;;; demo.lisp — cl-tty interactive demo
;;; Run: sbcl --script demo.lisp
;;;
;;; Demonstrates: backend detection, raw terminal mode, key/mouse input,
;;; layout engine, component rendering pipeline, framebuffer diff flush,
;;; text-input, textarea, select, dialog, scrollbox, tabbar.

(load "~/quicklisp/setup.lisp")
(ql:register-local-projects)
(ql:quickload :cl-tty :silent t)

(use-package :cl-tty.backend)
(use-package :cl-tty.input)
(use-package :cl-tty.box)
(use-package :cl-tty.layout)
(use-package :cl-tty.rendering)

;;; ─── Application state ───────────────────────────────────────────────────────

(defvar *app* nil "Application state plist")
(defvar *log* nil "Circular log buffer")
(defvar *log-pos* 0)

(defun log-append (fmt &rest args)
  (let* ((msg (apply #'format nil fmt args))
         (ts (multiple-value-bind (h m s) (get-decoded-time)
               (format nil "~2,'0d:~2,'0d:~2,'0d" h m s))))
    (push (format nil "[~a] ~a" ts msg) *log*)
    (when (> (length *log*) 100) (setf *log* (subseq *log* 0 100)))))

(defun init-app-state ()
  (setf *log* nil *log-pos* 0)
  (setf *app* (list :tab 0
                    :input (make-text-input :placeholder "Type here...")
                    :textarea (make-textarea :value "Hello\nWorld")
                    :running t
                    :mouse-x -1 :mouse-y -1))
  (log-append "Demo started"))

;;; ─── Tab renderers ──────────────────────────────────────────────────────────

(defun render-tab-home (backend x y w h)
  "Welcome screen with version info."
  (draw-border backend x y w h :style :double :title " Welcome ")
  (draw-text backend (+ x 2) (+ y 2) "cl-tty — Pure CL Terminal UI Framework" :bright-white nil :bold t)
  (draw-text backend (+ x 2) (+ y 4) "  components: Box, Text, TextInput, TextArea, Select," nil nil)
  (draw-text backend (+ x 2) (+ y 5) "              ScrollBox, TabBar, Dialog, Toast, Markdown" nil nil)
  (draw-text backend (+ x 2) (+ y 6) "  features:   24-bit truecolor, OSC 8 links, SGR mouse," nil nil)
  (draw-text backend (+ x 2) (+ y 7) "              DECICM sync, kitty keyboard, framebuffer" nil nil)
  (draw-text backend (+ x 2) (+ y 8) "  backend:    modern-backend | simple-backend (pipe-safe)" nil nil)
  (draw-text backend (+ x 2) (+ y 9) "  tests:      392, 100% passing" :green nil :bold t)
  (draw-text backend (+ x 2) (+ y 10) "  deps:       zero FFI, zero ncurses, pure CL" :bright-cyan nil)
  (draw-text backend (+ x 2) (+ y 12) "Controls" :bright-white nil :bold t)
  (draw-text backend (+ x 2) (+ y 13) "  Tab / arrows      switch tabs" nil nil)
  (draw-text backend (+ x 2) (+ y 14) "  q / Ctrl+C / Esc  quit" nil nil)
  (draw-text backend (+ x 2) (+ y 15) "  mouse click/drag  select text (test SGR mouse)" nil nil))

(defun render-tab-widgets (backend x y w h input ta)
  "Interactive widget demo."
  (declare (ignore h))
  (draw-border backend x y w 12 :style :single :title " Text Input ")
  (draw-text backend (+ x 2) (+ y 1) "Value: " :text-muted nil)
  (draw-text backend (+ x 10) (+ y 1) (text-input-value input) :text nil)
  (draw-text backend (+ x 2) (+ y 3) "Placeholder: \"Type here...\"" :text-muted nil)
  (draw-text backend (+ x 2) (+ y 5) "Keys: type to insert, arrows to move," nil nil)
  (draw-text backend (+ x 2) (+ y 6) "Enter to submit, Backspace to delete," nil nil)
  (draw-text backend (+ x 2) (+ y 7) "Ctrl+A/E for home/end" nil nil)
  (when (plusp (length (text-input-value input)))
    (draw-text backend (+ x 2) (+ y 9) (format nil "Submitted: ~a" (text-input-value input)) :accent nil))

  (let ((y2 (+ y 13)))
    (draw-border backend x y2 w 8 :style :single :title " TextArea ")
    (draw-text backend (+ x 2) (+ y2 1) "Value:" :text-muted nil)
    (loop for line in (textarea-lines ta)
          for row from 0 below 4
          do (draw-text backend (+ x 2) (+ y2 2 row)
                        (subseq line 0 (min (length line) (- w 4))) nil nil))))

(defun render-tab-console (backend x y w h)
  "Event log / debug console."
  (draw-border backend x y w h :style :single :title " Event Log ")
  (draw-text backend (+ x 2) (+ y 1) "Last 50 keyboard and mouse events:" :text-muted nil)
  (let* ((visible (min (length *log*) h))
         (lines (subseq *log* 0 visible)))
    (loop for line in lines
          for row from 0 below (min visible (- h 2))
          do (draw-text backend (+ x 2) (+ y 3 row)
                        (subseq line 0 (min (length line) (- w 4))) nil nil))))

;;; ─── Main loop ──────────────────────────────────────────────────────────────

(defun handle-event (event)
  "Process a key-event or mouse-event, returning t if consumed."
  (typecase event
    (key-event
     (let ((key (key-event-key event))
           (ctrl (key-event-ctrl event)))
       (log-append "Key: ~a (ctrl=~a alt=~a shift=~a)" key ctrl (key-event-alt event) (key-event-shift event))
       (cond
         ;; Tab navigation
         ((and (eql key :tab) ctrl) nil)  ; handled by global loop
         ;; Quit
         ((or (eql key :|Q|) (and ctrl (eql key :|C|)) (eql key :escape))
          (setf (getf *app* :running) nil) t)
         ;; Tab switching (left/right)
         ((eql key :left)
          (decf (getf *app* :tab))
          (when (minusp (getf *app* :tab)) (setf (getf *app* :tab) 2)) t)
         ((eql key :right)
          (incf (getf *app* :tab))
          (when (> (getf *app* :tab) 2) (setf (getf *app* :tab) 0)) t)
         ;; Forward key to active widget
         (t (handle-text-input (getf *app* :input) event)
            (handle-textarea-input (getf *app* :textarea) event)
            t))))
    (mouse-event
     (log-append "Mouse: ~a btn=~a pos=(~d,~d)" (mouse-event-type event)
                 (mouse-event-button event) (mouse-event-x event) (mouse-event-y event))
     (setf (getf *app* :mouse-x) (mouse-event-x event)
           (getf *app* :mouse-y) (mouse-event-y event))
     t)))

(defun run-demo ()
  (with-raw-terminal
    (init-app-state)
    (let* ((backend (detect-backend)))
      (initialize-backend backend)
      (unwind-protect
           (let* ((w 80) (h 24))
             (loop while (getf *app* :running)
                   do
                   ;; Clear and draw
                   (backend-clear backend)
                   ;; Title bar
                   (draw-border backend 2 1 (- w 4) 3 :style :double :title " cl-tty v0.15.0 ")
                   (draw-text backend 4 2 "arrows/tab: tabs   type: test input   mouse: test SGR   q/esc: quit"
                              :bright-white nil)
                   ;; Tab bar
                   (loop for (label . idx) in '((" Home " . 0) (" Widgets " . 1) (" Console " . 2))
                         for x-pos = 8 then (+ x-pos label-len 4)
                         for label-len = (length label)
                         do (let ((active (eql idx (getf *app* :tab))))
                              (if active
                                  (draw-text backend x-pos 4 label :bright-white :accent :bold t)
                                  (draw-text backend x-pos 4 label :text-muted nil))))
                   ;; Content area
                   (case (getf *app* :tab)
                     (0 (render-tab-home  backend 4 6 72 16))
                     (1 (render-tab-widgets backend 4 6 72 24
                                            (getf *app* :input)
                                            (getf *app* :textarea)))
                     (2 (render-tab-console backend 4 6 72 16)))
                   ;; Mouse cursor indicator
                   (let ((mx (getf *app* :mouse-x))
                         (my (getf *app* :mouse-y)))
                     (when (and (>= mx 0) (>= my 0))
                       (draw-text backend mx my "●" :bright-cyan nil)))
                   ;; Status bar
                   (draw-rect backend 2 23 (- w 4) 1 :bg :blue)
                   (draw-text backend 4 23
                              (format nil " Tab ~d/3 | ~d events received "
                                      (1+ (getf *app* :tab)) (length *log*))
                              :bright-white :blue :bold t)
                   ;; Flush
                   (finish-output *standard-output*)
                   ;; Read event — timeout so the render loop keeps going
                   (let ((event (read-event backend :timeout nil)))
                     (when event
                       (handle-event event)))))
        (shutdown-backend backend)))))

(uiop:quit (if (ignore-errors (run-demo)) 0 1))