use 'backend' setting for selecting make-engine implementation

storage/storage.lisp

@@ -14,8 +14,8 @@
 (defparameter *db-config* nil)
 (defparameter *db-engine* nil)
 
-(defparameter *backends*
-  '(:dbi #'dbi-make-storage))
+(defvar *backends*
+  '(:dbi dbi-make-engine))
 
 (defvar *db-params*
   '(:sqlite3 (:id-type integer :json-type json)
@@ -26,6 +26,15 @@
    (params :initarg :params)
    (config :initarg :config)))
 
+(defun make-engine () 
+  (let* ((config *db-config*)
+         (backend (getf config :backend))
+         (factory (getf *backends* backend)))
+    (print backend)
+    (print factory)
+    (print (type-of factory))
+    (funcall factory config)))
+
 (defclass storage ()
   ((engine :initarg :engine)
    (db :reader db)
@@ -45,9 +54,10 @@
     (print sql)
     (dbi:do-sql (db st) sql)))
 
-(defun make-engine ()
-  (let* ((config *db-config*)
-         (db-type (getf config :db-type))
+;;; backend-/driver-specific stuff
+
+(defun dbi-make-engine (config)
+  (let* ((db-type (getf config :db-type))
          (params (getf *db-params* db-type))
          (conn-args (getf config :connect-args)))
     (make-instance 'db-engine