(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 (only (srfi 1) list-copy))
(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")

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

;group rest arg is (list-of shape-plotter) or (list (list-ofshape-plotter))
;due to new group not using `apply'

(: 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

#; ;w/ check- & error-
(define (real-shape-vgroup #!rest args)
  (let ((shps (check-shapes 'real-shape-vgroup
                            (if (%length-1/kind? args list?) (car args)
                                args))) )
    (lambda (#!optional cv x0 y0)
      (if cv
          (begin
            (check-real-xy 'real-shape-vgroup x0 y0)
            (*canvas-draw-vgroup (check-canvas 'real-shape-vgroup cv)
                                 x0 y0 shps) )
          (^real-info 'vgroup shps)) ) ) )

(define (real-shape-vgroup #!rest args)
  (let ((shps (if (%length-1/kind? args list?) (car args) args)))
    (assert (%shapes? shps) 'real-shape-vgroup "bad argument type - not list-of shape" shps)
    (lambda (#!optional cv x0 y0)
      (if cv
          (*canvas-draw-vgroup cv x0 y0 shps)
          (^real-info 'vgroup shps) ) ) ) )

(define (shape-vgroup #!rest args)
  (let ((shps (if (%length-1/kind? args list?) (car args) args)))
    (assert (%shapes? shps) 'shape-vgroup "bad argument type - not list-of shape" shps)
    (lambda (#!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))) ) )

(define-inline (what-per shps per)
  (if (null? (cdr shps))
      ;then this is last
      (round per)
      ;else per bit
      (floor per)) )

(define (class-shape-layout shp info bb)
  (let-values (((rqr-wd rqr-ht) (class-shape-size shp info))) ;short-cut
    ; v is bottom to top
    (let* ((shps (*info-elements info))
           (nshps (length shps))
           (ht-per (/ (%rect-ht bb) nshps)) )
      (let ((rem-x (%rect-x bb))
            (rem-wd (%rect-wd bb))
            (rem-ht (%rect-ht bb)) )
        (if (or (< (%rect-wd bb) rqr-wd) (< (%rect-ht bb) rqr-ht))
            ;then can't fit
            (error 'vgroup-layout "overflows bounding-box" rqr-wd rqr-ht bb)
            ;else try to fit
            (let loop ((shps (reverse shps))
                       (new-y (%rect-y bb)) (rem-ht rem-ht)
                       (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 (what-per shps ht-per))
                           (this-bb (%rect rem-x new-y rem-wd this-ht)) ) ;rem-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))) ) ) ) )

(define (class-shape-reify-args noshp noinfo args)
  (let ((elm-infos (car args)))
    `(,(map shape-reify elm-infos) ,@(cdr args)) ) )

(define (class-shape-reflect shp info)
  (^info (@info-class info) (@info-coords info)
         (map (cut shape-reflect <>) (*info-elements info)) ) )

(register-shape 'vgroup shape-vgroup real-shape-vgroup)
(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) (list-copy (*info-elements info))))
(register-shape-method 'vgroup 'layout class-shape-layout)
(register-shape-method 'vgroup 'justified? class-shape-justified?)
(register-shape-method 'vgroup 'reify-args class-shape-reify-args)
(register-shape-method 'vgroup 'reflect class-shape-reflect)

) ;module (s9fes char-canvas shape vgroup)