const fs = require('fs');
const path = require('path');

// Authored by Jacob Levernier, 2021
// Released under a CC0 1.0 Universal Public Domain Dedication

// Fetch multiple URLs asynchronously
// For an explanation, see, e.g., the tutorial at
// https://www.shawntabrizi.com/code/programmatically-fetch-multiple-apis-parallel-using-async-await-javascript/
async function fetchAll(urls, api_token) {
  try {
    const data = await Promise.all(
      urls.map(
        url =>
          fetch(
            url, {
            method: 'GET',
            headers: new Headers({
              'Authorization': `Bearer ${api_token}`,
              'Content-Type': 'application/json',
              'Accept': 'application/vnd.github.v3+json'
            })
          }).then(
            (response) => response.json()
          )));

    return (data)

  } catch (error) {
    console.log(error)

    throw (error)
  }
}

async function insertGitHubLink(
  tp,
  repos = [],
  max_n = 750,
  // GitHub Token file (by default, in a file at ~/.obsidian-github-key).
  // You can create a token at https://github.com/settings/tokens. It may need
  // the following scopes to be able to see private issues: 
  //   admin:org
  //   read:enterprise
  //   repo
  api_key_file = path.join(process.env.HOME, '.obsidian-github-key'),
) {

  let api_key = ''

  try {
    api_key = fs.readFileSync(api_key_file, 'utf8');
  } catch (e) {
    console.log('Error reading GitHub API key:', e.stack);
    return
  }

  let issuesList = await (
    await fetchAll(
      repos.map(repo => `https://api.github.com/repos/${repo}/issues`), api_key
    ))
    .reduce((a, b) => a.concat(b))
    .sort((a, b) => a.updated_at - b.updated_at);

  if (issuesList.length > max_n) {
    issuesList = issuesList.slice(0, max_n);
  }
  // console.log(issuesList);

  const selection = await tp.system.suggester(
    issuesList.map(issue => `[${issue.state}] ${issue.repository_url.replace('https://api.github.com/repos/', '')}#${issue.number} "${issue.title || '[Untitled]'}" (Assignee: ${issue.assignee?.login || '[None]'}) (Milestone: ${issue.milestone?.title || '[None]'}) (Labels: ${issue.labels?.map(label => label.name).join(', ') || '[None]'})`),
    [...Array(issuesList.length).keys()],
    true,
    "Select an issue"
  );

  return `[\`${issuesList[selection].repository_url.replace('https://api.github.com/repos/', '')} #${issuesList[selection].number}\`](${issuesList[selection].html_url})`
}
module.exports = insertGitHubLink;