'use strict';

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

const utils = require('./utils');

module.exports = (options, allowedFonts) => {
  const app = express().disable('x-powered-by');

  const lastModified = new Date().toUTCString();

  const fontPath = options.paths.fonts;

  const existingFonts = {};
  const fontListingPromise = new Promise((resolve, reject) => {
    fs.readdir(options.paths.fonts, (err, files) => {
      if (err) {
        reject(err);
        return;
      }
      for (const file of files) {
        fs.stat(path.join(fontPath, file), (err, stats) => {
          if (err) {
            reject(err);
            return;
          }
          if (stats.isDirectory() &&
            fs.existsSync(path.join(fontPath, file, '0-255.pbf'))) {
            existingFonts[path.basename(file)] = true;
          }
        });
      }
      resolve();
    });
  });

  app.get('/fonts/:fontstack/:range([\\d]+-[\\d]+).pbf', (req, res, next) => {
    const fontstack = decodeURI(req.params.fontstack);
    const range = req.params.range;

    utils.getFontsPbf(options.serveAllFonts ? null : allowedFonts,
      fontPath, fontstack, range, existingFonts).then(concated => {
        res.header('Content-type', 'application/x-protobuf');
        res.header('Last-Modified', lastModified);
        return res.send(concated);
      }, err => res.status(400).send(err)
    );
  });

  app.get('/fonts.json', (req, res, next) => {
    res.header('Content-type', 'application/json');
    return res.send(
      Object.keys(options.serveAllFonts ? existingFonts : allowedFonts).sort()
    );
  });

  return fontListingPromise.then(() => app);
};