;;;; -*- Mode: Lisp; Syntax: ANSI-Common-Lisp; Base: 10 -*-
;;;; *************************************************************************
;;;; FILE IDENTIFICATION
;;;;
;;;; Name:          strings.lisp
;;;; Purpose:       UFFI source to handle strings, cstrings, and foreigns
;;;; Programmer:    Kevin M. Rosenberg
;;;; Date Started:  Feb 2002
;;;;
;;;; This file, part of UFFI, is Copyright (c) 2002-2010 by Kevin M. Rosenberg
;;;; *************************************************************************

(in-package #:uffi)


(def-pointer-var +null-cstring-pointer+
    #+(or cmu sbcl scl) nil
    #+allegro 0
    #+lispworks (fli:make-pointer :address 0 :type '(:unsigned :char))
    #+(or openmcl digitool) (ccl:%null-ptr)
)

(defmacro convert-from-cstring (obj)
  "Converts a string from a c-call. Same as convert-from-foreign-string, except
that LW/CMU automatically converts strings from c-calls."
  #+(or cmu sbcl lispworks scl) obj
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (zerop ,stored)
           nil
           (values (excl:native-to-string ,stored)))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (ccl:%null-ptr-p ,stored)
           nil
         (values (ccl:%get-cstring ,stored)))))
  )

(defmacro convert-to-cstring (obj)
  #+(or cmu sbcl scl lispworks) obj
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           0
           (values (excl:string-to-native ,stored)))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (if (null ,stored)
           +null-cstring-pointer+
           (let ((ptr (new-ptr (1+ (length ,stored)))))
             (ccl::%put-cstring ptr ,stored)
             ptr))))
  )

(defmacro free-cstring (obj)
  (declare (ignorable obj))
  #+allegro
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (unless (zerop ,stored)
         (ff:free-fobject ,stored))))
  #+(or openmcl digitool)
  (let ((stored (gensym)))
    `(let ((,stored ,obj))
       (unless (ccl:%null-ptr-p ,stored)
         (dispose-ptr ,stored))))
  )

(defmacro with-cstring ((cstring lisp-string) &body body)
  #+(or cmu sbcl scl lispworks)
  `(let ((,cstring ,lisp-string)) ,@body)
  #+allegro
  (let ((acl-native (gensym))
        (stored-lisp-string (gensym)))
    `(let ((,stored-lisp-string ,lisp-string))
       (excl:with-native-string (,acl-native ,stored-lisp-string)
         (let ((,cstring (if ,stored-lisp-string ,acl-native 0)))
           ,@body))))
  #+(or openmcl digitool)
  (let ((stored-lisp-string (gensym)))
    `(let ((,stored-lisp-string ,lisp-string))
       (if (stringp ,stored-lisp-string)
           (ccl:with-cstrs ((,cstring ,stored-lisp-string))
             ,@body)
           (let ((,cstring +null-cstring-pointer+))
             ,@body))))
  )

(defmacro with-cstrings (bindings &rest body)
  (if bindings
      `(with-cstring ,(car bindings)
        (with-cstrings ,(cdr bindings)
          ,@body))
      `(progn ,@body)))

;;; Foreign string functions

(defun %convert-to-foreign-string (str encoding)
  (declare (ignorable str encoding))
  #+(or cmu scl)
  (etypecase str
    (null
     (alien:sap-alien (system:int-sap 0) (* (alien:unsigned 8))))
    (string
     (locally
         (declare (optimize (speed 3) (safety 0)))
       (let* ((size (length str))
              (storage (alien:make-alien (alien:unsigned 8) (1+ size))))
         (declare (fixnum size))
         (setq storage (alien:cast storage (* (alien:unsigned 8))))
         (dotimes (i size)
           (declare (fixnum i))
           (setf (alien:deref storage i)
                 (char-code (char str i))))
         (setf (alien:deref storage size) 0)
         storage))))

  #+(and sbcl (not sb-unicode))
  (etypecase str
    (null
     (sb-alien:sap-alien (sb-sys:int-sap 0) (* (sb-alien:unsigned 8))))
    (string
     (locally
         (declare (optimize (speed 3) (safety 0)))
       (let* ((size (length str))
              (storage (sb-alien:make-alien (sb-alien:unsigned 8) (1+ size))))
         (declare (fixnum i))
         (setq storage (sb-alien:cast storage (* (sb-alien:unsigned 8))))
         (dotimes (i size)
           (declare (fixnum i))
           (setf (sb-alien:deref storage i)
                 (char-code (char str i))))
         (setf (sb-alien:deref storage size) 0))
       storage)))

  #+(and sbcl sb-unicode)
  (etypecase str
    (null
     (sb-alien:sap-alien (sb-sys:int-sap 0) (* (sb-alien:unsigned 8))))
    (string
     (locally
         (declare (optimize (speed 3) (safety 0)))
       (let* ((fe (or encoding *default-foreign-encoding*
                      sb-impl::*default-external-format*))
              (ife (when fe (lookup-foreign-encoding fe))))
         (if ife
             (let* ((octets (sb-ext:string-to-octets str :external-format ife))
                    (size (length octets))
                    (storage (sb-alien:make-alien (sb-alien:unsigned 8) (+ size 2))))
               (declare (fixnum size))
               (setq storage (sb-alien:cast storage (* (sb-alien:unsigned 8))))
               (dotimes (i size)
                 (declare (fixnum i))
                 (setf (sb-alien:deref storage i) (aref octets i)))
               ;; terminate with 2 nulls, maybe needed for some encodings
               (setf (sb-alien:deref storage size) 0)
               (setf (sb-alien:deref storage (1+ size)) 0)
               storage)

             (let* ((size (length str))
                    (storage (sb-alien:make-alien (sb-alien:unsigned 8) (1+ size))))
               (declare (fixnum size))
               (setq storage (sb-alien:cast storage (* (sb-alien:unsigned 8))))
               (dotimes (i size)
                 (declare (fixnum i))
                 (setf (sb-alien:deref storage i)
                       (char-code (char str i))))
               (setf (sb-alien:deref storage size) 0)
               storage))))))

  #+(and openmcl openmcl-unicode-strings)
  (if (null str)
      +null-cstring-pointer+
      (locally
          (declare (optimize (speed 3) (safety 0)))
        (let* ((fe (or encoding *default-foreign-encoding*))
               (ife (when fe (lookup-foreign-encoding fe))))
          (if ife
              (let* ((octets (ccl:encode-string-to-octets str :external-format ife))
                     (size (length octets))
                     (ptr (new-ptr (+ size 2))))
                (declare (fixnum size))
                (dotimes (i size)
                  (declare (fixnum i))
                  (setf (ccl:%get-unsigned-byte ptr i) (svref octets i)))
                (setf (ccl:%get-unsigned-byte ptr size) 0)
                (setf (ccl:%get-unsigned-byte ptr (1+ size)) 0)
                ptr)

              (let ((ptr (new-ptr (1+ (length str)))))
                (ccl::%put-cstring ptr str)
                ptr)))))

  #+(or digitool (and openmcl (not openmcl-unicode-strings)))
  (if (null str)
      +null-cstring-pointer+
      (let ((ptr (new-ptr (1+ (length str)))))
        (ccl::%put-cstring ptr str)
        ptr))

  #+(or allegro lispworks)
  nil
  )

(defmacro convert-to-foreign-string (obj &optional encoding)
  (declare (ignorable encoding))
  #+allegro
  (let ((stored (gensym "STR-"))
        (fe (gensym "FE-"))
        (ife (gensym "IFE-")))
    `(let* ((,stored ,obj)
            (,fe (or encoding *default-foreign-encoding*))
            (,ife (when ,fe
                    (lookup-foreign-encoding ,fe))))
       (cond
         ((null ,stored)
          0)
         ((null ,ife)
          (values (excl:string-to-native ,stored)))
         (t
           (values (excl:string-to-native ,stored :external-format ,ife))))))

  #+lispworks
  (let ((stored (gensym "STR-"))
        (fe (gensym "EF-"))
        (ife (gensym "NEF-")))
    `(let* ((,stored ,obj)
            (,fe (or ,encoding *default-foreign-encoding*))
            (,ife (when ,fe
                    (lookup-foreign-encoding ,fe))))
       (cond
         ((null ,stored)
          +null-cstring-pointer+)
         ((null ,ife)
          (fli:convert-to-foreign-string ,stored))
         (t
          (fli:convert-to-foreign-string ,stored :external-format ,ife)))))

  #+(or cmu scl sbcl digitool openmcl)
  `(%convert-to-foreign-string ,obj (lookup-foreign-encoding
                                     (or ,encoding *default-foreign-encoding*)))
)


;; Either length or null-terminated-p must be non-nil
(defmacro convert-from-foreign-string (obj &key
                                       length
                                       encoding
                                       (null-terminated-p t))
  (declare (ignorable length encoding null-terminated-p))
  #+allegro
  (let ((stored-obj (gensym "STR-"))
        (fe (gensym "FE-"))
        (ife (gensym "IFE-")))
    `(let ((,stored-obj ,obj))
       (if (zerop ,stored-obj)
           nil
           (let* ((,fe (or ,encoding *default-foreign-encoding*))
                  (,ife (when ,fe (lookup-foreign-encoding ,fe))))
             (if ,ife
                 (values
                  (excl:native-to-string
                   ,stored-obj
                   ,@(when length (list :length length))
                   :truncate (not ,null-terminated-p)
                   :external-format ,ife))
                 (fast-native-to-string ,stored-obj ,length))))))

  #+lispworks
  #|
  ;; FAST-NATIVE-TO-STRING (suprisingly) works just fine to make strings
  ;; for formatted printing with Lispworks and UTF-8 multibyte character strings.
  ;; However, without knowledge of specific-encoding, the LENGTH call in FAST-NATIVE-TO-STRING
  ;; will be be incorrect for some encodings/strings and strings consist of octets rather
  ;; than wide characters
  ;; This is a stop-gap until get tech support on why the below fails.
  (let ((stored-obj (gensym "STR-")))
    `(let ((,stored-obj ,obj))
       (if (fli:null-pointer-p ,stored-obj)
           nil
           (fast-native-to-string ,stored-obj ,length))))
  |#
  #|
  ;; Below code doesn't work on tesing with LW 6.0 testing with a UTF-8 string.
  ;; fli:convert-from-foreign-string with :external-format of :UTF-8 doesn't
  ;; properly code multibyte characters.
  |#
  (let ((stored-obj (gensym "STR-"))
        (fe (gensym "FE-"))
        (ife (gensym "IFE-")))
    `(let ((,stored-obj ,obj))
       (if (fli:null-pointer-p ,stored-obj)
           nil
           (let* ((,fe (or ,encoding *default-foreign-encoding*))
                  (,ife (when ,fe (lookup-foreign-encoding ,fe))))
             (if ,ife
                 (fli:convert-from-foreign-string
                  ,stored-obj
                  ,@(when length (list :length length))
                  :null-terminated-p ,null-terminated-p
                  :external-format (list ,ife :eol-style :lf))
                 (fast-native-to-string ,stored-obj ,length))))))

  #+(or cmu scl)
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (null-pointer-p ,stored-obj)
           nil
           (cmucl-naturalize-cstring (alien:alien-sap ,stored-obj)
                                     :length ,length
                                     :null-terminated-p ,null-terminated-p))))
  #+(and sbcl (not sb-unicode))
  (let ((stored-obj (gensym)))
    `(let ((,stored-obj ,obj))
       (if (null-pointer-p ,stored-obj)
           nil
           (sbcl-naturalize-cstring (sb-alien:alien-sap ,stored-obj)
                                    :length ,length
                                    :null-terminated-p ,null-terminated-p))))

  #+(and sbcl sb-unicode)
  (let ((stored-obj (gensym "STR-"))
        (fe (gensym "FE-"))
        (ife (gensym "IFE-")))
    `(let ((,stored-obj ,obj))
       (if (null-pointer-p ,stored-obj)
           nil
           (let* ((,fe (or ,encoding *default-foreign-encoding*))
                  (,ife (when ,fe (lookup-foreign-encoding ,fe))))
             (sb-alien::c-string-to-string (sb-alien:alien-sap ,stored-obj)
                                           (or ,ife sb-impl::*default-external-format* :latin-1)
                                           'character)))))

  #+(or openmcl digitool)
  (let ((stored-obj (gensym "STR-"))
        (fe (gensym "FE-")))
    `(let ((,stored-obj ,obj))
       (if (ccl:%null-ptr-p ,stored-obj)
           nil
           #+digitool
           (ccl:%get-cstring
            ,stored-obj 0
            ,@(if length (list length) nil))
           #+openmcl
           (let ((,fe (or ,encoding *default-foreign-encoding*)))
             (case ,fe
               (:utf-8
                (ccl::%get-utf-8-cstring ,stored-obj))
               (:ucs-2
                (ccl::%get-native-utf-16-cstring ,stored-obj))
               (t
                 ,@(if length
                       `((ccl:%str-from-ptr ,stored-obj ,length))
                       `((ccl:%get-cstring ,stored-obj)))))))))
  )


(defmacro allocate-foreign-string (size &key (unsigned t))
  (declare (ignorable unsigned))
  #+ignore
  (let ((array-def (gensym)))
    `(let ((,array-def (list 'alien:array 'c-call:char ,size)))
       (eval `(alien:cast (alien:make-alien ,,array-def)
                          ,(if ,unsigned
                               '(* (alien:unsigned 8))
                             '(* (alien:signed 8)))))))

  #+(or cmu scl)
  `(alien:make-alien ,(if unsigned
                             '(alien:unsigned 8)
                             '(alien:signed 8))
    ,size)

  #+sbcl
  `(sb-alien:make-alien ,(if unsigned
                             '(sb-alien:unsigned 8)
                             '(sb-alien:signed 8))
    ,size)

  #+lispworks
  `(fli:allocate-foreign-object :type
                                ,(if unsigned
                                     ''(:unsigned :char)
                                   :char)
                                :nelems ,size)
  #+allegro
  `(ff:allocate-fobject :char :c ,size)
  #+(or openmcl digitool)
  `(new-ptr ,size)
  )

(defun foreign-string-length (foreign-string)
  #+allegro (ff:foreign-strlen foreign-string)
  #-allegro
  (loop
     for size from 0
     until (zerop (deref-array foreign-string '(:array :unsigned-char) size))
     finally (return size)))


(defmacro with-foreign-string ((foreign-string lisp-string &optional encoding)
                               &body body)
  (let ((result (gensym))
        (fe (gensym)))
    `(let* ((,fe ,encoding)
            (,foreign-string (convert-to-foreign-string ,lisp-string ,fe))
            (,result (progn ,@body)))
      (declare (dynamic-extent ,foreign-string))
      (free-foreign-object ,foreign-string)
      ,result)))

(defmacro with-foreign-strings (bindings &body body)
  `(with-foreign-string ,(car bindings)
    ,@(if (cdr bindings)
          `((with-foreign-strings ,(cdr bindings) ,@body))
          body)))

;; Modified from CMUCL's source to handle non-null terminated strings
#+cmu
(defun cmucl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type system:system-area-pointer sap))
  (locally
      (declare (optimize (speed 3) (safety 0)))
    (let ((null-terminated-length
           (when null-terminated-p
             (loop
                 for offset of-type fixnum upfrom 0
                 until (zerop (system:sap-ref-8 sap offset))
                 finally (return offset)))))
      (if length
          (if (and null-terminated-length
                   (> (the fixnum length) (the fixnum null-terminated-length)))
              (setq length null-terminated-length))
        (setq length null-terminated-length)))
    (let ((result (make-string length)))
      (kernel:copy-from-system-area sap 0
                                    result (* vm:vector-data-offset
                                              vm:word-bits)
                                    (* length vm:byte-bits))
      result)))

#+scl
;; kernel:copy-from-system-area doesn't work like it does on CMUCL or SBCL,
;; so have to iteratively copy from sap
(defun cmucl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type system:system-area-pointer sap))
  (locally
      (declare (optimize (speed 3) (safety 0)))
    (let ((null-terminated-length
           (when null-terminated-p
             (loop
                 for offset of-type fixnum upfrom 0
                 until (zerop (system:sap-ref-8 sap offset))
                 finally (return offset)))))
      (if length
          (if (and null-terminated-length
                   (> (the fixnum length) (the fixnum null-terminated-length)))
              (setq length null-terminated-length))
        (setq length null-terminated-length)))
    (let ((result (make-string length)))
      (dotimes (i length)
        (declare (type fixnum i))
        (setf (char result i) (code-char (system:sap-ref-8 sap i))))
      result)))

#+(and sbcl (not sb-unicode))
(defun sbcl-naturalize-cstring (sap &key length (null-terminated-p t))
  (declare (type sb-sys:system-area-pointer sap)
           (type (or null fixnum) length))
  (locally
   (declare (optimize (speed 3) (safety 0)))
   (let ((null-terminated-length
          (when null-terminated-p
            (loop
             for offset of-type fixnum upfrom 0
             until (zerop (sb-sys:sap-ref-8 sap offset))
             finally (return offset)))))
     (if length
         (if (and null-terminated-length
                  (> (the fixnum length) (the fixnum null-terminated-length)))
             (setq length null-terminated-length))
       (setq length null-terminated-length)))
   (let ((result (make-string length)))
       (funcall *system-copy-fn* sap 0 result +system-copy-offset+
                (* length +system-copy-multiplier+))
       result)))


(eval-when (:compile-toplevel :load-toplevel :execute)
   (def-function "strlen"
     ((str (* :unsigned-char)))
     :returning :unsigned-int))

(def-type char-ptr-def (* :unsigned-char))

#+(or (and allegro (not ics)) (and lispworks (not lispworks5) (not lispworks6)))
(defun fast-native-to-string (s len)
  (declare (optimize (speed 3) (space 0) (safety 0) (compilation-speed 0))
           (type char-ptr-def s))
  (let* ((len (or len (strlen s)))
         (str (make-string len)))
    (declare (fixnum len)
             (type (simple-array #+lispworks base-char
                                 #-lispworks (signed-byte 8) (*)) str))
    (dotimes (i len str)
      (setf (aref str i)
        (uffi:deref-array s '(:array :char) i)))))

#+(or (and allegro ics) lispworks5 lispworks6)
(defun fast-native-to-string (s len)
  (declare (optimize (speed 3) (space 0) (safety 0) (compilation-speed 0))
           (type char-ptr-def s))
  (let* ((len (or len (strlen s)))
         (str (make-string len)))
    (dotimes (i len str)
      (setf (schar str i) (code-char (uffi:deref-array s '(:array :unsigned-byte) i))))))