message when cannot install

Introduces plugins loading in order of installation, BTCPay itself shows up as a system plugin, and that plugins can define other plugins as dependencies.

BTCPayServer.Abstractions/Contracts/IBTCPayServerPlugin.cs

@@ -14,8 +14,19 @@ namespace BTCPayServer.Contracts
         Version Version { get; }
         string Description { get; }
         bool SystemPlugin { get; set; }
-        string[] Dependencies { get; }
+        PluginDependency[] Dependencies { get; }
         void Execute(IApplicationBuilder applicationBuilder, IServiceProvider applicationBuilderApplicationServices);
         void Execute(IServiceCollection applicationBuilder);
+
+        public class PluginDependency
+        {
+            public string Identifier { get; set; }
+            public string Condition { get; set; }
+            public override string ToString()
+            {
+                return $"{Identifier}: {Condition}";
+            }
+        }
     }
+    
 }

BTCPayServer.Abstractions/Models/BaseBTCPayServerPlugin.cs

@@ -22,7 +22,7 @@ namespace BTCPayServer.Models
         public abstract string Description { get; }
         public bool SystemPlugin { get; set; }
         public bool SystemExtension { get; set; }
-        public virtual string[] Dependencies { get; } = Array.Empty<string>();
+        public virtual IBTCPayServerPlugin.PluginDependency[] Dependencies { get; } = Array.Empty<IBTCPayServerPlugin.PluginDependency>();
 
         public virtual void Execute(IApplicationBuilder applicationBuilder,
             IServiceProvider applicationBuilderApplicationServices)

BTCPayServer.Common/BTCPayNetwork.cs

@@ -25,7 +25,7 @@ namespace BTCPayServer
                 _Settings.Add(chainType, settings);
                 settings.DefaultDataDirectory = StandardConfiguration.DefaultDataDirectory.GetDirectory("BTCPayServer", NBXplorerDefaultSettings.GetFolderName(chainType));
                 settings.DefaultPluginDirectory =
-                    StandardConfiguration.DefaultDataDirectory.GetDirectory("BTCPayServer", "Extensions");
+                    StandardConfiguration.DefaultDataDirectory.GetDirectory("BTCPayServer", "Plugins");
                 settings.DefaultConfigurationFile = Path.Combine(settings.DefaultDataDirectory, "settings.config");
                 settings.DefaultPort = (chainType == NetworkType.Mainnet ? 23000 :
                                                       chainType == NetworkType.Regtest ? 23002 :

BTCPayServer.Tests/BTCPayServerTester.cs

@@ -206,9 +206,9 @@ namespace BTCPayServer.Tests
                 bitflyerMock.ExchangeRates.Add(new PairRate(CurrencyPair.Parse("BTC_JPY"), new BidAsk(700000m)));
                 rateProvider.Providers.Add("bitflyer", bitflyerMock);
 
-                var quadrigacx = new MockRateProvider();
-                quadrigacx.ExchangeRates.Add(new PairRate(CurrencyPair.Parse("BTC_CAD"), new BidAsk(6000m)));
-                rateProvider.Providers.Add("quadrigacx", quadrigacx);
+                var ndax = new MockRateProvider();
+                ndax.ExchangeRates.Add(new PairRate(CurrencyPair.Parse("BTC_CAD"), new BidAsk(6000m)));
+                rateProvider.Providers.Add("ndax", ndax);
 
                 var bittrex = new MockRateProvider();
                 bittrex.ExchangeRates.Add(new PairRate(CurrencyPair.Parse("DOGE_BTC"), new BidAsk(0.004m)));

BTCPayServer.Tests/UnitTest1.cs

@@ -1893,7 +1893,7 @@ namespace BTCPayServer.Tests
 
                 rateVm.ScriptTest = "BTC_USD,BTC_CAD,DOGE_USD,DOGE_CAD";
                 rateVm.Script = "DOGE_X = bittrex(DOGE_BTC) * BTC_X;\n" +
-                                "X_CAD = quadrigacx(X_CAD);\n" +
+                                "X_CAD = ndax(X_CAD);\n" +
                                 "X_X = coingecko(X_X);";
                 rateVm.Spread = 50;
                 rateVm = Assert.IsType<RatesViewModel>(Assert.IsType<ViewResult>(await store.Rates(rateVm, "Test"))

BTCPayServer/Configuration/BTCPayServerOptions.cs

@@ -241,9 +241,13 @@ namespace BTCPayServer.Configuration
             }
 
             DisableRegistration = conf.GetOrDefault<bool>("disable-registration", true);
+            PluginRemote = conf.GetOrDefault("plugin-remote", "btcpayserver/btcpayserver-plugins");
+            RecommendedPlugins = conf.GetOrDefault("recommended-plugins", "").ToLowerInvariant().Split('\r','\n','\t',' ').Where(s => !string.IsNullOrEmpty(s)).Distinct().ToArray();
         }
 
         public string PluginDir { get; set; }
+        public string PluginRemote { get; set; }
+        public string[] RecommendedPlugins { get; set; }
 
         private SSHSettings ParseSSHConfiguration(IConfiguration conf)
         {

BTCPayServer/Configuration/DefaultConfiguration.cs

@@ -43,6 +43,8 @@ namespace BTCPayServer.Configuration
             app.Option("--debuglog", "A rolling log file for debug messages.", CommandOptionType.SingleValue);
             app.Option("--debugloglevel", "The severity you log (default:information)", CommandOptionType.SingleValue);
             app.Option("--disable-registration", "Disables new user registrations (default:true)", CommandOptionType.SingleValue);
+            app.Option("--plugin-remote", "Which github repository to fetch the available plugins list (default:btcpayserver/btcpayserver-plugins)", CommandOptionType.SingleValue);
+            app.Option("--recommended-plugins", "Plugins which would be marked as recommended to be installed. Separated by newline or space", CommandOptionType.MultipleValue);
             app.Option("--xforwardedproto", "If specified, set X-Forwarded-Proto to the specified value, this may be useful if your reverse proxy handle https but is not configured to add X-Forwarded-Proto (example: --xforwardedproto https)", CommandOptionType.SingleValue);
             foreach (var network in provider.GetAll().OfType<BTCPayNetwork>())
             {

BTCPayServer/Controllers/AppsPublicController.cs

@@ -41,12 +41,13 @@ namespace BTCPayServer.Controllers
         [HttpGet("/apps/{appId}")]
         public async Task<IActionResult> RedirectToApp(string appId)
         {
-            switch (await _AppService.GetAppInfo(appId))
+           
+            switch ((await _AppService.GetApp(appId, null)).AppType)
             {
-                case ViewCrowdfundViewModel  _:
+                case nameof(AppType.Crowdfund):
                     return RedirectToAction("ViewCrowdfund", new {appId});
                 
-                case ViewPointOfSaleViewModel  _:
+                case nameof(AppType.PointOfSale):
                     return RedirectToAction("ViewPointOfSale", new {appId});
             }
 

BTCPayServer/Controllers/ServerController.Plugins.cs

@@ -16,13 +16,12 @@ namespace BTCPayServer.Controllers
         [HttpGet("server/plugins")]
         public async Task<IActionResult> ListPlugins(
             [FromServices] PluginService pluginService,
-            [FromServices] BTCPayServerOptions btcPayServerOptions,
-            string remote = "btcpayserver/btcpayserver-plugins")
+            [FromServices] BTCPayServerOptions btcPayServerOptions)
         {
             IEnumerable<PluginService.AvailablePlugin> availablePlugins;
             try
             {
-                availablePlugins = await pluginService.GetRemotePlugins(remote);
+                availablePlugins = await pluginService.GetRemotePlugins();
             }
             catch (Exception)
             {
@@ -37,7 +36,6 @@ namespace BTCPayServer.Controllers
             {
                 Installed = pluginService.LoadedPlugins,
                 Available = availablePlugins,
-                Remote = remote,
                 Commands = pluginService.GetPendingCommands(),
                 CanShowRestart = btcPayServerOptions.DockerDeployment
             };
@@ -46,7 +44,6 @@ namespace BTCPayServer.Controllers
 
         public class ListPluginsViewModel
         {
-            public string Remote { get; set; }
             public IEnumerable<IBTCPayServerPlugin> Installed { get; set; }
             public IEnumerable<PluginService.AvailablePlugin> Available { get; set; }
             public (string command, string plugin)[] Commands { get; set; }
@@ -82,12 +79,20 @@ namespace BTCPayServer.Controllers
 
         [HttpPost("server/plugins/install")]
         public async Task<IActionResult> InstallPlugin(
-            [FromServices] PluginService pluginService, string remote, string plugin)
+            [FromServices] PluginService pluginService, string plugin , bool update = false)
         {
             try
             {
-                await pluginService.DownloadRemotePlugin(remote, plugin);
-                pluginService.InstallPlugin(plugin);
+                await pluginService.DownloadRemotePlugin(plugin);
+                if (update)
+                {
+                    pluginService.UpdatePlugin(plugin);
+                }
+                else
+                {
+                    
+                    pluginService.InstallPlugin(plugin);
+                }
                 TempData.SetStatusMessageModel(new StatusMessageModel()
                 {
                     Message = "Plugin scheduled to be installed.",

BTCPayServer/Controllers/StoresController.cs

@@ -420,6 +420,7 @@ namespace BTCPayServer.Controllers
             }
             SetCryptoCurrencies(model, CurrentStore);
             model.SetLanguages(_LangService, model.DefaultLang);
+            model.PaymentMethodCriteria??= new List<PaymentMethodCriteriaViewModel>();
             for (var index = 0; index < model.PaymentMethodCriteria.Count; index++)
             {
                 var methodCriterion = model.PaymentMethodCriteria[index];
@@ -427,10 +428,12 @@ namespace BTCPayServer.Controllers
                 {
                     if (!CurrencyValue.TryParse(methodCriterion.Value, out var value))
                     {
-                        model.AddModelError(viewModel => viewModel.PaymentMethodCriteria[index].Value, $"{methodCriterion.PaymentMethod}: invalid format (1.0 USD)", this);
+                        model.AddModelError(viewModel => viewModel.PaymentMethodCriteria[index].Value,
+                            $"{methodCriterion.PaymentMethod}: invalid format (1.0 USD)", this);
                     }
                 }
             }
+            
 
             if (!ModelState.IsValid)
             {

BTCPayServer/Plugins/BTCPayServerPlugin.cs

@@ -0,0 +1,12 @@
+using BTCPayServer.Models;
+
+namespace BTCPayServer.Plugins
+{
+    public class BTCPayServerPlugin: BaseBTCPayServerPlugin
+    {
+        public override string Identifier { get; } = nameof(BTCPayServer);
+        public override string Name { get; } = "BTCPay Server";
+        public override string Description { get; }= "BTCPay Server core system";
+        
+    }
+}

BTCPayServer/Plugins/PluginManager.cs

@@ -30,10 +30,12 @@ namespace BTCPayServer.Plugins
             var pluginsFolder = config.GetPluginDir(DefaultConfiguration.GetNetworkType(config));
             var plugins = new List<IBTCPayServerPlugin>();
 
+
             _logger.LogInformation($"Loading plugins from {pluginsFolder}");
             Directory.CreateDirectory(pluginsFolder);
             ExecuteCommands(pluginsFolder);
-            List<(PluginLoader, Assembly, IFileProvider)> loadedPlugins = new List<(PluginLoader, Assembly, IFileProvider)>();
+            List<(PluginLoader, Assembly, IFileProvider)> loadedPlugins =
+                new List<(PluginLoader, Assembly, IFileProvider)>();
             var systemExtensions = GetDefaultLoadedPluginAssemblies();
             plugins.AddRange(systemExtensions.SelectMany(assembly =>
                 GetAllPluginTypesFromAssembly(assembly).Select(GetPluginInstanceFromType)));
@@ -41,7 +43,29 @@ namespace BTCPayServer.Plugins
             {
                 btcPayServerExtension.SystemPlugin = true;
             }
-            foreach (var dir in Directory.GetDirectories(pluginsFolder))
+
+            var orderFilePath = Path.Combine(pluginsFolder, "order");
+            var availableDirs = Directory.GetDirectories(pluginsFolder);
+            var orderedDirs = new List<string>();
+            if (File.Exists(orderFilePath))
+            {
+                var order = File.ReadLines(orderFilePath);
+                foreach (var s in order)
+                {
+                    if (availableDirs.Contains(s))
+                    {
+                        orderedDirs.Add(s);
+                    }
+                }
+
+                orderedDirs.AddRange(availableDirs.Where(s => !orderedDirs.Contains(s)));
+            }
+            else
+            {
+                orderedDirs = availableDirs.ToList();
+            }
+
+            foreach (var dir in orderedDirs)
             {
                 var pluginName = Path.GetFileName(dir);
 
@@ -71,7 +95,8 @@ namespace BTCPayServer.Plugins
                 }
                 catch (Exception e)
                 {
-                    _logger.LogError($"Error when loading plugin {plugin.Identifier} - {plugin.Version}{Environment.NewLine}{e.Message}");
+                    _logger.LogError(
+                        $"Error when loading plugin {plugin.Identifier} - {plugin.Version}{Environment.NewLine}{e.Message}");
                 }
             }
 
@@ -94,18 +119,17 @@ namespace BTCPayServer.Plugins
                     .Select(CreateEmbeddedFileProviderForAssembly));
             webHostEnvironment.WebRootFileProvider = new CompositeFileProvider(providers);
         }
+
         private static Assembly[] GetDefaultLoadedPluginAssemblies()
         {
-            return AppDomain.CurrentDomain.GetAssemblies().Where(assembly =>
-                    assembly?.FullName?.StartsWith("BTCPayServer.Plugins",
-                        StringComparison.InvariantCultureIgnoreCase) is true)
+            return AppDomain.CurrentDomain.GetAssemblies()
                 .ToArray();
         }
 
         private static Type[] GetAllPluginTypesFromAssembly(Assembly assembly)
         {
             return assembly.GetTypes().Where(type =>
-                typeof(IBTCPayServerPlugin).IsAssignableFrom(type) &&
+                typeof(IBTCPayServerPlugin).IsAssignableFrom(type) && type != typeof(PluginService.AvailablePlugin) &&
                 !type.IsAbstract).ToArray();
         }
 
@@ -130,15 +154,26 @@ namespace BTCPayServer.Plugins
             File.Delete(Path.Combine(pluginsFolder, "commands"));
         }
 
-        private static void ExecuteCommand((string command, string extension) command, string pluginsFolder)
+        private static void ExecuteCommand((string command, string extension) command, string pluginsFolder,
+            bool ignoreOrder = false)
         {
             var dirName = Path.Combine(pluginsFolder, command.extension);
             switch (command.command)
             {
+                case "update":
+                    ExecuteCommand(("delete", command.extension), pluginsFolder, true);
+                    ExecuteCommand(("install", command.extension), pluginsFolder, true);
+                    break;
                 case "delete":
                     if (Directory.Exists(dirName))
                     {
                         Directory.Delete(dirName, true);
+                        if (!ignoreOrder && File.Exists(Path.Combine(pluginsFolder, "order")))
+                        {
+                            var orders = File.ReadAllLines(Path.Combine(pluginsFolder, "order"));
+                            File.AppendAllLines(Path.Combine(pluginsFolder, "order"),
+                                orders.Where(s => s != command.extension));
+                        }
                     }
 
                     break;
@@ -147,6 +182,11 @@ namespace BTCPayServer.Plugins
                     if (File.Exists(fileName))
                     {
                         ZipFile.ExtractToDirectory(fileName, dirName, true);
+                        if (!ignoreOrder)
+                        {
+                            File.AppendAllLines(Path.Combine(pluginsFolder, "order"), new[] {command.extension});
+                        }
+
                         File.Delete(fileName);
                     }
 

BTCPayServer/Plugins/PluginService.cs

@@ -31,10 +31,10 @@ namespace BTCPayServer.Plugins
 
         public IEnumerable<IBTCPayServerPlugin> LoadedPlugins { get; }
 
-        public async Task<IEnumerable<AvailablePlugin>> GetRemotePlugins(string remote)
+        public async Task<IEnumerable<AvailablePlugin>> GetRemotePlugins()
         {
             var resp = await _githubClient
-                .GetStringAsync(new Uri($"https://api.github.com/repos/{remote}/contents"));
+                .GetStringAsync(new Uri($"https://api.github.com/repos/{_btcPayServerOptions.PluginRemote}/contents"));
             var files = JsonConvert.DeserializeObject<GithubFile[]>(resp);
             return await Task.WhenAll(files.Where(file => file.Name.EndsWith($"{PluginManager.BTCPayPluginSuffix}.json", StringComparison.InvariantCulture)).Select(async file =>
             {
@@ -43,11 +43,11 @@ namespace BTCPayServer.Plugins
             }));
         }
 
-        public async Task DownloadRemotePlugin(string remote, string plugin)
+        public async Task DownloadRemotePlugin(string plugin)
         {
             var dest = _btcPayServerOptions.PluginDir;
             var resp = await _githubClient
-                .GetStringAsync(new Uri($"https://api.github.com/repos/{remote}/contents"));
+                .GetStringAsync(new Uri($"https://api.github.com/repos/{_btcPayServerOptions.PluginRemote}/contents"));
             var files = JsonConvert.DeserializeObject<GithubFile[]>(resp);
             var ext = files.SingleOrDefault(file => file.Name == $"{plugin}{PluginManager.BTCPayPluginSuffix}");
             if (ext is null)
@@ -66,6 +66,11 @@ namespace BTCPayServer.Plugins
             UninstallPlugin(plugin);
             PluginManager.QueueCommands(dest, ("install", plugin));
         }
+        public void UpdatePlugin(string plugin)
+        {
+            var dest = _btcPayServerOptions.PluginDir;
+            PluginManager.QueueCommands(dest, ("update", plugin));
+        }
 
         public async Task UploadPlugin(IFormFile plugin)
         {
@@ -93,7 +98,7 @@ namespace BTCPayServer.Plugins
             public string Description { get; set; }
             public bool SystemPlugin { get; set; } = false;
 
-            public string[] Dependencies { get; } = Array.Empty<string>();
+            public IBTCPayServerPlugin.PluginDependency[] Dependencies { get; set; } = Array.Empty<IBTCPayServerPlugin.PluginDependency>();
 
             public void Execute(IApplicationBuilder applicationBuilder,
                 IServiceProvider applicationBuilderApplicationServices)

BTCPayServer/Properties/launchSettings.json

@@ -21,7 +21,8 @@
         "BTCPAY_TORRCFILE": "../BTCPayServer.Tests/TestData/Tor/torrc",
         "BTCPAY_SOCKSENDPOINT": "localhost:9050",
         "BTCPAY_UPDATEURL": "",
-        "BTCPAY_DOCKERDEPLOYMENT": "true"
+        "BTCPAY_DOCKERDEPLOYMENT": "true",
+        "BTCPAY_RECOMMENDED-PLUGINS": "BTCPayServer.Plugins.Test"
       },
       "applicationUrl": "http://127.0.0.1:14142/"
     },
@@ -53,7 +54,8 @@
         "BTCPAY_DEBUGLOG": "debug.log",
         "BTCPAY_TORRCFILE": "../BTCPayServer.Tests/TestData/Tor/torrc",
         "BTCPAY_SOCKSENDPOINT": "localhost:9050",
-        "BTCPAY_DOCKERDEPLOYMENT": "true"
+        "BTCPAY_DOCKERDEPLOYMENT": "true",
+        "BTCPAY_RECOMMENDED-PLUGINS": "BTCPayServer.Plugins.Test"
       },
       "applicationUrl": "https://localhost:14142/"
     },
@@ -87,7 +89,8 @@
         "BTCPAY_DEBUGLOG": "debug.log",
         "BTCPAY_TORRCFILE": "../BTCPayServer.Tests/TestData/Tor/torrc",
         "BTCPAY_SOCKSENDPOINT": "localhost:9050",
-        "BTCPAY_DOCKERDEPLOYMENT": "true"
+        "BTCPAY_DOCKERDEPLOYMENT": "true",
+        "BTCPAY_RECOMMENDED-PLUGINS": "BTCPayServer.Plugins.Test"
       },
       "applicationUrl": "https://localhost:14142/"
     }

BTCPayServer/Services/Apps/AppService.cs

@@ -248,13 +248,13 @@ namespace BTCPayServer.Services.Apps
             }
         }
 
-        public async Task<AppData> GetApp(string appId, AppType appType, bool includeStore = false)
+        public async Task<AppData> GetApp(string appId, AppType? appType, bool includeStore = false)
         {
             using (var ctx = _ContextFactory.CreateContext())
             {
                 var query = ctx.Apps
                     .Where(us => us.Id == appId &&
-                                 us.AppType == appType.ToString());
+                                 (appType == null || us.AppType == appType.ToString()));
 
                 if (includeStore)
                 {

BTCPayServer/Views/Server/ListPlugins.cshtml

@@ -1,8 +1,93 @@
+@using BTCPayServer.Configuration
+@using BTCPayServer.Contracts
 @model BTCPayServer.Controllers.ServerController.ListPluginsViewModel 
+@inject BTCPayServerOptions BTCPayServerOptions
 @{
     ViewData.SetActivePageAndTitle(ServerNavPages.Plugins);
-    var installed = Model.Installed.Select(plugin => plugin.Identifier);
-    var availableAndNotInstalled = Model.Available.Where(plugin => !installed.Contains(plugin.Identifier));
+    var installed = Model.Installed.ToDictionary(plugin => plugin.Identifier.ToLowerInvariant(), plugin => plugin.Version);
+    var availableAndNotInstalled = Model.Available.Where(plugin => !installed.ContainsKey(plugin.Identifier.ToLowerInvariant())).Select(plugin => (plugin,  BTCPayServerOptions.RecommendedPlugins.Contains(plugin.Identifier.ToLowerInvariant()))).OrderBy(tuple => tuple.Item1);
+
+    bool DependentOn(string plugin)
+    {
+        foreach (var installedPlugin in Model.Installed)
+        {
+            if (installedPlugin.Dependencies.Any(dep => dep.Identifier.Equals(plugin, StringComparison.InvariantCultureIgnoreCase)))
+            {
+                return true;
+            }
+        }
+
+        var pendingInstalls = Model.Commands.Where(tuple => tuple.command != "uninstall").Select(tuple => tuple.plugin).Distinct();
+        foreach (var pendingInstall in pendingInstalls)
+        {
+            if (Model.Available.Any(availablePlugin => availablePlugin.Identifier.Equals(pendingInstall, StringComparison.InvariantCultureIgnoreCase) &&
+                                                       availablePlugin.Dependencies.Any(dep => dep.Identifier.Equals(plugin, StringComparison.InvariantCultureIgnoreCase))))
+            {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    bool DependencyMet(IBTCPayServerPlugin.PluginDependency dependency)
+    {
+        var plugin = dependency.Identifier.ToLowerInvariant();
+        var versionReq = dependency.Condition;
+        if (!installed.ContainsKey(plugin) && !versionReq.Equals("!"))
+        {
+            return false;
+        }
+        if (installed.ContainsKey(plugin) && versionReq.Equals("!"))
+        {
+            return false;
+        }
+
+        var versionConditions = versionReq.Split("||", StringSplitOptions.RemoveEmptyEntries);
+        return versionConditions.Any(s =>
+        {
+            s = s.Trim();
+            var v = s.Substring(1);
+            if (s[1] == '=')
+            {
+                v = s.Substring(2);
+            }
+            var parsedV = Version.Parse(v);
+            switch (s)
+            {
+                case { } xx when xx.StartsWith(">="):
+                    return installed[plugin] >= parsedV;
+                case { } xx when xx.StartsWith("<="):
+                    return installed[plugin] <= parsedV;
+                case { } xx when xx.StartsWith(">"):
+                    return installed[plugin] > parsedV;
+                case { } xx when xx.StartsWith("<"):
+                    return installed[plugin] >= parsedV;
+                case { } xx when xx.StartsWith("^"):
+                    return installed[plugin] >= parsedV && installed[plugin].Major == parsedV.Major;
+                case { } xx when xx.StartsWith("~"):
+                    return installed[plugin] >= parsedV && installed[plugin].Major == parsedV.Major && installed[plugin].Minor == parsedV.Minor;
+                case { } xx when xx.StartsWith("!="):
+                    return installed[plugin] != parsedV;
+                case { } xx when xx.StartsWith("=="):
+                default:
+                    return installed[plugin] == parsedV;
+            }
+        });
+    }
+
+    bool DependenciesMet(IBTCPayServerPlugin.PluginDependency[] dependencies)
+    {
+        foreach (var dependency in dependencies)
+        {
+            if (!DependencyMet(dependency))
+            {
+                return false;
+            }
+            ;
+        }
+        return true;
+    }
+
 }
 
 <partial name="_StatusMessage"/>
@@ -27,28 +112,94 @@
         @foreach (var plugin in Model.Installed)
         {
             var matchedAvailable = Model.Available.SingleOrDefault(availablePlugin => availablePlugin.Identifier == plugin.Identifier);
-            var updateAvailable = matchedAvailable != null && plugin.Version < matchedAvailable.Version;
+            var updateAvailable = !plugin.SystemPlugin && matchedAvailable != null && plugin.Version < matchedAvailable.Version;
             <div class="col col-12 col-lg-6 mb-4">
                 <div class="card h-100">
                     <div class="card-body">
-                        <h4 class="card-title">@plugin.Name</h4>
-                        <h5 class="card-subtitle mb-3 text-muted d-flex align-items-center">
-                            @plugin.Version
-                            @if (plugin.SystemPlugin)
+                        <div class="row">
+                            <div class="col-xs-12 col-md-6">
+                                <h4 class="card-title" title="@plugin.Identifier" data-toggle="tooltip">@plugin.Name</h4>
+                                <h5 class="card-subtitle mb-3 text-muted d-flex align-items-center">
+
+                                    @plugin.Version
+                                    @if (plugin.SystemPlugin)
+                                    {
+                                        <div class="badge badge-secondary ml-2">System plugin</div>
+                                    }
+                                    else if (updateAvailable)
+                                    {
+                                        <div class="badge badge-secondary ml-2">@matchedAvailable.Version available</div>
+                                    }
+                                </h5>
+                            </div>
+                            @if (updateAvailable)
                             {
-                                <div class="badge badge-secondary ml-2">System plugin</div>
+                                <ul class="nav nav-pills col-xs-12 col-md-6 text-right">
+                                    <li class="nav-item">
+                                        <a data-toggle="tab" href="#@plugin.Identifier.ToLowerInvariant().Replace(".", "_")-current" class="nav-link show active">Current</a>
+                                    </li>
+                                    <li class="nav-item">
+                                        <a data-toggle="tab" href="#@plugin.Identifier.ToLowerInvariant().Replace(".", "_")-update" class="nav-link">Update</a>
+                                    </li>
+                                </ul>
                             }
-                            else if (updateAvailable)
+                        </div>
+
+
+                        <div class="tab-content">
+                            <div class="tab-pane show active" id="@plugin.Identifier.ToLowerInvariant().Replace(".", "_")-current">
+                                <p class="card-text">@plugin.Description</p>
+
+                                @if (plugin.Dependencies.Any())
+                                {
+                                    <h5 class=" text-muted">Dependencies</h5>
+                                    <ul class="list-group list-group-flush">
+                                        @foreach (var dependency in plugin.Dependencies)
+                                        {
+                                            <li class="list-group-item">
+                                                @dependency
+                                                @if (!DependencyMet(dependency))
+                                                {
+                                                    <span title="Dependency not met." data-toggle="tooltip" class="fa fa-warning text-danger"></span>
+                                                }
+                                            </li>
+                                        }
+                                    </ul>
+                                }
+                            </div>
+
+                            @if (updateAvailable)
                             {
-                                <div class="badge badge-secondary ml-2">@matchedAvailable.Version available</div>
+                                <div class="tab-pane" id="@plugin.Identifier.ToLowerInvariant().Replace(".", "_")-update">
+                                    <p class="card-text">@matchedAvailable.Description</p>
+
+                                    @if (matchedAvailable.Dependencies.Any())
+                                    {
+                                        <h5 class=" text-muted">Dependencies</h5>
+                                        <ul class="list-group list-group-flush">
+                                            @foreach (var dependency in matchedAvailable.Dependencies)
+                                            {
+                                                <li class="list-group-item ">
+                                                    @dependency
+                                                    @if (!DependencyMet(dependency))
+                                                    {
+                                                        <span title="Dependency not met." data-toggle="tooltip" class="fa fa-warning text-danger"></span>
+                                                    }
+                                                </li>
+                                            }
+                                        </ul>
+                                    }
+                                </div>
                             }
-                        </h5>
-                        <p class="card-text">@plugin.Description</p>
+                        </div>
                     </div>
-                    @if (!plugin.SystemPlugin)
+                    @{
+                        var pendingAction = Model.Commands.Any(tuple => tuple.plugin.Equals(plugin.Identifier, StringComparison.InvariantCultureIgnoreCase));
+                    }
+                    @if (!plugin.SystemPlugin && (pendingAction || (updateAvailable && DependenciesMet(matchedAvailable.Dependencies)) || !DependentOn(plugin.Identifier)))
                     {
                         <div class="card-footer border-0 pb-3 d-flex">
-                            @if (Model.Commands.Any(tuple => tuple.plugin.Equals(plugin.Identifier, StringComparison.InvariantCultureIgnoreCase)))
+                            @if (pendingAction)
                             {
                                 <form asp-action="CancelPluginCommands" asp-route-plugin="@plugin.Identifier">
                                     <button type="submit" class="btn btn-outline-secondary">Cancel pending action</button>
@@ -56,15 +207,22 @@
                             }
                             else
                             {
-                                @if (updateAvailable)
+                                @if (updateAvailable && DependenciesMet(matchedAvailable.Dependencies))
                                 {
-                                    <form asp-action="InstallPlugin" asp-route-plugin="@plugin.Identifier" asp-route-remote="@Model.Remote" class="mr-3">
+                                    <form asp-action="InstallPlugin" asp-route-plugin="@plugin.Identifier" asp-route-update="true" class="mr-3">
                                         <button type="submit" class="btn btn-secondary">Update</button>
                                     </form>
                                 }
-                                <form asp-action="UnInstallPlugin" asp-route-plugin="@plugin.Identifier">
-                                    <button type="submit" class="btn btn-outline-danger">Uninstall</button>
-                                </form>
+                                @if (DependentOn(plugin.Identifier))
+                                {
+                                    <button type="button" class="btn btn-outline-danger" data-toggle="tooltip" title="This plugin cannot be uninstalled as it is depended on by other plugins.">Uninstall <span class="fa fa-exclamation"></span></button>
+                                }
+                                else
+                                {
+                                    <form asp-action="UnInstallPlugin" asp-route-plugin="@plugin.Identifier">
+                                        <button type="submit" class="btn btn-outline-danger">Uninstall</button>
+                                    </form>
+                                }
                             }
                         </div>
                     }
@@ -77,28 +235,61 @@
 {
     <h3 class="mb-3">Available Plugins</h3>
     <div class="row mb-4">
-        @foreach (var plugin in availableAndNotInstalled)
+        @foreach (var pluginT in availableAndNotInstalled)
         {
+            var plugin = pluginT.Item1;
             <div class="col col-12 col-lg-6 mb-4">
                 <div class="card h-100">
                     <div class="card-body">
-                        <h4 class="card-title">@plugin.Name</h4>
-                        <h5 class="card-subtitle mb-3 text-muted">@plugin.Version</h5>
+                        <h4 class="card-title" data-toggle="tooltip" title="@plugin.Identifier">@plugin.Name</h4>
+                        <h5 class="card-subtitle mb-3 text-muted d-flex justify-content-between">
+                            <span>@plugin.Version</span>
+                            @if (pluginT.Item2)
+                            {
+                                <span data-toggle="tooltip" title="This plugin has been recommended to be installed by your deployment method.">Recommended <span class="fa fa-question-circle-o"></span></span>
+                            }
+                        </h5>
                         <p class="card-text">@plugin.Description</p>
+                        @if (plugin.Dependencies?.Any() is true)
+                        {
+                            <h5 class=" text-muted">Dependencies</h5>
+                            <ul class="list-group list-group-flush">
+
+                                @foreach (var dependency in plugin.Dependencies)
+                                {
+                                    <li class="list-group-item">
+                                        @dependency
+                                        @if (!DependencyMet(dependency))
+                                        {
+                                            <span title="Dependency not met." data-toggle="tooltip" class="fa fa-warning text-danger"></span>
+                                        }
+                                    </li>
+                                }
+                            </ul>
+                        }
                     </div>
+                    @{
+                        var pending = Model.Commands.Any(tuple => tuple.plugin.Equals(plugin.Identifier, StringComparison.InvariantCultureIgnoreCase));
+                    }
                     <div class="card-footer border-0 pb-3">
-                        @if (Model.Commands.Any(tuple => tuple.plugin.Equals(plugin.Identifier, StringComparison.InvariantCultureIgnoreCase)))
+                        @if (pending)
                         {
                             <form asp-action="CancelPluginCommands" asp-route-plugin="@plugin.Identifier">
                                 <button type="submit" class="btn btn-outline-secondary">Cancel pending install</button>
                             </form>
                         }
-                        else
+                        else if (DependenciesMet(plugin.Dependencies))
                         {
-                            <form asp-action="InstallPlugin" asp-route-plugin="@plugin.Identifier" asp-route-remote="@Model.Remote">
+                            <form asp-action="InstallPlugin" asp-route-plugin="@plugin.Identifier">
                                 <button type="submit" class="btn btn-primary">Install</button>
                             </form>
                         }
+                        else
+                        {
+                            <span class="text-danger">
+                                Cannot install until dependencies are met
+                            </span>
+                        }
                     </div>
                 </div>
             </div>

BTCPayServer/Views/Server/Policies.cshtml

@@ -1,5 +1,7 @@
 @using BTCPayServer.Services
+@using BTCPayServer.Services.Mails;
 @model BTCPayServer.Services.PoliciesSettings
+@inject BTCPayServer.Services.SettingsRepository _SettingsRepository
 @{
     ViewData.SetActivePageAndTitle(ServerNavPages.Policies);
 }
@@ -14,9 +16,22 @@
 <form method="post">
     <div class="form-group">
         <div class="form-check">
-            <input asp-for="RequiresConfirmedEmail" type="checkbox" class="form-check-input"/>
+            @{
+                var emailSettings = (await _SettingsRepository.GetSettingAsync<EmailSettings>()) ?? new EmailSettings();
+                /**
+                 * The "|| Model.RequiresConfirmedEmail" check is for the case when a user had checked
+                 * the checkbox without first configuring the e-mail settings so that they can uncheck it.
+                 **/
+                var isEmailConfigured = emailSettings.IsComplete() || Model.RequiresConfirmedEmail;
+            }
+            <input asp-for="RequiresConfirmedEmail" type="checkbox" class="form-check-input" disabled="@(isEmailConfigured ? null : "disabled")" />
             <label asp-for="RequiresConfirmedEmail" class="form-check-label"></label>
             <span asp-validation-for="RequiresConfirmedEmail" class="text-danger"></span>
+            @if (!isEmailConfigured) {
+                <div>
+                    <span class="text-secondary">Your email server has not been configured. <a asp-controller="Server" asp-action="Emails">Please configure it first.</a></span>
+                </div>
+            }
         </div>
         <div class="form-check">
             <input asp-for="LockSubscription" type="checkbox" class="form-check-input"/>

BTCPayServer/Views/Stores/Rates.cshtml

@@ -105,10 +105,10 @@
                             X_X = kraken(X_X);
                         </code>
                     </pre>
-                    <p>However, <code>kraken</code> does not support the <code>BTC_CAD</code> pair. For this reason you can add a rule mapping all <code>X_CAD</code> to <code>quadrigacx</code>, a Canadian exchange.</p>
+                    <p>However, <code>kraken</code> does not support the <code>BTC_CAD</code> pair. For this reason you can add a rule mapping all <code>X_CAD</code> to <code>ndax</code>, a Canadian exchange.</p>
                     <pre>
                     <code>
-                            X_CAD = quadrigacx(X_CAD);
+                            X_CAD = ndax(X_CAD);
                             X_X = kraken(X_X);
                         </code>
                     </pre>
@@ -120,19 +120,19 @@
                     <pre>
                     <code>
                             DOGE_X = bittrex(DOGE_BTC) * BTC_X
-                            X_CAD = quadrigacx(X_CAD);
+                            X_CAD = ndax(X_CAD);
                             X_X = kraken(X_X);
                         </code>
                     </pre>
                     <p>
-                        With <code>DOGE_USD</code> will be expanded to <code>bittrex(DOGE_BTC) * kraken(BTC_USD)</code>. And <code>DOGE_CAD</code> will be expanded to <code>bittrex(DOGE_BTC) * quadrigacx(BTC_CAD)</code>. <br />
+                        With <code>DOGE_USD</code> will be expanded to <code>bittrex(DOGE_BTC) * kraken(BTC_USD)</code>. And <code>DOGE_CAD</code> will be expanded to <code>bittrex(DOGE_BTC) * ndax(BTC_CAD)</code>. <br />
                         However, we advise you to write it that way to increase coverage so that <code>DOGE_BTC</code> is also supported:
                     </p>
                     <pre>
                     <code>
                             DOGE_X = DOGE_BTC * BTC_X
                             DOGE_BTC = bittrex(DOGE_BTC)
-                            X_CAD = quadrigacx(X_CAD);
+                            X_CAD = ndax(X_CAD);
                             X_X = kraken(X_X);
                         </code>
                     </pre>

BTCPayServer/Views/Stores/UpdateStore.cshtml

@@ -246,12 +246,20 @@
                             <span class="fa fa-question-circle-o" title="More information..."></span>
                         </a>
                     </div>
-                    <select asp-for="SpeedPolicy" class="form-control w-auto">
+                    <script>
+                        function handleSpeedPolicyChange(select) {
+                            document.getElementById('unconfirmed-warning').hidden = select.value !== '0';
+                        }
+                    </script>
+                    <select asp-for="SpeedPolicy" class="form-control w-auto" onchange="handleSpeedPolicyChange(this)">
                         <option value="0">Is unconfirmed</option>
                         <option value="1">Has at least 1 confirmation</option>
                         <option value="3">Has at least 2 confirmations</option>
                         <option value="2">Has at least 6 confirmations</option>
                     </select>
+                    <div class="alert alert-warning my-2" hidden="@(Model.SpeedPolicy != 0)" id="unconfirmed-warning" role="alert">
+                        Choosing to accept an unconfirmed invoice can lead to double-spending and is strongly discouraged.
+                    </div>
                     <span asp-validation-for="SpeedPolicy" class="text-danger"></span>
                     <button name="command" type="submit" class="btn btn-primary mt-3" value="Save" id="Save">Save Store Settings</button>
                 </div>

amd64.Dockerfile

@@ -3,6 +3,7 @@ ENV DOTNET_CLI_TELEMETRY_OPTOUT=1
 WORKDIR /source
 COPY nuget.config nuget.config
 COPY Build/Common.csproj Build/Common.csproj
+COPY BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj
 COPY BTCPayServer/BTCPayServer.csproj BTCPayServer/BTCPayServer.csproj
 COPY BTCPayServer.Common/BTCPayServer.Common.csproj BTCPayServer.Common/BTCPayServer.Common.csproj
 COPY BTCPayServer.Rating/BTCPayServer.Rating.csproj BTCPayServer.Rating/BTCPayServer.Rating.csproj
@@ -13,6 +14,7 @@ COPY BTCPayServer.Common/. BTCPayServer.Common/.
 COPY BTCPayServer.Rating/. BTCPayServer.Rating/.
 COPY BTCPayServer.Data/. BTCPayServer.Data/.
 COPY BTCPayServer.Client/. BTCPayServer.Client/.
+COPY BTCPayServer.Abstractions/. BTCPayServer.Abstractions/.
 COPY BTCPayServer/. BTCPayServer/.
 COPY Build/Version.csproj Build/Version.csproj
 ARG CONFIGURATION_NAME=Release

arm32v7.Dockerfile

@@ -7,6 +7,7 @@ RUN apt-get update \
 WORKDIR /source
 COPY nuget.config nuget.config
 COPY Build/Common.csproj Build/Common.csproj
+COPY BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj
 COPY BTCPayServer/BTCPayServer.csproj BTCPayServer/BTCPayServer.csproj
 COPY BTCPayServer.Common/BTCPayServer.Common.csproj BTCPayServer.Common/BTCPayServer.Common.csproj
 COPY BTCPayServer.Rating/BTCPayServer.Rating.csproj BTCPayServer.Rating/BTCPayServer.Rating.csproj
@@ -17,6 +18,7 @@ COPY BTCPayServer.Common/. BTCPayServer.Common/.
 COPY BTCPayServer.Rating/. BTCPayServer.Rating/.
 COPY BTCPayServer.Data/. BTCPayServer.Data/.
 COPY BTCPayServer.Client/. BTCPayServer.Client/.
+COPY BTCPayServer.Abstractions/. BTCPayServer.Abstractions/.
 COPY BTCPayServer/. BTCPayServer/.
 COPY Build/Version.csproj Build/Version.csproj
 ARG CONFIGURATION_NAME=Release

arm64v8.Dockerfile

@@ -8,6 +8,7 @@ RUN apt-get update \
 WORKDIR /source
 COPY nuget.config nuget.config
 COPY Build/Common.csproj Build/Common.csproj
+COPY BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj BTCPayServer.Abstractions/BTCPayServer.Abstractions.csproj
 COPY BTCPayServer/BTCPayServer.csproj BTCPayServer/BTCPayServer.csproj
 COPY BTCPayServer.Common/BTCPayServer.Common.csproj BTCPayServer.Common/BTCPayServer.Common.csproj
 COPY BTCPayServer.Rating/BTCPayServer.Rating.csproj BTCPayServer.Rating/BTCPayServer.Rating.csproj
@@ -18,6 +19,7 @@ COPY BTCPayServer.Common/. BTCPayServer.Common/.
 COPY BTCPayServer.Rating/. BTCPayServer.Rating/.
 COPY BTCPayServer.Data/. BTCPayServer.Data/.
 COPY BTCPayServer.Client/. BTCPayServer.Client/.
+COPY BTCPayServer.Abstractions/. BTCPayServer.Abstractions/.
 COPY BTCPayServer/. BTCPayServer/.
 COPY Build/Version.csproj Build/Version.csproj
 ARG CONFIGURATION_NAME=Release