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

* Controller

Event handlers + daemon I/O + main loop.

** Event Handlers
#+begin_src lisp
(in-package :passepartout.gateway-tui)

(defun on-key (&rest args)
  (let ((ch (car args)))
    (cond
      ;; Enter
      ((or (eql ch 10) (eql ch 13) (eq ch :enter)
           (eql ch #\Newline) (eql ch #\Return))
       (let ((text (string-trim '(#\Space #\Tab) (input-string))))
         (when (> (length text) 0)
           (push text (st :input-history))
           (setf (st :input-hpos) 0)
           (setf (st :scroll-offset) 0)
           (cond
             ;; /eval command
             ((and (>= (length text) 6)
                   (string-equal (subseq text 0 6) "/eval "))
              (handler-case
                  (let* ((*read-eval* t)
                         (*package* (find-package :passepartout.gateway-tui))
                         (r (eval (read-from-string (subseq text 6)))))
                    (add-msg :system (format nil "=> ~s" r)))
                (error (c) (add-msg :system (format nil "=> ✗ ~a" c)))))
             ;; Normal message
             (t
              (add-msg :user text)
              (send-daemon (list :type :event
                                :payload (list :sensor :user-input :text text)))))
           (setf (st :input-buffer) nil)
           (setf (st :dirty) (list t t t)))))
      ;; Backspace
      ((or (eql ch 127) (eql ch 8) (eq ch :backspace) (eql ch #\Backspace))
       (when (st :input-buffer) (pop (st :input-buffer)))
       (setf (st :dirty) (list nil nil t)))
      ;; Up arrow
      ((or (eq ch :up) (eql ch 259))
       (let* ((h (st :input-history)) (p (st :input-hpos)))
         (when (and h (< p (1- (length h))))
           (incf (st :input-hpos))
           (setf (st :input-buffer)
                 (reverse (coerce (nth (st :input-hpos) h) 'list)))
           (setf (st :dirty) (list nil nil t)))))
      ;; Down arrow
      ((or (eq ch :down) (eql ch 258))
       (when (> (st :input-hpos) 0)
         (decf (st :input-hpos))
         (let ((h (st :input-history)))
           (setf (st :input-buffer)
                 (if (and h (< (st :input-hpos) (length h)))
                     (reverse (coerce (nth (st :input-hpos) h) 'list))
                     nil))
           (setf (st :dirty) (list nil nil t)))))
      ;; PageUp
      ((or (eq ch :ppage) (eql ch 339))
       (incf (st :scroll-offset) 5)
       (setf (st :dirty) (list nil t nil)))
      ;; PageDown
      ((or (eq ch :npage) (eql ch 338))
       (setf (st :scroll-offset) (max 0 (- (st :scroll-offset) 5)))
       (setf (st :dirty) (list nil t nil)))
      ;; Printable
      (t
       (let ((chr (typecase ch
                    (character ch)
                    (integer (code-char ch))
                    (t nil))))
         (when (and chr (graphic-char-p chr))
           (push chr (st :input-buffer))
           (setf (st :dirty) (list nil nil t))))))))

(defun on-daemon-msg (msg)
  (let* ((payload (getf msg :payload))
         (text (getf payload :text))
         (action (getf payload :action)))
    (cond
      (text (add-msg :agent text))
      ((eq action :handshake)
       (add-msg :system (format nil "Connected v~a" (getf payload :version))))
      (t (add-msg :agent (format nil "~a" msg))))))
#+end_src

** Daemon Communication
#+begin_src lisp
(defun send-daemon (msg)
  (let ((s (st :stream)))
    (when (and s (open-stream-p s))
      (handler-case
          (progn
            (format s "~a" (frame-message msg))
            (finish-output s))
        (error (c) (log-message "TUI-SEND: ~a" c))))))

(defun recv-daemon (s)
  (handler-case
      (let* ((hdr (make-string 6)) (n 0))
        (loop while (< n 6)
              do (let ((ch (read-char s nil)))
                   (unless ch (return-from recv-daemon nil))
                   (setf (char hdr n) ch) (incf n)))
        (let* ((len (parse-integer hdr :radix 16 :junk-allowed t))
               (buf (make-string (or len 0))))
          (when (and len (> len 0))
            (loop for i from 0 below len
                  do (let ((ch (read-char s nil)))
                       (unless ch (return-from recv-daemon nil))
                       (setf (char buf i) ch)))
            (let ((*read-eval* nil))
              (read-from-string buf)))))
    (error (c) (log-message "TUI-RECV: ~a" c) nil)))

(defun reader-loop (s)
  (loop while (and (st :running) (open-stream-p s))
        do (let ((msg (recv-daemon s)))
             (when msg (queue-event (list :type :daemon :payload msg))))))
#+end_src

** Connection
#+begin_src lisp
(defun connect-daemon (&optional (host "127.0.0.1") (port 9105))
  (handler-case
      (let ((s (usocket:socket-connect host port :element-type 'character)))
        (setf (st :stream) (usocket:socket-stream s) (st :connected) t)
        (bt:make-thread (lambda () (reader-loop (st :stream))) :name "tui-reader")
        (add-msg :system "* Connected *")
        t)
    (error (c)
      (add-msg :system (format nil "* Connection failed: ~a *" c))
      nil)))

(defun disconnect-daemon ()
  (when (st :stream)
    (ignore-errors (close (st :stream)))
    (setf (st :stream) nil (st :connected) nil)
    (add-msg :system "* Disconnected *")))
#+end_src

** Main Loop
#+begin_src lisp
(defun tui-main ()
  (init-state)
  (with-screen (scr :input-blocking nil :input-echoing nil :cursor-visible nil)
    (let* ((h (or (height scr) 24))
           (w (or (width scr) 80))
           (sw (make-instance 'window :height 3 :width (- w 2) :y 0 :x 1))
           (ch (- h 5))
           (cw (make-instance 'window :height ch :width (- w 2) :y 3 :x 1))
           (iw (make-instance 'window :height 1 :width (- w 2) :y (- h 1) :x 1))
           (swank-port (or (ignore-errors
                             (parse-integer (uiop:getenv "TUI_SWANK_PORT")))
                           4006)))
      (setf (function-keys-enabled-p iw) t
            (st :dirty) (list t t t))
      (connect-daemon)
      (when (> swank-port 0)
        (handler-case
            (progn
              (ql:quickload :swank :silent t)
              (funcall (find-symbol "CREATE-SERVER" "SWANK")
                       :port swank-port :dont-close t)
              (add-msg :system
                       (format nil "* Swank ~d  M-x slime-connect *" swank-port)))
          (error ()
            (add-msg :system "* Swank unavailable *"))))
      (loop while (st :running) do
        (dolist (ev (drain-queue))
          (when (eq (getf ev :type) :daemon)
            (on-daemon-msg (getf ev :payload))))
        (let ((ch (get-char iw)))
          (when (and ch (not (equal ch -1)))
            (on-key ch)))
        (redraw sw cw ch iw)
        (refresh scr)
        (sleep 0.03))
       (disconnect-daemon))))

#+end_src

* Test Suite
#+begin_src lisp
(eval-when (:compile-toplevel :load-toplevel :execute)
  (ql:quickload :fiveam :silent t))

(defpackage :passepartout-tui-tests
  (:use :cl :passepartout)
  (:export #:tui-suite))

(in-package :passepartout-tui-tests)

(fiveam:def-suite tui-suite :description "Verification of the TUI parsing and styling logic")
(fiveam:in-suite tui-suite)

(fiveam:test test-tui-connection-drop
  "Tier 2 Chaos: Verify that handle-return degrades gracefully when the daemon connection is lost."
  (let ((passepartout.gateway-tui::*incoming-msgs* nil)
        (passepartout.gateway-tui::*input-buffer* (make-array 5 :element-type 'character :initial-contents "hello" :fill-pointer 5 :adjustable t))
        (mock-stream (make-string-output-stream)))
    (close mock-stream)
    (passepartout.gateway-tui::handle-return mock-stream)
    (fiveam:is (member "ERROR: Connection to daemon lost." passepartout.gateway-tui::*incoming-msgs* :test #'string=))))
#+end_src