"""Place independent Cutout stages using authored local layouts."""
from collections import Counter


def route_geometry(group, source, positions):
    """Guide a shared forward geometry reference through authored waypoints."""
    for position in positions:
        reroute = group.nodes.new("NodeReroute")
        reroute.location = position
        group.links.new(source, reroute.inputs[0])
        source = reroute.outputs[0]
    return source


def layout_stage(group, previous, positions, input_regions, offset=(0, 0)):
    """Map stage-local default names without renaming Blender nodes."""
    counts, stage = Counter(), {}
    for node in group.nodes:
        if node in previous or node.bl_idname == "NodeGroupInput":
            continue
        base, dot, suffix = node.name.rpartition(".")
        base = base if dot and suffix.isdigit() else node.name
        index = counts[base]
        counts[base] += 1
        stage[base if index == 0 else f"{base}.{index:03d}"] = node
    assert set(stage) == set(positions) - {"Set Shade Smooth", "Group Output"}, (group.name, set(stage) ^ set(positions))
    for name, node in stage.items():
        x, y = positions[name]
        node.location = (x + offset[0], y + offset[1])
    inputs = [(link.to_socket, link.from_socket.name) for link in group.links if link.to_node in stage.values() and link.from_node.bl_idname == "NodeGroupInput"]
    for targets, (x, y) in input_regions:
        sockets = [(socket, name) for socket, name in inputs if socket.node in [stage[key] for key in targets if key in stage]]
        if not sockets:
            continue
        control = group.nodes.new("NodeGroupInput")
        control.location = (x + offset[0], y + offset[1])
        for socket, name in sockets:
            group.links.new(control.outputs[name], socket)
    return stage


def finish_layout(group):
    """Expose linked fields and retain readable constants."""
    for node in group.nodes:
        node.select = False
        node.width = 200 if "Attribute" in node.bl_idname else 160
        if node.bl_idname in {"ShaderNodeMath", "ShaderNodeVectorMath"}:
            node.hide = all(socket.is_linked for socket in node.inputs if socket.enabled and not socket.hide)
        for socket in node.outputs:
            socket.hide = not socket.is_linked
    for node in list(group.nodes):
        if node.bl_idname == "NodeGroupInput" and not any(socket.is_linked for socket in node.outputs):
            group.nodes.remove(node)