GitHub digest webtask

hub-digest.js

"use latest";
const _ = require('lodash');
const request = require('superagent');
const moment = require('moment');
const mandrillApi = require('mandrill-api/mandrill');

/*
 * utilites
 */
function time(timestamp) {
  return moment(timestamp).format('MMMM Do, HH:mm:ss');
}

function format(str, n) {
  const truncated = (str.length > n) ? `${str.substr(0, n-1)}...` : str;
  return truncated.split('\n')[0];
}

/*
 * templating functions
 * the following functions construct a string containing the full email
 */
function main(data) {
  let ret = `
    Digest for ${data.repo}
    ${time(data.from)} - ${time(data.to)}
  `;
  _.each(data.events, event => {
    ret += event;
  });
  return ret;
}

function def(event) {
  const name = event.actor.display_login;
  return `
    ${time(event.created_at)}: ${name} performed ${event.type}
  `;
}

function push(event) {
  const count = event.payload.commits.length;
  const name = event.actor.display_login;
  const commitStr = count === 1 ? 'commit' : 'commits';

  let ret = `
    ${time(event.created_at)}: ${name} pushed ${count} ${commitStr}
  `;

  _.each(event.payload.commits, (commit) => {
    ret += `
      - ${format(commit.message, 80)}
        ${commit.url}
    `;
  });
  return ret;
}

function issues(event) {
  const name = event.actor.display_login;
  const verb = event.payload.action;
  const title = event.payload.issue.title;
  const issue = event.payload.issue.body;
  return `
    ${time(event.created_at)}: ${name} ${verb} ${title}
      - ${format(issue, 80)}
  `;
}

function comment(event) {
  const name = event.actor.display_login;
  const title = event.payload.issue.title;
  const comment = (event.payload.comment.body);
  return `
    ${time(event.created_at)}: ${name} commented on ${title}
      - ${format(comment, 80)}
  `;
}

/*
 * map github events to tpl funcs
 */
const eventTpl = {
  PushEvent: push,
  IssuesEvent: issues,
  IssueCommentEvent: comment,
};

module.exports = (ctx, done) => {
  ctx.storage.get((err, data) => {
    if (err) return done(err);
    const mandrill = new mandrillApi.Mandrill(ctx.data.MANDRILL_API_KEY);

    const lastTimestamp = (data && data.lastTimestamp) ?
      data.lastTimestamp :
      moment().subtract(1, 'days').toDate();

    request.get(
      `https://api.github.com/repos/${ctx.params.repository}/events`
    ).end((err, res) => {
      if (err || !res.body.length) return done(err);

      // filter out events we've already seen and pass them through the templates
      const events = _.filter(res.body, event => new Date(event.created_at).getTime() > new Date(lastTimestamp).getTime())
        .map(event => eventTpl[event.type] ? eventTpl[event.type](event) : def(event));

      if (events.length === 0) {
        console.log('Nothing new to send');
        return done(null);
      }

      const mail = main({
        repo: ctx.params.repository,
        from: lastTimestamp,
        to: new Date().getTime(),
        events,
      });

      const message = {
        text: mail,
        subject: `Digest for ${ctx.params.repository}`,
        from_email: ctx.params.from,
        from_name: 'Hub Digest',
        to: [
          {
            email: ctx.params.to,
            type: 'to',
          }
        ]
      };

      mandrill.messages.send({
        message
      }, (result) => {
        console.log(`Sent ${events.length} events`, result);
        ctx.storage.set({ lastTimestamp: events[0].created_at }, done);
      }, done
      );
    });
  });
};