(defpackage #:clog-tut-17
  (:use #:cl #:clog)
  (:export start-tutorial))

(in-package :clog-tut-17)

;;; In this tutorial we will use a CSS only alternative to bootstrap -
;;;   https://www.w3schools.com/w3css/default.asp
;;;
;;; It is also a demonstration of how various ways to use HTML Forms
(defun on-index (body)
  ;; Load css files
  (load-css (html-document body) "https://www.w3schools.com/w3css/4/w3.css")
  (load-css (html-document body) "https://www.w3schools.com/lib/w3-theme-teal.css")
  ;; Setup page
  (setf (title (html-document body)) "Tutorial 17: Hello W3.CSS")
  (let* ((header (create-section body :header :class "w3-container w3-card w3-theme"))
         (tmp    (create-section header :h1 :content "Explore Forms"))
         ;; Main area of page
         (data-area (create-div body :class "w3-container"))
         (tmp (create-hr data-area))
         ;; This is a traditional "post" form that will submit data
         ;; to a server.
         (fcontainer (create-div data-area :class "w3-container"))
         (tmp        (create-section fcontainer :h2 :content "Post Form"))
         (tmp        (create-br fcontainer))
         (form1      (create-form fcontainer :method :post :action "/page2"))
         (finput     (create-form-element form1 :input :name "yourname" :label
                                          (create-label form1 :content "Enter name:")))
         (fsubmit    (create-form-element form1 :submit))
         (tmp        (create-br fcontainer))
         (tmp (create-hr data-area))
         ;; This is a traditional "get" form that will submit data
         ;; to a server.
         (fcontainer (create-div data-area :class "w3-container"))
         (tmp        (create-section fcontainer :h2 :content "Get Form"))
         (tmp        (create-br fcontainer))
         (form2      (create-form fcontainer :method :get :action "/page3"))
         (finput     (create-form-element form2 :input :name "yourname" :label
                                          (create-label form2 :content "Enter name:")))
         (fsubmit    (create-form-element form2 :submit))
         (tmp        (create-br fcontainer))
         (tmp (create-hr data-area))
         ;; This is a file upload form that will submit data and files
         ;; to a server.
         (fcontainer (create-div data-area :class "w3-container"))
         (tmp        (create-section fcontainer :h2 :content "File Upload Form"))
         (tmp        (create-br fcontainer))
         (form4      (create-form fcontainer :method :post
                                             :encoding "multipart/form-data"
                                             :action "/page4"))
         (finput     (create-form-element form4 :file :name "filename"))
         (fsubmit    (create-form-element form4 :submit))
         (tmp        (create-br fcontainer))
         (tmp (create-hr data-area))
         ;; This is a CLOG style form, instead of submitting data
         ;; to another page it is dealt with in place.
         (fcontainer (create-div data-area :class "w3-container"))
         (tmp        (create-section fcontainer :h2 :content "CLOG Style Form"))
         (tmp        (create-br fcontainer))
         (form3      (create-form fcontainer))
         (finput3    (create-form-element form3 :input :name "yourname3" :label
                                          (create-label form3 :content "Enter name:")))
         (fsubmit3   (create-form-element form3 :submit))
         (tmp        (create-br fcontainer))
         (tmp (create-hr data-area))
         (footer (create-section body :footer :class "w3-container w3-theme"))
         (tmp    (create-section footer :p :content "(c) All's well that ends well")))
    (declare (ignore tmp) (ignore finput) (ignore fsubmit))

    (set-on-click fsubmit3
      (lambda (obj)
        (declare (ignore obj))
        (setf (hiddenp data-area) t)
        (place-before footer
                      (create-div body
                         :content (format nil "yourname3 = using NAME-VALUE ~A or VALUE ~A"
                                          (name-value form3 "yourname3")
                                          (value finput3))))))))

(defun on-page2 (body)
  (let ((params (form-post-data body)))
    (create-div body :content params)
    (create-div body :content (format nil "yourname = ~A"
                                      (form-data-item params "yourname")))))

(defun on-page3 (body)
  (let ((params (form-get-data body)))
    (create-div body :content params)
    (create-div body :content (format nil "yourname = ~A"
                                      (form-data-item params "yourname")))))

(defun on-page4 (body)
  (let ((params (form-multipart-data body)))
    (create-div body :content params)
    (destructuring-bind (stream fname content-type)
        (form-data-item params "filename")
      (create-div body :content (format nil "filename = ~A - (contents printed in REPL)" fname))
      (let ((s (flexi-streams:make-flexi-stream stream :external-format :utf-8))
            (b (make-string 1000)))
        (loop
          (let ((c (read-sequence b s)))
            (unless (plusp c) (return))
            (princ (subseq b 1 c))))))
    (delete-multipart-data body)))

(defun start-tutorial ()
  "Start tutorial."
  (initialize 'on-index)
  (set-on-new-window 'on-page2 :path "/page2")
  (set-on-new-window 'on-page3 :path "/page3")
  (set-on-new-window 'on-page4 :path "/page4")
  (open-browser))