list broken dependencies first in 'skipped mods' list

docs/release-notes.md

@@ -6,6 +6,7 @@
 * For players:
   * Added friendly log message for save file-not-found errors.
   * Updated for the 'Force Off' gamepad mode added in Stardew Valley 1.4.1.
+  * The 'skipped mods' list now shows broken dependencies first, so it's easier to see which ones to fix first.
   * Fixed compatibility with Linux Mint 18 (thanks to techge!) and Arch Linux.
   * Fixed compatibility with Linux systems which have libhybris-utils installed.
   * Fixes for the bundled Console Commands mod:

src/SMAPI/Framework/IModMetadata.cs

@@ -105,6 +105,10 @@ namespace StardewModdingAPI.Framework
         /// <param name="validOnly">Only return valid update keys.</param>
         IEnumerable<UpdateKey> GetUpdateKeys(bool validOnly = true);
 
+        /// <summary>Get the mod IDs that must be installed to load this mod.</summary>
+        /// <param name="includeOptional">Whether to include optional dependencies.</param>
+        IEnumerable<string> GetRequiredModIds(bool includeOptional = false);
+
         /// <summary>Whether the mod has at least one valid update key set.</summary>
         bool HasValidUpdateKeys();
 

src/SMAPI/Framework/ModLoading/ModMetadata.cs

@@ -188,6 +188,27 @@ namespace StardewModdingAPI.Framework.ModLoading
             }
         }
 
+        /// <summary>Get the mod IDs that must be installed to load this mod.</summary>
+        /// <param name="includeOptional">Whether to include optional dependencies.</param>
+        public IEnumerable<string> GetRequiredModIds(bool includeOptional = false)
+        {
+            HashSet<string> required = new HashSet<string>(StringComparer.InvariantCultureIgnoreCase);
+
+            // yield dependencies
+            if (this.Manifest?.Dependencies != null)
+            {
+                foreach (var entry in this.Manifest?.Dependencies)
+                {
+                    if ((entry.IsRequired || includeOptional) && required.Add(entry.UniqueID))
+                        yield return entry.UniqueID;
+                }
+            }
+
+            // yield content pack parent
+            if (this.Manifest?.ContentPackFor?.UniqueID != null && required.Add(this.Manifest.ContentPackFor.UniqueID))
+                yield return this.Manifest.ContentPackFor.UniqueID;
+        }
+
         /// <summary>Whether the mod has at least one valid update key set.</summary>
         public bool HasValidUpdateKeys()
         {

src/SMAPI/Framework/SCore.cs

@@ -1046,26 +1046,48 @@ namespace StardewModdingAPI.Framework
             // log skipped mods
             if (skippedMods.Any())
             {
+                // get logging logic
+                HashSet<string> logged = new HashSet<string>();
+                void LogSkippedMod(IModMetadata mod, string errorReason, string errorDetails)
+                {
+                    string message = $"      - {mod.DisplayName}{(mod.Manifest?.Version != null ? " " + mod.Manifest.Version.ToString() : "")} because {errorReason}";
+
+                    if (logged.Add($"{message}|{errorDetails}"))
+                    {
+                        this.Monitor.Log(message, LogLevel.Error);
+                        if (errorDetails != null)
+                            this.Monitor.Log($"        ({errorDetails})", LogLevel.Trace);
+                    }
+                }
+
+                // find skipped dependencies
+                KeyValuePair<IModMetadata, Tuple<string, string>>[] skippedDependencies;
+                {
+                    HashSet<string> skippedDependencyIds = new HashSet<string>(StringComparer.InvariantCultureIgnoreCase);
+                    HashSet<string> skippedModIds = new HashSet<string>(from mod in skippedMods where mod.Key.HasID() select mod.Key.Manifest.UniqueID, StringComparer.InvariantCultureIgnoreCase);
+                    foreach (IModMetadata mod in skippedMods.Keys)
+                    {
+                        foreach (string requiredId in skippedModIds.Intersect(mod.GetRequiredModIds()))
+                            skippedDependencyIds.Add(requiredId);
+                    }
+                    skippedDependencies = skippedMods.Where(p => p.Key.HasID() && skippedDependencyIds.Contains(p.Key.Manifest.UniqueID)).ToArray();
+                }
+
+                // log skipped mods
                 this.Monitor.Log("   Skipped mods", LogLevel.Error);
                 this.Monitor.Log("   " + "".PadRight(50, '-'), LogLevel.Error);
                 this.Monitor.Log("      These mods could not be added to your game.", LogLevel.Error);
                 this.Monitor.Newline();
 
-                HashSet<string> logged = new HashSet<string>();
+                if (skippedDependencies.Any())
-                foreach (var pair in skippedMods.OrderBy(p => p.Key.DisplayName))
                 {
-                    IModMetadata mod = pair.Key;
+                    foreach (var pair in skippedDependencies.OrderBy(p => p.Key.DisplayName))
-                    string errorReason = pair.Value.Item1;
+                        LogSkippedMod(pair.Key, pair.Value.Item1, pair.Value.Item2);
-                    string errorDetails = pair.Value.Item2;
+                    this.Monitor.Newline();
-                    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(message, LogLevel.Error);
-                    if (errorDetails != null)
-                        this.Monitor.Log($"        ({errorDetails})", LogLevel.Trace);
                 }
+
+                foreach (var pair in skippedMods.OrderBy(p => p.Key.DisplayName))
+                    LogSkippedMod(pair.Key, pair.Value.Item1, pair.Value.Item2);
                 this.Monitor.Newline();
             }