migrate update checks to FluentHttpClient

WebClient isn't needed for compatibility with macOS after the .NET 5 update in Stardew Valley 1.5.5, and causes noticeable lag for some players even when running on a background thread.

9 files changed, 78 insertions, 64 deletions

diff --git a/build/deploy-local-smapi.targets b/build/deploy-local-smapi.targets
index cb330e24..6ea5f0a2 100644
--- a/build/deploy-local-smapi.targets
+++ b/build/deploy-local-smapi.targets
@@ -35,6 +35,10 @@ This assumes `find-game-folder.targets` has already been imported and validated.
     <Copy SourceFiles="$(TargetDir)\Mono.Cecil.Pdb.dll" DestinationFolder="$(GamePath)\smapi-internal" />
     <Copy SourceFiles="$(TargetDir)\MonoMod.Common.dll" DestinationFolder="$(GamePath)\smapi-internal" />
 
+    <!-- FluentHttpClient + dependencies -->
+    <Copy SourceFiles="$(TargetDir)\Pathoschild.Http.Client.dll" DestinationFolder="$(GamePath)\smapi-internal" />
+    <Copy SourceFiles="$(TargetDir)\System.Net.Http.Formatting.dll" DestinationFolder="$(GamePath)\smapi-internal" />
+
     <!-- .NET dependencies -->
     <Copy SourceFiles="$(TargetDir)\System.Management.dll" DestinationFolder="$(GamePath)\smapi-internal" Condition="$(OS) == 'Windows_NT'" />
 
diff --git a/build/unix/prepare-install-package.sh b/build/unix/prepare-install-package.sh
index 01cd2080..1d805e00 100755
--- a/build/unix/prepare-install-package.sh
+++ b/build/unix/prepare-install-package.sh
@@ -134,7 +134,7 @@ for folder in ${folders[@]}; do
     cp -r "$smapiBin/i18n" "$bundlePath/smapi-internal"
 
     # bundle smapi-internal
-    for name in "0Harmony.dll" "0Harmony.xml" "Mono.Cecil.dll" "Mono.Cecil.Mdb.dll" "Mono.Cecil.Pdb.dll" "MonoMod.Common.dll" "Newtonsoft.Json.dll" "Pintail.dll" "TMXTile.dll" "SMAPI.Toolkit.dll" "SMAPI.Toolkit.pdb" "SMAPI.Toolkit.xml" "SMAPI.Toolkit.CoreInterfaces.dll" "SMAPI.Toolkit.CoreInterfaces.pdb" "SMAPI.Toolkit.CoreInterfaces.xml"; do
+    for name in "0Harmony.dll" "0Harmony.xml" "Mono.Cecil.dll" "Mono.Cecil.Mdb.dll" "Mono.Cecil.Pdb.dll" "MonoMod.Common.dll" "Newtonsoft.Json.dll" "Pathoschild.Http.Client.dll" "Pintail.dll" "TMXTile.dll" "SMAPI.Toolkit.dll" "SMAPI.Toolkit.pdb" "SMAPI.Toolkit.xml" "SMAPI.Toolkit.CoreInterfaces.dll" "SMAPI.Toolkit.CoreInterfaces.pdb" "SMAPI.Toolkit.CoreInterfaces.xml" "System.Net.Http.Formatting.dll"; do
         cp "$smapiBin/$name" "$bundlePath/smapi-internal"
     done
 
diff --git a/build/windows/prepare-install-package.ps1 b/build/windows/prepare-install-package.ps1
index 7e3c6c86..87a4fe01 100644
--- a/build/windows/prepare-install-package.ps1
+++ b/build/windows/prepare-install-package.ps1
@@ -154,7 +154,7 @@ foreach ($folder in $folders) {
     cp -Recurse "$smapiBin/i18n" "$bundlePath/smapi-internal"
 
     # bundle smapi-internal
-    foreach ($name in @("0Harmony.dll", "0Harmony.xml", "Mono.Cecil.dll", "Mono.Cecil.Mdb.dll", "Mono.Cecil.Pdb.dll", "MonoMod.Common.dll", "Newtonsoft.Json.dll", "Pintail.dll", "TMXTile.dll", "SMAPI.Toolkit.dll", "SMAPI.Toolkit.pdb", "SMAPI.Toolkit.xml", "SMAPI.Toolkit.CoreInterfaces.dll", "SMAPI.Toolkit.CoreInterfaces.pdb", "SMAPI.Toolkit.CoreInterfaces.xml")) {
+    foreach ($name in @("0Harmony.dll", "0Harmony.xml", "Mono.Cecil.dll", "Mono.Cecil.Mdb.dll", "Mono.Cecil.Pdb.dll", "MonoMod.Common.dll", "Newtonsoft.Json.dll", "Pathoschild.Http.Client.dll", "Pintail.dll", "TMXTile.dll", "SMAPI.Toolkit.dll", "SMAPI.Toolkit.pdb", "SMAPI.Toolkit.xml", "SMAPI.Toolkit.CoreInterfaces.dll", "SMAPI.Toolkit.CoreInterfaces.pdb", "SMAPI.Toolkit.CoreInterfaces.xml", "System.Net.Http.Formatting.dll")) {
         cp "$smapiBin/$name" "$bundlePath/smapi-internal"
     }
 
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 4c504150..414396f4 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -9,9 +9,12 @@
 
 ## Upcoming release
 * For players:
-  * Minor optimizations.
+  * Fixed lag which occurred for some players since Stardew Valley 1.5.5.
   * Fixed `smapi-internal/config.user.json` overrides not applied after SMAPI 3.14.0.
 
+* For mod authors:
+  * The [FluentHttpClient package](https://github.com/Pathoschild/FluentHttpClient#readme) is now loaded by SMAPI.
+
 * For the web UI:
   * Updated the JSON validator/schema for Content Patcher 1.27.0.
   * Fixed the mod count in the log parser metadata.
diff --git a/src/SMAPI.Toolkit/Framework/Clients/WebApi/WebApiClient.cs b/src/SMAPI.Toolkit/Framework/Clients/WebApi/WebApiClient.cs
index d4282617..ef1904d4 100644
--- a/src/SMAPI.Toolkit/Framework/Clients/WebApi/WebApiClient.cs
+++ b/src/SMAPI.Toolkit/Framework/Clients/WebApi/WebApiClient.cs
@@ -1,27 +1,24 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Net;
-using Newtonsoft.Json;
+using System.Threading.Tasks;
+using Pathoschild.Http.Client;
 using StardewModdingAPI.Toolkit.Serialization;
 using StardewModdingAPI.Toolkit.Utilities;
 
 namespace StardewModdingAPI.Toolkit.Framework.Clients.WebApi
 {
     /// <summary>Provides methods for interacting with the SMAPI web API.</summary>
-    public class WebApiClient
+    public class WebApiClient : IDisposable
     {
         /*********
         ** Fields
         *********/
-        /// <summary>The base URL for the web API.</summary>
-        private readonly Uri BaseUrl;
-
         /// <summary>The API version number.</summary>
         private readonly ISemanticVersion Version;
 
-        /// <summary>The JSON serializer settings to use.</summary>
-        private readonly JsonSerializerSettings JsonSettings = new JsonHelper().JsonSettings;
+        /// <summary>The underlying HTTP client.</summary>
+        private readonly IClient Client;
 
 
         /*********
@@ -32,8 +29,11 @@ namespace StardewModdingAPI.Toolkit.Framework.Clients.WebApi
         /// <param name="version">The web API version.</param>
         public WebApiClient(string baseUrl, ISemanticVersion version)
         {
-            this.BaseUrl = new Uri(baseUrl);
             this.Version = version;
+            this.Client = new FluentClient(baseUrl)
+                .SetUserAgent($"SMAPI/{version}");
+
+            this.Client.Formatters.JsonFormatter.SerializerSettings = JsonHelper.CreateDefaultSettings();
         }
 
         /// <summary>Get metadata about a set of mods from the web API.</summary>
@@ -42,36 +42,22 @@ namespace StardewModdingAPI.Toolkit.Framework.Clients.WebApi
         /// <param name="gameVersion">The Stardew Valley version installed by the player.</param>
         /// <param name="platform">The OS on which the player plays.</param>
         /// <param name="includeExtendedMetadata">Whether to include extended metadata for each mod.</param>
-        public IDictionary<string, ModEntryModel> GetModInfo(ModSearchEntryModel[] mods, ISemanticVersion apiVersion, ISemanticVersion gameVersion, Platform platform, bool includeExtendedMetadata = false)
+        public async Task<IDictionary<string, ModEntryModel>> GetModInfoAsync(ModSearchEntryModel[] mods, ISemanticVersion apiVersion, ISemanticVersion gameVersion, Platform platform, bool includeExtendedMetadata = false)
         {
-            return this.Post<ModSearchModel, ModEntryModel[]>(
-                $"v{this.Version}/mods",
-                new ModSearchModel(mods, apiVersion, gameVersion, platform, includeExtendedMetadata)
-            ).ToDictionary(p => p.ID);
+            ModEntryModel[] result = await this.Client
+                .PostAsync(
+                    $"v{this.Version}/mods",
+                    new ModSearchModel(mods, apiVersion, gameVersion, platform, includeExtendedMetadata)
+                )
+                .As<ModEntryModel[]>();
+
+            return result.ToDictionary(p => p.ID);
         }
 
-
-        /*********
-        ** Private methods
-        *********/
-        /// <summary>Fetch the response from the backend API.</summary>
-        /// <typeparam name="TBody">The body content type.</typeparam>
-        /// <typeparam name="TResult">The expected response type.</typeparam>
-        /// <param name="url">The request URL, optionally excluding the base URL.</param>
-        /// <param name="content">The body content to post.</param>
-        private TResult Post<TBody, TResult>(string url, TBody content)
+        /// <inheritdoc />
+        public void Dispose()
         {
-            // note: avoid HttpClient for macOS compatibility
-            using WebClient client = new();
-
-            Uri fullUrl = new(this.BaseUrl, url);
-            string data = JsonConvert.SerializeObject(content);
-
-            client.Headers["Content-Type"] = "application/json";
-            client.Headers["User-Agent"] = $"SMAPI/{this.Version}";
-            string response = client.UploadString(fullUrl, data);
-            return JsonConvert.DeserializeObject<TResult>(response, this.JsonSettings)
-                ?? throw new InvalidOperationException($"Could not parse the response from POST {url}.");
+            this.Client.Dispose();
         }
     }
 }
diff --git a/src/SMAPI.Toolkit/Serialization/JsonHelper.cs b/src/SMAPI.Toolkit/Serialization/JsonHelper.cs
index 1a003c51..a5d7e2e8 100644
--- a/src/SMAPI.Toolkit/Serialization/JsonHelper.cs
+++ b/src/SMAPI.Toolkit/Serialization/JsonHelper.cs
@@ -15,21 +15,27 @@ namespace StardewModdingAPI.Toolkit.Serialization
         ** Accessors
         *********/
         /// <summary>The JSON settings to use when serializing and deserializing files.</summary>
-        public JsonSerializerSettings JsonSettings { get; } = new()
-        {
-            Formatting = Formatting.Indented,
-            ObjectCreationHandling = ObjectCreationHandling.Replace, // avoid issue where default ICollection<T> values are duplicated each time the config is loaded
-            Converters = new List<JsonConverter>
-            {
-                new SemanticVersionConverter(),
-                new StringEnumConverter()
-            }
-        };
+        public JsonSerializerSettings JsonSettings { get; } = JsonHelper.CreateDefaultSettings();
 
 
         /*********
         ** Public methods
         *********/
+        /// <summary>Create an instance of the default JSON serializer settings.</summary>
+        public static JsonSerializerSettings CreateDefaultSettings()
+        {
+            return new()
+            {
+                Formatting = Formatting.Indented,
+                ObjectCreationHandling = ObjectCreationHandling.Replace, // avoid issue where default ICollection<T> values are duplicated each time the config is loaded
+                Converters = new List<JsonConverter>
+                {
+                    new SemanticVersionConverter(),
+                    new StringEnumConverter()
+                }
+            };
+        }
+
         /// <summary>Read a JSON file.</summary>
         /// <typeparam name="TModel">The model type.</typeparam>
         /// <param name="fullPath">The absolute file path.</param>
diff --git a/src/SMAPI.Web/Startup.cs b/src/SMAPI.Web/Startup.cs
index 9980d00c..54c25979 100644
--- a/src/SMAPI.Web/Startup.cs
+++ b/src/SMAPI.Web/Startup.cs
@@ -199,7 +199,7 @@ namespace StardewModdingAPI.Web
         /// <param name="settings">The serializer settings to edit.</param>
         private void ConfigureJsonNet(JsonSerializerSettings settings)
         {
-            foreach (JsonConverter converter in new JsonHelper().JsonSettings.Converters)
+            foreach (JsonConverter converter in JsonHelper.CreateDefaultSettings().Converters)
                 settings.Converters.Add(converter);
 
             settings.Formatting = Formatting.Indented;
diff --git a/src/SMAPI/Framework/SCore.cs b/src/SMAPI/Framework/SCore.cs
index 16c168a0..fdfe70fc 100644
--- a/src/SMAPI/Framework/SCore.cs
+++ b/src/SMAPI/Framework/SCore.cs
@@ -10,6 +10,7 @@ using System.Runtime.ExceptionServices;
 using System.Security;
 using System.Text;
 using System.Threading;
+using System.Threading.Tasks;
 using Microsoft.Xna.Framework;
 #if SMAPI_FOR_WINDOWS
 using Microsoft.Win32;
@@ -406,7 +407,7 @@ namespace StardewModdingAPI.Framework
                 this.CheckForSoftwareConflicts();
 
                 // check for updates
-                this.CheckForUpdatesAsync(mods);
+                _ = this.CheckForUpdatesAsync(mods); // ignore task since the main thread doesn't need to wait for it
             }
 
             // update window titles
@@ -1450,16 +1451,15 @@ namespace StardewModdingAPI.Framework
 
         /// <summary>Asynchronously check for a new version of SMAPI and any installed mods, and print alerts to the console if an update is available.</summary>
         /// <param name="mods">The mods to include in the update check (if eligible).</param>
-        private void CheckForUpdatesAsync(IModMetadata[] mods)
+        private async Task CheckForUpdatesAsync(IModMetadata[] mods)
         {
-            if (!this.Settings.CheckForUpdates)
-                return;
-
-            new Thread(() =>
+            try
             {
+                if (!this.Settings.CheckForUpdates)
+                    return;
+
                 // create client
-                string url = this.Settings.WebApiBaseUrl;
-                WebApiClient client = new(url, Constants.ApiVersion);
+                using WebApiClient client = new(this.Settings.WebApiBaseUrl, Constants.ApiVersion);
                 this.Monitor.Log("Checking for updates...");
 
                 // check SMAPI version
@@ -1469,9 +1469,15 @@ namespace StardewModdingAPI.Framework
                     try
                     {
                         // fetch update check
-                        ModEntryModel response = client.GetModInfo(new[] { new ModSearchEntryModel("Pathoschild.SMAPI", Constants.ApiVersion, new[] { $"GitHub:{this.Settings.GitHubProjectName}" }) }, apiVersion: Constants.ApiVersion, gameVersion: Constants.GameVersion, platform: Constants.Platform).Single().Value;
-                        updateFound = response.SuggestedUpdate?.Version;
-                        updateUrl = response.SuggestedUpdate?.Url;
+                        IDictionary<string, ModEntryModel> response = await client.GetModInfoAsync(
+                            mods: new[] { new ModSearchEntryModel("Pathoschild.SMAPI", Constants.ApiVersion, new[] { $"GitHub:{this.Settings.GitHubProjectName}" }) },
+                            apiVersion: Constants.ApiVersion,
+                            gameVersion: Constants.GameVersion,
+                            platform: Constants.Platform
+                        );
+                        ModEntryModel updateInfo = response.Single().Value;
+                        updateFound = updateInfo.SuggestedUpdate?.Version;
+                        updateUrl = updateInfo.SuggestedUpdate?.Url;
 
                         // log message
                         if (updateFound != null)
@@ -1480,10 +1486,10 @@ namespace StardewModdingAPI.Framework
                             this.Monitor.Log("   SMAPI okay.");
 
                         // show errors
-                        if (response.Errors.Any())
+                        if (updateInfo.Errors.Any())
                         {
                             this.Monitor.Log("Couldn't check for a new version of SMAPI. This won't affect your game, but you may not be notified of new versions if this keeps happening.", LogLevel.Warn);
-                            this.Monitor.Log($"Error: {string.Join("\n", response.Errors)}");
+                            this.Monitor.Log($"Error: {string.Join("\n", updateInfo.Errors)}");
                         }
                     }
                     catch (Exception ex)
@@ -1523,7 +1529,7 @@ namespace StardewModdingAPI.Framework
 
                         // fetch results
                         this.Monitor.Log($"   Checking for updates to {searchMods.Count} mods...");
-                        IDictionary<string, ModEntryModel> results = client.GetModInfo(searchMods.ToArray(), apiVersion: Constants.ApiVersion, gameVersion: Constants.GameVersion, platform: Constants.Platform);
+                        IDictionary<string, ModEntryModel> results = await client.GetModInfoAsync(searchMods.ToArray(), apiVersion: Constants.ApiVersion, gameVersion: Constants.GameVersion, platform: Constants.Platform);
 
                         // extract update alerts & errors
                         var updates = new List<Tuple<IModMetadata, ISemanticVersion, string>>();
@@ -1573,7 +1579,15 @@ namespace StardewModdingAPI.Framework
                         );
                     }
                 }
-            }).Start();
+            }
+            catch (Exception ex)
+            {
+                this.Monitor.Log("Couldn't check for updates. This won't affect your game, but you won't be notified of SMAPI or mod updates if this keeps happening.", LogLevel.Warn);
+                this.Monitor.Log(ex is WebException && ex.InnerException == null
+                    ? ex.Message
+                    : ex.ToString()
+                );
+            }
         }
 
         /// <summary>Create a directory path if it doesn't exist.</summary>
diff --git a/src/SMAPI/SMAPI.csproj b/src/SMAPI/SMAPI.csproj
index 3abefeab..c05512e9 100644
--- a/src/SMAPI/SMAPI.csproj
+++ b/src/SMAPI/SMAPI.csproj
@@ -25,6 +25,7 @@
     <PackageReference Include="Mono.Cecil" Version="0.11.4" />
     <PackageReference Include="MonoMod.Common" Version="22.3.5.1" />
     <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
+    <PackageReference Include="Pathoschild.Http.FluentClient" Version="4.1.1" />
     <PackageReference Include="Pintail" Version="2.2.0" />
     <PackageReference Include="Platonymous.TMXTile" Version="1.5.9" />
     <PackageReference Include="System.Reflection.Emit" Version="4.7.0" />