;;; llm-chat.el --- Use llm's in emacs -*- lexical-binding: t; -*-

;; This file is not part of GNU Emacs.

;; Copyright (C) 2025 Devyn Challman

;; Author: Devyn Challman devyn@challman.org
;; Maintainer: Devyn Challman devyn@challman.org
;; Version: 0.0.1
;; Keywords: llm, ai, chat

;;; License:

;; llm-chat.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.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 'transient)
(require 'llm-chat-api)
(require 'llm-chat-replacements)
(require 'llm-chat-gemini)
(require 'llm-chat-claude)
(require 'llm-chat-openai)
(require 'llm-chat-deepseek)

(transient-define-prefix llm-chat-prompt-menu ()
  ["llm-chat prompt menu"
   ("u" "user prompt" llm-chat-insert-user-prompt)
   ("y" "youtube summary" llm-chat-youtube-transcript-prompt)
   ("s" "system prompt" llm-chat-insert-system-prompt)])

(transient-define-prefix llm-chat-settings-menu ()
  ["llm-chat settings menu"
   ("t" "temperature" llm-chat-set-temperature)
   ("s" "stream" ignore)])

(transient-define-prefix llm-chat-model-menu ()
  ["llm-chat settings menu"
   ("dc" "deepseek-chat" (lambda () (interactive) (llm-chat-set-model "deepseek-chat")))
   ("dk" "deepseek-coder" (lambda () (interactive )(llm-chat-set-model "deepseek-coder")))
   ("dr" "deepseek-reasoner" (lambda () (interactive) (llm-chat-set-model "deepseek-reasoner")))
   ("g4" "gpt-4.1" (lambda () (interactive) (llm-chat-set-model "gpt-4.1")))
   ("g5" "gpt-5" (lambda () (interactive) (llm-chat-set-model "gpt-5")))
   ("ch" "claude-3-5-haiku-latest" (lambda () (interactive) (llm-chat-set-model "claude-3-5-haiku-latest")))])

(transient-define-prefix llm-chat-menu ()
  ["llm-chat menu"
   ("p" "prompt evaluate" llm-chat-capture-prompt)
   ("i" "insert prompt" llm-chat-prompt-menu)
   ("m" "model select" llm-chat-model-menu)
   ("hs" "history save" ignore)
   ("hl" "history load" ignore)
   ("hc" "history clear" llm-chat-reset-history)
   ("s" "settings" llm-chat-settings-menu)
   ("q" "close menu" ignore)])

(defun llm-chat-resolve-backend ()
  (cond ((llm-chat-resolve-model-backend 'deepseek (llm-chat-get-model))
	 (llm-chat-make-deepseek-backend))
	((llm-chat-resolve-model-backend 'gemini (llm-chat-get-model))
	 (llm-chat-make-gemini-backend))
	((llm-chat-resolve-model-backend 'claude (llm-chat-get-model))
	 (llm-chat-make-claude-backend))
	((llm-chat-resolve-model-backend 'openai (llm-chat-get-model))
	 (llm-chat-make-openai-backend))
	(t
	 (progn
	   (message "Supported model not selected cannot resolve backend")
	   nil))))

(defun llm-chat-capture-prompt ()
  (interactive)
  (if-let* ((end-pos (point))
	   (search (re-search-backward "(\\(AI\\|USR\\|SYS\\)):" nil t))
	   (match (car (member (match-string 1) '("USR" "SYS"))))
	   (start-pos (+ (point) 6))
	   (prompt (buffer-substring-no-properties start-pos end-pos)))
      (cond ((string= match "USR")
	     (when-let (backend (llm-chat-resolve-backend))
	       (if (not (string= (buffer-name) "*LLM Chat*"))
		   (with-current-buffer (get-buffer-create "*LLM Chat*")
		     (goto-char (point-max))
		     (insert prompt)))
	       (llm-chat-request backend
				 (llm-chat-bulk-replacements-with-dict  prompt (llm-chat-get-replacements-dict)))
	       (goto-char end-pos)))
	    ((string= match "SYS")
	      (progn
	       (llm-chat-set-system-prompt prompt)
	       (goto-char end-pos))))
    (message "could not process prompt, no (USR) or (SYS) prompt")))

(defun llm-chat-youtube-transcript-prompt ()
  (interactive)
  (let ((file (read-file-name "Select YouTube transcript file: ")))
    (when (file-exists-p file)
      (with-current-buffer (get-buffer-create "*LLM Chat*")
	(goto-char (point-max))
	(insert "(USR): You are an expert summarizer tasked with creating a concise, structured summary of a YouTube video based on its subtitles. Follow these rules:

1. **Identify the Core Topic**:
   - What is the main subject of the video? (1 sentence)

2. **Key Points**:
   - Extract 3–5 central arguments, steps, or insights. Use bullet points.
   - Ignore filler words, ads, or off-topic tangents.

3. **Conclusion/Takeaway**:
   - What should the viewer remember? (1–2 sentences)

4. **Style**:
   - Neutral tone, avoid opinionated language.
   - Use plain English (no jargon unless necessary).
   - Keep the summary under 200 words.

Here are the subtitles:\n")
	(insert-file-contents file)
	(goto-char (point-max))
	))))

(provide 'llm-chat)

;;; llm-chat.el ends here