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.

4 files changed, 19 insertions, 6 deletions

diff --git a/src/SMAPI/Framework/IModMetadata.cs b/src/SMAPI/Framework/IModMetadata.cs
index 85d1b619..a62c9950 100644
--- a/src/SMAPI/Framework/IModMetadata.cs
+++ b/src/SMAPI/Framework/IModMetadata.cs
@@ -18,6 +18,9 @@ namespace StardewModdingAPI.Framework
         /// <summary>The mod's full directory path.</summary>
         string DirectoryPath { get; }
 
+        /// <summary>The <see cref="DirectoryPath"/> relative to the game's Mods folder.</summary>
+        string RelativeDirectoryPath { get; }
+
         /// <summary>Metadata about the mod from SMAPI's internal data (if any).</summary>
         ModDataRecordVersionedFields DataRecord { get; }
 
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))}).");
                     }
                 }
             }
diff --git a/src/SMAPI/Framework/SCore.cs b/src/SMAPI/Framework/SCore.cs
index 2c5cd2bd..af517379 100644
--- a/src/SMAPI/Framework/SCore.cs
+++ b/src/SMAPI/Framework/SCore.cs
@@ -908,7 +908,7 @@ namespace StardewModdingAPI.Framework
             }
 
             // validate dependencies
-            // Although dependences are validated before mods are loaded, a dependency may have failed.
+            // Although dependences are validated before mods are loaded, a dependency may have failed to load.
             if (mod.Manifest.Dependencies?.Any() == true)
             {
                 foreach (IManifestDependency dependency in mod.Manifest.Dependencies)
@@ -955,7 +955,6 @@ namespace StardewModdingAPI.Framework
                 catch (IncompatibleInstructionException) // details already in trace logs
                 {
                     string[] updateUrls = new[] { modDatabase.GetModPageUrlFor(manifest.UniqueID), "https://smapi.io/compat" }.Where(p => p != null).ToArray();
-
                     errorReasonPhrase = $"it's no longer compatible. Please check for a new version at {string.Join(" or ", updateUrls)}.";
                     return false;
                 }
@@ -1050,13 +1049,18 @@ namespace StardewModdingAPI.Framework
                 this.Monitor.Log("      These mods could not be added to your game.", LogLevel.Error);
                 this.Monitor.Newline();
 
+                HashSet<string> logged = new HashSet<string>();
                 foreach (var pair in skippedMods.OrderBy(p => p.Key.DisplayName))
                 {
                     IModMetadata mod = pair.Key;
                     string errorReason = pair.Value.Item1;
                     string errorDetails = pair.Value.Item2;
+                    string message = $"      - {mod.DisplayName}{(mod.Manifest?.Version != null ? " " + mod.Manifest.Version.ToString() : "")} because {errorReason}";
+
+                    if (!logged.Add($"{message}|{errorDetails}"))
+                        continue; // skip duplicate messages (e.g. if multiple copies of the mod are installed)
 
-                    this.Monitor.Log($"      - {mod.DisplayName}{(mod.Manifest?.Version != null ? " " + mod.Manifest.Version.ToString() : "")} because {errorReason}", LogLevel.Error);
+                    this.Monitor.Log(message, LogLevel.Error);
                     if (errorDetails != null)
                         this.Monitor.Log($"        ({errorDetails})", LogLevel.Trace);
                 }