Rework how we fetch community plugin data

Flow.Launcher.Core/ExternalPlugins/CommunityPluginSource.cs

@@ -0,0 +1,57 @@
+using Flow.Launcher.Infrastructure.Http;
+using Flow.Launcher.Infrastructure.Logger;
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Flow.Launcher.Core.ExternalPlugins
+{
+    public record CommunityPluginSource(string ManifestFileUrl)
+    {
+        private string latestEtag = "";
+
+        private List<UserPlugin> plugins = new();
+
+        /// <summary>
+        /// Fetch and deserialize the contents of a plugins.json file found at <see cref="ManifestFileUrl"/>.
+        /// We use conditional http requests to keep repeat requests fast.
+        /// </summary>
+        /// <remarks>
+        /// This method will only return plugin details when the underlying http request is successful (200 or 304).
+        /// In any other case, an exception is raised
+        /// </remarks>
+        public async Task<List<UserPlugin>> FetchAsync(CancellationToken token)
+        {
+            Log.Info(nameof(CommunityPluginSource), $"Loading plugins from {ManifestFileUrl}");
+
+            var request = new HttpRequestMessage(HttpMethod.Get, ManifestFileUrl);
+
+            request.Headers.Add("If-None-Match", latestEtag);
+
+            using var response = await Http.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, token).ConfigureAwait(false);
+
+            if (response.StatusCode == HttpStatusCode.OK)
+            {
+                this.plugins = await response.Content.ReadFromJsonAsync<List<UserPlugin>>(cancellationToken: token).ConfigureAwait(false);
+                this.latestEtag = response.Headers.ETag.Tag;
+
+                Log.Info(nameof(CommunityPluginSource), $"Loaded {this.plugins.Count} plugins from {ManifestFileUrl}");
+                return this.plugins;
+            }
+            else if (response.StatusCode == HttpStatusCode.NotModified)
+            {
+                Log.Info(nameof(CommunityPluginSource), $"Resource {ManifestFileUrl} has not been modified.");
+                return this.plugins;
+            }
+            else
+            {
+                Log.Warn(nameof(CommunityPluginSource), $"Failed to load resource {ManifestFileUrl} with response {response.StatusCode}");
+                throw new Exception($"Failed to load resource {ManifestFileUrl} with response {response.StatusCode}");
+            }
+        }
+    }
+}

Flow.Launcher.Core/ExternalPlugins/CommunityPluginStore.cs

@@ -0,0 +1,54 @@
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Flow.Launcher.Core.ExternalPlugins
+{
+    /// <summary>
+    /// Describes a store of community-made plugins.
+    /// The provided URLs should point to a json file, whose content
+    /// is deserializable as a <see cref="UserPlugin"/> array.
+    /// </summary>
+    /// <param name="primaryUrl">Primary URL to the manifest json file.</param>
+    /// <param name="secondaryUrls">Secondary URLs to access the <paramref name="primaryUrl"/>, for example CDN links</param>
+    public record CommunityPluginStore(string primaryUrl, params string[] secondaryUrls)
+    {
+        private readonly List<CommunityPluginSource> pluginSources =
+            secondaryUrls
+                .Append(primaryUrl)
+                .Select(url => new CommunityPluginSource(url))
+                .ToList();
+
+        public async Task<List<UserPlugin>> FetchAsync(CancellationToken token, bool onlyFromPrimaryUrl = false)
+        {
+            // we create a new cancellation token source linked to the given token.
+            // Once any of the http requests completes successfully, we call cancel
+            // to stop the rest of the running http requests.
+            var cts = CancellationTokenSource.CreateLinkedTokenSource(token);
+
+            var tasks = onlyFromPrimaryUrl
+                ? new() { pluginSources.Last().FetchAsync(cts.Token) }
+                : pluginSources.Select(pluginSource => pluginSource.FetchAsync(cts.Token)).ToList();
+
+            var pluginResults = new List<UserPlugin>();
+
+            // keep going until all tasks have completed
+            while (tasks.Any())
+            {
+                var completedTask = await Task.WhenAny(tasks);
+                if (completedTask.IsCompletedSuccessfully)
+                {
+                    // one of the requests completed successfully; keep its results
+                    // and cancel the remaining http requests.
+                    pluginResults = await completedTask;
+                    cts.Cancel();
+                }
+                tasks.Remove(completedTask);
+            }
+
+            // all tasks have finished
+            return pluginResults;
+        }
+    }
+}

Flow.Launcher.Core/ExternalPlugins/PluginsManifest.cs

@@ -1,49 +1,38 @@
-using Flow.Launcher.Infrastructure.Http;
-using Flow.Launcher.Infrastructure.Logger;
+using Flow.Launcher.Infrastructure.Logger;
 using System;
 using System.Collections.Generic;
-using System.Net;
-using System.Net.Http;
-using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 
 namespace Flow.Launcher.Core.ExternalPlugins
 {
     public static class PluginsManifest
     {
-        private const string manifestFileUrl = "https://cdn.jsdelivr.net/gh/Flow-Launcher/Flow.Launcher.PluginsManifest@plugin_api_v2/plugins.json";
+        private static readonly CommunityPluginStore mainPluginStore =
+            new("https://raw.githubusercontent.com/Flow-Launcher/Flow.Launcher.PluginsManifest/plugin_api_v2/plugins.json",
+                "https://fastly.jsdelivr.net/gh/Flow-Launcher/Flow.Launcher.PluginsManifest@plugin_api_v2/plugins.json",
+                "https://gcore.jsdelivr.net/gh/Flow-Launcher/Flow.Launcher.PluginsManifest@plugin_api_v2/plugins.json",
+                "https://cdn.jsdelivr.net/gh/Flow-Launcher/Flow.Launcher.PluginsManifest@plugin_api_v2/plugins.json");
 
         private static readonly SemaphoreSlim manifestUpdateLock = new(1);
 
-        private static string latestEtag = "";
+        private static DateTime lastFetchedAt = DateTime.MinValue;
+        private static TimeSpan fetchTimeout = TimeSpan.FromMinutes(2);
 
-        public static List<UserPlugin> UserPlugins { get; private set; } = new List<UserPlugin>();
+        public static List<UserPlugin> UserPlugins { get; private set; }
 
-        public static async Task UpdateManifestAsync(CancellationToken token = default)
+        public static async Task UpdateManifestAsync(CancellationToken token = default, bool usePrimaryUrlOnly = false)
         {
             try
             {
                 await manifestUpdateLock.WaitAsync(token).ConfigureAwait(false);
 
-                var request = new HttpRequestMessage(HttpMethod.Get, manifestFileUrl);
-                request.Headers.Add("If-None-Match", latestEtag);
-
-                using var response = await Http.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, token).ConfigureAwait(false);
-
-                if (response.StatusCode == HttpStatusCode.OK)
+                if (UserPlugins == null || usePrimaryUrlOnly || DateTime.Now.Subtract(lastFetchedAt) >= fetchTimeout)
                 {
-                    Log.Info($"|PluginsManifest.{nameof(UpdateManifestAsync)}|Fetched plugins from manifest repo");
-
-                    await using var json = await response.Content.ReadAsStreamAsync(token).ConfigureAwait(false);
+                    var results = await mainPluginStore.FetchAsync(token, usePrimaryUrlOnly).ConfigureAwait(false);
 
-                    UserPlugins = await JsonSerializer.DeserializeAsync<List<UserPlugin>>(json, cancellationToken: token).ConfigureAwait(false);
-
-                    latestEtag = response.Headers.ETag.Tag;
-                }
-                else if (response.StatusCode != HttpStatusCode.NotModified)
-                {
-                    Log.Warn($"|PluginsManifest.{nameof(UpdateManifestAsync)}|Http response for manifest file was {response.StatusCode}");
+                    UserPlugins = results;
+                    lastFetchedAt = DateTime.Now;
                 }
             }
             catch (Exception e)

Plugins/Flow.Launcher.Plugin.PluginsManager/Main.cs

@@ -1,4 +1,5 @@
-using Flow.Launcher.Plugin.PluginsManager.ViewModels;
+using Flow.Launcher.Core.ExternalPlugins;
+using Flow.Launcher.Plugin.PluginsManager.ViewModels;
 using Flow.Launcher.Plugin.PluginsManager.Views;
 using System.Collections.Generic;
 using System.Linq;
@@ -34,7 +35,7 @@ public async Task InitAsync(PluginInitContext context)
             contextMenu = new ContextMenu(Context);
             pluginManager = new PluginsManager(Context, Settings);
 
-            _ = pluginManager.UpdateManifestAsync();
+            await PluginsManifest.UpdateManifestAsync();
         }
 
         public List<Result> LoadContextMenus(Result selectedResult)
@@ -50,9 +51,9 @@ public async Task<List<Result>> QueryAsync(Query query, CancellationToken token)
             return query.FirstSearch.ToLower() switch
             {
                 //search could be url, no need ToLower() when passed in
-                Settings.InstallCommand => await pluginManager.RequestInstallOrUpdate(query.SecondToEndSearch, token),
+                Settings.InstallCommand => await pluginManager.RequestInstallOrUpdate(query.SecondToEndSearch, token, query.IsReQuery),
                 Settings.UninstallCommand => pluginManager.RequestUninstall(query.SecondToEndSearch),
-                Settings.UpdateCommand => await pluginManager.RequestUpdateAsync(query.SecondToEndSearch, token),
+                Settings.UpdateCommand => await pluginManager.RequestUpdateAsync(query.SecondToEndSearch, token, query.IsReQuery),
                 _ => pluginManager.GetDefaultHotKeys().Where(hotkey =>
                 {
                     hotkey.Score = StringMatcher.FuzzySearch(query.Search, hotkey.Title).Score;

Plugins/Flow.Launcher.Plugin.PluginsManager/PluginsManager.cs

@@ -49,26 +49,6 @@ internal PluginsManager(PluginInitContext context, Settings settings)
             Settings = settings;
         }
 
-        private Task _downloadManifestTask = Task.CompletedTask;
-
-        internal Task UpdateManifestAsync(CancellationToken token = default, bool silent = false)
-        {
-            if (_downloadManifestTask.Status == TaskStatus.Running)
-            {
-                return _downloadManifestTask;
-            }
-            else
-            {
-                _downloadManifestTask = PluginsManifest.UpdateManifestAsync(token);
-                if (!silent)
-                    _downloadManifestTask.ContinueWith(_ =>
-                            Context.API.ShowMsg(Context.API.GetTranslation("plugin_pluginsmanager_update_failed_title"),
-                                Context.API.GetTranslation("plugin_pluginsmanager_update_failed_subtitle"), icoPath, false),
-                        TaskContinuationOptions.OnlyOnFaulted);
-                return _downloadManifestTask;
-            }
-        }
-
         internal List<Result> GetDefaultHotKeys()
         {
             return new List<Result>()
@@ -182,9 +162,9 @@ internal async Task InstallOrUpdateAsync(UserPlugin plugin)
             Context.API.RestartApp();
         }
 
-        internal async ValueTask<List<Result>> RequestUpdateAsync(string search, CancellationToken token)
+        internal async ValueTask<List<Result>> RequestUpdateAsync(string search, CancellationToken token, bool usePrimaryUrlOnly = false)
         {
-            await UpdateManifestAsync(token);
+            await PluginsManifest.UpdateManifestAsync(token, usePrimaryUrlOnly);
 
             var resultsForUpdate =
                 from existingPlugin in Context.API.GetAllPlugins()
@@ -357,9 +337,9 @@ private bool InstallSourceKnown(string url)
             return url.StartsWith(acceptedSource) && Context.API.GetAllPlugins().Any(x => x.Metadata.Website.StartsWith(contructedUrlPart));
         }
 
-        internal async ValueTask<List<Result>> RequestInstallOrUpdate(string search, CancellationToken token)
+        internal async ValueTask<List<Result>> RequestInstallOrUpdate(string search, CancellationToken token, bool usePrimaryUrlOnly = false)
         {
-            await UpdateManifestAsync(token);
+            await PluginsManifest.UpdateManifestAsync(token, usePrimaryUrlOnly);
 
             if (Uri.IsWellFormedUriString(search, UriKind.Absolute)
                 && search.Split('.').Last() == zip)