module StaticLiteralParser

# File lib/static_literal_parser.rb, line 4
def self.parse(str, constants)
  case constants
  when Array
    parse(str, constant_strs_array_to_hash(constants))
  when Hash
    parse_(RubyVM::AbstractSyntaxTree.parse(str), constants)
  else
    raise ArgumentError, "Unsupported constants type: #{constants}"
  end
end

# File lib/static_literal_parser.rb, line 43
                     def self.constant_strs_array_to_hash(constant_strs_array)
  constant_strs_array.flat_map {|constant|
    constant.split('::').inject([]) {|memo, part|
      [*memo, [memo.last, part].compact.join('::')]
    }
  }.to_h {|name|
    c = Object.const_get(name)
    [name.to_sym, c]
  }
end

# File lib/static_literal_parser.rb, line 15
                     def self.parse_(node, constants)
  case node.type
  when :SCOPE
    parse_(node.children[2], constants)
  when :LIST, :ZLIST, :ZARRAY, :ARRAY
    node.children[0..-2].map {|x| parse_(x, constants) }
  when :HASH
    Hash[*parse_(node.children[0], constants)]
  when :LIT, :STR, :NIL
    node.children[0]
  when :CONST
    constants[node.children[0]] or raise "Missing const: #{node.children[0]}"
  when :COLON2
    (parent, child) = node.children
    case parent.type
    when :CONST, :COLON2
      parent = parse_(parent, constants)
      constants[:"#{parent}::#{child}"] or raise "Missing nested const: #{[parent, child]}"
    else
      raise "Unexpected COLON2 parent #{parent.type}"
    end
  when :DSTR, :DOT2, :DREGX
    raise "Unsupported node: #{node.type}\nStaticLiteralParser does not support any dyanmic evaluations."
  else
    raise "Unexpected node #{node.type}"
  end
end