#lang racket/base

(require ffi/unsafe)

(define libhpdf (ffi-lib "../3rdparty/libhpdf"))

(define pdf-new-raw
  (get-ffi-obj "HPDF_New" libhpdf
               (_fun _int _int -> _pointer)))

(define pdf-save-raw
  (get-ffi-obj "HPDF_SaveToFile" libhpdf
               (_fun _pointer _string/utf-8 -> _int)))

(define pdf-free-raw
  (get-ffi-obj "HPDF_Free" libhpdf
               (_fun _pointer -> _void)))

(define add-page-raw
  (get-ffi-obj "HPDF_AddPage" libhpdf
               (_fun _pointer -> _pointer)))

(define load-ttf-raw
  (get-ffi-obj "HPDF_LoadTTFontFromFile" libhpdf
               (_fun _pointer _string/utf-8 _bool -> _string)))

(define use-utf-encodingd-raw
  (get-ffi-obj "HPDF_UseUTFEncodings" libhpdf
               (_fun _pointer -> _int)))

(define set-current-encoder-raw
  (get-ffi-obj "HPDF_SetCurrentEncoder" libhpdf
               (_fun _pointer _string -> _pointer)))

(define get-font-raw
  (get-ffi-obj "HPDF_GetFont" libhpdf
               (_fun _pointer _string _string/utf-8 -> _pointer)))

(define set-font-size-raw
  (get-ffi-obj "HPDF_Page_SetFontAndSize" libhpdf
               (_fun _pointer _pointer _float -> _pointer)))

(define page-begin-text-raw
  (get-ffi-obj "HPDF_Page_BeginText" libhpdf
               (_fun _pointer -> _pointer)))

(define page-text-out-raw
  (get-ffi-obj "HPDF_Page_TextOut" libhpdf
               (_fun _pointer _float _float _string/utf-8  -> _pointer)))

(define page-end-text-raw
  (get-ffi-obj "HPDF_Page_EndText" libhpdf
               (_fun _pointer -> _pointer)))


(define (new-pdf) (pdf-new-raw 0 0))
(define (save-pdf pdf path) (pdf-save-raw pdf path))
(define (new-page pdf) (add-page-raw pdf))
(define (free-pdf p) (pdf-free-raw p))

(define (new-ttf-font p font)
  (define ttf-loaded (load-ttf-raw p font #t))
  (get-font-raw p ttf-loaded "UTF-8"))
(define (use-utf8 p)
  (use-utf-encodingd-raw p)
  (set-current-encoder-raw p "UTF-8"))

(define (set-font-size page font size) (set-font-size-raw page font size))
(define (put-text page x y text)
  (page-begin-text-raw page)
  (page-text-out-raw page x y text)
  (page-end-text-raw page)
  )

(provide new-pdf save-pdf new-page free-pdf new-ttf-font use-utf8 set-font-size put-text)
 (module+ test
   (require rackunit)
; 以下是測試區
(define doc (new-pdf))
(define pg (new-page doc))
(use-utf8 doc)
(define ian-sui (new-ttf-font doc "/home/yoxem/.local/share/fonts/Iansui-Regular.ttf"))
(set-font-size pg ian-sui 15.0)
(put-text pg 140.0 150.0 "天地人123abc")
(save-pdf doc  "/tmp/a.pdf")
(void? (free-pdf doc))
   )