class InfoAnimation( val actor : Actor, val showInSeconds : double, val hideAfterSeconds : double, val duration : double ) {

    var initialScale = actor.scaleXY

    init {
        // Hide it. Move it below the bottom of the screen.
        actor.y -= actor.stage.firstView().worldHeight
        actor.scaleXY = 0.1
    }
    
    fun createAction() : Action {
        return if (showInSeconds < 0 ) {
            null
        } else {
            val show = Delay( showInSeconds ) then showAction()

            if (hideAfterSeconds > 0) {
                show then Delay( hideAfterSeconds ) then hideAction()
            } else {
                show
            }
        }
    }

    /**
        Some Info are not displayed when the scene is loaded. For example, the tutorial can display message(s) when the
        exit gate is open. See Play.showInfo() and Play.checkCargo().
    */
    fun show() {
        actor.scaleXY = 0.1
        (actor.role as ActionRole).replaceAction( showAction() )
    }

    /**
        The action to animate the appeaance of this Info.
        Scales the Actor to [initialScale] at the same time moving the Info into place.
    */
    fun showAction() : Action {
        return MoveBy( actor.position, duration, Vector2(0, actor.stage.firstView().worldHeight), Eases.easeOutBack ) and
            ScaleTo( actor, duration,  initialScale )
    }

    fun hideAction() : Action {

        return MoveBy( actor.position, duration, Vector2(0, -actor.stage.firstView().worldHeight), Eases.easeIn ) and
            ScaleTo( actor, duration, 0.1 )
    }

}

/**
    Text which is initially hidden.
    If [showInSeconds] >= 0, then the message will automatically appear soon after the scene is loaded.
    If [showInSeconds] < 0 then this Info will only appear when show() is called.

    These should be placed on the glass stage.
*/
class Info : ActionRole() {

    @Attribute
    var event = ""


    @Attribute
    var showInSeconds = -1.0

    @Attribute
    var hideAfterSeconds = 5.0

    @Attribute
    var duration = 1.0

    var animation : InfoAnimation

    override fun createAction() : Action {
        animation = InfoAnimation( actor, showInSeconds, hideAfterSeconds, duration )
        return animation.createAction()
    }

    fun show() {
        animation.show()
    }

}


class AnnimatedOptionButton : Button, OptionButtonRole {


    @Attribute
    var showInSeconds = -1.0

    @Attribute
    var duration = 1.0

    val handler = OptionButtonHandler( this )
    override fun getHandler() = handler
    
    override fun onClicked(event:MouseEvent) {
       handler.onClicked()
    }

    override fun createAction() : Action {
        return InfoAnimation( actor, showInSeconds, 0, duration ).createAction()
    }


}