From f57132317477048642f5c17a4083f807b9be2a5e Mon Sep 17 00:00:00 2001
From: Karthik Chikmagalur <karthikchikmagalur@gmail.com>
Date: Wed, 27 Dec 2023 22:35:41 -0800
Subject: [PATCH] gptel-gemini: Simulate system-message for gemini

* gptel-gemini.el (gptel--parse-buffer): The Gemini API does not
provide an explicit system message parameter.  In the interest of
providing a uniform interface, simulate this in gptel by
prepending the first user message with `gptel--system-message`.
---
 gptel-gemini.el | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/gptel-gemini.el b/gptel-gemini.el
index 63453b6..fe4f0c5 100644
--- a/gptel-gemini.el
+++ b/gptel-gemini.el
@@ -26,6 +26,7 @@
 (require 'gptel)
 (require 'cl-generic)
 (require 'map)
+(require 'cl-macs)
 
 (declare-function prop-match-value "text-property-search")
 (declare-function text-property-search-backward "text-property-search")
@@ -95,6 +96,10 @@
                                        (regexp-quote (gptel-response-prefix-string))))))
             prompts)
       (and max-entries (cl-decf max-entries)))
+    (cl-callf (lambda (msg) (concat gptel--system-message "\n\n" msg))
+        (thread-first (car prompts)
+                      (plist-get :parts)
+                      (plist-get :text)))
     prompts))
 
 ;;;###autoload