;;; -*- mode:newlisp; coding:utf-8 -*-

;; @module iconv.lsp
;; @description Yet Another Iconv Library
;; @version 0.5 初版
;; @version 0.6 Windows(DLL)でも使えるように
;; @version 0.7 関数を増やした
;; @version 0.8 変換後のNULL文字に対応したつもり
;; @version 0.8b newlisp_sjisでのバッファあふれ修正
;; @version 0.8c Rename iconv-handler -> call-with-iconv-descriptor
;; @version 0.8d a few modified.
;; @version 0.9 SunOS 5.10 sparc にて動作テスト。
;;              ロード時にIconv:initを呼び出すように変更
;; @version 0.9b Tested FreeBSD 8.1
;; @version 0.9c Tested CYGWIN_NT-5.1
;; @author KOBAYASHI Shigeru <shigeru.kb[at]gmail.com>, 2009-2011
;; @location https://raw.github.com/gist/242697

;; @example
;; (load "iconv.lsp")
;; ;(Iconv:init)
;;
;; $ echo -n 'おはよう、朝だよ！' | iconv -t EUC-JP > euc.txt
;; (write-file "euc.txt" (Iconv:encode "おはよう、朝だよ！" "EUC-JP"))
;;
;; $ cat euc.txt | iconv -f EUC-JP
;; (Iconv:decode (read-file "euc.txt") "EUC-JP")
;; => "おはよう、朝だよ！"
;;
;; (let ((str "\xa3\xb1\xa1\xdc\xa3\xb1\xa1\xe1\xa3\xb2"))
;;   (Iconv:decode str "EUC-JP"))
;; => "１＋１＝２"
;;
;; (define (my-unicode str)
;;   (Iconv:convert str "UTF-8" "UTF-32LE"))
;; (my-unicode "new") => "n\000\000\000e\000\000\000w\000\000\000"
;;
;; (define (my-utf8 str)
;;   (Iconv:convert str "UTF-32LE" "UTF-8"))
;; (my-utf8 (unicode "new")) => "new\000"
;; (my-utf8 (my-unicode "new")) => "new"

;; @KnownBugs
;; 端末以外から利用すると正しく表示されないかもしれない

;; @TODO
;; (! "iconv --list")   list all known coded character sets
;; メモリ不足を避けるために分割して変換する関数も欲しい
;; 変換用に用意するバッファのサイズが適当過ぎる
;; ポインタ変数の分かりやすい表記方法があれば取り込みたい (p_str, *str)
;; iconv/libiconv を区別する方法
;; エラーを投げるよりも無理矢理変換する方が良い？

;;; Code:

(context 'Iconv)

; See man 3 iconv.
;
; size_t iconv(iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft);
; iconv_t iconv_open(const char *tocode, const char *fromcode);
; int iconv_close(iconv_t cd);

;; NOTE:
;; - KaoriYa.net provides "iconv.dll"
;; - GnuWin32 provides "libiconv2.dll"
(define libiconv-lib
  (case ostype
    ("Win32" "iconv.dll")               ; or "libiconv.dll" "libiconv2.dll"
    ("Cygwin" "cygiconv-2.dll")
    ("Linux" "libc.so.6")               ; Ubuntu 9.04
    ("SunOS" "libc.so.1")               ; SunOS 5.10
    ("OSX" "libiconv.dylib")            ; Mac OS X
    ("BSD" "libiconv.so")               ; FreeBSD 8.1
    (true "libc.so.6")))

;; @syntax (Iconv:init [<library-name>])
;; @return true (but not meaningful)
;; Loadup iconv library functions.
;;
;; @example
;; (Iconv:init)
;; (Iconv:init "C:/usr/lib/libiconv.dll") ; specifies library pathname
(define (init (libname nil))
  (when libname
    (setq libiconv-lib libname))
  (cond
    ((member ostype '("Win32" "Cygwin"))
     (define iconv       (import libiconv-lib "libiconv"))
     (define iconv_open  (import libiconv-lib "libiconv_open"))
     (define iconv_close (import libiconv-lib "libiconv_close")))
   (true
    (define iconv       (import libiconv-lib "iconv"))
    (define iconv_open  (import libiconv-lib "iconv_open"))
    (define iconv_close (import libiconv-lib "iconv_close"))))
  true)

(define newlisp-encoding
  (if (primitive? unicode) "UTF-8" "Shift_JIS"))

(define (error)
  (throw-error (apply format (args))))

;; @syntax (unwind-protect <protected-form> <cleanup-form*>)
;; @return the value of <protected-form>.
;; @location http://www.lispworks.com/documentation/HyperSpec/Body/s_unwind.htm
;; evaluates protected-form and guarantees that cleanup-forms are executed 
;; before unwind-protect exits, whether it terminates normally or is 
;; aborted by a control transfer of some kind.
(letex ((result (sym (uuid))))
(define-macro (unwind-protect )
  (local (result)
    (if (catch (eval (args 0)) 'result)
        (begin (map eval (1 (args))) result)
        (begin (map eval (1 (args))) (throw-error (5 result))))))
)

(define (call-with-iconv-descriptor proc fromcode tocode)
  (let ((cd (iconv_open tocode fromcode)))
    (if (= cd -1)
        (error "iconv_open: %s" (last (sys-error))))
    (unwind-protect
         (proc cd)
      (if (= (iconv_close cd) -1)
          (error "iconv_close: %s" (last (sys-error)))))))

(if (= (& (sys-info -1) 0x100) 0x100)   ; 64-bit?
    (define void* "Lu")
    (define void* "lu"))

(define (convert-1 cd inbuf)
  (iconv cd 0 0 0 0)
  (letn (;; source buffer
         (src inbuf)
         (**src (pack void* (address src)))
         (src_len (length src))
         (*src_len (pack void* src_len))
         ;; distribute buffer
         ;; FIXME: もうちょっと使い勝手の良いメモリ領域の確保ができるはず
         (dst (dup "\000\000\000\000" (+ (* 2 src_len) 4)))
         (**dst (pack void* (address dst)))
         (dst_len (- (length dst) 1))
         (*dst_len (pack void* dst_len))
         result)
    ;; Do iconv convert
    (setf result (iconv cd **src *src_len **dst *dst_len))
    (if (= result -1)
        (error "iconv: %s" (last (sys-error))))
    ;; NOTE: The converted string may contain null characters.
    (slice dst 0 (- dst_len (first (unpack void* *dst_len))))))

;; @syntax (Iconv:convert <string> <fromcode> <tocode>)
;; @return Returns the converted string <fromcode> to <tocode>.
(define (convert str fromcode tocode)
  "Convert string FROMCODE to TOCODE."
  (call-with-iconv-descriptor (lambda (cd)
                                (convert-1 cd str))
                              (or fromcode newlisp-encoding)
                              (or tocode newlisp-encoding)))

;; @syntax (Iconv:encode <string> <tocode>)
;; @return Returns the converted string internal to <tocode>.
(define (encode str tocode)
  "Convert string internal to TOCODE."
  (convert str newlisp-encoding tocode))

;; @syntax (Iconv:decode <string> <fromcode>)
;; @return Returns the converted string <fromcode> to internal.
(define (decode str fromcode)
  "Convert string FROMCODE to internal."
  (convert str fromcode newlisp-encoding))

;; Shift_JIS
;; EUC-JP
;; ISO-2022-JP
;; UTF-8
;; ISO-8859-1
;; ISO-8859-15
;; WINDOWS-1252

(or (catch (Iconv:init) 'init-result)
    (write 2 "WARNING: iconv.lsp initialize error\n"))

(context MAIN)

;;; EOF