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.

pkg/cache/directory.go

@@ -72,6 +72,18 @@ func (d *Directory) AutoCleanupRoutine(ctx context.Context) error {
 	}
 }
 
+func (d *Directory) openFileForWriting(key string) (*os.File, error) {
+	path := d.GetPath(key)
+
+	fp, err := os.Create(path)
+
+	if err != nil {
+		return nil, err
+	}
+
+	return fp, nil
+}
+
 func (d *Directory) openFile(key string) (*os.File, error) {
 	path := d.GetPath(key)
 
@@ -91,7 +103,7 @@ func (d *Directory) Set(key string, value io.Reader) error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
-	fp, err := d.openFile(key)
+	fp, err := d.openFileForWriting(key)
 	if err != nil {
 		return err
 	}
@@ -109,7 +121,7 @@ func (d *Directory) SetJSON(key string, value any) error {
 	d.lock.Lock()
 	defer d.lock.Unlock()
 
-	fp, err := d.openFile(key)
+	fp, err := d.openFileForWriting(key)
 	if err != nil {
 		return err
 	}