OpenTween/Thumbnail/Services/FoursquareCheckin.cs

   1 // OpenTween - Client of Twitter
   2 // Copyright (c) 2012 kim_upsilon (@kim_upsilon) <https://upsilo.net/~upsilon/>
   3 // All rights reserved.
   4 //
   5 // This file is part of OpenTween.
   6 //
   7 // This program is free software; you can redistribute it and/or modify it
   8 // under the terms of the GNU General Public License as published by the Free
   9 // Software Foundation; either version 3 of the License, or (at your option)
  10 // any later version.
  11 //
  12 // This program is distributed in the hope that it will be useful, but
  13 // WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  14 // or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
  15 // for more details.
  16 //
  17 // You should have received a copy of the GNU General Public License along
  18 // with this program. If not, see <http://www.gnu.org/licenses/>, or write to
  19 // the Free Software Foundation, Inc., 51 Franklin Street - Fifth Floor,
  20 // Boston, MA 02110-1301, USA.
  21
  22 using System;
  23 using System.Collections.Generic;
  24 using System.Net.Http;
  25 using System.Runtime.Serialization.Json;
  26 using System.Text.RegularExpressions;
  27 using System.Threading;
  28 using System.Threading.Tasks;
  29 using System.Web;
  30 using System.Xml;
  31 using System.Xml.Linq;
  32 using System.Xml.XPath;
  33
  34 namespace OpenTween.Thumbnail.Services
  35 {
  36     class FoursquareCheckin : IThumbnailService
  37     {
  38         public static readonly Regex UrlPatternRegex =
  39             new Regex(@"^https?://foursquare\.com/.+?/checkin/(?<checkin_id>[0-9a-z]+)(?:\?s=(?<signature>[^&]+))?");
  40
  41         public static readonly string ApiBase = "https://api.foursquare.com/v2";
  42
  43         protected readonly HttpClient http;
  44
  45         public FoursquareCheckin(HttpClient http)
  46         {
  47             this.http = http;
  48         }
  49
  50         public override async Task<ThumbnailInfo> GetThumbnailInfoAsync(string url, PostClass post, CancellationToken token)
  51         {
  52             // ツイートに位置情報が付与されている場合は何もしない
  53             if (post.PostGeo.Lat != 0 || post.PostGeo.Lng != 0)
  54                 return null;
  55
  56             var match = UrlPatternRegex.Match(url);
  57
  58             if (!match.Success)
  59                 return null;
  60
  61             var checkinIdGroup = match.Groups["checkin_id"];
  62             var signatureGroup = match.Groups["signature"];
  63
  64             try
  65             {
  66                 // Foursquare のベニュー情報を取得
  67                 // 参照: https://developer.foursquare.com/docs/venues/venues
  68
  69                 var query = new Dictionary<string, string>
  70                 {
  71                     {"client_id", ApplicationSettings.FoursquareClientId},
  72                     {"client_secret", ApplicationSettings.FoursquareClientSecret},
  73                     {"v", "20140419"}, // https://developer.foursquare.com/overview/versioning
  74                 };
  75
  76                 if (signatureGroup.Success)
  77                     query["signature"] = signatureGroup.Value;
  78
  79                 var apiUrl = new Uri(ApiBase + "/checkins/" + checkinIdGroup.Value + "?" + MyCommon.BuildQueryString(query));
  80
  81                 using (var response = await this.http.GetAsync(apiUrl, token).ConfigureAwait(false))
  82                 {
  83                     response.EnsureSuccessStatusCode();
  84
  85                     var jsonBytes = await response.Content.ReadAsByteArrayAsync()
  86                         .ConfigureAwait(false);
  87
  88                     var location = ParseIntoLocation(jsonBytes);
  89                     if (location == null)
  90                         return null;
  91
  92                     var map = MapThumb.GetDefaultInstance();
  93
  94                     return new ThumbnailInfo
  95                     {
  96                         ImageUrl = map.CreateMapLinkUrl(location.Latitude, location.Longitude),
  97                         ThumbnailUrl = map.CreateStaticMapUrl(location.Latitude, location.Longitude),
  98                         TooltipText = null,
  99                     };
 100                 }
 101             }
 102             catch (HttpRequestException) { }
 103
 104             return null;
 105         }
 106
 107         internal static GlobalLocation ParseIntoLocation(byte[] jsonBytes)
 108         {
 109             using (var jsonReader = JsonReaderWriterFactory.CreateJsonReader(jsonBytes, XmlDictionaryReaderQuotas.Max))
 110             {
 111                 var xElm = XElement.Load(jsonReader);
 112
 113                 var locationElm = xElm.XPathSelectElement("/response/checkin/venue/location");
 114
 115                 // 座標が得られなかった場合
 116                 if (locationElm == null)
 117                     return null;
 118
 119                 // 月など、地球以外の星の座標である場合
 120                 var planetElm = locationElm.Element("planet");
 121                 if (planetElm != null && planetElm.Value != "earth")
 122                     return null;
 123
 124                 return new GlobalLocation
 125                 {
 126                     Latitude = double.Parse(locationElm.Element("lat").Value),
 127                     Longitude = double.Parse(locationElm.Element("lng").Value),
 128                 };
 129             }
 130         }
 131     }
 132 }