require 'pg'

require 'common/davical_plugin'
require 'prune/prune_plugin'
require 'rm/plugins/davical'

class DavicalPrune < DavicalRm
  #
  # DAViCal only supports Postgres, so even if we ever are
  # database-agnostic, this plugin can't be.
  #
  include DavicalPlugin
  include PrunePlugin


  def get_leftover_domains(db_domains)
    # AgenDAV doesn't have a concept of domains.
    return []
  end


  def get_leftover_accounts(db_accounts)
    # Get a list of all users who have logged in to DAViCal.
    davical_accounts = self.get_davical_usernames()
    return davical_accounts - db_accounts
  end


  protected;

  def get_davical_usernames()
    usernames = []

    begin
      connection = PGconn.connect(@db_host,
                                  @db_port,
                                  @db_opts,
                                  @db_tty,
                                  @db_name,
                                  @db_user,
                                  @db_pass)

      # User #1 is the super-user, and not tied to an email address.
      sql_query  = 'SELECT username FROM usr WHERE user_no > 1;'

      connection.query(sql_query) do |result|
        usernames = result.field_values('username')
      end

      connection.close()
    rescue PGError => e
      # Pretend like we're database-agnostic in case we ever are.
      raise DatabaseError.new(e)
    end

    return usernames
  end


end