github.js

require("isomorphic-unfetch");

const express = require("express");
const router = express.Router();
const apicache = require("apicache");
const fs = require("fs");

const set = require("lodash.set");
const get = require("lodash.get");

// router.use(apicache.middleware('60 minutes'))

router.get("/tree", async (req, res) => {
  let lessons;

  try {
    const repoReq = await fetch(
      `https://api.github.com/repos/${process.env.GITHUB_CONTENT_REPO}/branches/master`,
      {
        method: "GET",
        headers: {
          Authorization: `token ${process.env.GITHUB_ACCESS_TOKEN}`,
        },
      }
    );

    const repo = await repoReq.json();

    const masterTreeReq = await fetch(
      `https://api.github.com/repos/${process.env.GITHUB_CONTENT_REPO}/git/trees/${repo.commit.sha}?recursive=1`,
      {
        method: "GET",
        headers: {
          Authorization: `token ${process.env.GITHUB_ACCESS_TOKEN}`,
        },
      }
    );

    lessons = await masterTreeReq.json();
  } catch (err) {
    console.error("[API] /github/tree - Tree fetch error: ", err);
    res.statusMessage = "Failed to retrieve GitHub repository";
    return res.status(500).end();
  }

  try {
    lessons = lessons.tree.reduce((lessonsSet, node) => {
      // if the node is a directory
      if (node.type === "tree") {
        // get the path string in dot notation
        const pathDotNotation = node.path.replace(/\//g, ".");
        // preset path with content array
        set(
          lessonsSet,
          pathDotNotation,
          get(lessonsSet, pathDotNotation, { content: [] })
        );
      }
      // otherwise if the node is a file
      else if (node.type === "blob") {
        // get the path string without filname in dot notation
        const nodePaths = node.path.split("/");
        const pathDotNotation = nodePaths.slice(0, -1).join(".");
        const filename = nodePaths.slice(-1)[0];
        // get the original object, default {content: []}
        let obj = get(lessonsSet, pathDotNotation);
        // add file sha
        obj.content.push({ filename, sha: node.sha, url: node.url });
        // overwrite the object
        set(lessonsSet, pathDotNotation, obj);
      } else
        console.error(
          `[API] /github/tree - Content type ${node.type} is neither tree nor blob.`
        );

      return lessonsSet;
    }, {});
  } catch (e) {
    console.error("[API] /github/tree - Create lesson JSON exception: ", e);
    res.statusMessage = "Failed to retrieve GitHub repository";
    return res.status(500).end();
  }

  if (!lessons) {
    console.error("[API] /github/tree - Failed to create lessons object.");
    res.statusMessage = "Failed to retrieve GitHub repository";
    return res.status(500).end();
  }

  return res.status(200).send(lessons);
});

router.get("/content/:sha", async (req, res) => {
  let content;

  try {
    const contentReq = await fetch(
      `https://api.github.com/repos/${process.env.GITHUB_CONTENT_REPO}/git/blobs/${req.params.sha}`,
      {
        method: "GET",
        headers: {
          Authorization: `token ${process.env.GITHUB_ACCESS_TOKEN}`,
        },
      }
    );

    content = await contentReq.json();
  } catch (err) {
    console.error("[API] /github/content/:sha - Content fetch error: ", err);
    res.statusMessage = "Failed to retrieve content";
    return res.status(500).end();
  }

  if (!content) {
    console.error(
      "[API] /github/content/:sha - Failed to create content object."
    );
    res.statusMessage = "Failed to retrieve content";
    return res.status(500).end();
  }

  return res.status(200).send(content.content);
});

router.get("/locale", (req, res) => {
  try {
    const file = fs.readFileSync(
      appRoot + "/static/assets/locale/github-locale.json"
    );
    const json = JSON.parse(file);

    return res.status(200).send(JSON.stringify(json));
  } catch (err) {
    console.error("[API] /github/locale - File retrieval error: ", err);
    res.statusMessage = "Failed to retrieve content";
    return res.status(500).end();
  }
});

module.exports = router;