; Digital Photo Frame for M5Stack Tab5
;
; see http://forum.ulisp.com/t/a-digital-photo-frame-written-in-lisp/1870

(defun collect-pics-list nil
  (with-client (s "www.wackyimage.com" 80)
    (format s "GET /show?K5A HTTP/1.0~a~%" #\Return)
    (format s "Host: www.wackyimage.com~a~%" #\Return)
    (format s "Cookie: LOGIN=KCJQaG90b0ZyYW1lIiAuICJmYWI1NDlkNmE4YzBmZmE4MTQyYzNjODk2YzRkZDEwMiIp~a~%" #\Return)
    (format s "Connection: close~a~%" #\Return)
    (format s "~a~%" #\Return)
    (skip-headers s)
    (collect-pics s)))

(defun skip-headers (s)
  (loop (when (= (length (read-line s)) 1) (return))))

(defun collect-pics (s)
  (let (line pics)
    (loop
     (setq line (read-line s))
     (when (search "</html>" line) (return pics))
     (let ((pic (search "/k58/" line))
           (end (search "\" alt=\"" line)))
       (when (and pic end) (push (subseq line (+ pic 5) end) pics))))))

(defun display-pic (pic)
  (with-client (s "www.wackyimage.com" 80)
    (format s "GET /pictures/k58/~a HTTP/1.0~a~%" pic #\return)
    (format s "Host: www.wackyimage.com~a~%" #\return)
    (format s "Connection: close~a~%" #\return)
    (format s "~a~%" #\return)
    (skip-headers s)
    (decode-gif s)))

(defvar *minutes* 10)

(defun photo-frame ()
  (wifi-connect "Mynetwork" "mypassword")
  (delay 5000)
  (let ((nextpic 0) (lastpics 0))
    (loop
     (let* ((pics (collect-pics-list))
            (npics (length pics)))
       (when (> npics lastpics)
         (setq nextpic lastpics)
         (setq lastpics npics))
       (display-pic (nth (mod nextpic npics) pics)))
     (incf nextpic)
     (delay (* 1000 60 *minutes*)))))