/**
 * Example Signal K Server plugin that teaches the NMEA0183 parser a custom
 * sentence. Registering `nmea0183sentenceParser` as a PropertyValue makes the
 * parser call `parser` for every `XXX` sentence it sees.
 *
 * To test the plugin
 * - install the plugin (for example with npm link)
 * - activate the plugin
 * - add an UDP NMEA0183 connection to the server
 * - send data via udp
 *     echo '$IIXXX,1,2,3,foobar,D*17' | nc -u -w 0 127.0.0.1 7777
 */

module.exports = function (app) {
  const plugin = {}
  plugin.id =
    plugin.name =
    plugin.description =
      'signalk-nmea0183-custom-sentence-plugin'

  plugin.start = function () {
    app.emitPropertyValue('nmea0183sentenceParser', {
      sentence: 'XXX',
      // For "$IIXXX,1,2,3,foobar,D*17" the parser hands over
      //   id: 'XXX', talker: 'II', parts: ['1', '2', '3', 'foobar', 'D']
      // so parts[0] is the first field after the sentence id.
      parser: ({ id, sentence, parts, tags, talker }, session) => {
        return {
          updates: [
            {
              values: [
                { path: 'navigation.speedOverGround', value: Number(parts[0]) }
              ]
            }
          ]
        }
      }
    })
  }

  plugin.stop = function () {}
  plugin.schema = {}
  return plugin
}