feat: Smiplify configuration helpers

3 files changed, 92 insertions, 26 deletions

diff --git a/lib/VNLib.Plugins.Extensions.Loading/src/Configuration/ConfigScope.cs b/lib/VNLib.Plugins.Extensions.Loading/src/Configuration/ConfigScope.cs
index 7f5c09c..d8f4347 100644
--- a/lib/VNLib.Plugins.Extensions.Loading/src/Configuration/ConfigScope.cs
+++ b/lib/VNLib.Plugins.Extensions.Loading/src/Configuration/ConfigScope.cs
@@ -1,5 +1,5 @@
 /*
-* Copyright (c) 2023 Vaughn Nugent
+* Copyright (c) 2024 Vaughn Nugent
 * 
 * Library: VNLib
 * Package: VNLib.Plugins.Extensions.Loading
@@ -29,13 +29,15 @@ using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
+using VNLib.Utils.Resources;
+
 
 namespace VNLib.Plugins.Extensions.Loading
 {
     internal sealed class ConfigScope: IConfigScope
     {
 
-        private readonly Lazy<IReadOnlyDictionary<string, JsonElement>> _config;
+        private readonly LazyInitializer<IReadOnlyDictionary<string, JsonElement>> _config;
 
         private readonly JsonElement _element;
 
@@ -48,36 +50,40 @@ namespace VNLib.Plugins.Extensions.Loading
 
         private IReadOnlyDictionary<string, JsonElement> LoadTable()
         {
-            return _element.EnumerateObject().ToDictionary(static k => k.Name, static k => k.Value);
+            return _element.EnumerateObject()
+                .ToDictionary(
+                    static k => k.Name, 
+                    static k => k.Value
+                );
         }
 
         ///<inheritdoc/>
-        public JsonElement this[string key] => _config.Value[key];
+        public JsonElement this[string key] => _config.Instance[key];
 
         ///<inheritdoc/>
-        public IEnumerable<string> Keys => _config.Value.Keys;
+        public IEnumerable<string> Keys => _config.Instance.Keys;
 
         ///<inheritdoc/>
-        public IEnumerable<JsonElement> Values => _config.Value.Values;
+        public IEnumerable<JsonElement> Values => _config.Instance.Values;
 
         ///<inheritdoc/>
-        public int Count => _config.Value.Count;
+        public int Count => _config.Instance.Count;
 
         ///<inheritdoc/>
         public string ScopeName { get; }
 
         ///<inheritdoc/>
-        public bool ContainsKey(string key) => _config.Value.ContainsKey(key);
+        public bool ContainsKey(string key) => _config.Instance.ContainsKey(key);
 
         ///<inheritdoc/>
         public T Deserialze<T>() => _element.Deserialize<T>()!;
 
         ///<inheritdoc/>
-        public IEnumerator<KeyValuePair<string, JsonElement>> GetEnumerator() => _config.Value.GetEnumerator();
+        public IEnumerator<KeyValuePair<string, JsonElement>> GetEnumerator() => _config.Instance.GetEnumerator();
 
         ///<inheritdoc/>
-        public bool TryGetValue(string key, [MaybeNullWhen(false)] out JsonElement value) => _config.Value.TryGetValue(key, out value);
+        public bool TryGetValue(string key, [MaybeNullWhen(false)] out JsonElement value) => _config.Instance.TryGetValue(key, out value);
 
-        IEnumerator IEnumerable.GetEnumerator() => _config.Value.GetEnumerator();
+        IEnumerator IEnumerable.GetEnumerator() => _config.Instance.GetEnumerator();
     }
 }
diff --git a/lib/VNLib.Plugins.Extensions.Loading/src/ConfigurationExtensions.cs b/lib/VNLib.Plugins.Extensions.Loading/src/ConfigurationExtensions.cs
index 0a1bc7f..39bdc86 100644
--- a/lib/VNLib.Plugins.Extensions.Loading/src/ConfigurationExtensions.cs
+++ b/lib/VNLib.Plugins.Extensions.Loading/src/ConfigurationExtensions.cs
@@ -31,6 +31,7 @@ using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
 
 using VNLib.Utils.Extensions;
+using VNLib.Plugins.Extensions.Loading.Configuration;
 
 namespace VNLib.Plugins.Extensions.Loading
 {
@@ -67,7 +68,6 @@ namespace VNLib.Plugins.Extensions.Loading
         public const string S3_SECRET_KEY = "s3_secret";
         public const string PLUGIN_ASSET_KEY = "assets";
         public const string PLUGINS_HOST_KEY = "plugins";
-        public const string PLUGIN_PATHS_KEY = "paths";
 
         /// <summary>
         /// Retrieves a top level configuration dictionary of elements for the specified type.
@@ -200,13 +200,28 @@ namespace VNLib.Plugins.Extensions.Loading
             ArgumentNullException.ThrowIfNull(getter);
 
             //Get the property
-            if (!config.TryGetValue(property, out JsonElement el))
-            {
-                throw new ConfigurationException($"Missing required configuration property '{property}' in config {config.ScopeName}");
-            }
+            bool hasValue = config.TryGetValue(property, out JsonElement el);
+            Validate.Assert(hasValue, $"Missing required configuration property '{property}' in config {config.ScopeName}");
+
+            T? value = getter(el);
+            Validate.Assert(value is not null, $"Missing required configuration property '{property}' in config {config.ScopeName}");
 
-            //Even if the getter returns null, throw
-            return getter(el) ?? throw new ConfigurationException($"Missing required configuration property '{property}' in config {config.ScopeName}");
+            return value;
+        }
+
+
+        /// <summary>
+        /// Gets a required configuration property from the specified configuration scope
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="config"></param>
+        /// <param name="property">The name of the property to get</param>
+        /// <returns>The property value</returns>
+        /// <exception cref="ArgumentNullException"></exception>
+        /// <exception cref="ConfigurationException"></exception>
+        public static T GetRequiredProperty<T>(this IConfigScope config, string property)
+        {
+            return GetRequiredProperty(config, property, static p => p.Deserialize<T>()!);
         }
 
         /// <summary>
@@ -258,6 +273,28 @@ namespace VNLib.Plugins.Extensions.Loading
         }
 
         /// <summary>
+        /// Gets a configuration property from the specified configuration scope
+        /// and invokes your callback function on the element if found to transform the
+        /// output value, or returns the default value if the property is not found.
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="config"></param>
+        /// <param name="property">The name of the configuration element to get</param>
+        /// <param name="defaultValue">The default value to return</param>
+        /// <returns>The property value returned from your getter callback, or the default value if not found</returns>
+        /// <exception cref="ArgumentNullException"></exception>
+        [return: NotNullIfNotNull(nameof(defaultValue))]
+        public static T? GetValueOrDefault<T>(this IConfigScope config, string property, T defaultValue)
+        {
+            return GetValueOrDefault(
+                config, 
+                property, 
+                static p => p.Deserialize<T>(), 
+                defaultValue
+            );
+        }
+
+        /// <summary>
         /// Gets the configuration property name for the type
         /// </summary>
         /// <param name="type">The type to get the configuration name for</param>
@@ -442,7 +479,6 @@ namespace VNLib.Plugins.Extensions.Loading
             }
         }
 
-
         /// <summary>
         /// Attempts to load the basic S3 configuration variables required
         /// for S3 client access
@@ -483,11 +519,34 @@ namespace VNLib.Plugins.Extensions.Loading
             //Get global plugin config element
             IConfigScope config = plugin.GetConfig(PLUGINS_HOST_KEY);
 
-            //Get the plugins path or throw because it should ALWAYS be defined if this method is called
-            return config[PLUGIN_PATHS_KEY].EnumerateArray()
-                .Select(static p => p.GetString()!)
-                .Select(Path.GetFullPath)   //Get absolute file paths
-                .ToArray();
+            /*
+             * Hosts are allowed to define mutliple plugin loading paths. A
+             * single path is supported for compat. Multi path takes precidence 
+             * of course so attempt to load a string array first
+             */
+
+            if (!config.TryGetValue("paths", out JsonElement searchPaths)
+                && !config.TryGetValue("path", out searchPaths))
+            {
+                return [];
+            }
+
+            if (searchPaths.ValueKind == JsonValueKind.Array)
+            {
+                //Get the plugins path or throw because it should ALWAYS be defined if this method is called
+                return searchPaths.EnumerateArray()
+                    .Select(static p => p.GetString()!)
+                    .Select(Path.GetFullPath)   //Get absolute file paths
+                    .ToArray();
+            }
+            else if (searchPaths.ValueKind == JsonValueKind.String)
+            {
+                return [Path.GetFullPath(searchPaths.GetString()!)];
+            }
+            else
+            {
+                return [];
+            }
         }
     }
 }
diff --git a/lib/VNLib.Plugins.Extensions.Loading/src/LoadingExtensions.cs b/lib/VNLib.Plugins.Extensions.Loading/src/LoadingExtensions.cs
index 4ffb3a1..58478d4 100644
--- a/lib/VNLib.Plugins.Extensions.Loading/src/LoadingExtensions.cs
+++ b/lib/VNLib.Plugins.Extensions.Loading/src/LoadingExtensions.cs
@@ -123,7 +123,7 @@ namespace VNLib.Plugins.Extensions.Loading
             */
             if (searchDirs.Length == 0)
             {
-                throw new ArgumentException("No plugin asset directory is defined for the current host configuration, this is likely a bug");
+                throw new ConfigurationException("No plugin asset directory is defined for the current host configuration, this is likely a bug");
             }
 
             //Get the first file that matches the search file
@@ -268,9 +268,10 @@ namespace VNLib.Plugins.Extensions.Loading
         /// </summary>
         /// <param name="plugin"></param>
         /// <exception cref="ObjectDisposedException"></exception>
-        public static void ThrowIfUnloaded(this PluginBase plugin)
+        public static void ThrowIfUnloaded(this PluginBase? plugin)
         {
             //See if the plugin was unlaoded
+            ArgumentNullException.ThrowIfNull(plugin);
             ObjectDisposedException.ThrowIf(plugin.UnloadToken.IsCancellationRequested, plugin);
         }