class RuboCop::Cop::Lint::FormatParameterMismatch

def called_on_string?(node)
  receiver_node, _method, format_string, = *node
  if receiver_node.nil? || receiver_node.const_type?
    format_string && format_string.str_type?
  else
    receiver_node.str_type?
  end
end

def count_matches(node)
  receiver_node, _method_name, *args = *node
  if (sprintf?(node) || format?(node)) && !heredoc?(node)
    number_of_args_for_format = (args.size - 1)
    number_of_expected_fields = expected_fields_count(args.first)
  elsif percent?(node) && args.first.array_type?
    number_of_expected_fields = expected_fields_count(receiver_node)
    number_of_args_for_format = args.first.child_nodes.size
  else
    number_of_args_for_format = number_of_expected_fields = :unknown
  end
  [number_of_args_for_format, number_of_expected_fields]
end

def expected_fields_count(node)
  return :unknown unless node.str_type?
  return 1 if node.source =~ NAMED_INTERPOLATION
  node
    .source
    .scan(FIELD_REGEX)
    .select { |x| x.first != PERCENT_PERCENT }
    .reduce(0) { |a, e| a + (e[2] =~ /\*/ ? 2 : 1) }
end

def format?(node)
  format_method?(:format, node)
end

def format_method?(name, node)
  receiver, method_name, *args = *node
  if receiver && receiver.const_type?
    return false unless receiver.loc.name.is?(KERNEL)
  end
  return false unless method_name == name
  args.size > 1 && args.first.str_type?
end

def heredoc?(node)
  _receiver, _name, args = *node
  args.source[0, 2] == SHOVEL
end

def message(node)
  _receiver, method_name, *_args = *node
  num_args_for_format, num_expected_fields = count_matches(node)
  method_name = 'String#%' if PERCENT == method_name.to_s
  format(MSG, num_args_for_format, method_name, num_expected_fields)
end

def method_with_format_args?(node)
  sprintf?(node) || format?(node) || percent?(node)
end

def named_mode?(node)
  receiver_node, _method_name, *args = *node
  relevant_node = if sprintf?(node) || format?(node)
                    args.first
                  elsif percent?(node)
                    receiver_node
                  end
  !relevant_node.source.scan(NAMED_FIELD_REGEX).empty?
end

def node_with_splat_args?(node)
  return false if percent?(node)
  _receiver_node, _method_name, *args = *node
  args.butfirst.any?(&:splat_type?)
end

def offending_node?(node)
  return false unless called_on_string?(node)
  return false unless method_with_format_args?(node)
  return false if named_mode?(node) || node_with_splat_args?(node)
  num_of_format_args, num_of_expected_fields = count_matches(node)
  num_of_format_args != :unknown &&
    num_of_expected_fields != num_of_format_args
end

def on_send(node)
  add_offense(node, :selector) if offending_node?(node)
end

def percent?(node)
  receiver_node, method_name, *arg_nodes = *node
  percent = method_name == :% &&
            (STRING_TYPES.include?(receiver_node.type) ||
             arg_nodes[0].array_type?)
  if percent && STRING_TYPES.include?(receiver_node.type)
    return false if heredoc?(node)
  end
  percent
end

def sprintf?(node)
  format_method?(:sprintf, node)
end