require 'common/plugin'
require 'common/user'

module DavicalPlugin
  # Code that all Davical plugins (Prune, Rm, Mv...) will share.  That
  # is, we implement the Plugin interface.
  include Plugin

  def initialize(cfg)
    @db_host = cfg.davical_dbhost
    @db_port = cfg.davical_dbport
    @db_opts = cfg.davical_dbopts
    @db_tty  = cfg.davical_dbtty
    @db_name = cfg.davical_dbname
    @db_user = cfg.davical_dbuser
    @db_pass = cfg.davical_dbpass
  end


  def describe_user(user)
    principal_id = self.get_principal_id(user)
    return "Principal ID: #{principal_id}"
  end


  def list_users()
    #
    # Produce a list of DAViCal users. This is public because it's
    # useful for testing.
    #
    usernames = []

    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()

    return usernames.map{ |u| User.new(u) }
  end


  protected;

  def get_principal_id(user)
    principal_id = nil

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

    sql_query =  'SELECT principal.principal_id '
    sql_query += 'FROM (principal INNER JOIN usr '
    sql_query += '      ON principal.user_no = usr.user_no) '
    sql_query += 'WHERE usr.username = $1;'

    connection.query(sql_query, [user.to_s()]) do |result|
      if result.num_tuples > 0
        principal_id = result[0]['principal_id']
      end
    end

    connection.close()

    return principal_id
  end

end