container-labs/functions-compose

// @flow

import watchman from 'fb-watchman';
import path from 'path';
import yaml from 'js-yaml';
import fs from 'fs';

import onFileChanged from './onFileChanged';

const client = new watchman.Client();
let config = null;
const configPath = path.join(process.cwd(), './functions-compose.yml');
const ourSubsciptions = {};

try {
  config = yaml.safeLoad(fs.readFileSync(configPath, 'utf8'));
} catch (e) {
  console.error(e);
}

client.capabilityCheck({ optional: [], required: ['relative_root'] },
  (error) => {
    if (error) {
      console.error(error);
      client.end();
      return;
    }

    // clear past watches
    // client.command(['watch-del-all']);

    const globalContext = { yarn: config.yarn, env: config.env };
    Object.keys(config.services).forEach((key) => {
      const serviceContext = config.services[key];

      // Initiate the watch
      client.command(['watch-project', `${process.cwd()}/${serviceContext.directory}`],
        (watchError, resp) => {
          if (watchError) {
            console.error('Error initiating watch:', watchError);
            return;
          }

          if ('warning' in resp) {
            console.log('warning: ', resp.warning);
          }
          console.log(`watch established on ${resp.watch} relative_path ${resp.relative_path}`);
        },
      );

      const subscriptionName = `${serviceContext.functions.name}-subscription`;
      const stateName = `${serviceContext.functions.name}-state`;
      const sub = {
        // Match any `.js` file in the dir_of_interest
        expression: ['allof', ['type', 'f'], ['suffix', 'js']],
        // Which fields we're interested in
        fields: ['name', 'size', 'exists', 'mtime_ms', 'type'],
        defer: [stateName],
      };

      const watchWithFolder = `${process.cwd()}/${serviceContext.directory}`; // functionsES6
      client.command(['subscribe', watchWithFolder, subscriptionName, sub],
        (subscribeError, resp) => {
          if (error) {
            // Probably an error in the subscription criteria
            console.error('failed to subscribe: ', subscribeError);
            return;
          }
          console.log(`subscription ${resp.subscribe} established`);

          ourSubsciptions[subscriptionName] = {
            watchWithFolder,
            serviceContext,
            subscriptionName,
            stateName,
          };
        },
      );
    });

    client.on('subscription', (resp: Object) => {
      console.debug('#### subscription response', resp.subscription);
      const thisSubscription = ourSubsciptions[resp.subscription];

      if (resp['state-leave']) {
        console.debug('### bailing, state-leave');
        return;
      }

      if (resp['state-enter']) {
        console.debug('#### state-enter, onFileChanged');
        onFileChanged(client, thisSubscription, globalContext);
        return;
      }

      resp.files.forEach((file) => {
        console.log(`#### file changed: ${file.name}`);
      });

      // we didn't just leave state
      // and we dind't just enter state
      // so let's enter state! (like a highway...)
      client.command(['state-enter', thisSubscription.watchWithFolder, thisSubscription.stateName], (stateEnterError, resp2) => {
        if (stateEnterError) {
          console.error(stateEnterError);
        }
        console.debug('#### state-enter, command', resp2.root);
      });
    });
  },
);