;;; load the persons stuff
(load "persons.scm")

;;; some utitlities

(define first car)
(define rest cdr)

;;; some file globals
(define top-frame #f) ; needed to be here because of possible other 
; manipulations as in quit-button-callback

(define a-person (make-object p2% "dummy" "dummy" "dummy" "dummy"))
(define counter 0)
(define persons '())
(define number-of-persons 0)
(define address-file "addresses")
(define dialog-title "Adressausgabe")

;;; some other constants
;; sizes
(define initial-text-field-width 200)
(define initial-text-field-height 30)
(define initial-frame-width 700)
(define initial-frame-height 100)
(define initial-button-width 70)

;; other magical numbers
(define button-label-const 0)
(define button-callback-const 1)


;; in vp1 name-const is the first element
;; 
(define first-name-const 0)
(define name-const 1)

;; in vp2 is address-const the first element
;; reminder: list-ref start with 0
(define address-const 0)
(define email-const 1)
(define vp1 #f) ;; first pane contents First Name, Name
(define vp2 #f) ;; second pane contents Address, Email

;;(send top-frame show #t)
(define (button-list-template) 
  `(("&previous" ,previous-button-callback)
    ("&next" ,next-button-callback)
    ("&Quit" ,quit-button-callback)))


;;; callbacks

(define (quit-button-callback button event) 
  (send top-frame on-exit))


(define (change-persons-data data)
  ;; set the data for a-person to the new values
  ;; from the list of persons
  (set! a-person (send a-person build-from-list data)))


(define (update-persons-data)
  (let* ((el (list-ref persons counter)))
    (change-persons-data el)
    (fill-dialog a-person))
  (values))

(define (previous-button-callback button event)
  (if (= counter 0)
      (set! counter number-of-persons)
      (set! counter (- counter 1)))
  (update-persons-data))
  
  
         
(define (next-button-callback button event)
  (if (= counter number-of-persons)
      (set! counter 0)
      (set! counter (+ counter 1)))
  (update-persons-data))
  

;;; Vertical panes  with simplte text fields for the
;;; objects examples

(define first-vertical-pane-template
  '("First Name: " "Name: "))

(define second-vertical-pane-template
  '("Address: " "Email: "))

(define (make-button label parent callback)
  ;; make a new button with parent <parent> and callback <callback>
  (make-object button% label parent callback))




(define (fill-dialog person)
  ;; possible I would be better of with naming all 
  ;; the text fields
  (let ((elements (send vp1 get-children)))
    (send  (list-ref elements first-name-const) 
           set-value
           (send a-person first-name))
    (send (list-ref elements name-const)
          set-value
          (send a-person last-name))
    (set! elements (send vp2 get-children))
    (send (list-ref elements address-const)
          set-value
          (ivar a-person address))
    (send (list-ref elements email-const)
          set-value
          (ivar a-person email))))
                         
  
    
    

(define (make-button-pane parent)
  ;; two buttons to click through a list of addresses
  ;; one quit button for finishing the program
  (let ((button-pane (make-object vertical-pane% parent)))
    (let loop ((btn-list (button-list-template)))
      (cond 
        ((null? btn-list) '())
        (else (cons (send (make-button 
                           (list-ref (first btn-list) 
                                     button-label-const)
                           button-pane
                           ;void)
                           (list-ref (first btn-list)
                                     button-callback-const)) 
                          min-width initial-button-width)
                    (loop (rest btn-list))))))
    button-pane))
        
(define (make-vertical-pane parent elements)
  ;; a vertical pane just for displayint the contents of a list of
  ;; addresses
  (let ((vertical-pane (make-object vertical-pane% parent)))
    (let loop ((el elements))
      (cond
        ((null? el) '())
        (else (cons (make-single-text-field
                     (first el) ; label for the field
                     vertical-pane 
                     void ; callback here do nothing
                     initial-text-field-width 
                     initial-text-field-height) ;initial size
                    (loop (cdr el))))))
    vertical-pane))

(define (make-single-text-field label parent 
                                callback req-width 
                                req-height)
  ;; make the single text field
  (let ((tf (make-object text-field% 
              label parent 
              callback "" '(single))))
    ;; do not allow filling and/or resizing
    (send tf min-height req-height)
    (send tf stretchable-height #f)
    (send tf min-width req-width)
    ;(send tf stretchable-width #f)
    tf))
                      


(define (make-dialog)
  (let* ((frame (make-object frame% 
                  dialog-title 
                  #f 
                  initial-frame-width
                  initial-frame-height))
         (hp (make-object horizontal-pane% frame))) ;; md 1 
    (set! vp1 (make-vertical-pane hp first-vertical-pane-template))
          ; md 2
    (set! vp2 (make-vertical-pane hp second-vertical-pane-template))
          ; md 2
    (let ((btn-pane (make-button-pane hp)))
          ; md 2
      ;(send frame stretchable-width #f)
      (send frame stretchable-height #f)
      frame)))
    
    

(define (main)
  (set! persons (list-of-persons address-file))
  (set! number-of-persons (- (length persons) 1))
    ;; counting for list-ref starts with 0
  (set! top-frame (make-dialog))
  (update-persons-data)
  (send top-frame show #t))