From 2e92c0303caf574ed3d4e3129ebb9a9f5936c3fd Mon Sep 17 00:00:00 2001
From: Karthik Chikmagalur <karthikchikmagalur@gmail.com>
Date: Fri, 22 Dec 2023 16:25:32 -0800
Subject: [PATCH] gptel: gptel-backend-url can accept functions

* gptel.el (gptel--url-get-response): If the backend-url is a
function, call it to find the full url to query.

* gptel-gemini.el: Gemini uses different urls for
streaming/oneshot responses.  Set the backend-url to a function to
account for the value of gptel-stream.  This is also safer than
before as the API key is not stored as part of a static url string
in memory. Fix #153.

* gptel-curl.el (gptel-curl--get-args): If the backend-url is a
function, call it to find the full url to query.
---
 gptel-curl.el   | 11 ++++++-----
 gptel-gemini.el | 19 +++++++------------
 gptel.el        | 11 ++++++-----
 3 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/gptel-curl.el b/gptel-curl.el
index 53bbbc1..4f624f9 100644
--- a/gptel-curl.el
+++ b/gptel-curl.el
@@ -49,16 +49,17 @@
   "Produce list of arguments for calling Curl.
 
 PROMPTS is the data to send, TOKEN is a unique identifier."
-  (let* ((url (gptel-backend-url gptel-backend))
+  (let* ((url (let ((backend-url (gptel-backend-url gptel-backend)))
+                    (if (functionp backend-url)
+                        (funcall backend-url) backend-url)))
          (data (encode-coding-string
                 (json-encode (gptel--request-data gptel-backend prompts))
                 'utf-8))
          (headers
           (append '(("Content-Type" . "application/json"))
-                  (when-let ((backend-header (gptel-backend-header gptel-backend)))
-                    (if (functionp backend-header)
-                        (funcall backend-header)
-                      backend-header)))))
+                  (when-let ((header (gptel-backend-header gptel-backend)))
+                    (if (functionp header)
+                        (funcall header) header)))))
     (append
      gptel-curl--common-args
      (list (format "-w(%s . %%{size_header})" token))
diff --git a/gptel-gemini.el b/gptel-gemini.el
index 7763c18..63453b6 100644
--- a/gptel-gemini.el
+++ b/gptel-gemini.el
@@ -139,19 +139,14 @@ function that returns the key."
                   :protocol protocol
                   :endpoint endpoint
                   :stream stream
+                  :key key
                   :url
-                  (let ((key (cond
-                              ((functionp key) (funcall key))
-                              ((symbolp key) (symbol-value key))
-                              ((stringp key) key)
-                              (t (user-error "gptel-make-gemini: arg :key is malformed")))))
-                    (if protocol
-                        (concat protocol "://" host endpoint
-                                (if stream
-                                    "streamGenerateContent"
-                                  "generateContent")
-                                "?key=" key)
-                      (concat host endpoint "?key=" key))))))
+                  (lambda ()
+                    (concat protocol "://" host endpoint
+                            (if gptel-stream
+                                "streamGenerateContent"
+                              "generateContent")
+                            "?key=" (gptel--get-api-key))))))
     (prog1 backend
       (setf (alist-get name gptel--known-backends
                        nil nil #'equal)
diff --git a/gptel.el b/gptel.el
index b1da565..b2ddb5b 100644
--- a/gptel.el
+++ b/gptel.el
@@ -979,16 +979,17 @@ the response is inserted into the current buffer after point."
          (url-request-method "POST")
          (url-request-extra-headers
           (append '(("Content-Type" . "application/json"))
-                  (when-let ((backend-header (gptel-backend-header gptel-backend)))
-                    (if (functionp backend-header)
-                        (funcall backend-header)
-                      backend-header))))
+                  (when-let ((header (gptel-backend-header gptel-backend)))
+                    (if (functionp header)
+                        (funcall header) header))))
         (url-request-data
          (encode-coding-string
           (json-encode (gptel--request-data
                         gptel-backend (plist-get info :prompt)))
           'utf-8)))
-    (url-retrieve (gptel-backend-url gptel-backend)
+    (url-retrieve (let ((backend-url (gptel-backend-url gptel-backend)))
+                    (if (functionp backend-url)
+                        (funcall backend-url) backend-url))
                   (lambda (_)
                     (pcase-let ((`(,response ,http-msg ,error)
                                  (gptel--url-parse-response backend (current-buffer))))