;;; whisper-posframe.el --- Record speech into a posframe -*- lexical-binding: t; -*-

(require 'whisper)
(require 'posframe)

(defgroup whisper-posframe nil
  "Record speech into a temporary posframe buffer."
  :group 'whisper)

(defcustom whisper-posframe-buffer-name "*whisper-capture*"
  "Name of the temporary Whisper capture buffer."
  :type 'string
  :group 'whisper-posframe)

(defcustom whisper-posframe-width 80
  "Width of the Whisper posframe in columns."
  :type 'integer
  :group 'whisper-posframe)

(defcustom whisper-posframe-height 12
  "Height of the Whisper posframe in lines."
  :type 'integer
  :group 'whisper-posframe)

(defvar whisper-posframe--parent-frame nil)

(defvar whisper-posframe-mode-map
  (let ((map (make-sparse-keymap)))
    ;; Finish recording and begin transcription.
    (define-key map (kbd "C-c C-c") #'whisper-posframe-finish)

    ;; Cancel recording/transcription without copying anything.
    (define-key map (kbd "C-c C-k") #'whisper-posframe-cancel)

    ;; Make C-g and Escape dismiss the capture.
    (define-key map (kbd "C-g") #'whisper-posframe-cancel)
    (define-key map (kbd "<escape>") #'whisper-posframe-cancel)

    map)
  "Keymap for `whisper-posframe-mode'.")

(defvar-local whisper-posframe--status-timer nil)

(defun whisper-posframe--recording-p ()
  "Return non-nil when Whisper is recording."
  (process-live-p whisper--recording-process))

(defun whisper-posframe--transcribing-p ()
  "Return non-nil when Whisper is transcribing."
  (process-live-p whisper--transcribing-process))

(defvar whisper-posframe--capture-buffer nil)

(defun whisper-posframe--set-status (status)
  "Display STATUS at the beginning of the capture buffer."
  (when (derived-mode-p 'whisper-posframe-mode)
    (let ((inhibit-read-only t))
      (save-excursion
        (goto-char (point-min))

        ;; Remove the previous status line.
        (when (looking-at "^\\[Whisper:.*\\]\n")
          (delete-region (point)
                         (line-beginning-position 2)))

        ;; Insert the new status line as actual displayed buffer text.
        (insert
         (propertize
          (format "[Whisper: %s]\n" status)
          'face 'font-lock-keyword-face
          'read-only t
          'rear-nonsticky '(read-only face)))))))

(defun whisper-posframe--update-status ()
  "Update the status line according to Whisper's current process."
  (when (buffer-live-p (current-buffer))
    (cond
     ((whisper-posframe--recording-p)
      (whisper-posframe--set-status
       "recording — C-c C-c to finish, C-g or Esc to cancel"))

     ((whisper-posframe--transcribing-p)
      (whisper-posframe--set-status
       "transcribing…"))

     (t
      ;; This can occur briefly while whisper.el is compiling, checking
      ;; its model, or transitioning between recording and transcription.
      (whisper-posframe--set-status
       "preparing Whisper…")))))

(defun whisper-posframe--stop-status-timer ()
  "Stop the status update timer."
  (when (timerp whisper-posframe--status-timer)
    (cancel-timer whisper-posframe--status-timer)
    (setq whisper-posframe--status-timer nil)))

(defun whisper-posframe--copy-and-close ()
  "Copy only the transcription and close the capture posframe."
  (let ((buffer whisper-posframe--capture-buffer))
    (when (buffer-live-p buffer)
      (with-current-buffer buffer
        (whisper-posframe--stop-status-timer)

        (let ((inhibit-read-only t)
              text)
          ;; Remove the status line from the actual capture buffer.
          (save-excursion
            (goto-char (point-min))
            (when (looking-at "^\\[Whisper:.*\\]\n")
              (delete-region (point)
                             (line-beginning-position 2))))

          ;; Extract only the remaining transcription.
          (setq text
                (string-trim
                 (buffer-substring-no-properties
                  (point-min)
                  (point-max))))

          (when (> (length text) 0)
            (kill-new text)
            (message "Whisper transcription copied to the kill ring")))))

      ;; Clear Whisper's asynchronous insertion target.
      (set-marker whisper--marker nil)
      (setq whisper--point-buffer nil)

      ;; Delete the posframe and the known capture buffer.
      (ignore-errors
        (posframe-delete-frame whisper-posframe-buffer-name))

      (when (buffer-live-p buffer)
        (kill-buffer buffer))

      (setq whisper-posframe--capture-buffer nil)))


(define-derived-mode whisper-posframe-mode text-mode "Whisper"
  "Major mode for a temporary Whisper capture buffer."
  (use-local-map whisper-posframe-mode-map)

  (setq-local whisper-insert-text-at-point t)
  (setq-local whisper-display-transcription-buffer nil)

  (whisper-posframe--set-status "preparing Whisper…")

  ;; This hook runs after whisper.el has inserted the final transcription.
  (add-hook 'whisper-after-insert-hook
            #'whisper-posframe--copy-and-close
            nil
            t))

(defun whisper-posframe--delete ()
  "Delete the Whisper posframe, if it exists."
  (when (buffer-live-p (get-buffer whisper-posframe-buffer-name))
    (ignore-errors
      (posframe-delete-frame whisper-posframe-buffer-name))))

(defun whisper-posframe-finish ()
  "Stop recording and begin Whisper transcription."
  (interactive)
  (cond
   ((whisper-posframe--recording-p)
    (whisper-posframe--set-status "transcribing…")
    ;; whisper-run toggles recording off and starts transcription.
    (whisper-run))

   ((whisper-posframe--transcribing-p)
    (message "Whisper is already transcribing"))

   (t
    (message "Whisper is not currently recording"))))

(defun whisper-posframe-cancel ()
  "Cancel the active Whisper operation and close the posframe."
  (interactive)
  (when (or (whisper-recording-p)
            (whisper-transcribing-p))
    ;; `whisper-run' interrupts recording or cancels transcription,
    ;; depending on Whisper's current state.
    (whisper-run))

  (whisper-posframe--stop-status-timer)
  (set-marker whisper--marker nil)
  (setq whisper--point-buffer nil)

  (whisper-posframe--delete)

  (let ((buffer (current-buffer)))
    (when (buffer-live-p buffer)
      (kill-buffer buffer)))

  (message "Whisper recording canceled"))


(defun whisper-posframe--focus (buffer frame)
  "Focus FRAME and select its window displaying BUFFER."
  (when (frame-live-p frame)
    (select-frame-set-input-focus frame)
    (when-let ((window (get-buffer-window buffer frame)))
      (select-window window))
    (with-current-buffer buffer
      (goto-char (point-max)))))

(defun whisper-posframe--start-whisper (buffer)
  "Start Whisper with BUFFER as its explicit insertion target."
  (with-current-buffer buffer
    (setq-local whisper-insert-text-at-point t)

    ;; These are the variables whisper.el uses asynchronously when
    ;; inserting the completed transcription.
    (setq whisper--point-buffer buffer)
    (set-marker whisper--marker (point) buffer)

    (whisper-run)))

;;;###autoload
(defun whisper-posframe-record ()
  "Open a posframe and start recording with Whisper."
  (interactive)
  (require 'whisper)
  (require 'posframe)

  (when (or (whisper-recording-p)
            (whisper-transcribing-p))
    (user-error "Whisper is already busy"))

  (let ((buffer (get-buffer-create whisper-posframe-buffer-name)))
    (setq whisper-posframe--capture-buffer buffer)
    (setq whisper-posframe--parent-frame (selected-frame))

    (with-current-buffer buffer
      (erase-buffer)
      (whisper-posframe-mode)

      ;; Refresh the visible status every 200 ms.
      (setq-local whisper-posframe--status-timer
                  (run-at-time
                   0
                   0.2
                   (lambda (buffer)
                     (when (buffer-live-p buffer)
                       (with-current-buffer buffer
                         (whisper-posframe--update-status))))
                   buffer)))

    ;; `:accept-focus t' ensures that C-g, Escape, and the other local
    ;; keybindings are received by the posframe.
    (let ((posframe
           (posframe-show
            buffer
            :parent-frame (selected-frame)
            :position (point)
            :poshandler #'posframe-poshandler-frame-center
            :width whisper-posframe-width
            :height whisper-posframe-height
            :internal-border-color "gray50"
            :border-width 2
            :accept-focus t)))

      ;; Focus after posframe-show has created and displayed the child frame.
      (run-at-time
       0 nil
       (lambda ()
         (whisper-posframe--focus buffer posframe))))

    ;; Start recording.  `whisper-run' records into the current buffer.
    (whisper-posframe--start-whisper buffer)))

(provide 'whisper-posframe)
;;; whisper-posframe.el ends here