#+TITLE: Passepartout TUI — View
#+PROPERTY: header-args:lisp :tangle ../lisp/gateway-tui-view.lisp

* View

Pure render functions. Each takes a Croatoan window and current state.
State is read via ~(st :key)~ — no mutation here.

** Contract

1. (view-status win): renders the status bar with connection info,
   version, and timestamp.
2. (view-chat win): renders the scrolled chat message list. Messages
   are color-coded: green (user), white (agent), yellow (system).
3. (view-input win): renders the input line with cursor and typing
   indicator.
4. (redraw scr chat-win status-win input-win): dispatches redraws
   based on ~(st :dirty)~ flags. Minimizes terminal writes.

** Status Bar
#+begin_src lisp
(in-package :passepartout.gateway-tui)

(defun view-status (win)
  (clear win)
  (box win 0 0)
  (add-string win
   (format nil " Passepartout  ~a  [~a]  msgs:~a  scroll:~a"
           (if (st :connected) "● Connected" "○ Disconnected")
           (string-upcase (string (st :mode)))
           (length (st :messages))
           (if (> (st :scroll-offset) 0) (format nil "~a↑" (st :scroll-offset)) "0"))
   :y 1 :x 1 :fgcolor (if (st :connected) :green :red))
  (add-string win (format nil " ~a" (now)) :y 2 :x 1 :fgcolor :yellow)
  (refresh win))
#+end_src

** Chat Area
#+begin_src lisp
(defun view-chat (win h)
  (clear win)
  (box win 0 0)
  (let* ((w (or (width win) 78))
         (msgs (reverse (st :messages)))
         (max-lines (- h 2))
         (total (length msgs))
         (start (max 0 (- total max-lines (st :scroll-offset))))
         (y 1))
    (loop for i from start below total
          while (< y (1- h))
          do (let ((msg (nth i msgs)))
               (let* ((role (getf msg :role))
                      (content (getf msg :content))
                      (time (or (getf msg :time) ""))
                      (label (case role
                               (:user (format nil "⬆ [~a] ~a" time content))
                               (:agent (format nil "⬇ [~a] ~a" time content))
                               (:system (format nil "   [~a] ~a" time content))
                               (t (format nil "   [~a] ~a" time content))))
                      (color (case role
                               (:user :green)
                               (:agent :white)
                               (:system :yellow)
                               (t :white))))
                 (add-string win label :y y :x 1 :n (1- w) :fgcolor color)
                 (incf y)))))
  (refresh win))
#+end_src

** Input Line
#+begin_src lisp
(defun view-input (win)
  (let* ((text (input-string))
         (w (or (width win) 78))
         (clip (min (length text) (1- w))))
    (clear win)
    (add-string win (format nil "~a " text) :y 0 :x 0 :n (1- w) :fgcolor :cyan)
    (setf (cursor-position win) (list 0 clip)))
  (refresh win))
#+end_src

** Redraw (dirty-flag dispatch)
#+begin_src lisp
(defun redraw (sw cw ch iw)
  (destructuring-bind (sd cd id) (st :dirty)
    (when sd (view-status sw))
    (when cd (view-chat cw ch))
    (when id (view-input iw))
    (setf (st :dirty) (list nil nil nil))))
#+end_src