const logger = require('../util/logger');
const instrumentConfig = require('../config/instrumentConfig');
const { createHttpJsonConnector } = require('../instrument/connectors/httpJson');
const { createHl7TcpConnector } = require('../instrument/connectors/tcp');
const { createAstmSerialConnector } = require('../instrument/connectors/serial');
const { createIngestMessageHandler } = require('../instrument/ingest');

const connectorFactories = {
  'http-json': createHttpJsonConnector,
  'hl7-tcp': createHl7TcpConnector,
  'astm-serial': createAstmSerialConnector
};

function buildConnectors() {
  return instrumentConfig.list()
    .filter((entry) => entry.enabled)
    .map((entry) => {
      const createConnector = connectorFactories[entry.connector];
      if (!createConnector) {
        logger.warn({ connector: entry.connector, instrument_id: entry.instrument_id }, 'unknown connector in instrument config, skipping startup');
        return null;
      }

      return createConnector({
        ...(entry.connectorConfig || {}),
        instrument_id: entry.instrument_id
      });
    })
    .filter(Boolean);
}

function attachConnectorHandlers(connectors) {
  connectors.forEach((connector) => {
    connector.onMessage(createIngestMessageHandler(connector));
    connector.onError((err) => {
      logger.error({ err: err.message }, `${connector.name()} emitted error`);
    });
  });
}

async function startConnectors(connectors) {
  await Promise.all(connectors.map((connector) => connector.start()));
}

async function stopConnectors(connectors) {
  await Promise.all(connectors.map((connector) => connector.stop()));
}

module.exports = {
  buildConnectors,
  attachConnectorHandlers,
  startConnectors,
  stopConnectors
};