package ui

import (
	"image"

	"github.com/hajimehoshi/ebiten"

	"code.ur.gs/lupine/ordoor/internal/assetstore"
	"code.ur.gs/lupine/ordoor/internal/menus"
)

// Widget represents an interactive area of the screen. Backgrounds and other
// non-interactive areas are not widgets.
type Widget struct {
	// Position on the screen in original (i.e., unscaled) coordinates
	Bounds  image.Rectangle
	Tooltip string
	Value   string // #dealwithit for bools and ints and so on :p

	OnHoverEnter func()
	OnHoverLeave func()

	// Mouse up can happen without a click taking place if, for instance, the
	// mouse cursor leaves the bounds while still pressed.
	OnMouseDown  func()
	OnMouseClick func()
	OnMouseUp    func()

	disabled      bool
	disabledImage *ebiten.Image

	// These are expected to have the same dimensions as the Bounds
	hoverAnimation []*ebiten.Image
	hoverState     bool

	// FIXME: We assume right mouse button isn't needed here
	// TODO: down, up, and click hooks.
	mouseButtonDownImage *ebiten.Image
	mouseButtonState     bool

	path   []int
	record *menus.Record
	sprite *assetstore.Sprite

	valueToImage func() *ebiten.Image
}

func (w *Widget) Disable() {
	w.hovering(false)
	w.mouseButton(false)

	w.disabled = true
}

func (w *Widget) hovering(value bool) {
	if w.OnHoverEnter != nil && !w.hoverState && value {
		w.OnHoverEnter()
	}

	if w.OnHoverLeave != nil && w.hoverState && !value {
		w.OnHoverLeave()
	}

	w.hoverState = value

	return
}

func (w *Widget) mouseButton(value bool) {
	if w.OnMouseDown != nil && !w.mouseButtonState && value {
		w.OnMouseDown()
	}

	if w.mouseButtonState && !value {
		if w.OnMouseClick != nil && w.hoverState {
			w.OnMouseClick()
		}

		if w.OnMouseUp != nil {
			w.OnMouseUp()
		}
	}

	w.mouseButtonState = value
}

func (w *Widget) Image(aniStep int) (*ebiten.Image, error) {
	if w.disabled {
		return w.disabledImage, nil
	}

	if w.mouseButtonDownImage != nil && w.hoverState && w.mouseButtonState {
		return w.mouseButtonDownImage, nil
	}

	if w.hoverState && len(w.hoverAnimation) > 0 {
		return w.hoverAnimation[(aniStep)%len(w.hoverAnimation)], nil
	}

	if w.valueToImage != nil {
		return w.valueToImage(), nil
	}

	return w.sprite.Image, nil
}