;;; lc-org.el --- LeetCode CLI integration for org source blocks -*- lexical-binding: t; -*-

;; Usage:
;;   In an org source block:
;;     #+BEGIN_SRC python :lc-problem two-sum
;;     class Solution:
;;         def twoSum(self, nums, target):
;;             ...
;;     #+END_SRC
;;
;;   M-x lc-org-submit   — submit the block's code
;;   M-x lc-org-run      — run with test input
;;   M-x lc-org-status   — check last submission
;;
;; Header args:
;;   :lc-problem SLUG   — problem number or slug (required)
;;   :lc-lang LANG      — language (default: python3)
;;   :lc-input INPUT    — test input for `lc run`

(defvar lc-org-bin "lc"
  "Path to the `lc` CLI binary.
Set this if `lc` is not on PATH, e.g. \"uv run lc\" or \"/home/you/.local/bin/lc\".")

(defvar lc-org-default-lang "python3"
  "Default language when :lc-lang is not specified in the source block.")

(defun lc-org--block-params ()
  "Extract lc parameters and code from the current org source block.
Returns a plist (:problem :lang :input :code) or signals an error."
  (let* ((info (org-babel-get-src-block-info t))
         (lang (nth 0 info))
         (body (nth 1 info))
         (params (nth 2 info))
         (problem (cdr (assq :lc-problem params)))
         (lc-lang (or (cdr (assq :lc-lang params))
                      (cond
                       ((string= lang "python") "python3")
                       ((string= lang "python3") "python3")
                       ((string= lang "cpp") "cpp")
                       ((string= lang "c++") "cpp")
                       ((string= lang "c") "c")
                       ((string= lang "java") "java")
                       ((string= lang "javascript") "javascript")
                       ((string= lang "typescript") "typescript")
                       ((string= lang "rust") "rust")
                       ((string= lang "go") "golang")
                       ((string= lang "golang") "golang")
                       (t lc-org-default-lang))))
         (input (cdr (assq :lc-input params))))
    (unless problem
      (user-error "No :lc-problem header arg on this source block"))
    (list :problem (format "%s" problem) :lang lc-lang :input input :code body)))

(defun lc-org--run-command (cmd)
  "Run CMD in a compilation buffer named *lc*."
  (let ((buf (get-buffer-create "*lc*")))
    (with-current-buffer buf
      (read-only-mode -1)
      (erase-buffer)
      (insert "$ " cmd "\n\n"))
    (make-process
     :name "lc"
     :buffer buf
     :command (list shell-file-name shell-command-switch cmd)
     :sentinel (lambda (proc _event)
                 (when (memq (process-status proc) '(exit signal))
                   (with-current-buffer (process-buffer proc)
                     (goto-char (point-max))
                     (insert "\n--- finished (exit " (number-to-string (process-exit-code proc)) ") ---\n")
                     (read-only-mode 1))
                   (display-buffer (process-buffer proc)))))
    (display-buffer buf)))

(defvar lc-org-mode-map
  (let ((map (make-sparse-keymap))
        (prefix (make-sparse-keymap)))
    (define-key prefix (kbd "s") #'lc-org-submit)
    (define-key prefix (kbd "r") #'lc-org-run)
    (define-key prefix (kbd "t") #'lc-org-status)
    (define-key prefix (kbd "p") #'lc-org-show-problem)
    (define-key prefix (kbd "d") #'lc-org-daily)
    (define-key map (kbd "C-c l") prefix)
    map)
  "Keymap for `lc-org-mode'.")

;;;###autoload
(define-minor-mode lc-org-mode
  "Minor mode for LeetCode CLI integration in org source blocks.
Keybindings under C-c l:
  s  submit   — submit current block
  r  run      — run with test input
  t  status   — check submission status
  p  problem  — show problem description
  d  daily    — today's daily challenge"
  :lighter " LC"
  :keymap lc-org-mode-map)

;;;###autoload
(defun lc-org-submit ()
  "Submit the current org source block to LeetCode."
  (interactive)
  (let* ((params (lc-org--block-params))
         (problem (plist-get params :problem))
         (lang (plist-get params :lang))
         (code (plist-get params :code))
         (tmpfile (make-temp-file "lc-org-" nil
                   (concat "." (cond ((string= lang "python3") "py")
                                     ((string= lang "cpp") "cpp")
                                     ((string= lang "c") "c")
                                     ((string= lang "java") "java")
                                     ((string= lang "javascript") "js")
                                     ((string= lang "typescript") "ts")
                                     ((string= lang "rust") "rs")
                                     ((string= lang "golang") "go")
                                     (t "txt"))))))
    (with-temp-file tmpfile (insert code))
    (lc-org--run-command (format "%s submit %s --lang %s --file %s"
                                 lc-org-bin
                                 (shell-quote-argument problem)
                                 (shell-quote-argument lang)
                                 (shell-quote-argument tmpfile)))))

;;;###autoload
(defun lc-org-run ()
  "Run the current org source block against test input.
Input is taken from :lc-input header arg, or prompted interactively."
  (interactive)
  (let* ((params (lc-org--block-params))
         (problem (plist-get params :problem))
         (lang (plist-get params :lang))
         (code (plist-get params :code))
         (input (or (plist-get params :input)
                    (read-string "Test input: ")))
         (tmpfile (make-temp-file "lc-org-" nil
                   (concat "." (cond ((string= lang "python3") "py")
                                     ((string= lang "cpp") "cpp")
                                     ((string= lang "c") "c")
                                     ((string= lang "java") "java")
                                     ((string= lang "javascript") "js")
                                     ((string= lang "typescript") "ts")
                                     ((string= lang "rust") "rs")
                                     ((string= lang "golang") "go")
                                     (t "txt"))))))
    (with-temp-file tmpfile (insert code))
    (lc-org--run-command (format "%s run %s --lang %s --file %s --input %s"
                                 lc-org-bin
                                 (shell-quote-argument problem)
                                 (shell-quote-argument lang)
                                 (shell-quote-argument tmpfile)
                                 (shell-quote-argument input)))))

;;;###autoload
(defun lc-org-status (submission-id)
  "Check the status of a LeetCode submission by SUBMISSION-ID."
  (interactive "sSubmission ID: ")
  (lc-org--run-command (format "%s status %s"
                               lc-org-bin
                               (shell-quote-argument submission-id))))

;;;###autoload
(defun lc-org-show-problem ()
  "Show the problem description for the :lc-problem on the current block."
  (interactive)
  (let* ((params (lc-org--block-params))
         (problem (plist-get params :problem)))
    (lc-org--run-command (format "%s problems show %s"
                                 lc-org-bin
                                 (shell-quote-argument problem)))))

;;;###autoload
(defun lc-org-daily ()
  "Show today's daily challenge."
  (interactive)
  (lc-org--run-command (format "%s problems daily" lc-org-bin)))

(provide 'lc-org)
;;; lc-org.el ends here