Made PageResponse<T> covariant and readonly, changed signature of PageResponse.CreateSuccessResponse method, tests for album.getTagsByUserCommand

src/IF.Lastfm.Core.Tests/Api/Commands/AlbumGetTagsByUserCommandTests.cs

@@ -0,0 +1,83 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using IF.Lastfm.Core.Api.Commands.AlbumApi;
+using IF.Lastfm.Core.Api.Enums;
+using IF.Lastfm.Core.Objects;
+using IF.Lastfm.Core.Tests.Resources;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
+
+namespace IF.Lastfm.Core.Tests.Api.Commands
+{
+    [TestClass]
+    public class AlbumGetTagsByUserCommandTests : CommandTestsBase
+    {
+        private AlbumGetTagsByUserCommand _command;
+
+        [TestInitialize]
+        public void Initialise()
+        {
+            _command = new AlbumGetTagsByUserCommand(MAuth.Object, "", "", "");
+        }
+
+        [TestMethod]
+        public async Task HandleResponseSingle()
+        {
+            var expectedTags = new List<LastTag>
+            {
+                new LastTag("Test Tag", "http://www.last.fm/tag/test%20tag")
+            };
+
+            var response = CreateResponseMessage(Encoding.UTF8.GetString(AlbumApiResponses.AlbumGetTagsSingle));
+            var parsed = await _command.HandleResponse(response);
+
+            var expectedJson = expectedTags.TestSerialise();
+            var actualJson = parsed.Content.TestSerialise();
+
+            parsed.AssertValues(true, 1, 1, 1, 1);
+            Assert.AreEqual(expectedJson, actualJson, expectedJson.DifferencesTo(actualJson));
+        }
+
+        [TestMethod]
+        public async Task HandleResponseMultiple()
+        {
+            var expectedTags = new List<LastTag>
+            {
+                new LastTag("test tag 2: electric boogaloo", "http://www.last.fm/tag/test%20tag%202%3A%20electric%20boogaloo"),
+                new LastTag("Test Tag", "http://www.last.fm/tag/test%20tag")
+            };
+
+            var response = CreateResponseMessage(Encoding.UTF8.GetString(AlbumApiResponses.AlbumGetTagsMultiple));
+            var parsed = await _command.HandleResponse(response);
+
+            var expectedJson = expectedTags.TestSerialise();
+            var actualJson = parsed.Content.TestSerialise();
+
+            parsed.AssertValues(true, 2, 2, 1, 1);
+            Assert.AreEqual(expectedJson, actualJson, expectedJson.DifferencesTo(actualJson));
+        }
+
+        [TestMethod]
+        public async Task HandleResponseEmpty()
+        {
+            var response = CreateResponseMessage(Encoding.UTF8.GetString(AlbumApiResponses.AlbumGetTagsEmpty));
+            var parsed = await _command.HandleResponse(response);
+
+            parsed.AssertValues(true, 0, 0, 1, 1);
+            Assert.IsTrue(!parsed.Content.Any());
+        }
+
+        [TestMethod]
+        public async Task HandleResponseError()
+        {
+            var response = CreateResponseMessage(Encoding.UTF8.GetString(AlbumApiResponses.AlbumGetTagsError));
+            var parsed = await _command.HandleResponse(response);
+
+            parsed.AssertValues(false, 0, 0, 1, 1);
+            Assert.IsFalse(parsed.Success);
+            Assert.IsTrue(parsed.Error == LastFmApiError.MissingParameters);
+            Assert.IsTrue(!parsed.Content.Any());
+        }
+    }
+}

src/IF.Lastfm.Core.Tests/Api/Commands/CommandTestsBase.cs

@@ -1,4 +1,5 @@
-using IF.Lastfm.Core.Api;
+using System.Threading.Tasks;
+using IF.Lastfm.Core.Api;
 using IF.Lastfm.Core.Api.Commands;
 using IF.Lastfm.Core.Api.Helpers;
 using IF.Lastfm.Core.Objects;
@@ -8,7 +9,6 @@
 using System.Net;
 using System.Net.Http;
 using System.Text;
-using System.Threading.Tasks;
 
 namespace IF.Lastfm.Core.Tests.Api.Commands
 {

src/IF.Lastfm.Core.Tests/IF.Lastfm.Core.Tests.csproj

@@ -42,6 +42,7 @@
     <Prefer32Bit>false</Prefer32Bit>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.CSharp" />
     <Reference Include="Microsoft.VisualStudio.QualityTools.UnitTestFramework, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL" />
     <Reference Include="Moq, Version=4.2.1409.1722, Culture=neutral, PublicKeyToken=69f491c39445e920, processorArchitecture=MSIL">
       <SpecificVersion>False</SpecificVersion>
@@ -78,6 +79,7 @@
     <Compile Include="Api\Commands\AlbumApi\GetAlbumShoutsCommandTests.cs" />
     <Compile Include="Api\Commands\AlbumApi\GetAlbumTopTagsCommandTest.cs" />
     <Compile Include="Api\Commands\AlbumApi\SearchAlbumsCommandTests.cs" />
+    <Compile Include="Api\Commands\AlbumGetTagsByUserCommandTests.cs" />
     <Compile Include="Api\Commands\CommandTestsBase.cs" />
     <Compile Include="Api\Commands\Library\LibraryGetTracksCommandTests.cs" />
     <Compile Include="Api\Commands\TrackApi\GetTrackShoutsCommandTests.cs" />

src/IF.Lastfm.Core.Tests/Resources/AlbumApi/AlbumGetTagsEmpty.json

@@ -0,0 +1,7 @@
+{
+  "tags": {
+    "#text": "\n",
+    "artist": "Hot Chip",
+    "album": "Made in the Dark"
+  }
+}

src/IF.Lastfm.Core.Tests/Resources/AlbumApi/AlbumGetTagsError.json

@@ -0,0 +1,5 @@
+{
+  "error": 6,
+  "message": "Invalid user supplied",
+  "links": []
+}

src/IF.Lastfm.Core.Tests/Resources/AlbumApi/AlbumGetTagsMultiple.json

@@ -0,0 +1,18 @@
+{
+  "tags": {
+    "tag": [
+      {
+        "name": "test tag 2: electric boogaloo",
+        "url": "http://www.last.fm/tag/test%20tag%202%3A%20electric%20boogaloo"
+      },
+      {
+        "name": "Test Tag",
+        "url": "http://www.last.fm/tag/test%20tag"
+      }
+    ],
+    "@attr": {
+      "artist": "Hot Chip",
+      "album": "Coming on Strong"
+    }
+  }
+}

src/IF.Lastfm.Core.Tests/Resources/AlbumApi/AlbumGetTagsSingle.json

@@ -0,0 +1,12 @@
+{
+  "tags": {
+    "tag": {
+      "name": "Test Tag",
+      "url": "http://www.last.fm/tag/test%20tag"
+    },
+    "@attr": {
+      "artist": "Hot Chip",
+      "album": "The Warning"
+    }
+  }
+}

src/IF.Lastfm.Core.Tests/Resources/AlbumApiResponses.Designer.cs

@@ -120,6 +120,46 @@ internal static byte[] AlbumGetShoutsSingle {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized resource of type System.Byte[].
+        /// </summary>
+        internal static byte[] AlbumGetTagsEmpty {
+            get {
+                object obj = ResourceManager.GetObject("AlbumGetTagsEmpty", resourceCulture);
+                return ((byte[])(obj));
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized resource of type System.Byte[].
+        /// </summary>
+        internal static byte[] AlbumGetTagsError {
+            get {
+                object obj = ResourceManager.GetObject("AlbumGetTagsError", resourceCulture);
+                return ((byte[])(obj));
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized resource of type System.Byte[].
+        /// </summary>
+        internal static byte[] AlbumGetTagsMultiple {
+            get {
+                object obj = ResourceManager.GetObject("AlbumGetTagsMultiple", resourceCulture);
+                return ((byte[])(obj));
+            }
+        }
+        
+        /// <summary>
+        ///   Looks up a localized resource of type System.Byte[].
+        /// </summary>
+        internal static byte[] AlbumGetTagsSingle {
+            get {
+                object obj = ResourceManager.GetObject("AlbumGetTagsSingle", resourceCulture);
+                return ((byte[])(obj));
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized resource of type System.Byte[].
         /// </summary>

src/IF.Lastfm.Core.Tests/Resources/AlbumApiResponses.resx

@@ -136,6 +136,18 @@
   <data name="AlbumGetShoutsSingle" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>albumapi\albumgetshoutssingle.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </data>
+  <data name="AlbumGetTagsEmpty" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>AlbumApi\AlbumGetTagsEmpty.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </data>
+  <data name="AlbumGetTagsError" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>AlbumApi\AlbumGetTagsError.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </data>
+  <data name="AlbumGetTagsMultiple" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>AlbumApi\AlbumGetTagsMultiple.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </data>
+  <data name="AlbumGetTagsSingle" type="System.Resources.ResXFileRef, System.Windows.Forms">
+    <value>AlbumApi\AlbumGetTagsSingle.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </data>
   <data name="AlbumGetTopTags" type="System.Resources.ResXFileRef, System.Windows.Forms">
     <value>AlbumApi\AlbumGetTopTags.json;System.Byte[], mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
   </data>

src/IF.Lastfm.Core.Tests/TestHelper.cs

@@ -2,6 +2,8 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
+using IF.Lastfm.Core.Api.Helpers;
+using Microsoft.VisualStudio.TestTools.UnitTesting;
 using Newtonsoft.Json;
 
 namespace IF.Lastfm.Core.Tests
@@ -83,5 +85,22 @@ public static DateTime RoundToNearestSecond(this DateTime dt)
                 ? dt.AddMilliseconds(-ms)
                 : dt.AddMilliseconds(1000 - ms);
         }
+
+        public static void AssertValues<T>(this PageResponse<T> pageResponse, bool success, int totalItems, int pageSize, int page, int totalPages)
+            where T : new()
+        {
+            const string messageFormat = "Page response:\n{0}\n\nExpected {1} to equal {2}";
+            var json = pageResponse.TestSerialise();
+            Func<string, dynamic, string> testMessage = (property, count) => string.Format(messageFormat, json, property, count);
+            
+            Assert.IsTrue(pageResponse.Success == success, testMessage("success", success));
+            Assert.IsTrue(pageResponse.TotalItems == totalItems, testMessage("totalitems", totalItems));
+            Assert.IsTrue(pageResponse.PageSize == pageSize, testMessage("pagesize", pageSize));
+            Assert.IsTrue(pageResponse.Page == page, testMessage("page", page));
+            Assert.IsTrue(pageResponse.TotalPages == totalPages, testMessage("totalpages", totalPages));
+
+            Assert.IsNotNull(pageResponse.Content, "page content is null");
+            Assert.IsTrue(pageResponse.Content.Count == totalItems, testMessage("content length", totalItems));
+        }
     }
 }

src/IF.Lastfm.Core/Api/AlbumApi.cs

@@ -36,14 +36,19 @@ public async Task<LastResponse<LastAlbum>> GetAlbumInfoByMbidAsync(string albumM
             return await command.ExecuteAsync();
         }
 
-        public Task<PageResponse<BuyLink>> GetBuyLinksForAlbumAsync(string artist, string album, CountryCode country, bool autocorrect = false)
+        //public Task<PageResponse<BuyLink>> GetBuyLinksForAlbumAsync(string artist, string album, CountryCode country, bool autocorrect = false)
-        {
+        //{
-            throw new NotImplementedException();
+        //    throw new NotImplementedException();
-        }
+        //}
 
-        public Task<PageResponse<LastTag>> GetUserTagsForAlbumAsync(string artist, string album, string username, bool autocorrect = false)
+        public Task<PageResponse<LastTag>> GetTagsByUserAsync(string artist, string album, string username, bool autocorrect = false)
         {
-            throw new NotImplementedException();
+            var command = new AlbumGetTagsByUserCommand(Auth, artist, album, username)
+            {
+                Autocorrect = autocorrect
+            };
+
+            return command.ExecuteAsync();
         }
 
         public async Task<PageResponse<LastTag>> GetTopTagsForAlbumAsync(string artist, string album, bool autocorrect = false)

src/IF.Lastfm.Core/Api/Commands/AlbumApi/AlbumGetTagsByUserCommand.cs

@@ -12,40 +12,31 @@
 
 namespace IF.Lastfm.Core.Api.Commands.AlbumApi
 {
-    internal class GetUserTagsForAlbumCommand: GetAsyncCommandBase<PageResponse<LastTag>>
+    internal class AlbumGetTagsByUserCommand : GetAsyncCommandBase<PageResponse<LastTag>>
     {
-        public string AlbumMbid { get; set; }
-
         public string ArtistName { get; set; }
 
         public string AlbumName { get; set; }
 
-        public string UserName { get; set; }
+        public string Username { get; set; }
+
         public bool Autocorrect { get; set; }
 
-        public GetUserTagsForAlbumCommand(ILastAuth auth, string album, string artist, string username)
+        public AlbumGetTagsByUserCommand(ILastAuth auth, string artist, string album, string username)
             : base(auth)
         {
             Method = "album.getTags";
 
-            AlbumName = album;
             ArtistName = artist;
-            UserName = username;
+            AlbumName = album;
+            Username = username;
         }
 
-
         public override void SetParameters()
-        {
-            if (AlbumMbid != null)
-            {
-                Parameters.Add("mbid", AlbumMbid);
-            }
-            else
         {
             Parameters.Add("artist", ArtistName);
             Parameters.Add("album", AlbumName);
-                Parameters.Add("user", UserName);
+            Parameters.Add("user", Username);
-            }
             Parameters.Add("autocorrect", Convert.ToInt32(Autocorrect).ToString());
 
             AddPagingParameters();
@@ -60,14 +51,14 @@ public async override Task<PageResponse<LastTag>> HandleResponse(HttpResponseMes
             if (LastFm.IsResponseValid(json, out error) && response.IsSuccessStatusCode)
             {
                 var jtoken = JsonConvert.DeserializeObject<JToken>(json);
-                var resultsToken = jtoken.SelectToken("toptags");
+                var resultsToken = jtoken.SelectToken("tags");
                 var itemsToken = resultsToken.SelectToken("tag");
 
-                return PageResponse<LastTag>.CreateSuccessResponse(itemsToken, resultsToken, LastTag.ParseJToken, false);
+                return PageResponse<LastTag>.CreateSuccessResponse(itemsToken, LastTag.ParseJToken);
             }
             else
             {
-                return LastResponse.CreateErrorResponse<PageResponse<LastTag>>(error);
+                return PageResponse<LastTag>.CreateErrorResponse(error);
             }
         }
     }

src/IF.Lastfm.Core/Api/Commands/AlbumApi/GetAlbumShoutsCommand.cs

@@ -47,7 +47,7 @@ public async override Task<PageResponse<LastShout>> HandleResponse(HttpResponseM
                 var itemsToken = jtoken.SelectToken("shout");
                 var pageInfoToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken);
+                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/AlbumApi/GetAlbumTopTagsCommand.cs

@@ -64,7 +64,7 @@ public async override Task<PageResponse<LastTag>> HandleResponse(HttpResponseMes
                 var resultsToken = jtoken.SelectToken("toptags");
                 var itemsToken = resultsToken.SelectToken("tag");
 
-                return PageResponse<LastTag>.CreateSuccessResponse(itemsToken, resultsToken, LastTag.ParseJToken, false);
+                return PageResponse<LastTag>.CreateSuccessResponse(itemsToken, resultsToken, LastTag.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/AlbumApi/SearchAlbumsCommand.cs

@@ -39,7 +39,7 @@ public async override Task<PageResponse<LastAlbum>> HandleResponse(HttpResponseM
                 var resultsToken = jtoken.SelectToken("results");
                 var itemsToken = resultsToken.SelectToken("albummatches").SelectToken("album");
 
-                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, resultsToken, LastAlbum.ParseJToken, true);
+                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, resultsToken, LastAlbum.ParseJToken, LastPageResultsType.OpenQuery);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ArtistApi/GetArtistShoutsCommand.cs

@@ -42,7 +42,7 @@ public override async Task<PageResponse<LastShout>> HandleResponse(HttpResponseM
                 var itemsToken = shoutsToken.SelectToken("shout");
                 var pageInfoToken = shoutsToken.SelectToken("@attr");
 
-                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken);
+                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ArtistApi/GetSimilarArtistsCommand.cs

@@ -50,7 +50,7 @@ public async override Task<PageResponse<LastArtist>> HandleResponse(HttpResponse
                 var jtoken = JsonConvert.DeserializeObject<JToken>(json);
                 var itemsToken = jtoken.SelectToken("similarartists").SelectToken("artist");
 
-                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, null, LastArtist.ParseJToken);
+                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, LastArtist.ParseJToken);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ArtistApi/GetTopAlbumsCommand.cs

@@ -39,7 +39,7 @@ public async override Task<PageResponse<LastAlbum>> HandleResponse(HttpResponseM
                 var itemsToken = albumsToken.SelectToken("album");
                 var pageInfoToken = albumsToken.SelectToken("@attr");
 
-                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, pageInfoToken, LastAlbum.ParseJToken);
+                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, pageInfoToken, LastAlbum.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ArtistApi/GetTopTracksCommand.cs

@@ -39,7 +39,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var itemsToken = tracksToken.SelectToken("track");
                 var pageInfoToken = tracksToken.SelectToken("@attr");
 
-                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, pageInfoToken, LastTrack.ParseJToken);
+                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, pageInfoToken, LastTrack.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ArtistApi/SearchArtistsCommand.cs

@@ -38,7 +38,7 @@ public async override Task<PageResponse<LastArtist>> HandleResponse(HttpResponse
                 var resultsToken = jtoken.SelectToken("results");
                 var itemsToken = resultsToken.SelectToken("artistmatches").SelectToken("artist");
 
-                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, resultsToken, LastArtist.ParseJToken, true);
+                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, resultsToken, LastArtist.ParseJToken, LastPageResultsType.OpenQuery);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ChartApi/GetTopArtistsCommand.cs

@@ -33,7 +33,7 @@ public async override Task<PageResponse<LastArtist>> HandleResponse(HttpResponse
                 var itemsToken = jtoken.SelectToken("artist");
                 var pageInfoToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, pageInfoToken, LastArtist.ParseJToken);
+                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, pageInfoToken, LastArtist.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/ChartApi/GetTopTracksCommand.cs

@@ -34,7 +34,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var itemsToken = tracksToken.SelectToken("track");
                 var pageInfoToken = tracksToken.SelectToken("@attr");
 
-                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, pageInfoToken, LastTrack.ParseJToken);
+                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, pageInfoToken, LastTrack.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/LibraryApi/LibraryGetTracksCommand.cs

@@ -51,7 +51,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var tracksToken = jtoken.SelectToken("track");
                 var pageInfoToken = jtoken.SelectToken("@attr");
  
-                return PageResponse<LastTrack>.CreateSuccessResponse(tracksToken, pageInfoToken, LastTrack.ParseJToken, false);
+                return PageResponse<LastTrack>.CreateSuccessResponse(tracksToken, pageInfoToken, LastTrack.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/TrackApi/GetSimilarTracksCommand.cs

@@ -55,7 +55,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var jtoken = JsonConvert.DeserializeObject<JToken>(json);
                 var itemsToken = jtoken.SelectToken("similartracks").SelectToken("track");
 
-                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, null, LastTrack.ParseJToken);
+                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, LastTrack.ParseJToken);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/TrackApi/GetTrackShoutsCommand.cs

@@ -47,7 +47,7 @@ public async override Task<PageResponse<LastShout>> HandleResponse(HttpResponseM
                 var itemsToken = jtoken.SelectToken("shout");
                 var pageInfoToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken);
+                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/TrackApi/SearchTracksCommand.cs

@@ -38,7 +38,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var resultsToken = jtoken.SelectToken("results");
                 var itemsToken = resultsToken.SelectToken("trackmatches").SelectToken("track");
 
-                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, resultsToken, LastTrack.ParseJToken, true);
+                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, resultsToken, LastTrack.ParseJToken, LastPageResultsType.OpenQuery);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/UserApi/GetRecommendedArtistsCommand.cs

@@ -31,7 +31,7 @@ public async override Task<PageResponse<LastArtist>> HandleResponse(HttpResponse
                 var resultsToken = jtoken.SelectToken("recommendations");
                 var itemsToken = resultsToken.SelectToken("artist");
 
-                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, resultsToken, LastArtist.ParseJToken, false);
+                return PageResponse<LastArtist>.CreateSuccessResponse(itemsToken, resultsToken, LastArtist.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/UserApi/GetTopAlbumsCommand.cs

@@ -40,7 +40,7 @@ public async override Task<PageResponse<LastAlbum>> HandleResponse(HttpResponseM
                 var itemsToken = jtoken.SelectToken("topalbums").SelectToken("album");
                 var pageInfoToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, pageInfoToken, LastAlbum.ParseJToken);
+                return PageResponse<LastAlbum>.CreateSuccessResponse(itemsToken, pageInfoToken, LastAlbum.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/UserApi/GetUserShoutsCommand.cs

@@ -38,7 +38,7 @@ public async override Task<PageResponse<LastShout>> HandleResponse(HttpResponseM
                 var itemsToken = shoutsToken.SelectToken("shout");
                 var pageInfoToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken);
+                return PageResponse<LastShout>.CreateSuccessResponse(itemsToken, pageInfoToken, LastShout.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Commands/UserApi/UserGetRecentTracksCommand.cs

@@ -48,7 +48,7 @@ public async override Task<PageResponse<LastTrack>> HandleResponse(HttpResponseM
                 var itemsToken = jtoken.SelectToken("track");
                 var attrToken = jtoken.SelectToken("@attr");
 
-                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, attrToken, LastTrack.ParseJToken, false);
+                return PageResponse<LastTrack>.CreateSuccessResponse(itemsToken, attrToken, LastTrack.ParseJToken, LastPageResultsType.Attr);
             }
             else
             {

src/IF.Lastfm.Core/Api/Enums/LastStatsTimeSpan.cs

@@ -29,4 +29,11 @@ public enum Gender
         Male,
         Female
     }
+
+    public enum LastPageResultsType
+    {
+        None = 0,
+        Attr,
+        OpenQuery
+    }
 }

src/IF.Lastfm.Core/Api/Helpers/LastResponse.cs

@@ -4,7 +4,14 @@
 
 namespace IF.Lastfm.Core.Api.Helpers
 {
-    public class LastResponse
+    public interface ILastResponse
+    {
+        bool Success { get; set; }
+
+        LastFmApiError Error { get; set; }
+    }
+
+    public class LastResponse : ILastResponse
     {
         #region Properties
 

src/IF.Lastfm.Core/Api/Helpers/PageResponse.cs

@@ -1,28 +1,48 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Collections.ObjectModel;
 using System.Linq;
 using IF.Lastfm.Core.Api.Enums;
-using IF.Lastfm.Core.Objects;
+using IF.Lastfm.Core.Json;
+using Newtonsoft.Json;
 using Newtonsoft.Json.Linq;
 
 namespace IF.Lastfm.Core.Api.Helpers
 {
-    public class PageResponse<T> : LastResponse, IEnumerable<T> where T : new()
+    public interface IPageResponse<out T> : ILastResponse, IEnumerable<T> where T : new()
+    {
+        IReadOnlyList<T> Content { get; }
+
+        int Page { get; }
+
+        int PageSize { get; }
+
+        int TotalPages { get; }
+
+        int TotalItems { get; }
+    }
+
+    [JsonConverter(typeof(PageResponseJsonConverter))]
+    public class PageResponse<T> : LastResponse, IPageResponse<T> where T : new()
     {
         private int? _totalItems;
         private int? _pageSize;
 
-        public PageResponse()
+        public PageResponse() : this(Enumerable.Empty<T>())
+        {
+        }
+
+        public PageResponse(IEnumerable<T> content)
         {
             Page = 1;
             TotalPages = 1;
-            Content = new List<T>();
+            Content = new ReadOnlyCollection<T>(content.ToList());
         }
 
         #region Properties
 
-        public List<T> Content { get; internal set; }
+        public IReadOnlyList<T> Content { get; internal set; }
 
         public int Page { get; internal set; }
 
@@ -46,14 +66,9 @@ public int PageSize
 
         public IEnumerator<T> GetEnumerator()
         {
-            if (Content != null)
+            return Content != null
-            {
+                ? Content.GetEnumerator()
-                return Content.GetEnumerator();
+                : null;
-            }
-            else
-            {
-                return null;
-            }
         }
 
         IEnumerator IEnumerable.GetEnumerator()
@@ -72,6 +87,20 @@ IEnumerator IEnumerable.GetEnumerator()
 
         #region Factory methods
 
+        public static PageResponse<T> CreateErrorResponse(LastFmApiError error)
+        {
+            var r = new PageResponse<T>
+            {
+                Success = false,
+                Error = error
+            };
+
+            r.AddDefaultPageInfo();
+
+            return r;
+        }
+
+
         public new static PageResponse<T> CreateSuccessResponse()
         {
             var r = new PageResponse<T>
@@ -80,71 +109,86 @@ IEnumerator IEnumerable.GetEnumerator()
                 Error = LastFmApiError.None
             };
 
+            r.AddDefaultPageInfo();
+
             return r;
         }
 
         [Obsolete]
         public static PageResponse<T> CreateSuccessResponse(IEnumerable<T> content)
         {
-            var r = new PageResponse<T>
+            var r = new PageResponse<T>(content)
             {
                 Success = true,
                 Error = LastFmApiError.None
             };
             
-            r.Content.AddRange(content);
-
             return r;
         }
 
-        public static PageResponse<T> CreateSuccessResponse(JToken itemsToken, JToken pageInfoToken, Func<JToken, T> parseToken, bool isOpenQueryToken = false)
+        public static PageResponse<T> CreateSuccessResponse(JToken itemsToken, Func<JToken, T> parseToken)
         {
-            var pageresponse = CreateSuccessResponse();
+            return CreateSuccessResponse(itemsToken, null, parseToken, LastPageResultsType.None);
+        }
         
+        public static PageResponse<T> CreateSuccessResponse(JToken itemsToken, JToken pageInfoToken, Func<JToken, T> parseToken, LastPageResultsType pageResultsType)
+        {
+            IEnumerable<T> items;
             if (itemsToken != null && itemsToken.Children().Any())
             {
                 // array notation isn't used on the api when only one object is available
                 if (itemsToken.Type != JTokenType.Array)
                 {
                     var item = parseToken(itemsToken);
-                    pageresponse.Content.Add(item);
+                    items = new[] {item};
+
                 }
                 else
                 {
-                    var items = itemsToken.Children().Select(parseToken);
+                    items = itemsToken.Children().Select(parseToken);
-                    pageresponse.Content.AddRange(items);
                 }
             }
+            else
+            {
+                items = Enumerable.Empty<T>();
+            }
 
-            if (pageInfoToken != null)
+            var pageresponse = new PageResponse<T>(items);
-            {
+
-                if (isOpenQueryToken)
+            switch (pageResultsType)
-                {
-                    pageresponse.AddPageInfoFromOpenQueryJToken(pageInfoToken);
-                }
-                else
             {
+                case LastPageResultsType.Attr:
                     pageresponse.AddPageInfoFromJToken(pageInfoToken);
+                    break;
+                case LastPageResultsType.OpenQuery:
+                    pageresponse.AddPageInfoFromOpenQueryJToken(pageInfoToken);
+                    break;
+                case LastPageResultsType.None:
+                default:
+                    pageresponse.AddDefaultPageInfo(pageresponse.Content);
+                    break;
             }
-            }
+
-            else
+            pageresponse.Success = true;
-            {
-                pageresponse.AddDefaultPageInfo(pageresponse.Content.Count);
-            }
 
             return pageresponse;
         }
 
-        private void AddDefaultPageInfo(int count)
+        #endregion
+
+        private void AddDefaultPageInfo()
+        {
+            AddDefaultPageInfo(Enumerable.Empty<T>().ToList());
+        }
+
+        private void AddDefaultPageInfo(IReadOnlyCollection<T> items)
         {
             Page = 1;
             TotalPages = 1;
-            TotalItems = count;
+            TotalItems = items.Count;
-            PageSize = count;
+            PageSize = items.Count;
         }
 
-        #endregion
-
         internal void AddPageInfoFromJToken(JToken attrToken)
         {
             if (attrToken == null)

src/IF.Lastfm.Core/Api/IAlbumApi.cs

@@ -12,12 +12,12 @@ public interface IAlbumApi
 
         Task<LastResponse<LastAlbum>> GetAlbumInfoByMbidAsync(string albumMbid, bool autocorrect = false);
         
-        Task<PageResponse<BuyLink>> GetBuyLinksForAlbumAsync(string artist,
+        //Task<PageResponse<BuyLink>> GetBuyLinksForAlbumAsync(string artist,
-            string album,
+        //    string album,
-            CountryCode country,
+        //    CountryCode country,
-            bool autocorrect = false);
+        //    bool autocorrect = false);
         
-        Task<PageResponse<LastTag>> GetUserTagsForAlbumAsync(string artist,
+        Task<PageResponse<LastTag>> GetTagsByUserAsync(string artist,
             string album,
             string username,
             bool autocorrect = false);

src/IF.Lastfm.Core/IF.Lastfm.Core.csproj

@@ -41,7 +41,7 @@
     <Compile Include="Api\AlbumApi.cs" />
     <Compile Include="Api\ArtistApi.cs" />
     <Compile Include="Api\Commands\AlbumApi\GetAlbumTopTagsCommand.cs" />
-    <Compile Include="Api\Commands\AlbumApi\GetUserTagsForAlbumCommand.cs" />
+    <Compile Include="Api\Commands\AlbumApi\AlbumGetTagsByUserCommand.cs" />
     <Compile Include="Api\Commands\LibraryApi\LibraryGetTracksCommand.cs" />
     <Compile Include="Api\Commands\TrackApi\TrackScrobbleCommand.cs" />
     <Compile Include="Api\Commands\TrackApi\TrackUpdateNowPlayingCommand.cs" />
@@ -99,6 +99,7 @@
     <Compile Include="Api\TrackApi.cs" />
     <Compile Include="Api\UserApi.cs" />
     <Compile Include="Json\LastFmBooleanConverter.cs" />
+    <Compile Include="Json\PageResponseJsonConverter.cs" />
     <Compile Include="LastFm.cs" />
     <Compile Include="MD5.cs" />
     <Compile Include="Objects\LastAlbum.cs" />

src/IF.Lastfm.Core/Json/LastFmBooleanConverter.cs

@@ -1,5 +1,6 @@
 using System;
 using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
 
 namespace IF.Lastfm.Core.Json
 {

src/IF.Lastfm.Core/Json/PageResponseJsonConverter.cs

@@ -0,0 +1,39 @@
+using System;
+using IF.Lastfm.Core.Api.Helpers;
+using Newtonsoft.Json;
+
+namespace IF.Lastfm.Core.Json
+{
+    public class PageResponseJsonConverter : JsonConverter
+    {
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            var pageResponse = (IPageResponse<object>) value;
+
+            dynamic container = new
+            {
+                success = pageResponse.Success,
+                items = pageResponse.Content,
+                page = new
+                {
+                    totalItems = pageResponse.TotalItems,
+                    pageSize = pageResponse.PageSize,
+                    page = pageResponse.Page,
+                    totalPages = pageResponse.TotalPages
+                }
+            };
+
+            serializer.Serialize(writer, container);
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            return serializer.Deserialize(reader, objectType);
+        }
+
+        public override bool CanConvert(Type objectType)
+        {
+            return objectType == typeof (PageResponse<>);
+        }
+    }
+}