class PgSearch::Configuration::Column

def alias
  Configuration.alias(association.subselect_alias, @column_name)
end

def foreign?
  @association.present?
end

def full_name
  "#{@model.connection.quote_table_name(table)}.#{@model.connection.quote_column_name(@column_name)}"
end

def initialize(column_name, weight, model, association = nil)
  @column_name = column_name.to_s
  @weight = weight
  @model = model
  @association = association
end

def table
  foreign? ? @association.table_name : @model.table_name
end

def to_sql
  name = if foreign?
           "#{@association.subselect_alias}.#{self.alias}"
         else
           full_name
         end
  "coalesce(#{name}, '')"
end