move basic mod scanning into the toolkit (#532)

6 files changed, 200 insertions, 43 deletions

diff --git a/src/SMAPI.Tests/Core/ModResolverTests.cs b/src/SMAPI.Tests/Core/ModResolverTests.cs
index 9e91b993..a38621f8 100644
--- a/src/SMAPI.Tests/Core/ModResolverTests.cs
+++ b/src/SMAPI.Tests/Core/ModResolverTests.cs
@@ -7,8 +7,8 @@ using Newtonsoft.Json;
 using NUnit.Framework;
 using StardewModdingAPI.Framework;
 using StardewModdingAPI.Framework.ModLoading;
+using StardewModdingAPI.Toolkit;
 using StardewModdingAPI.Toolkit.Framework.ModData;
-using StardewModdingAPI.Toolkit.Serialisation;
 using StardewModdingAPI.Toolkit.Serialisation.Models;
 
 namespace StardewModdingAPI.Tests.Core
@@ -31,7 +31,7 @@ namespace StardewModdingAPI.Tests.Core
             Directory.CreateDirectory(rootFolder);
 
             // act
-            IModMetadata[] mods = new ModResolver().ReadManifests(rootFolder, new JsonHelper(), new ModDatabase()).ToArray();
+            IModMetadata[] mods = new ModResolver().ReadManifests(new ModToolkit(), rootFolder, new ModDatabase()).ToArray();
 
             // assert
             Assert.AreEqual(0, mods.Length, 0, $"Expected to find zero manifests, found {mods.Length} instead.");
@@ -46,7 +46,7 @@ namespace StardewModdingAPI.Tests.Core
             Directory.CreateDirectory(modFolder);
 
             // act
-            IModMetadata[] mods = new ModResolver().ReadManifests(rootFolder, new JsonHelper(), new ModDatabase()).ToArray();
+            IModMetadata[] mods = new ModResolver().ReadManifests(new ModToolkit(), rootFolder, new ModDatabase()).ToArray();
             IModMetadata mod = mods.FirstOrDefault();
 
             // assert
@@ -85,7 +85,7 @@ namespace StardewModdingAPI.Tests.Core
             File.WriteAllText(filename, JsonConvert.SerializeObject(original));
 
             // act
-            IModMetadata[] mods = new ModResolver().ReadManifests(rootFolder, new JsonHelper(), new ModDatabase()).ToArray();
+            IModMetadata[] mods = new ModResolver().ReadManifests(new ModToolkit(), rootFolder, new ModDatabase()).ToArray();
             IModMetadata mod = mods.FirstOrDefault();
 
             // assert
diff --git a/src/SMAPI/Framework/ModLoading/ModResolver.cs b/src/SMAPI/Framework/ModLoading/ModResolver.cs
index 174820a1..9ac95fd4 100644
--- a/src/SMAPI/Framework/ModLoading/ModResolver.cs
+++ b/src/SMAPI/Framework/ModLoading/ModResolver.cs
@@ -3,8 +3,9 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
+using StardewModdingAPI.Toolkit;
 using StardewModdingAPI.Toolkit.Framework.ModData;
-using StardewModdingAPI.Toolkit.Serialisation;
+using StardewModdingAPI.Toolkit.Framework.ModScanning;
 using StardewModdingAPI.Toolkit.Serialisation.Models;
 using StardewModdingAPI.Toolkit.Utilities;
 
@@ -17,38 +18,15 @@ namespace StardewModdingAPI.Framework.ModLoading
         ** Public methods
         *********/
         /// <summary>Get manifest metadata for each folder in the given root path.</summary>
+        /// <param name="toolkit">The mod toolkit.</param>
         /// <param name="rootPath">The root path to search for mods.</param>
-        /// <param name="jsonHelper">The JSON helper with which to read manifests.</param>
         /// <param name="modDatabase">Handles access to SMAPI's internal mod metadata list.</param>
         /// <returns>Returns the manifests by relative folder.</returns>
-        public IEnumerable<IModMetadata> ReadManifests(string rootPath, JsonHelper jsonHelper, ModDatabase modDatabase)
+        public IEnumerable<IModMetadata> ReadManifests(ModToolkit toolkit, string rootPath, ModDatabase modDatabase)
         {
-            foreach (DirectoryInfo modDir in this.GetModFolders(rootPath))
+            foreach (ModFolder folder in toolkit.GetModFolders(rootPath))
             {
-                // read file
-                Manifest manifest = null;
-                string error = null;
-                {
-                    string path = Path.Combine(modDir.FullName, "manifest.json");
-                    try
-                    {
-                        manifest = jsonHelper.ReadJsonFile<Manifest>(path);
-                        if (manifest == null)
-                        {
-                            error = File.Exists(path)
-                                ? "its manifest is invalid."
-                                : "it doesn't have a manifest.";
-                        }
-                    }
-                    catch (SParseException ex)
-                    {
-                        error = $"parsing its manifest failed: {ex.Message}";
-                    }
-                    catch (Exception ex)
-                    {
-                        error = $"parsing its manifest failed:\n{ex.GetLogSummary()}";
-                    }
-                }
+                Manifest manifest = folder.Manifest;
 
                 // parse internal data record (if any)
                 ModDataRecordVersionedFields dataRecord = modDatabase.Get(manifest?.UniqueID)?.GetVersionedFields(manifest);
@@ -58,7 +36,7 @@ namespace StardewModdingAPI.Framework.ModLoading
                 if (string.IsNullOrWhiteSpace(displayName))
                     displayName = dataRecord?.DisplayName;
                 if (string.IsNullOrWhiteSpace(displayName))
-                    displayName = PathUtilities.GetRelativePath(rootPath, modDir.FullName);
+                    displayName = PathUtilities.GetRelativePath(rootPath, folder.ActualDirectory?.FullName ?? folder.SearchDirectory.FullName);
 
                 // apply defaults
                 if (manifest != null && dataRecord != null)
@@ -68,10 +46,10 @@ namespace StardewModdingAPI.Framework.ModLoading
                 }
 
                 // build metadata
-                ModMetadataStatus status = error == null
+                ModMetadataStatus status = folder.ManifestParseError == null
                     ? ModMetadataStatus.Found
                     : ModMetadataStatus.Failed;
-                yield return new ModMetadata(displayName, modDir.FullName, manifest, dataRecord).SetStatus(status, error);
+                yield return new ModMetadata(displayName, folder.ActualDirectory?.FullName, manifest, dataRecord).SetStatus(status, folder.ManifestParseError);
             }
         }
 
diff --git a/src/SMAPI/Program.cs b/src/SMAPI/Program.cs
index a88db105..c9266c69 100644
--- a/src/SMAPI/Program.cs
+++ b/src/SMAPI/Program.cs
@@ -104,8 +104,8 @@ namespace StardewModdingAPI
             new Regex(@"^DebugOutput: (?:added CLOUD|dismount tile|Ping|playerPos)", RegexOptions.Compiled | RegexOptions.CultureInvariant)
         };
 
-        /// <summary>Encapsulates SMAPI's JSON file parsing.</summary>
-        private readonly JsonHelper JsonHelper = new JsonHelper();
+        /// <summary>The mod toolkit used for generic mod interactions.</summary>
+        private readonly ModToolkit Toolkit = new ModToolkit();
 
 
         /*********
@@ -205,7 +205,7 @@ namespace StardewModdingAPI
                     new RectangleConverter()
                 };
                 foreach (JsonConverter converter in converters)
-                    this.JsonHelper.JsonSettings.Converters.Add(converter);
+                    this.Toolkit.JsonHelper.JsonSettings.Converters.Add(converter);
 
                 // add error handlers
 #if SMAPI_FOR_WINDOWS
@@ -423,14 +423,14 @@ namespace StardewModdingAPI
                 ModResolver resolver = new ModResolver();
 
                 // load manifests
-                IModMetadata[] mods = resolver.ReadManifests(Constants.ModPath, this.JsonHelper, modDatabase).ToArray();
+                IModMetadata[] mods = resolver.ReadManifests(toolkit, Constants.ModPath, modDatabase).ToArray();
                 resolver.ValidateManifests(mods, Constants.ApiVersion, toolkit.GetUpdateUrl);
 
                 // process dependencies
                 mods = resolver.ProcessDependencies(mods, modDatabase).ToArray();
 
                 // load mods
-                this.LoadMods(mods, this.JsonHelper, this.ContentCore, modDatabase);
+                this.LoadMods(mods, this.Toolkit.JsonHelper, this.ContentCore, modDatabase);
 
                 // write metadata file
                 if (this.Settings.DumpMetadata)
@@ -443,7 +443,7 @@ namespace StardewModdingAPI
                         ModFolderPath = Constants.ModPath,
                         Mods = mods
                     };
-                    this.JsonHelper.WriteJsonFile(Path.Combine(Constants.LogDir, $"{Constants.LogNamePrefix}.metadata-dump.json"), export);
+                    this.Toolkit.JsonHelper.WriteJsonFile(Path.Combine(Constants.LogDir, $"{Constants.LogNamePrefix}.metadata-dump.json"), export);
                 }
 
                 // check for updates
@@ -875,7 +875,7 @@ namespace StardewModdingAPI
                                 {
                                     IMonitor packMonitor = this.GetSecondaryMonitor(packManifest.Name);
                                     IContentHelper packContentHelper = new ContentHelper(contentCore, packDirPath, packManifest.UniqueID, packManifest.Name, packMonitor);
-                                    return new ContentPack(packDirPath, packManifest, packContentHelper, this.JsonHelper);
+                                    return new ContentPack(packDirPath, packManifest, packContentHelper, this.Toolkit.JsonHelper);
                                 }
 
                                 modHelper = new ModHelper(manifest.UniqueID, metadata.DirectoryPath, jsonHelper, this.GameInstance.Input, events, contentHelper, commandHelper, modRegistryHelper, reflectionHelper, multiplayerHelper, translationHelper, contentPacks, CreateTransitionalContentPack, this.DeprecationManager);
@@ -1117,7 +1117,7 @@ namespace StardewModdingAPI
         /// <param name="mods">The mods for which to reload translations.</param>
         private void ReloadTranslations(IEnumerable<IModMetadata> mods)
         {
-            JsonHelper jsonHelper = this.JsonHelper;
+            JsonHelper jsonHelper = this.Toolkit.JsonHelper;
             foreach (IModMetadata metadata in mods)
             {
                 if (metadata.IsContentPack)
diff --git a/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModFolder.cs b/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModFolder.cs
new file mode 100644
index 00000000..9b6853b4
--- /dev/null
+++ b/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModFolder.cs
@@ -0,0 +1,60 @@
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using StardewModdingAPI.Toolkit.Serialisation.Models;
+
+namespace StardewModdingAPI.Toolkit.Framework.ModScanning
+{
+    /// <summary>The info about a mod read from its folder.</summary>
+    public class ModFolder
+    {
+        /*********
+        ** Accessors
+        *********/
+        /// <summary>The Mods subfolder containing this mod.</summary>
+        public DirectoryInfo SearchDirectory { get; }
+
+        /// <summary>The folder containing manifest.json.</summary>
+        public DirectoryInfo ActualDirectory { get; }
+
+        /// <summary>The mod manifest.</summary>
+        public Manifest Manifest { get; }
+
+        /// <summary>The error which occurred parsing the manifest, if any.</summary>
+        public string ManifestParseError { get; }
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance when a mod wasn't found in a folder.</summary>
+        /// <param name="searchDirectory">The directory that was searched.</param>
+        public ModFolder(DirectoryInfo searchDirectory)
+        {
+            this.SearchDirectory = searchDirectory;
+        }
+
+        /// <summary>Construct an instance.</summary>
+        /// <param name="searchDirectory">The Mods subfolder containing this mod.</param>
+        /// <param name="actualDirectory">The folder containing manifest.json.</param>
+        /// <param name="manifest">The mod manifest.</param>
+        /// <param name="manifestParseError">The error which occurred parsing the manifest, if any.</param>
+        public ModFolder(DirectoryInfo searchDirectory, DirectoryInfo actualDirectory, Manifest manifest, string manifestParseError = null)
+        {
+            this.SearchDirectory = searchDirectory;
+            this.ActualDirectory = actualDirectory;
+            this.Manifest = manifest;
+            this.ManifestParseError = manifestParseError;
+        }
+
+        /// <summary>Get the update keys for a mod.</summary>
+        /// <param name="manifest">The mod manifest.</param>
+        public IEnumerable<string> GetUpdateKeys(Manifest manifest)
+        {
+            return
+                (manifest.UpdateKeys ?? new string[0])
+                .Where(p => !string.IsNullOrWhiteSpace(p))
+                .ToArray();
+        }
+    }
+}
diff --git a/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModScanner.cs b/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModScanner.cs
new file mode 100644
index 00000000..d3662c9c
--- /dev/null
+++ b/src/StardewModdingAPI.Toolkit/Framework/ModScanning/ModScanner.cs
@@ -0,0 +1,103 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using StardewModdingAPI.Toolkit.Serialisation;
+using StardewModdingAPI.Toolkit.Serialisation.Models;
+
+namespace StardewModdingAPI.Toolkit.Framework.ModScanning
+{
+    /// <summary>Scans folders for mod data.</summary>
+    public class ModScanner
+    {
+        /*********
+        ** Properties
+        *********/
+        /// <summary>The JSON helper with which to read manifests.</summary>
+        private readonly JsonHelper JsonHelper;
+
+
+        /*********
+        ** Public methods
+        *********/
+        /// <summary>Construct an instance.</summary>
+        /// <param name="jsonHelper">The JSON helper with which to read manifests.</param>
+        public ModScanner(JsonHelper jsonHelper)
+        {
+            this.JsonHelper = jsonHelper;
+        }
+
+        /// <summary>Extract information about all mods in the given folder.</summary>
+        /// <param name="rootPath">The root folder containing mods.</param>
+        public IEnumerable<ModFolder> GetModFolders(string rootPath)
+        {
+            foreach (DirectoryInfo folder in new DirectoryInfo(rootPath).EnumerateDirectories())
+                yield return this.ReadFolder(rootPath, folder);
+        }
+
+        /// <summary>Extract information from a mod folder.</summary>
+        /// <param name="rootPath">The root folder containing mods.</param>
+        /// <param name="searchFolder">The folder to search for a mod.</param>
+        public ModFolder ReadFolder(string rootPath, DirectoryInfo searchFolder)
+        {
+            // find manifest.json
+            FileInfo manifestFile = this.FindManifest(searchFolder);
+            if (manifestFile == null)
+                return new ModFolder(searchFolder);
+
+            // read mod info
+            Manifest manifest = null;
+            string manifestError = null;
+            {
+                try
+                {
+                    manifest = this.JsonHelper.ReadJsonFile<Manifest>(manifestFile.FullName);
+                    if (manifest == null)
+                    {
+                        manifestError = File.Exists(manifestFile.FullName)
+                            ? "its manifest is invalid."
+                            : "it doesn't have a manifest.";
+                    }
+                }
+                catch (SParseException ex)
+                {
+                    manifestError = $"parsing its manifest failed: {ex.Message}";
+                }
+                catch (Exception ex)
+                {
+                    manifestError = $"parsing its manifest failed:\n{ex}";
+                }
+            }
+
+            return new ModFolder(searchFolder, manifestFile.Directory, manifest, manifestError);
+        }
+
+
+        /*********
+        ** Private methods
+        *********/
+        /// <summary>Find the manifest for a mod folder.</summary>
+        /// <param name="folder">The folder to search.</param>
+        private FileInfo FindManifest(DirectoryInfo folder)
+        {
+            while (true)
+            {
+                // check for manifest in current folder
+                FileInfo file = new FileInfo(Path.Combine(folder.FullName, "manifest.json"));
+                if (file.Exists)
+                    return file;
+
+                // check for single subfolder
+                FileSystemInfo[] entries = folder.EnumerateFileSystemInfos().Take(2).ToArray();
+                if (entries.Length == 1 && entries[0] is DirectoryInfo subfolder)
+                {
+                    folder = subfolder;
+                    continue;
+                }
+
+                // not found
+                return null;
+            }
+        }
+    }
+}
diff --git a/src/StardewModdingAPI.Toolkit/ModToolkit.cs b/src/StardewModdingAPI.Toolkit/ModToolkit.cs
index 18fe1ff3..8c78b2f3 100644
--- a/src/StardewModdingAPI.Toolkit/ModToolkit.cs
+++ b/src/StardewModdingAPI.Toolkit/ModToolkit.cs
@@ -6,6 +6,8 @@ using System.Threading.Tasks;
 using Newtonsoft.Json;
 using StardewModdingAPI.Toolkit.Framework.Clients.Wiki;
 using StardewModdingAPI.Toolkit.Framework.ModData;
+using StardewModdingAPI.Toolkit.Framework.ModScanning;
+using StardewModdingAPI.Toolkit.Serialisation;
 
 namespace StardewModdingAPI.Toolkit
 {
@@ -28,6 +30,13 @@ namespace StardewModdingAPI.Toolkit
 
 
         /*********
+        ** Accessors
+        *********/
+        /// <summary>Encapsulates SMAPI's JSON parsing.</summary>
+        public JsonHelper JsonHelper { get; } = new JsonHelper();
+
+
+        /*********
         ** Public methods
         *********/
         /// <summary>Construct an instance.</summary>
@@ -53,6 +62,13 @@ namespace StardewModdingAPI.Toolkit
             return new ModDatabase(records, this.GetUpdateUrl);
         }
 
+        /// <summary>Extract information about all mods in the given folder.</summary>
+        /// <param name="rootPath">The root folder containing mods.</param>
+        public IEnumerable<ModFolder> GetModFolders(string rootPath)
+        {
+            return new ModScanner(this.JsonHelper).GetModFolders(rootPath);
+        }
+
         /// <summary>Get an update URL for an update key (if valid).</summary>
         /// <param name="updateKey">The update key.</param>
         public string GetUpdateUrl(string updateKey)