/**
    An example demonstrating the use of Path Actions.

    This role can produce different paths, depending on the [type] @Attribute value.
    
*/

class PathRole : ActionRole {
   
    @Attribute
    var type = PathType.LINE

    override fun createAction() : Action {

        // Create a path starting at (0,0). A big if..else it... else,

        val path = if ( type == PathType.BOX ) {
            // A box made up of straight lines
            Path().apply {
                // Note, we are using *absolute* positions for each section of the path
                lineTo( 200, 0 )
                lineTo( 200, 100 )
                lineTo( 0, 100 )
                lineTo( 0, 0 )
            }
        } else if ( type == PathType.SAUSSAGE ) {
            // Two paralledl lines joined by semi-circles.
            val r = 50
            Path().apply {
                // Note, we are using *relative* values for each section of the path.
                lineBy( 300, 0 )
                circularArcBy( Vector2(0, r*2), r, true, true ) // Semicircle
                lineBy( -300, 0 )
                circularArcBy( Vector2(0, r*-2), r, true, true ) // Semicircle
            }

        } else if (type == PathType.BEZIER ) {
            Path().apply {
                bezierBy( Vector2(400, 100), Vector2( 200, 0 ), Vector2( -200, 0 ) )
            }

        } else if (type == PathType.BEZIER_LOOP ) {
            Path().apply {
                bezierBy( Vector2(400, 100), Vector2( 200, 0 ), Vector2( 0, -20 ) )
                bezierBy( Vector2(-400,-100), Vector2( 200, 0 ) )
            }

        } else {
            // Not a Path, just a straight line.
            // NOTE, because this isn't a closed loop, it will JUMP back to the start,
            // when forever() restarts the follow action.
            Line( Vector2(0,0), Vector2(400, 0) )
        }

        // So that all movements has the same speed
        val seconds = path.length() / 100
        // If we wanted a fixed time, rather than a fixed speed, just replace it by :
        //val seconds = 1

        // I've chosen easeInOut, to demonstrate that the easing function is applied to the whole
        // path, not to individual sections of the path.
        // If you omit ease, the balls will move with constant speed.
        val ease = Eases.easeInOut

        // Now return an Action which follows the path. Updating the actor's position.
        // We use 'relativeTo' because the paths all start at (0,0), and we want them to start
        // at the Actor's current position.
        return path.relativeTo( actor.position ).follow( actor.position, seconds /*, ease*/ ).forever()

    }

}

enum class PathType {
    LINE,
    BOX,
    SAUSSAGE,
    BEZIER,
    BEZIER_LOOP
}