(module (s9fes char-canvas shape vgroup)

(;export
  ;
  real-shape-vgroup
  ;
  shape-vgroup)

(import scheme utf8)
(import (chicken base))
(import (chicken fixnum))
(import (chicken type))
(import record-variants)
(import (s9fes char-canvas)
        (s9fes char-canvas rect)
        (s9fes char-canvas shape shape))

(include-relative "s9fes.char-canvas.types")
(include-relative "s9fes.char-canvas.inlines")

(: real-shape-vgroup (#!rest real-shape-plotter -> real-shape-plotter))
(: shape-vgroup (#!rest shape-plotter -> shape-plotter))

;; Private

(define (*info-elements info) (the (list-of shape-plotter) (@info 0 info)))

(define (*new-vgroup info elms)
  (case (@info-coords info)
    ((real) (real-shape-vgroup elms))
    (else   (shape-vgroup elms))) )

(define (*canvas-draw-vgroup cv x0 y0 shps)
  ;FIXME
  (define (next shp x y) (receive (w h) (shape-size shp) (values x (fx+ y h))))
  (let loop ((shps (reverse shps)) (x x0) (y y0))
    (unless (null? shps)
      (let ((shp (car shps)))
        (shp cv x y)
        (receive (x y) (next shp x y)
          (loop (cdr shps) x y)) ) ) )
  cv )

(define (*canvas-plot-vgroup cv x0 y0 shps)
  ;FIXME
  (define (next shp x y) (receive (w h) (shape-size shp) (values x (+ y h))))
  (let loop ((shps (reverse shps)) (x x0) (y y0))
    (unless (null? shps)
      (let ((shp (car shps)))
        (shp cv x y)
        (receive (x y) (next shp x y)
          (loop (cdr shps) x y)) ) ) )
  cv )

;; Public

(define ((real-shape-vgroup #!rest shps) #!optional cv x0 y0)
  (if cv
      (*canvas-draw-vgroup cv x0 y0 shps)
      (^real-info vgroup shps) ) )

;;

(define ((shape-vgroup #!rest shps) #!optional cv x0 y0)
  (if cv
      (*canvas-plot-vgroup cv 0 y0 shps)
      (^virtual-info vgroup shps) ) )

;;

(define (class-shape-size shp info)
  (let* ((shps (*info-elements info))
         (sizs (map (lambda (shp) (receive (shape-size shp))) shps)) )
    (values (apply max (map car sizs)) (apply + (map cadr sizs))) ) )

;FIXME layout should take wd & ht (as original, dip)

(define (class-shape-layout shp info bb)
  ;FIXME finish apportionment - rqr-wd rqr-ht
  (let-values (((rqr-wd rqr-ht) (class-shape-size shp info)))
    ; v is bottom to top
    (let* ((shps (reverse (*info-elements info)))
           (ht-per (/ (%rect-ht bb) (length shps)))
           (rem-x (%rect-x bb))
           (rem-wd (%rect-wd bb)) )
      (if (or (< (%rect-wd bb) rqr-wd) (< (%rect-ht bb) rqr-ht))
          ;then can't fit
          ;FIXME should error? or just stack
          (let ((outs (map (cut shape-layout <> bb) shps)))
            (*new-vgroup info outs) )
          ;else try to fit
          (let loop ((shps shps) (new-y (%rect-y bb)) (rem-ht (%rect-ht bb)) (jsts '()))
            ;FIXME what if out of room
            (if (null? shps)
                (*new-vgroup info jsts)
                (let ((shp (car shps)))
                  ;FIXME new-ht negotiated how?
                  (let* ((this-ht ht-per) ;FIXME !!!!!!
                         (this-bb (%rect rem-x new-y rem-wd this-ht)) )
                    (loop (cdr shps)
                          (+ new-y this-ht) (- rem-ht this-ht)
                          (cons (shape-layout shp this-bb) jsts) ) ) ) ) ) ) ) ) )

(define (class-shape-justified? shp info)
  (let loop ((shps (*info-elements info)))
    (or (null? shps)
        (let ((shp (car shps)))
          (and (shape-justified? shp)
               (loop (cdr shps))) ) ) ) )

(register-shape-method 'vgroup 'size class-shape-size)
(register-shape-method 'vgroup 'cardinality (lambda (shp info) (length (*info-elements info))))
(register-shape-method 'vgroup 'elements (lambda (shp info) (*info-elements info)))
(register-shape-method 'vgroup 'layout class-shape-layout)
(register-shape-method 'vgroup 'justified? class-shape-justified?)

) ;module (s9fes char-canvas shape vgroup)