var _            = require('lodash');
var async        = require('async');
var should       = require('should');
var redis        = require('redis');
var express      = require('express');
var supertest    = require('supertest');
var middleware   = require('../lib/middleware');

describe('Middleware', function() {

  this.slow(5000);
  this.timeout(5000);

  var client  = null;
  var limiter = null;

  before(function(done) {
    client = redis.createClient(6379, 'localhost', {enable_offline_queue: false});
    client.on('ready', done);
  });

  describe('IP throttling', function() {

    before(function() {
      limiter = middleware({
        redis: client,
        key: 'ip',
        rate: '10/second'
      });
    });

    beforeEach(function(done) {
      client.del('ratelimit:127.0.0.1', done);
    });

    it('passes through under the limit', function(done) {
      var server = express();
      server.use(limiter);
      server.use(okResponse);
      var reqs = requests(server, 9, '/test');
      async.parallel(reqs, function(err, data) {
        withStatus(data, 200).should.have.length(9);
        done();
      });
    });

    it('returns HTTP 429 over the limit', function(done) {
      var server = express();
      server.use(limiter);
      server.use(okResponse);
      var reqs = requests(server, 12, '/test');
      async.parallel(reqs, function(err, data) {
        withStatus(data, 200).should.have.length(10);
        withStatus(data, 429).should.have.length(2);
        done();
      });
    });

    it('works across several rate-limit windows', function(done) {
      var server = express();
      server.use(limiter);
      server.use(okResponse);
      async.series([
        parallelRequests(server, 9, '/test'),
        wait(1100),
        parallelRequests(server, 12, '/test'),
        wait(1100),
        parallelRequests(server, 9, '/test')
      ], function(err, data) {
        withStatus(data[0], 200).should.have.length(9);
        withStatus(data[2], 200).should.have.length(10);
        withStatus(data[2], 429).should.have.length(2);
        withStatus(data[4], 200).should.have.length(9);
        done();
      });
    });

  });

  describe('Custom key throttling', function() {

    before(function() {
      limiter = middleware({
        redis: client,
        key: function(req) { return req.query.user; },
        rate: '10/second'
      });
    });

    beforeEach(function(done) {
      async.series([
        client.del.bind(client, 'ratelimit:a'),
        client.del.bind(client, 'ratelimit:b'),
        client.del.bind(client, 'ratelimit:c')
      ], done);
    });

    it('uses a different bucket for each custom key (user)', function(done) {
      var server = express();
      server.use(limiter);
      server.use(okResponse);
      var reqs = _.flatten([
        requests(server,  5, '/test?user=a'),
        requests(server, 12, '/test?user=b'),
        requests(server, 10, '/test?user=c')
      ]);
      async.parallel(reqs, function(err, data) {
        withStatus(data, 200).should.have.length(25);
        withStatus(data, 429).should.have.length(2);
        withStatus(data, 429)[0].url.should.eql('/test?user=b');
        withStatus(data, 429)[1].url.should.eql('/test?user=b');
        done();
      });
    });

  });

});

function requests(server, count, url) {
  return _.times(count, function() {
    return function(next) {
      supertest(server).get(url).end(next);
    };
  });
}

function parallelRequests(server, count, url) {
  return function(next) {
    async.parallel(requests(server, count, url), next);
  };
}

function wait(millis) {
  return function(next) {
    setTimeout(next, 1100);
  };
}

function okResponse(req, res, next) {
  res.writeHead(200);
  res.end('ok');
}

function withStatus(data, code) {
  var pretty = data.map(function(d) {
    return {
      url: d.req.path,
      statusCode: d.res.statusCode,
      body: d.res.body
    }
  });
  return _.filter(pretty, {statusCode: code});
}