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

;; This file is not part of GNU Emacs.

;;; License:

;; llm-chat-claude.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-claude.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-claude-models '("claude-3-7-sonnet-latest" "claude-3-5-haiku-latest" "claude-3-5-sonnet-latest" "claude-3-sonnet-20240229" "claude-3-haiku-20240307"))

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

(defun llm-chat-claude-get-model ()
  (if (member (llm-chat-get-model) llm-chat-claude-models)
      (llm-chat-get-model)
    "claude-3-haiku-20240307"))

(defun llm-chat-make-claude-backend ()
  (make-llm-chat-backend
   :api-endpoint "https://api.anthropic.com/v1/messages"
   :api-key (auth-source-pick-first-password :host "api.anthropic.com")
   :headers-fn #'llm-chat-claude-headers
   :json-fn #'llm-chat-claude-json
   :filter-fn #'llm-chat-claude-filter))

(defun llm-chat-claude-json ()
  (let ((json-object `((model . ,(llm-chat-claude-get-model))
		       (system . ,(llm-chat-get-system-prompt))
		       (messages . ,(cdr (llm-chat-get-history)))
		       (temperature . ,(llm-chat-get-temperature))
		       (max_tokens . 4096)
		       (stream . ,(llm-chat-get-stream?)))))
    (json-encode json-object)))

(defun llm-chat-claude-headers (backend)
  (list "-H" "anthropic-version: 2023-06-01"
	"-H" (concat "x-api-key: " (llm-chat-backend-api-key backend))))

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

(defun llm-chat-claude-finished-p (string)
  (let* ((json-object (json-read-from-string string))
	 (type (alist-get 'type json-object)))
    (string-equal type "message_stop")))

(defun llm-chat-claude-parse-content (string)
  (when-let* ((json-object (json-read-from-string string))
	      (type (alist-get 'type json-object))
	      (delta (alist-get 'delta json-object))
	      (text (alist-get 'text delta)))
    (when (string-equal type "content_block_delta")
      text)))

(provide 'llm-chat-claude)

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