feat: Local project settings singleton

com.stansassets.plugins-dev-kit/Runtime/Config/PackagesConfig.cs

@@ -9,5 +9,10 @@ public static class PackagesConfig
         /// Package runtime settings location path.
         /// </summary>
         public const string SettingsPath = "Assets/Plugins/StansAssets/Settings";
+
+        /// <summary>
+        /// Library settings folder path.
+        /// </summary>
+        public const string LibraryPath = "Library/StansAssets";
     }
 }

com.stansassets.plugins-dev-kit/Runtime/PackageSettings/LocalProjectSettings.cs

@@ -0,0 +1,41 @@
+using System;
+using UnityEngine;
+
+namespace StansAssets.Plugins
+{
+    [Serializable]
+    public class LocalProjectSettings
+    {
+        public LocalProjectSettings()
+        {
+            PackageName = "newPackage";
+            SettingsFileName = GetType().Name;
+        }
+
+        public LocalProjectSettings(string packageName, string settingsFileName = null)
+        {
+            PackageName = packageName;
+            SettingsFileName = settingsFileName == null ? settingsFileName : GetType().Name;
+        }
+
+        /// <summary>
+        /// Plugin package name.
+        /// </summary>
+        public string PackageName { get; }
+
+        /// <summary>
+        /// Plugin settings folder path.
+        /// </summary>
+        public string SettingsFolderPath => $"{Application.dataPath}/{PackagesConfig.LibraryPath}/{PackageName}";
+
+        /// <summary>
+        /// Plugin settings file path.
+        /// </summary>
+        public string SettingsFilePath => $"{SettingsFolderPath}/{SettingsFileName}.json";
+
+        /// <summary>
+        /// Settings file name.
+        /// </summary>
+        public string SettingsFileName { get; }
+    }
+}

com.stansassets.plugins-dev-kit/Runtime/PackageSettings/LocalProjectSettingsSingleton.cs

@@ -0,0 +1,110 @@
+using System;
+using System.IO;
+using System.Threading.Tasks;
+using UnityEngine;
+
+namespace StansAssets.Plugins
+{
+    public abstract class LocalProjectSettingsSingleton<T> : LocalProjectSettings where T : LocalProjectSettings, new()
+    {
+        static T s_Instance;
+
+        /// <summary>
+        ///     Returns a singleton class instance
+        ///     If current instance is not assigned it will try to find an object of the instance type,
+        ///     in case instance already exists in a project. If not, new instance will be created,
+        ///     and saved under a <see cref="PackagesConfig.SettingsPath" /> location
+        /// </summary>
+        public static T Instance
+        {
+            get
+            {
+                if (s_Instance == null)
+                {
+                    var inst = new T();
+                    s_Instance = InitFromCache(inst);
+
+                    if (s_Instance == null)
+                    {
+                        s_Instance = inst;
+                        Save(inst);
+                    }
+                }
+
+                return s_Instance;
+            }
+        }
+
+        /// <summary>
+        ///     Saves instance to an editor database.
+        ///     Only applicable while in the editor.
+        /// </summary>
+        public static void Save()
+        {
+            // Only applicable while in the editor.
+#if UNITY_EDITOR
+            Save(Instance);
+#endif
+        }
+
+        /// <summary>
+        ///     // Only applicable while in the editor.
+        /// </summary>
+        static void Save(T asset)
+        {
+            // Only applicable while in the editor.
+#if UNITY_EDITOR
+            var path = asset.SettingsFilePath;
+            var directory = Path.GetDirectoryName(path);
+
+            if (directory == null)
+                throw new InvalidOperationException($"Failed to get directory from package settings path: {path}");
+
+            if (!Directory.Exists(directory))
+                Directory.CreateDirectory(directory);
+
+            CacheDocument(asset);
+#endif
+        }
+
+        static T InitFromCache(T asset)
+        {
+            var path = asset.SettingsFilePath;
+            if (File.Exists(path))
+            {
+                StreamReader reader = null;
+                try
+                {
+                    reader = new StreamReader(path);
+                    var text = reader.ReadToEnd();
+                    return JsonUtility.FromJson<T>(text);
+                }
+                finally
+                {
+                    reader?.Close();
+                }
+            }
+
+            return null;
+        }
+
+        static Task CacheDocument(T asset)
+        {
+            var path = asset.SettingsFilePath;
+            return Task.Run(() => {
+                try
+                {
+                    File.WriteAllText(path, JsonUtility.ToJson(asset));
+                }
+                catch (Exception e)
+                {
+                    Debug.LogException(e);
+                }
+                finally
+                {
+                    Debug.Log($"Personal project settings saved: {path}");
+                }
+            });
+        }
+    }
+}