ircMessages.js

const postgres = require('../index')

const getMessagesQuery = (serverId, channelName, connectionId) =>
  postgres('ircMessages')
    .where({ serverId, to: channelName })
    .where(function() {
      this.where({ isPublic: true })
      if (connectionId) {
        this.orWhere({ connectionId })
      }
    })

const getMessageCreatedAtQuery = messageId =>
  postgres
    .select('createdAt')
    .from('ircMessages')
    .where({ id: messageId })
    .limit(1)

const getMessages = async ({ serverId, channelName, connectionId, limit }) =>
  getMessagesQuery(serverId, channelName, connectionId)
    .orderBy('createdAt')
    .limit(limit)

const getMessagesBefore = async ({ serverId, channelName, connectionId, before, limit }) =>
  postgres
    .select()
    .from(
      getMessagesQuery(serverId, channelName, connectionId)
        .where('createdAt', '<=', getMessageCreatedAtQuery(before))
        .where('id', '!=', before)
        .orderBy('createdAt', 'desc')
        .limit(limit)
        .as('messages')
    )
    .orderBy('createdAt')

const getMessagesAfter = async ({ serverId, channelName, connectionId, after, limit }) =>
  getMessagesQuery(serverId, channelName, connectionId)
    .where('createdAt', '>=', getMessageCreatedAtQuery(after))
    .where('id', '!=', after)
    .orderBy('createdAt')
    .limit(limit)

const getMessagesAround = async ({ serverId, channelName, connectionId, around, limit }) => {
  const halfLimit = Math.ceil(limit / 2)
  return postgres
    .select()
    .from(
      postgres.union([
        getMessagesQuery(serverId, channelName, connectionId)
          .where('createdAt', '<=', getMessageCreatedAtQuery(around))
          .orderBy('createdAt', 'desc')
          .limit(halfLimit),
        getMessagesQuery(serverId, channelName, connectionId)
          .where('createdAt', '>', getMessageCreatedAtQuery(around))
          .where('id', '!=', around)
          .orderBy('createdAt')
          .limit(limit - halfLimit),
      ], true).as('messages')
    )
    .orderBy('createdAt')
}

module.exports = {
  getMessages,
  getMessagesBefore,
  getMessagesAfter,
  getMessagesAround,
}