app.js

'use strict';

let express = require('express');
let fs = require('fs');
let app = express();

let authors = require('./authors.js');
let metadata = {all: []};

app.disable('x-powered-by');

for (let meta of require('./content-gen.js')) {
  metadata.all.push(meta);
  if (!metadata[meta.category])
    metadata[meta.category] = [];
  metadata[meta.category].push(meta);
}

app.get('/content/*', function(request, response) {
  response.header("Access-Control-Allow-Origin", "*");
  if (!fs.existsSync('documents/'+ request.params[0])) {
    response.status(404).send('Invalid path');
    return;
  }

  let requestedPath = fs.realpathSync('documents/' + request.params[0]);
  let isolatedDir = fs.realpathSync('documents');

  if (requestedPath.indexOf(isolatedDir) != 0) {
    response.status(400).send('Invalid path');
    return;
  }

  fs.readFile(requestedPath, 'utf8', function(err, data) {
    if (err) {
      response.status(404).send('Cannot find ' + err.path);
      return;
    }
    data = data.replace(/([^]*<!-- Excerpt -->)/m, '').trim();
    response.status(200).send(data);
  });
});

app.get('/author/:id', function(request, response) {
  response.header("Access-Control-Allow-Origin", "*");

  const id = request.params.id;
  if (!authors[id]) {
    response.status(404).send('Cannot find author ' + id);
    return;
  }
  response.setHeader('Content-Type', 'application/json');
  response.status(200).send(authors[id]);
});

/**
 * @param {!Array.<Object>} metadata
 * @param {number} offset
 * @param {number} limit
 */
function createResult(bucket, offset, limit) {
  return {count: bucket.length, results: bucket.slice(offset, offset + limit)};
}

app.get('/resources', function(request, response) {
  response.header("Access-Control-Allow-Origin", "*");
  const offset = parseInt(request.query.offset) || 0;
  const limit = parseInt(request.query.limit) || 10;
  response.status(200).send(createResult(metadata.all, offset, limit));
});

app.get('/resources/:bucket', function(request, response) {
  response.header("Access-Control-Allow-Origin", "*");
  if (!metadata[request.params.bucket]) {
    response.status(404).send('Unknown category');
    return;
  }
  const offset = parseInt(request.query.offset) || 0;
  const limit = parseInt(request.query.limit) || 10;
  response.status(200).send(createResult(metadata[request.params.bucket], offset, limit));
});

// Start the server
let server = app.listen(process.env.PORT || '8080', function() {
  console.log('App listening on port %s', server.address().port);
  console.log('Press Ctrl+C to quit.');
});

module.exports = server;