text: /* Copyright 2014-2016 OpenMarket Ltd
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   *    http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  CREATE TABLE IF NOT EXISTS presence(
    user_id TEXT NOT NULL,
    state VARCHAR(20),
    status_msg TEXT,
    mtime BIGINT, -- miliseconds since last state change
    UNIQUE (user_id)
  );
  
  -- For each of /my/ users which possibly-remote users are allowed to see their
  -- presence state
  CREATE TABLE IF NOT EXISTS presence_allow_inbound(
    observed_user_id TEXT NOT NULL,
    observer_user_id TEXT NOT NULL, -- a UserID,
    UNIQUE (observed_user_id, observer_user_id)
  );
  
  -- For each of /my/ users (watcher), which possibly-remote users are they
  -- watching?
  CREATE TABLE IF NOT EXISTS presence_list(
    user_id TEXT NOT NULL,
    observed_user_id TEXT NOT NULL, -- a UserID,
    accepted BOOLEAN NOT NULL,
    UNIQUE (user_id, observed_user_id)
  );
  
  CREATE INDEX presence_list_user_id ON presence_list (user_id);
  