Fix unmarshalling issues and adjust logging for debugging

Modify `FunctionCall` struct to handle arguments as strings. Add debugging logs to facilitate error tracing and improve JSON unmarshalling in various functions.

function.go

@@ -37,16 +37,17 @@ func (f *Function) Execute(ctx context.Context, input string) (string, error) {
 	}
 
 	// first, we need to parse the input into the struct
-	p := reflect.New(f.paramType).Elem()
+	p := reflect.New(f.paramType)
+	fmt.Println("Function.Execute", f.Name, "input:", input)
 	//m := map[string]any{}
-	err := json.Unmarshal([]byte(input), p.Addr().Interface())
+	err := json.Unmarshal([]byte(input), p.Interface())
 	if err != nil {
-		return "", fmt.Errorf("failed to unmarshal input: %w", err)
+		return "", fmt.Errorf("failed to unmarshal input: %w (input: %s)", err, input)
 	}
 
 	// now we can call the function
 	exec := func(ctx context.Context) (string, error) {
-		out := f.fn.Call([]reflect.Value{reflect.ValueOf(ctx), p})
+		out := f.fn.Call([]reflect.Value{reflect.ValueOf(ctx), p.Elem()})
 
 		if len(out) != 2 {
 			return "", fmt.Errorf("function %s must return two values, got %d", f.Name, len(out))
@@ -87,5 +88,5 @@ func (f *Function) toOpenAIDefinition() jsonschema.Definition {
 
 type FunctionCall struct {
 	Name      string `json:"name,omitempty"`
-	Arguments any    `json:"arguments,omitempty"`
+	Arguments string `json:"arguments,omitempty"`
 }