const parserMap = {
  'http-json': require('../parsers/httpParser'),
  'hl7-tcp': require('../parsers/hl7Parser'),
  'astm-serial': require('../parsers/astmParser'),
  hl7: require('../parsers/hl7Parser'),
  astm: require('../parsers/astmParser'),
  http: require('../parsers/httpParser')
};

function resolveCustomParser(parserName) {
  if (!parserName || typeof parserName !== 'string') return null;
  try {
    const custom = require(`../../config/${parserName}`);
    if (custom && typeof custom.parse === 'function') {
      return custom;
    }
  } catch (error) {
    return null;
  }
  return null;
}

function resolveParser(connector, instrumentEntry) {
  const parserName = instrumentEntry?.translator?.parser || connector;
  const parser = parserMap[parserName] || resolveCustomParser(parserName);
  if (!parser) {
    throw new Error(`no parser registered for ${parserName}`);
  }
  return parser;
}

module.exports = {
  resolveParser
};