extends Node
class_name TK_GridController

## Composable 4-way grid controller.
## Depends on placement below some Node2D below some GridContext.

signal moved(p_new_cell_position)

func _input(p_event: InputEvent):
    var direction := InputUtils.input_event_to_4way_direction(p_event)
    if direction == Vector2.ZERO:
        return

    var context := _get_grid_context()
    var cell = context.position_to_cell_position(get_parent().global_position)
    var new_cell = cell + direction
    if context.is_cell_traversible(new_cell):
        # todo: Should we move the outmost node2d?
        get_parent().position += context.cell_size * direction
        emit_signal("moved", new_cell)

func _get_grid_context() -> Node:
    var current := self.get_parent().get_parent()
    while current.name != "GridContext":
        current = current.get_parent()
    return current