RenderPriority int

const (
	// RenderPriorityBackground is the first element drawn
	RenderPriorityBackground RenderPriority = iota
	// RenderPriorityForeground is the last element drawn
	RenderPriorityForeground
)

// Widget defines an object that is a UI widget
type Widget interface {
	Drawable
	bindManager(ui *UIManager)
}

// ClickableWidget defines an object that can be clicked
type ClickableWidget interface {
	Widget
	SetEnabled(enabled bool)
	SetPressed(pressed bool)
	GetEnabled() bool
	GetPressed() bool
	OnActivated(callback func())
	Activate()
}

// BaseWidget contains default functionality that all widgets share
type BaseWidget struct {
	manager        *UIManager
	x              int
	y              int
	width          int
	height         int
	renderPriority RenderPriority
	visible        bool
}

// NewBaseWidget creates a new BaseWidget with defaults
func NewBaseWidget(manager *UIManager) *BaseWidget {
	return &BaseWidget{
		manager:        manager,
		x:              0,
		y:              0,
		width:          0,
		height:         0,
		visible:        true,
		renderPriority: RenderPriorityBackground,
	}
}

func (b *BaseWidget) bindManager(manager *UIManager) {
	b.manager = manager
}

// GetSize returns the size of the widget
func (b *BaseWidget) GetSize() (width, height int) {
	return b.width, b.height
}

// SetPosition sets the position of the widget
func (b *BaseWidget) SetPosition(x, y int) {
	b.x, b.y = x, y
}

// OffsetPosition moves the widget by x and y
func (b *BaseWidget) OffsetPosition(x, y int) {
	b.x += x
	b.y += y
}

// GetPosition returns the position of the widget
func (b *BaseWidget) GetPosition() (x, y int) {
	return b.x, b.y
}

// GetVisible returns whether the widget is visible
func (b *BaseWidget) GetVisible() (visible bool) {
	return b.visible
}

// SetVisible make the widget visible, not visible
func (b *BaseWidget) SetVisible(visible bool) {
	b.visible = visible
}

// GetRenderPriority returns the order in which this widget is rendered
func (b *BaseWidget) GetRenderPriority() (prio RenderPriority) {
	return b.renderPriority
}

// SetRenderPriority sets the order in which this widget is rendered
func (b *BaseWidget) SetRenderPriority(prio RenderPriority) {
	b.renderPriority = prio
}