fix: modify tool class to have static methods and create input schema from function

src/AnthropicClient/Models/Tool.cs

@@ -1,3 +1,5 @@
+using System.Reflection;
+using System.Text.Json.Nodes;
 using System.Text.Json.Serialization;
 
 using AnthropicClient.Utils;
@@ -12,40 +14,106 @@ public class Tool
   /// <summary>
   /// Gets the name of the tool.
   /// </summary>
-  public string Name { get; init; } = string.Empty;
+  public string Name { get; }
 
   /// <summary>
   /// Gets the description of the tool.
   /// </summary>
-  public string Description { get; init; } = string.Empty;
+  public string Description { get; }
 
   /// <summary>
   /// Gets the input schema of the tool.
   /// </summary>
   [JsonPropertyName("input_schema")]
-  public InputSchema InputSchema { get; init; } = new();
-
-  [JsonConstructor]
-  internal Tool()
-  {
-  }
+  public JsonNode InputSchema { get; }
 
   /// <summary>
-  /// Initializes a new instance of the <see cref="Tool"/> class.
+  /// Gets the function of the tool.
   /// </summary>
-  /// <param name="name">The name of the tool.</param>
-  /// <param name="description">The description of the tool.</param>
-  /// <param name="inputSchema">The input schema of the tool.</param>
-  /// <exception cref="ArgumentNullException">Thrown when the name, description, or input schema is null.</exception>
-  /// <returns>A new instance of the <see cref="Tool"/> class.</returns>
-  public Tool(string name, string description, InputSchema inputSchema)
+  [JsonIgnore]
+  public AnthropicFunction Function { get; }
+  
+  internal Tool(string name, string description, AnthropicFunction function)
   {
     ArgumentValidator.ThrowIfNull(name, nameof(name));
     ArgumentValidator.ThrowIfNull(description, nameof(description));
-    ArgumentValidator.ThrowIfNull(inputSchema, nameof(inputSchema));
+    ArgumentValidator.ThrowIfNull(function, nameof(function));
 
     Name = name;
     Description = description;
-    InputSchema = inputSchema;
+    Function = function;
+    InputSchema = JsonSchemaGenerator.GenerateInputSchema(function);
+  }
+
+  /// <summary>
+  /// Creates a tool from a static method.
+  /// </summary>
+  /// <param name="name">The name of the tool.</param>
+  /// <param name="description">The description of the tool.</param>
+  /// <param name="type">The type that contains the method.</param>
+  /// <param name="methodName">The name of the method.</param>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/>, <paramref name="description"/>, <paramref name="type"/>, or <paramref name="methodName"/> is null.</exception>
+  /// <exception cref="ArgumentException">Thrown when the method is not found in the type.</exception>
+  /// <returns>The created tool as instance of <see cref="Tool"/>.</returns>
+  public static Tool CreateFromStaticMethod(string name, string description, Type type, string methodName)
+  {
+    ArgumentValidator.ThrowIfNull(name, nameof(name));
+    ArgumentValidator.ThrowIfNull(description, nameof(description));
+    ArgumentValidator.ThrowIfNull(type, nameof(type));
+    ArgumentValidator.ThrowIfNull(methodName, nameof(methodName));
+
+    var method = type.GetMethod(methodName, BindingFlags.Public | BindingFlags.Static);
+    
+    if (method is null)
+    {
+      throw new ArgumentException($"Method '{methodName}' not found in type '{type.FullName}'.", nameof(methodName));
+    }
+
+    return new Tool(name, description, new AnthropicFunction(method));
+  }
+
+  /// <summary>
+  /// Creates a tool from an instance method.
+  /// </summary>
+  /// <param name="name">The name of the tool.</param>
+  /// <param name="description">The description of the tool.</param>
+  /// <param name="instance">The instance that contains the method.</param>
+  /// <param name="methodName">The name of the method.</param>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/>, <paramref name="description"/>, <paramref name="instance"/>, or <paramref name="methodName"/> is null.</exception>
+  /// <exception cref="ArgumentException">Thrown when the method is not found in the type.</exception>
+  /// <returns>The created tool as instance of <see cref="Tool"/>.</returns>
+  public static Tool CreateFromInstanceMethod(string name, string description, object instance, string methodName)
+  {
+    ArgumentValidator.ThrowIfNull(name, nameof(name));
+    ArgumentValidator.ThrowIfNull(description, nameof(description));
+    ArgumentValidator.ThrowIfNull(instance, nameof(instance));
+    ArgumentValidator.ThrowIfNull(methodName, nameof(methodName));
+
+    var method = instance.GetType().GetMethod(methodName, BindingFlags.Public | BindingFlags.Instance);
+    
+    if (method is null)
+    {
+      throw new ArgumentException($"Method '{methodName}' not found in type '{instance.GetType().FullName}'.", nameof(methodName));
+    }
+
+    return new Tool(name, description, new AnthropicFunction(method, instance));
+  }
+
+  /// <summary>
+  /// Creates a tool from a function.
+  /// </summary>
+  /// <typeparam name="TResult">The type of the result.</typeparam>
+  /// <param name="name">The name of the tool.</param>
+  /// <param name="description">The description of the tool.</param>
+  /// <param name="func">The function.</param>
+  /// <exception cref="ArgumentNullException">Thrown when <paramref name="name"/>, <paramref name="description"/>, or <paramref name="func"/> is null.</exception>
+  /// <returns>The created tool as instance of <see cref="Tool"/>.</returns>
+  public static Tool CreateFromFunction<TResult>(string name, string description, Func<TResult> func)
+  {
+    ArgumentValidator.ThrowIfNull(name, nameof(name));
+    ArgumentValidator.ThrowIfNull(description, nameof(description));
+    ArgumentValidator.ThrowIfNull(func, nameof(func));
+
+    return new Tool(name, description, new AnthropicFunction(func.Method, func.Target));
   }
 }