// Copyright 2015-2016, Google, Inc.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

// http://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

// [START app]

'use strict';

var format = require('util').format;

var express = require('express');

var gcloud = require('gcloud');

var crypto = require('crypto');

var app = express();

app.enable('trust proxy');

var dataset = gcloud.datastore({

// This environment variable is set by app.yaml when running on GAE, but will

// need to be manually set when running locally.

projectId: process.env.GCLOUD_PROJECT

});

app.get('/', function (req, res, next) {

var hash = crypto.createHash('sha256');

// Add this visit to the datastore

dataset.save({

key: dataset.key('visit'),

data: {

timestamp: new Date(),

// Store a hash of the ip address

userIp: hash.update(req.ip).digest('hex').substr(0, 7)

}

}, function (err) {

if (err) {

return next(err);

}

// Query the last 10 visits from the datastore.

var query = dataset.createQuery('visit')

.order('-timestamp')

.limit(10);

dataset.runQuery(query, function (err, entities) {

if (err) {

return next(err);

}

var visits = entities.map(function (entity) {

return format(

'Time: %s, AddrHash: %s',

entity.data.timestamp,

entity.data.userIp);

});

var output = format('Last 10 visits:\n%s', visits.join('\n'));

res.set('Content-Type', 'text/plain');

res.status(200).send(output);

});

});

});

/* Start the server */

var 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.');

});

// [END app]