package objects

import "image"
import "git.tebibyte.media/tomo/tomo"
import "git.tebibyte.media/tomo/tomo/input"
// import "git.tebibyte.media/tomo/tomo/event"
import "git.tebibyte.media/tomo/objects/layouts"

// Menu is a menu window.
//
// Sub-components:
//   - TearLine is a horizontal line at the top of the menu that, when clicked,
//     causes the menu to be "torn off" into a movable window.
type Menu struct {
	tomo.Window

	parent        tomo.Window
	bounds        image.Rectangle
	rootContainer tomo.ContainerBox
	tearLine      tomo.Object
	torn          bool
}

// NewMenu creates a new menu with the specified items. The menu will appear
// directly under the mouse pointer.
func NewMenu (parent tomo.Window, items ...tomo.Object) (*Menu, error) {
	bounds := (image.Rectangle { }).Add(parent.MousePosition())
	return newMenu(parent, bounds, items...)
}

// NewAnchoredMenu creates a new menu with the specified items. The menu will
// appear directly under the anchor.
func NewAnchoredMenu (anchor tomo.Object, items ...tomo.Object) (*Menu, error) {
	parent := anchor.GetBox().Window()
	bounds := menuBoundsFromAnchor(anchor)
	return newMenu(parent, bounds, items...)
}

func newMenu (parent tomo.Window, bounds image.Rectangle, items ...tomo.Object) (*Menu, error) {
	menu := &Menu { }
	menu.bounds = bounds
	menu.parent = parent
	window, err := menu.parent.NewMenu(menu.bounds)
	if err != nil { return nil, err }
	menu.Window = window
	
	menu.rootContainer = tomo.NewContainerBox()
	menu.rootContainer.SetAttr(tomo.ALayout(layouts.ContractVertical))

	if !menu.torn {
		menu.tearLine = menu.newTearLine()
		menu.rootContainer.Add(menu.tearLine)
	}
	
	for _, item := range items {
		menu.rootContainer.Add(item)
		if item, ok := item.(*MenuItem); ok {
			item.OnClick(func () {
				if !menu.torn {
					menu.Close()
				}
			})
		}
	}
	menu.rootContainer.SetRole(tomo.R("objects", "Container"))
	menu.rootContainer.SetTag("menu", true)

	menu.Window.SetRoot(menu.rootContainer)
	return menu, nil
}

// TearOff converts this menu into a tear-off menu.
func (this *Menu) TearOff () {
	if this.torn          { return }
	if this.parent == nil { return }
	this.torn = true

	window, err := this.parent.NewChild(this.bounds)
	window.SetIcon(tomo.IconListChoose)
	if err != nil { return }

	visible := this.Window.Visible()
	this.Window.SetRoot(nil)
	this.Window.Close()

	this.rootContainer.Remove(this.tearLine)
	this.rootContainer.SetTag("torn", true)
	
	this.Window = window
	this.Window.SetRoot(this.rootContainer)
	this.Window.SetVisible(visible)
}

func (this *Menu) newTearLine () tomo.Object {
	tearLine := tomo.NewBox()
	tearLine.SetRole(tomo.R("objects", "TearLine"))
	tearLine.SetFocusable(true)
	tearLine.OnMouseEnter(func () {
		tearLine.SetFocused(true)
	})
	tearLine.OnMouseLeave(func () {
		tearLine.SetFocused(false)
	})
	tearLine.OnKeyDown(func (key input.Key, numberPad bool) bool {
		if !isClickingKey(key) { return false }
		return true
	})
	tearLine.OnKeyUp(func (key input.Key, numberPad bool) bool {
		if !isClickingKey(key) { return false }
		this.TearOff()
		return true
	})
	tearLine.OnButtonDown(func (button input.Button) bool {
		if !isClickingButton(button) { return false }
		return true
	})
	tearLine.OnButtonUp(func (button input.Button) bool {
		if !isClickingButton(button) { return false }
		if tearLine.Window().MousePosition().In(tearLine.Bounds()) {
			this.TearOff()
		}
		return true
	})
	return tearLine
}

func menuBoundsFromAnchor (anchor tomo.Object) image.Rectangle {
	bounds := anchor.GetBox().Bounds()
	return image.Rect (
		bounds.Min.X, bounds.Max.Y,
		bounds.Max.X, bounds.Max.Y)//.Add(windowBounds.Min)
}