class Rock : Item {

    var fallImmediately = true

    override fun createAction() : Action {
        return this:>movement.action()
    }

    fun movement() : bool {
        if ( actor.stage == null ) {
            println( "Stage is null" )
        } else if (! actor.stage.actors.contains( actor ) ) {
            println( "Hmm, weird" )
            println( actor.stage )
            println( actor.stage.actors.size() )
        }

        val below = lookSouth()
        if ( ! below.isSolid() ) {
            if ( fallImmediately ) {
                fall( below )
            } else {
                replaceAction( delayedFall() )
            }
        }
        return false
    }

    fun fall( below : Item ) {
        fallImmediately = true
        if ( below is Enemy ) {
            val spawns = actor.stage.findRolesByClass<Spawn>( Spawn )
            if ( spawns.size() > 0 ) {
                var spawned = false
                for ( n in 0..10 ) { // Try 10 times to find a free spot, then give up
                    val spawn = spawns[ Rand.between( 0, spawns.size() ) ]
                    val swawnBlock = spawn.block()
                    if ( look( swawnBlock ).isEmpty() ) {
                        below.getBlock().remove(below)
                        below.actor.createChild( "squash" )
                        below.actor.position.set( spawn.actor.position )
                        block.add( below )
                        spawned = true
                        break
                    }
                }
                if ( ! spawned ) {
                    below.getBlock().remove(below)
                    below.actor.createChild( "squash" )
                    below.kill()
                }
            }
        } else if ( below is Player ) {
            below.actor.event("squash")
            below.getBlock().remove(below) // Just to prevent the warning message.
            below.actor.createChild( "squash" )
            below.kill()
        } else {
            moveSouth()
        }
    }

    fun delayedFall() : Action {
        fallImmediately = true
        return Delay( 0.6 ).then( createAction() )
    }
}