class Seahorse::Model::ShapeMap

def build_shape(shape_ref)
  Shapes::Shape.new(resolve(shape_ref), shape_map: self)
end

def initialize(shape_defs = {})
  @definitions = shape_defs
  @shapes = {}
end

def resolve(shape_ref)
  if definition = @definitions[shape_ref['shape']]
    definition.merge(shape_ref)
  else
    raise ArgumentError, "shape not found for #{shape_ref.inspect}"
  end
end

def shape(shape_ref)
  @shapes[shape_ref] ||= build_shape(shape_ref)
end

def shape_names
  @definitions.keys
end