#lang debug racket/base
(require racket/string
         racket/format
         racket/match
         "attr.rkt"
         "quad.rkt"
         "pipeline.rkt"
         "struct.rkt")
(provide (all-defined-out))

(define-pass (make-drawing-insts qs)
  ;; TODO: stronger precondition. but `has-position?` is too strong
  #:pre (list-of quad?)
  #:post (list-of $drawing-inst?)
  (apply append
         (let ([current-font #false])
           (for/list ([q (in-list qs)])
             (cond
               [(eq? bod q) (list ($doc-start))]
               [(eq? eod q) (list ($doc-end))]
               [(bop-quad? q) (list ($page-start (quad-ref q :page-width) (quad-ref q :page-height)))]
               [(eop-quad? q) (list ($page-end))]
               [(quad? q)
                (append
                 (match (quad-ref q :font-path)
                   [(== current-font) null]
                   [font-path
                    (set! current-font font-path)
                    (list ($font font-path))])
                 (if (pair? (quad-elems q))
                     (list ($move (quad-origin q)) ($text (char->integer (car (string->list (car (quad-elems q)))))))
                     null))]
               [else (raise-argument-error 'make-drawing-insts "known thing" q)])))))

(define valid-tokens '(doc-start doc-end page-start page-end text move set-font))

(define-pass (stackify xs)
  #:pre (list-of $drawing-inst?)
  #:post string?
  (define move-points (map $move-posn (filter $move? xs)))
  (define xmax (if (pair? move-points) (add1 (apply max (map $point-x move-points))) 0))
  (define ymax (if (pair? move-points) (add1 (apply max (map $point-y move-points))) 0))
  (string-join
   (for/list ([x (in-list xs)])
     (string-join (map ~a (match x
                            ;; TODO: embed these code-generating functions
                            ;; as properties of the structs
                            [($move ($point x y)) (list y x 'move)]
                            [($text charint) (list charint 'text)]
                            [($font path-string) (list path-string 'set-font)]
                            [($doc-start) '(doc-start)]
                            [($doc-end) '(doc-end)]
                            [($page-start width height) (list height width 'page-start)]
                            [($page-end) '(page-end)]
                            [_ (error 'unknown-drawing-inst)])) " ")) "\n"))