Remove all own formatting code in favor of markdown-mode formatting

Do not attempt to format the Markdown returned by FastGPT ourselves,
but rely on markdown-mode to do this for us. This means an additional
dependency on the kagi.el package.

Cask

@@ -8,6 +8,7 @@
  "kagi.el"
  "ob-kagi-fastgpt.el")
 
+(depends-on "markdown-mode")
 (depends-on "shell-maker")
 
 (development

kagi.el

@@ -6,7 +6,7 @@
 ;; Maintainer: Bram Schoenmakers <me@bramschoenmakers.nl>
 ;; Created: 16 Dec 2023
 ;; Package-Version: 0.5
-;; Package-Requires: ((emacs "29.1") (shell-maker "0.46.1"))
+;; Package-Requires: ((emacs "29.1") (markdown-mode "2.6") (shell-maker "0.46.1"))
 ;; Keywords: terminals wp
 ;; URL: https://codeberg.org/bram85/kagi.el
 
@@ -53,6 +53,7 @@
 
 ;;; Code:
 
+(require 'markdown-mode)
 (require 'shell-maker)
 
 (defcustom kagi-api-token nil
@@ -203,14 +204,20 @@ returns a bullet list."
   "Face for bold parts in the Kagi output."
   :group 'kagi)
 
+(define-obsolete-face-alias 'kagi-bold nil "0.6")
+
 (defface kagi-italic '((t :inherit italic))
   "Face for italic parts in the Kagi output."
   :group 'kagi)
 
+(define-obsolete-face-alias 'kagi-italic nil "0.6")
+
 (defface kagi-code '((t :inherit fixed-pitch))
   "Face for code parts in the Kagi output."
   :group 'kagi)
 
+(define-obsolete-face-alias 'kagi-code nil "0.6")
+
 (defun kagi--gethash (hash &rest keys)
   "Get the value inside a (nested) HASH following the sequence of KEYS."
   (let ((value hash))
@@ -221,43 +228,6 @@ returns a bullet list."
         nil
       value)))
 
-(defconst kagi--markup-to-face
-  '(("<b>" "</b>" kagi-bold)
-    ("**" "**" kagi-bold)
-    ("$" "$" kagi-italic)
-    ("```" "```" kagi-code))
-  "Contains a mapping from markup elements to faces.")
-
-(defun kagi--convert-markup-to-faces (string)
-  "Convert markup elements inside STRING to faces.
-
-Fun fact: the initial version of this function was generated by
-FastGPT with the following prompt:
-
-  write an Emacs Lisp function that accepts a string with html
-  bold tags, and returns a string with bold face text properties
-  applied for the tags content and the tags removed"
-  (with-temp-buffer
-    (insert string)
-    (dolist (entry kagi--markup-to-face)
-      (cl-destructuring-bind (start end face) entry
-        (goto-char (point-min))
-        (let ((regexp (rx (seq (literal start)
-                               (group (*? any))
-                               (literal end)))))
-          (while (re-search-forward regexp nil t)
-            (let ((escaped-replacement (string-replace "\\" "\\\\" (match-string 1))))
-              (replace-match (propertize escaped-replacement 'font-lock-face face) t nil))))))
-    (buffer-string)))
-
-(defun kagi--format-output (output)
-  "Format the OUTPUT by replacing markup elements to proper faces."
-  (kagi--convert-markup-to-faces output))
-
-(defun kagi--format-reference-index (i)
-  "Format the index of reference number I."
-  (propertize (format "[%d]" i) 'font-lock-face 'kagi-bold))
-
 (defun kagi--format-references (references)
   "Format the REFRENCES as a string.
 
@@ -269,9 +239,8 @@ https://help.kagi.com/kagi/api/fastgpt.html for more information."
                             (snippet (gethash "snippet" ref))
                             (url (gethash "url" ref)))
                         (format "%s %s\n%s\n%s"
-                                (kagi--format-reference-index (1+ i))
-                                title
-                                (kagi--convert-markup-to-faces snippet) url)))
+                                (format "[%d]" (1+ i))
+                                title snippet url)))
                     references)
    "\n\n"))
 
@@ -375,7 +344,7 @@ Lisp code."
          (references (kagi--gethash parsed-response "data" "references")))
     (if output
         (string-trim (format "%s\n\n%s"
-                             (kagi--format-output output)
+                             output
                              (kagi--format-references references)))
       (if-let ((firsterror (aref (kagi--gethash parsed-response "error") 0)))
           (error (format "%s (%s)"
@@ -391,9 +360,7 @@ Lisp code."
     (with-current-buffer (get-buffer-create buffer-name)
       (save-excursion
         (insert result))
-      (if (featurep 'markdown-mode)
-          (markdown-mode)
-        (text-mode))
+      (markdown-mode)
       (read-only-mode)
       (display-buffer buffer-name))))
 
@@ -682,7 +649,7 @@ content."
                           (kagi--call-text-summarizer text-or-url)))
               (parsed-response (json-parse-string response))
               (output (kagi--gethash parsed-response "data" "output")))
-        (kagi--format-output output)
+        output
       (if-let ((firsterror (aref (kagi--gethash parsed-response "error") 0)))
           (error (format "%s (%s)"
                          (gethash "msg" firsterror)