mpd-avr-client/src/clients/cec-client.js

AVR as a MPD client

const { spawn } = require('child_process');
const { defer, Observable } = require('rxjs');
const { share } = require('rxjs/operators');

const CecClient = function () {
  return (() => {
    let cecClientProcess;

    const publishedCecClientEvent$ =
      /** @type Observable<CecClientEvent>*/ defer(() => {
        cecClientProcess = spawn('cec-client', ['-o', 'Loading...']);

        return new Observable((subscriber) => {
          const source = 'cecClient';
          const onData = (data) =>
            subscriber.next({
              source,
              data,
            });
          const onClose = (exitCode) => {
            console.log(`cec-client exited with code ${exitCode}\n`);

            if (exitCode === 0) {
              return subscriber.complete();
            }

            subscriber.error(exitCode);
          };
          const onUnsubscribe = () => {};

          // emit next event
          cecClientProcess.stdout.on('data', onData);
          cecClientProcess.stderr.on('data', onData);

          // emit complete and error event
          cecClientProcess.on('close', onClose);

          return onUnsubscribe;
        });
      }).pipe(share());

    const publisher = () => publishedCecClientEvent$;

    const terminate = () => {
      if (cecClientProcess) {
        cecClientProcess.kill();
      }
    };

    const write = (command) => {
      if (cecClientProcess) {
        cecClientProcess.stdin.write(command);
      }
    };

    return { publisher, terminate, write };
  })();
};

let instance;

module.exports = {
  getInstance: () => {
    if (!instance) {
      instance = new CecClient();
    }

    return instance;
  },
};