;;; llm-chat-api.el --- Common interfaces to use -*- lexical-binding: t; -*-

;; This file is not part of GNU Emacs.

;;; Code:

(defvar llm-chat-system-prompt "You are a helpful bot. You make concise accurate responses. You only give the choice you think is best - not multiple examples. You are a professional at creating custom operating systems. Excelling at performance and optimization for running programs on low spec devices that still provide the best user experience")
(defvar llm-chat-history `(((role . "system") (content . ,llm-chat-system-prompt))))
(defvar llm-chat-model nil)
(defvar llm-chat-temperature 0.3)
(defvar llm-chat-stream t)
(defvar llm-chat-buffer nil)
(defvar llm-chat--incomplete "")

(defun llm-chat-get-system-prompt ()
  llm-chat-system-prompt)

(defun llm-chat-set-system-prompt (prompt)
  (setf (cdr (assoc 'content (car llm-chat-history))) prompt)
  (setq llm-chat-system-prompt prompt))

(defun llm-chat-get-history ()
  llm-chat-history)

(defun llm-chat-add-history (entry)
  (setq llm-chat-history (append llm-chat-history entry)))

(defun llm-chat-add-user-history (prompt)
  (llm-chat-add-history `(((role . "user") (content . ,prompt)))))

(defun llm-chat-add-assistant-history (prompt)
  (llm-chat-add-history `(((role . "assistant") (content . ,prompt)))))

(defun llm-chat-reset-history ()
  (interactive)
  (setq llm-chat-history `(((role . "system") (content . ,(llm-chat-get-system-prompt)))))
  (message "history has been reset to current system prompt"))

(defun llm-chat-save-history (path))

(defun llm-chat-load-history (path))

(defun llm-chat-get-model ()
  llm-chat-model)

(defun llm-chat-set-model (model)
  (setq llm-chat-model model)
  (message (concat "model set to " llm-chat-model)))

(defun llm-chat-get-temperature ()
  llm-chat-temperature)

(defun llm-chat-set-temperature (temp)
  (interactive "nenter a value between 0.0 and 1.0: ")
  (if (and (>= temp 0.0) (<= temp 1.0))
      (setq llm-chat-temperature temp)
    (message "temperature must be between 0.0 and 1.0")))

(defun llm-chat-get-stream? ()
  llm-chat-stream)

(defun llm-chat-set-stream (stream?)
  (setq llm-chat-stream stream?))

(defun llm-chat-get-buffer ()
  llm-chat-buffer)

(defun llm-chat-set-buffer (buffer)
  (setq llm-chat-buffer buffer))

(defun llm-chat-insert-user-prompt ()
  (interactive)
  (insert "(USR):"))

(defun llm-chat-insert-system-prompt ()
  (interactive)
  (insert "(SYS):"))

(cl-defstruct llm-chat-backend
  api-endpoint
  api-key
  headers-fn
  json-fn
  filter-fn)

(cl-defgeneric llm-chat-resolve-model-backend (backend model))

(cl-defgeneric llm-chat-request (backend prompt)
  "This is to make a llm api request")

(cl-defmethod llm-chat-request ((backend llm-chat-backend) prompt)
  (llm-chat-set-buffer nil)
  (llm-chat-add-user-history prompt)
  (with-current-buffer (get-buffer-create "*LLM Chat*")
    (unless (derived-mode-p 'markdown-mode)
      (markdown-mode)))
  (let ((temp-file (make-temp-file "llm-chat-request-" nil ".json"))
	(headers-fn (llm-chat-backend-headers-fn backend))
	(json-fn (llm-chat-backend-json-fn backend))
	(filter-fn (llm-chat-backend-filter-fn backend)))
    (with-temp-file temp-file
      (insert (funcall json-fn)))
    (make-process
     :name "llm-chat-stream"
     :command (append (list "curl" "--no-buffer" "-X" "POST"
			    "-H" "Content-Type: application/json"
			    "-d" (concat "@" temp-file)
			    (llm-chat-backend-api-endpoint backend))
		    (funcall headers-fn backend))
     :filter filter-fn)))

(defun llm-chat-data-filter (proc string backend-finished-p-fn backend-parse-content-fn)
  (with-current-buffer (get-buffer-create "*LLM Chat*")
    (save-excursion
      (goto-char (point-max))
      (let ((data (concat llm-chat--incomplete string))
	    (start 0)
	    matches)
	(while (string-match "data: \\(.*\\)\n\n" data start)
	  (write-region data nil "/tmp/stream.txt" t)
	  (push (match-string 1 data) matches)
	  (setq start (match-end 0)))
	(setq llm-chat--incomplete (substring data start))
	(dolist (match (nreverse matches))
	  (if (funcall backend-finished-p-fn match)
	      (progn
		(if (not (bolp)) (insert "\n"))
		(insert "(USR):")
		(llm-chat-add-assistant-history (llm-chat-get-buffer))
		(llm-chat-set-buffer nil)
		(setq llm-chat--incomplete ""))
	    (when-let ((content (funcall backend-parse-content-fn match)))
	      (if (not (llm-chat-get-buffer))
		  (progn
		    (if (not (bolp)) (insert "\n"))
		    (insert "(AI): ")))
	      (insert content)
	      (llm-chat-set-buffer (concat (llm-chat-get-buffer) content)))))))))

(provide 'llm-chat-api)

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