make duplicate-mod more intuitive

The error now shows the relative folder paths (instead of manifest IDs), and only one error will be logged instead of one per duplicate.

2 files changed, 9 insertions, 3 deletions

diff --git a/src/SMAPI/Framework/ModLoading/ModMetadata.cs b/src/SMAPI/Framework/ModLoading/ModMetadata.cs
index c02f0830..0a5f5d3f 100644
--- a/src/SMAPI/Framework/ModLoading/ModMetadata.cs
+++ b/src/SMAPI/Framework/ModLoading/ModMetadata.cs
@@ -19,6 +19,9 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <summary>The mod's full directory path.</summary>
         public string DirectoryPath { get; }
 
+        /// <summary>The <see cref="IModMetadata.DirectoryPath"/> relative to the game's Mods folder.</summary>
+        public string RelativeDirectoryPath { get; }
+
         /// <summary>The mod manifest.</summary>
         public IManifest Manifest { get; }
 
@@ -59,12 +62,14 @@ namespace StardewModdingAPI.Framework.ModLoading
         /// <summary>Construct an instance.</summary>
         /// <param name="displayName">The mod's display name.</param>
         /// <param name="directoryPath">The mod's full directory path.</param>
+        /// <param name="relativeDirectoryPath">The <paramref name="directoryPath"/> relative to the game's Mods folder.</param>
         /// <param name="manifest">The mod manifest.</param>
         /// <param name="dataRecord">Metadata about the mod from SMAPI's internal data (if any).</param>
-        public ModMetadata(string displayName, string directoryPath, IManifest manifest, ModDataRecordVersionedFields dataRecord)
+        public ModMetadata(string displayName, string directoryPath, string relativeDirectoryPath, IManifest manifest, ModDataRecordVersionedFields dataRecord)
         {
             this.DisplayName = displayName;
             this.DirectoryPath = directoryPath;
+            this.RelativeDirectoryPath = relativeDirectoryPath;
             this.Manifest = manifest;
             this.DataRecord = dataRecord;
         }
diff --git a/src/SMAPI/Framework/ModLoading/ModResolver.cs b/src/SMAPI/Framework/ModLoading/ModResolver.cs
index 65a311dc..26ec82d7 100644
--- a/src/SMAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/SMAPI/Framework/ModLoading/ModResolver.cs
@@ -41,7 +41,8 @@ namespace StardewModdingAPI.Framework.ModLoading
                 ModMetadataStatus status = folder.ManifestParseError == null
                     ? ModMetadataStatus.Found
                     : ModMetadataStatus.Failed;
-                yield return new ModMetadata(folder.DisplayName, folder.Directory.FullName, manifest, dataRecord).SetStatus(status, folder.ManifestParseError);
+                string relativePath = PathUtilities.GetRelativePath(rootPath, folder.Directory.FullName);
+                yield return new ModMetadata(folder.DisplayName, folder.Directory.FullName, relativePath, manifest, dataRecord).SetStatus(status, folder.ManifestParseError);
             }
         }
 
@@ -188,7 +189,7 @@ namespace StardewModdingAPI.Framework.ModLoading
                     {
                         if (mod.Status == ModMetadataStatus.Failed)
                             continue; // don't replace metadata error
-                        mod.SetStatus(ModMetadataStatus.Failed, $"its unique ID '{mod.Manifest.UniqueID}' is used by multiple mods ({string.Join(", ", group.Select(p => p.DisplayName))}).");
+                        mod.SetStatus(ModMetadataStatus.Failed, $"you have multiple copies of this mod installed ({string.Join(", ", group.Select(p => p.RelativeDirectoryPath).OrderBy(p => p))}).");
                     }
                 }
             }