const http = require("http");
const express = require("express");
const morgan = require("morgan");

const staticAssets = require("./middleware/staticAssets");
const createRouter = require("./createRouter");

morgan.token("fwd", req => {
  return req.get("x-forwarded-for").replace(/\s/g, "");
});

function errorHandler(err, req, res, next) {
  console.error(err.stack);

  res
    .status(500)
    .type("text")
    .send("Internal Server Error");

  next(err);
}

function createServer(publicDir, statsFile) {
  const app = express();

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

  if (process.env.NODE_ENV !== "test") {
    app.use(
      morgan(
        // Modified version of the Heroku router's log format
        // https://devcenter.heroku.com/articles/http-routing#heroku-router-log-format
        'method=:method path=":url" host=:req[host] request_id=:req[x-request-id] cf_ray=:req[cf-ray] fwd=:fwd status=:status bytes=:res[content-length]'
      )
    );
  }

  app.use(errorHandler);
  app.use(express.static(publicDir, { maxAge: "365d" }));
  app.use(staticAssets(statsFile));
  app.use(createRouter());

  const server = http.createServer(app);

  // Heroku dynos automatically timeout after 30s. Set our
  // own timeout here to force sockets to close before that.
  // https://devcenter.heroku.com/articles/request-timeout
  server.setTimeout(25000, socket => {
    const message = `Timeout of 25 seconds exceeded`;

    socket.end(
      [
        "HTTP/1.1 503 Service Unavailable",
        "Date: " + new Date().toGMTString(),
        "Content-Length: " + Buffer.byteLength(message),
        "Content-Type: text/plain",
        "Connection: close",
        "",
        message
      ].join("\r\n")
    );
  });

  return server;
}

module.exports = createServer;