package tomo

import "image"
import "image/color"
import "golang.org/x/image/font"
import "git.tebibyte.media/tomo/tomo/data"
import "git.tebibyte.media/tomo/tomo/event"
import "git.tebibyte.media/tomo/tomo/input"
import "git.tebibyte.media/tomo/tomo/canvas"

type Inset [4]int
type Gap   image.Point

type Border struct {
	Width Inset
	Color [4]color.Color
}

type Align int; const (
	AlignStart Align = iota // similar to left-aligned text
	AlignMiddle             // similar to center-aligned text
	AlignEnd                // similar to right-aligned text
	AlignEven               // similar to justified text
)

type Object interface {
	Box () Box
}

type Box interface {
	Object
	Bounds         () image.Rectangle
	InnerBounds    () image.Rectangle
	SetBounds      (image.Rectangle)
	SetColor       (color.Color)
	SetBorder      (...Border)
	SetMinimumSize (int, int)
	SetPadding     (Inset)

	SetDNDData   (data.Data)
	SetDNDAccept (...data.Mime)
	SetFocused   (bool)
	SetFocusable (bool)
	
	Focused       () bool
	Modifiers     (func ()) input.Modifiers
	MousePosition (func ()) image.Point

	OnFocusEnter  (func ()) event.Cookie
	OnFocusLeave  (func ()) event.Cookie
	OnDNDEnter    (func ()) event.Cookie
	OnDNDLeave    (func ()) event.Cookie
	OnDNDDrop     (func (data.Data)) event.Cookie
	OnMouseEnter  (func ()) event.Cookie
	OnMouseLeave  (func ()) event.Cookie
	OnMouseMove   (func ()) event.Cookie
	OnMouseDown   (func (input.Button)) event.Cookie
	OnMouseUp     (func (input.Button)) event.Cookie
	OnScroll      (func (deltaX, deltaY float64)) event.Cookie
	OnKeyDown     (func (key input.Key, numberPad bool)) event.Cookie
	OnKeyUp       (func (key input.Key, numberPad bool)) event.Cookie

	ContentBounds         () image.Rectangle
	ScrollTo              (image.Point)
	OnContentBoundsChange (func ()) event.Cookie
}

type TextBox interface {
	Box
	SetTextColor (color.Color)
	SetFace      (font.Face)
	SetHAlign    (Align)
	SetVAlign    (Align)
}

type CanvasBox interface {
	Box
	SetDrawer  (canvas.Drawer)
	Invalidate ()
}

type ContainerBox interface {
	Box
	SetGap    (Gap)
	Add       (Object)
	Delete    (Object)
	Insert    (child Object, before Object)
	Clear     ()
	Length    () int
	At        (int) Object
	SetLayout (Layout)
}

type Window interface {
	SetRoot  (Object)
	SetIcon  (sizes []image.Image)
	NewMenu  (image.Rectangle) (Window, error)
	NewModal (image.Rectangle) (Window, error)
	Widget   () (Window, error)
	Copy     (data.Data)
	Paste    (callback func (data.Data, error), accept ...data.Mime)
	Close    ()
	Show     ()
	Hide     ()
	OnClose  (func ()) event.Cookie
}

type MainWindow interface {
	Window
	NewChild (image.Rectangle) (Window, error)
}

type Layout interface {
	Arrange (image.Rectangle, Gap, []Box)
}