WeightbotClient

WeightbotClient.cs

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;
using System.Net;
using System.Web;

namespace coffeeInjection {

    public class WeightbotDataEntry {
        public DateTime DateTime { get; set; }
        public double WeightInKg { get; set; }
        public double WeightInLbs { get; set; }
    }

    public sealed class WeightbotClient {
        private CookieContainer _cookieJar;
        private bool _dataLoaded;
        private readonly List<WeightbotDataEntry> _dataEntries;
        private const string BaseUrl = "https://www.weightbot.com";
        private const string LoginIndexUrl = "https://www.weightbot.com/account/login";
        private const string LoginUrl = "https://www.weightbot.com/account/login";
        private const string ExportUrl = "https://www.weightbot.com/export";
        private const string LogoutUrl = "https://www.weightbot.com/account/logout";
        private const string ExceptionNoData = "No data available. Call DownloadWeightbotData first!";

        public WeightbotClient() {
            _cookieJar = new CookieContainer();
            _dataEntries = new List<WeightbotDataEntry>();
            _dataLoaded = false;
        }

        public bool DownloadWeightbotData(string email, string password) {
            _dataLoaded = false;
            var loginIndexData = PerformRequest(CreateRequest(LoginIndexUrl, WebRequestMethods.Http.Get));
            var authenticityToken = FindAuthenticityToken(loginIndexData).Trim();
            var loginResponseData = PerformRequest(CreatePostRequest(LoginUrl, LoginIndexUrl,
                                                 Encoding.Default.GetBytes(string.Format("authenticity_token={0}&email={1}&password={2}",
                                                                   HttpUtility.UrlEncode(authenticityToken),
                                                                   HttpUtility.UrlEncode(email),
                                                                   HttpUtility.UrlEncode(password)))));

            if (loginResponseData.IndexOf("logout", StringComparison.Ordinal) == -1)
                return false;

            var exportResponse = PerformRequest(CreatePostRequest(ExportUrl, BaseUrl, Encoding.Default.GetBytes(string.Format("authenticity_token={0}",HttpUtility.UrlEncode(authenticityToken)))));
            ProcessExportData(exportResponse);

            PerformRequest(CreateRequest(LogoutUrl, WebRequestMethods.Http.Get));
            
            _dataLoaded = true;
            return _dataLoaded;
        }
        
        public double AvgWeightKg {
            get {
                if(!_dataLoaded)
                    throw new Exception(ExceptionNoData);

                return Math.Round(_dataEntries.Sum(e => e.WeightInKg)/_dataEntries.Count, 2);
            }
        }

        public double MaxWeightKg {
            get {
                if (!_dataLoaded)
                    throw new Exception(ExceptionNoData);

                return _dataEntries.Max(e => e.WeightInKg);
            }
        }

        public double MinWeightKg {
            get {
                if (!_dataLoaded)
                    throw new Exception(ExceptionNoData);

                return _dataEntries.Min(e => e.WeightInKg);
            }
        }

        private HttpWebRequest CreateRequest(string url, string method) {
            var request = (HttpWebRequest) WebRequest.Create(url);
            request.UserAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.11 (KHTML, like Gecko) Chrome/23.0.1271.64 Safari/537.11";
            request.CookieContainer = _cookieJar;
            request.Method = method;
            return request;
        }

        private HttpWebRequest CreatePostRequest(string url, string referer, byte[] data) {
            var request = CreateRequest(url, WebRequestMethods.Http.Post);
            request.ContentType = "application/x-www-form-urlencoded";
            request.Accept = "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8";
            request.ContentLength = data.Length;
            request.Referer = referer;
            using(var requestStream = request.GetRequestStream())
                requestStream.Write(data, 0, data.Length);

            return request;
        }

        private string PerformRequest(HttpWebRequest request) {
            var response = (HttpWebResponse)request.GetResponse();
            string responseData;
            using (var reader = new StreamReader(response.GetResponseStream()))
                responseData = reader.ReadToEnd();
            response.Close();
            
            _cookieJar = new CookieContainer();
            foreach(Cookie cookie in response.Cookies)
                _cookieJar.Add(cookie);

            return responseData;
        }

        private string FindAuthenticityToken(string body) {
            var fieldIndex = body.IndexOf("authenticity_token", StringComparison.Ordinal);
            var valueBegin = body.IndexOf("value=", fieldIndex, StringComparison.Ordinal) + 7;
            var valueEnd = body.IndexOf("/>", valueBegin, StringComparison.Ordinal);
            return body.Substring(valueBegin, (valueEnd - valueBegin)-2);
        }

        private void ProcessExportData(string data) {
            _dataEntries.Clear();
            //We skip the first entry because it contains the column descriptions
            foreach (var entryParts in data.Split(new[] {"\r","\n","\r\n"}, StringSplitOptions.RemoveEmptyEntries)
                        .Skip(1)
                        .Select(entry => entry.Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries))) {
                _dataEntries.Add(new WeightbotDataEntry {
                                                            DateTime = DateTime.Parse(entryParts[0], new CultureInfo("en-US")),
                                                            WeightInKg = double.Parse(entryParts[1], new CultureInfo("en-US")),
                                                            WeightInLbs = double.Parse(entryParts[2], new CultureInfo("en-US"))
                                                        });
            }
        }
    }
}