From 9ccb6af61b4cd95ffcbde3b3cc2fe5fe4847c26c Mon Sep 17 00:00:00 2001
From: Bogdan <mynameisbogdan@users.noreply.github.com>
Date: Wed, 25 Oct 2023 15:11:41 +0300
Subject: [PATCH] New: Add Download Client validation for indexers

(cherry picked from commit e53b7f8c945e3597ca1719961e82540f1f01f0e9)

Closes #4246
---
 .../Indexers/IndexerController.cs             |  4 ++-
 .../DownloadClientExistsValidator.cs          | 27 +++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)
 create mode 100644 src/NzbDrone.Core/Validation/DownloadClientExistsValidator.cs

diff --git a/src/Lidarr.Api.V1/Indexers/IndexerController.cs b/src/Lidarr.Api.V1/Indexers/IndexerController.cs
index 101faf018..2ebcd3f29 100644
--- a/src/Lidarr.Api.V1/Indexers/IndexerController.cs
+++ b/src/Lidarr.Api.V1/Indexers/IndexerController.cs
@@ -1,5 +1,6 @@
 using Lidarr.Http;
 using NzbDrone.Core.Indexers;
+using NzbDrone.Core.Validation;
 
 namespace Lidarr.Api.V1.Indexers
 {
@@ -9,9 +10,10 @@ namespace Lidarr.Api.V1.Indexers
         public static readonly IndexerResourceMapper ResourceMapper = new ();
         public static readonly IndexerBulkResourceMapper BulkResourceMapper = new ();
 
-        public IndexerController(IndexerFactory indexerFactory)
+        public IndexerController(IndexerFactory indexerFactory, DownloadClientExistsValidator downloadClientExistsValidator)
             : base(indexerFactory, "indexer", ResourceMapper, BulkResourceMapper)
         {
+            SharedValidator.RuleFor(c => c.DownloadClientId).SetValidator(downloadClientExistsValidator);
         }
     }
 }
diff --git a/src/NzbDrone.Core/Validation/DownloadClientExistsValidator.cs b/src/NzbDrone.Core/Validation/DownloadClientExistsValidator.cs
new file mode 100644
index 000000000..cf021f464
--- /dev/null
+++ b/src/NzbDrone.Core/Validation/DownloadClientExistsValidator.cs
@@ -0,0 +1,27 @@
+using FluentValidation.Validators;
+using NzbDrone.Core.Download;
+
+namespace NzbDrone.Core.Validation
+{
+    public class DownloadClientExistsValidator : PropertyValidator
+    {
+        private readonly IDownloadClientFactory _downloadClientFactory;
+
+        public DownloadClientExistsValidator(IDownloadClientFactory downloadClientFactory)
+        {
+            _downloadClientFactory = downloadClientFactory;
+        }
+
+        protected override string GetDefaultMessageTemplate() => "Download Client does not exist";
+
+        protected override bool IsValid(PropertyValidatorContext context)
+        {
+            if (context?.PropertyValue == null || (int)context.PropertyValue == 0)
+            {
+                return true;
+            }
+
+            return _downloadClientFactory.Exists((int)context.PropertyValue);
+        }
+    }
+}