gptel-org: Read config from Org properties (karthink#141)

* gptel.el: Load gptel-org after Org is loaded.

* gptel-org.el (gptel-org--send-with-props): Advise `gptel-send`
and `gptel--suffix-send` to use gptel's local config (stored under
the current Org heading) when applicable.  Advice is a hacky way
to do it, but this is the simplest option without explicit
indirection via `derived-mode-p`-based dispatch code in many more
places in gptel.

Author: karthink

gptel-org.el

@@ -174,6 +174,31 @@ value of `gptel-org-branching-context', which see."
       ;; Create prompt the usual way
       (gptel--parse-buffer gptel-backend max-entries))))
 
+(defun gptel-org--send-with-props (send-fun &rest args)
+  "Conditionally modify SEND-FUN's calling environment.
+
+If in an Org buffer under a heading containing a stored gptel
+configuration, use that for requests instead.  This includes the
+system message, model and provider (backend), among other
+parameters."
+  (if (derived-mode-p 'org-mode)
+      (pcase-let ((`(,gptel--system-message ,gptel-backend ,gptel-model
+                     ,gptel-temperature ,gptel-max-tokens)
+                   (seq-mapn (lambda (a b) (or a b))
+                             (gptel-org--entry-properties)
+                             (list gptel--system-message gptel-backend gptel-model
+                                   gptel-temperature gptel-max-tokens))))
+        (apply send-fun args))
+    (apply send-fun args)))
+
+(advice-add 'gptel-send :around #'gptel-org--send-with-props)
+(advice-add 'gptel--suffix-send :around #'gptel-org--send-with-props)
+
+;; ;; NOTE: Basic uses in org-mode are covered by advising gptel-send and
+;; ;; gptel--suffix-send.  For custom commands it might be necessary to advise
+;; ;; gptel-request instead.
+;; (advice-add 'gptel-request :around #'gptel-org--send-with-props)
+
 
 ;;; Saving and restoring state
 (defun gptel-org--entry-properties (&optional pt)

gptel.el

@@ -133,6 +133,9 @@
 (require 'cl-generic)
 (require 'gptel-openai)
 
+(with-eval-after-load 'org
+  (require 'gptel-org))
+
 
 ;; User options