// <bitbar.title>Github Pull requests</bitbar.title>
// <bitbar.version>v2.0</bitbar.version>
// <bitbar.author>Noam Knispel</bitbar.author>
// <bitbar.author.github>noamknispel</bitbar.author.github>
// <bitbar.desc>Get list of pull requests from Github for multiple repositories</bitbar.desc>
// <bitbar.dependencies>node.js request co bluebird</bitbar.dependencies>

import nodeFetch, { FetchError } from 'node-fetch';

const GITHUB_API = 'https://api.github.com';

// make fetch sane
const fetch = async (...args) => {
  const res = await nodeFetch(...args);
  if (res.ok) return res;
  throw new FetchError(`Unsuccessful Request (${args[0]}) [${res.status}]`);
};

const api = ({ username, token }) => {
  const getPull = async (repo, id) =>
    fetch(`${GITHUB_API}/repos/${repo}/pulls/${id}`, {
      method: 'GET',
      headers: {
        Authorization: `Basic ${Buffer.from(`${username}:${token}`).toString('base64')}`,
      },
    }).then(res => res.json());

  return {
    getPulls: async repo => {
      const issues = await fetch(
        `${GITHUB_API}/repos/${repo}/issues?state=open&sort=updated&creator=w33ble`,
        {
          method: 'GET',
          headers: {
            Authorization: `Basic ${Buffer.from(`${username}:${token}`).toString('base64')}`,
          },
        }
      ).then(res => res.json());

      // remove non-pull issues
      const pulls = issues.filter(issue => !!issue.pull_request);

      // return actual pull info
      return Promise.all(pulls.map(pull => getPull(repo, pull.number)));
    },

    getStatus: async (repo, sha) =>
      fetch(`${GITHUB_API}/repos/${repo}/commits/${sha}/status`, {
        method: 'GET',
        headers: {
          Authorization: `Basic ${Buffer.from(`${username}:${token}`).toString('base64')}`,
        },
      }).then(res => res.json()),
  };
};

const getStatusColor = status => {
  if (status === 'failure') return ' color=#aa0000';
  if (status === 'success') return ' color=#00aa00';
  if (status === 'pending') return ' color=#aaaa00';
  return '';
};

export default async ({ username, token, repos = [] }) => {
  const { getPulls, getStatus } = api({ username, token });

  let failed = false;
  const tasks = await (() => {
    try {
      return Promise.all(
        repos.map(async repo => {
          // fetch pulls for repo
          const pulls = await getPulls(repo);

          // fetch status for each pull
          return Promise.all(
            pulls.map(async pull => {
              const status = await getStatus(repo, pull.head.sha);
              return { repo, pull, status };
            })
          );
        }, [])
      );
    } catch (err) {
      console.log(`Request failed: ${err.message}`);
      failed = true;
      return false;
    }
  })();

  if (failed) return false;

  const { totalCount, failCount, strings } = tasks.reduce(
    (acc, info) => {
      // skip repo if there are no matches
      if (info.length <= 0) return acc;

      // build bitbar output
      info.forEach(({ repo, pull, status }, i) => {
        // append repo name
        if (i === 0) acc.strings.push(`${repo} | color=#0000ff`);

        // append information about each PR
        acc.strings.push(
          `#${pull.number} ${pull.title} | href=${pull.html_url} ${getStatusColor(status.state)}`
        );

        // add count to tally
        acc.totalCount += 1;
        if (status.state === 'failure') acc.failCount += 1;
      });
      return acc;
    },
    { totalCount: 0, failCount: 0, strings: ['---'] }
  );

  strings.unshift(`${totalCount}/${failCount} PRs`);
  strings.forEach(s => console.log(s));
  return true;
};