;;; llm-chat-deepseek.el --- Implements deepseek llm intergration -*- lexical-binding: t; -*-

;; This file is not part of GNU Emacs.

;;; License:

;; llm-chat-deepseek.el is free software: you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.

;; llm-chat-deepseek.el is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with this program.  If not, see <https://www.gnu.org/licenses/>.

;;; Code:

(require 'llm-chat-api)

(defvar llm-chat-deepseek-models '("deepseek-chat" "deepseek-coder" "deepseek-reasoner"))

(cl-defgeneric llm-chat-resolve-model-backend ((backend (eql 'deepseek))
					       model)
  (if (member model llm-chat-deepseek-models)
      t))

(defun llm-chat-deepseek-get-model ()
  (if (member (llm-chat-get-model) llm-chat-deepseek-models)
      (llm-chat-get-model)
    "deepseek-coder"))

(defun llm-chat-make-deepseek-backend ()
  (make-llm-chat-backend
   :api-endpoint "https://api.deepseek.com/chat/completions"
   :api-key (auth-source-pick-first-password :host "api.deepseek.com")
   :headers-fn #'llm-chat-deepseek-headers
   :json-fn #'llm-chat-deepseek-json
   :filter-fn #'llm-chat-deepseek-filter))

(defun llm-chat-deepseek-json ()
  (let ((json-object `((model . ,(llm-chat-deepseek-get-model))
		       (messages . ,(llm-chat-get-history))
		       (temperature . ,(llm-chat-get-temperature))
		       (stream . ,(llm-chat-get-stream?)))))
    (json-encode json-object)))

(defun llm-chat-deepseek-headers (backend)
  (list "-H" (concat "Authorization: " (concat "Bearer "
					       (llm-chat-backend-api-key backend)))))

(defun llm-chat-deepseek-filter (proc string)
  (llm-chat-data-filter proc string
			#'llm-chat-deepseek-finished-p
			#'llm-chat-deepseek-parse-content))

(defun llm-chat-deepseek-finished-p (match)
  (string-equal "[DONE]" match))

(defun llm-chat-deepseek-parse-content (string)
  (let* ((json-object (json-read-from-string string))
	 (choices (alist-get 'choices json-object))
	 (first-choice (aref choices 0))
	 (delta (alist-get 'delta first-choice))
	 (content (alist-get 'content delta nil))
	 (reasoning-content (when (assoc 'reasoning_content delta)
			     (alist-get 'reasoning_content delta nil))))
    (cond
     ((and (stringp content) (not (equal content "null"))) content)
     ((stringp reasoning-content) reasoning-content))))

(provide 'llm-chat-deepseek)

;;; llm-chat-deepseek.el ends here