#!/usr/bin/env node

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

const
fs = require('fs'),
path = require('path'),
url = require('url'),
http = require('http'),
urlparse = require('urlparse'),
express = require('express');

const
wsapi = require('../lib/wsapi.js'),
config = require('../lib/configuration.js'),
heartbeat = require('../lib/heartbeat.js'),
logger = require('../lib/logging.js').logger,
forward = require('../lib/http_forward').forward,
shutdown = require('../lib/shutdown');

var app = undefined;

app = express.createServer();

logger.info("router server starting up");

// verify that we have a keysigner configured
if (!config.get('keysigner_url')) {
  logger.error('missing required configuration - url for the keysigner (KEYSIGNER_URL in env)');
  process.exit(1);
}

// verify that we have a dbwriter configured
if (!config.get('dbwriter_url')) {
  logger.error('missing required configuration - url for the dbwriter (DBWRITER_URL in env)');
  process.exit(1);
}

// verify that we have a browserid configured
if (!config.get('browserid_url')) {
  logger.error('missing required configuration - url for browserid (BROWSERID_URL in env)');
  process.exit(1);
}

// NOTE: ordering of middleware registration is important in this file, it is the
// order in which middleware will be invoked as requests are processed.

// #1 - Setup health check / heartbeat middleware.
// Depends on positive health checks from browserid and static processes
// This is in front of logging on purpose.  see issue #537
var browserid_url = urlparse(config.get('browserid_url')).validate().normalize().originOnly();
var static_url = urlparse(config.get('static_url')).validate().normalize().originOnly();
heartbeat.setup(app, {
  dependencies: [browserid_url, static_url]
});

// #2 - logging!  all requests other than __heartbeat__ are logged
app.use(express.logger({
  format: config.get('express_log_format'),
  stream: {
    write: function(x) {
      logger.info(typeof x === 'string' ? x.trim() : x);
    }
  }
}));

// limit all content bodies to 10kb, at which point we'll forcefully
// close down the connection.
app.use(express.limit("10kb"));

var statsd_config = config.get('statsd');
if (statsd_config && statsd_config.enabled) {
  var logger_statsd = require("connect-logger-statsd");
  app.use(logger_statsd({
    host: statsd_config.hostname || "localhost",
    port: statsd_config.port || 8125,
    prefix: statsd_config.prefix || "browserid.router."
  }));
}

// Add Strict-Transport-Security headers if we're serving over SSL
if (config.get('scheme') == 'https') {
  app.use(function(req, res, next) {
    // expires in 30 days, include subdomains like www
    res.setHeader("Strict-Transport-Security", "max-age=2592000; includeSubdomains");
    next();
    });
}

// redirect requests to the "verifier" processes
if (config.get('verifier_url')) {
  var verifier_url = urlparse(config.get('verifier_url')).validate().normalize();

  // support requests coming into the verifier hostname as well as those with /verify in the path,
  // iff the verifier is configured explicitly with a distinct hostname
  var verifier_host;
  if (config.get('public_verifier_url') !== config.get('public_url')) {
    verifier_host = urlparse(config.get('public_verifier_url')).validate().host;
  }

  app.use(function(req, res, next) {
    if (/^\/verify$/.test(req.url) ||
        (req.headers.host && verifier_host && req.headers.host === verifier_host))
    {
      forward(
        verifier_url, req, res,
        function(err) {
          if (err) {
            logger.error("error forwarding request:", err);
          }
        });
    } else {
      return next();
    }
  });
}

// #10 if the BROWSERID_FAKE_VERIFICATION env var is defined, we'll include
// fake_verification.js.  This is used during testing only and should
// never be included in a production deployment
if (process.env['BROWSERID_FAKE_VERIFICATION']) {
  app.use(function(req, res, next) {
    if (url.parse(req.url).pathname == '/wsapi/fake_verification') {
      forward(
        browserid_url+req.url, req, res,
        function(err) {
          if (err) {
            logger.error("error forwarding request:", err);
          }
        });
    } else {
      return next();
    }
  });
}

// handle /wsapi reads/writes
var dbwriter_url = urlparse(config.get('dbwriter_url')).validate().normalize().originOnly();

wsapi.routeSetup(app, {
  read_url: browserid_url,
  write_url: dbwriter_url
});

//catch-all
app.use(function(req, res, next) {
  forward(
    static_url+req.url, req, res,
    function(err) {
      if (err) {
        logger.error("error forwarding request:", err);
      }
    });
});

var bindTo = config.get('bind_to');
app.listen(bindTo.port, bindTo.host, function(conn) {
  logger.info("running on http://" + app.address().address + ":" + app.address().port);
});