class Baza::Driver::Mysql::Index < Baza::Index
  attr_reader :args, :columns

  def initialize(args)
    @args = args
    @columns = []
  end

  #Used to validate in Knj::Wrap_map.
  def __object_unique_id__
    return @args[:data][:Key_name]
  end

  def name
    return @args[:data][:Key_name]
  end

  def table
    return @args[:db].tables[@args[:table_name]]
  end

  def drop
    sql = "DROP INDEX `#{self.name}` ON `#{self.table.name}`"

    begin
      @args[:db].query(sql)
    rescue => e
      #The index has already been dropped - ignore.
      if e.message.index("check that column/key exists") != nil
        #ignore.
      else
        raise e
      end
    end
  end

  def rename newname
    newname = newname.to_sym
    create_args = data
    create_args[:name] = newname

    drop
    table.create_indexes([create_args])
    @args[:data][:Key_name] = newname
  end

  def data
    return {
      name: name,
      columns: @columns
    }
  end

  #Returns true if the index is a unique-index.
  def unique?
    if @args[:data][:Index_type] == "UNIQUE" || @args[:data][:Non_unique].to_i == 0
      return true
    else
      return false
    end
  end

  #Returns true if the index is a primary-index.
  def primary?
    return true if @args[:data][:Key_name] == "PRIMARY"
    return false
  end
end