class PgSearch::Normalizer

def add_normalization(sql_expression)
  return sql_expression unless config.ignore.include?(:accents)
  if config.postgresql_version < 90000
    raise PgSearch::NotSupportedForPostgresqlVersion.new(<<-MESSAGE.strip_heredoc)
      Sorry, {:ignoring => :accents} only works in PostgreSQL 9.0 and above.
      #{config.inspect}
    MESSAGE
  end
  sql_node = case sql_expression
             when Arel::Nodes::Node
               sql_expression
             else
               Arel.sql(sql_expression)
             end
  Arel::Nodes::NamedFunction.new(
    PgSearch.unaccent_function,
    [sql_node]
  ).to_sql
end

def initialize(config)
  @config = config
end