/* Header */

/*
 * Copyright (c) 1988-1997 Sam Leffler
 * Copyright (c) 1991-1997 Silicon Graphics, Inc.
 *
 * Permission to use, copy, modify, distribute, and sell this software and 
 * its documentation for any purpose is hereby granted without fee, provided
 * that (i) the above copyright notices and this permission notice appear in
 * all copies of the software and related documentation, and (ii) the names of
 * Sam Leffler and Silicon Graphics may not be used in any advertising or
 * publicity relating to the software without the specific, prior written
 * permission of Sam Leffler and Silicon Graphics.
 * 
 * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY 
 * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.  
 * 
 * IN NO EVENT SHALL SAM LEFFLER OR SILICON GRAPHICS BE LIABLE FOR
 * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF 
 * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 
 * OF THIS SOFTWARE.
 */

/*
 * TIFF Library
 *
 * Compression Scheme Configuration Support.
 */
#include "tiffiop.h"

static int
TIFFNoEncode(TIFF* tif, char* method)
{
        const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);

        if (c) { 
          if (! strncmp(c->name, "LZW", 3) ){ 
            TIFFError(tif->tif_name, 
                      "%s %s encoding is no longer implemented due to Unisys patent enforcement", 
                      c->name, method); 
          } else { 
            TIFFError(tif->tif_name, "%s %s encoding is not implemented",
                      c->name, method);
          }
        }
        else { 
                TIFFError(tif->tif_name,
                          "Compression scheme %u %s encoding is not implemented",
                    tif->tif_dir.td_compression, method);
        }
        return (-1);
}

int
_TIFFNoRowEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoEncode(tif, "scanline"));
}

int
_TIFFNoStripEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoEncode(tif, "strip"));
}

int
_TIFFNoTileEncode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoEncode(tif, "tile"));
}

static int
TIFFNoDecode(TIFF* tif, char* method)
{
        const TIFFCodec* c = TIFFFindCODEC(tif->tif_dir.td_compression);

        if (c)
                TIFFError(tif->tif_name, "%s %s decoding is not implemented",
                    c->name, method);
        else
                TIFFError(tif->tif_name,
                    "Compression scheme %u %s decoding is not implemented",
                    tif->tif_dir.td_compression, method);
        return (-1);
}

int
_TIFFNoRowDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoDecode(tif, "scanline"));
}

int
_TIFFNoStripDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoDecode(tif, "strip"));
}

int
_TIFFNoTileDecode(TIFF* tif, tidata_t pp, tsize_t cc, tsample_t s)
{
        (void) pp; (void) cc; (void) s;
        return (TIFFNoDecode(tif, "tile"));
}

int
_TIFFNoSeek(TIFF* tif, uint32 off)
{
        (void) off;
        TIFFError(tif->tif_name,
            "Compression algorithm does not support random access");
        return (0);
}

int
_TIFFNoPreCode(TIFF* tif, tsample_t s)
{
        (void) tif; (void) s;
        return (1);
}

static int _TIFFtrue(TIFF* tif) { (void) tif; return (1); }
static void _TIFFvoid(TIFF* tif) { (void) tif; }

void
_TIFFSetDefaultCompressionState(TIFF* tif)
{
        tif->tif_setupdecode = _TIFFtrue;
        tif->tif_predecode = _TIFFNoPreCode;
        tif->tif_decoderow = _TIFFNoRowDecode;
        tif->tif_decodestrip = _TIFFNoStripDecode;
        tif->tif_decodetile = _TIFFNoTileDecode;
        tif->tif_setupencode = _TIFFtrue;
        tif->tif_preencode = _TIFFNoPreCode;
        tif->tif_postencode = _TIFFtrue;
        tif->tif_encoderow = _TIFFNoRowEncode;
        tif->tif_encodestrip = _TIFFNoStripEncode;
        tif->tif_encodetile = _TIFFNoTileEncode;
        tif->tif_close = _TIFFvoid;
        tif->tif_seek = _TIFFNoSeek;
        tif->tif_cleanup = _TIFFvoid;
        tif->tif_defstripsize = _TIFFDefaultStripSize;
        tif->tif_deftilesize = _TIFFDefaultTileSize;
        tif->tif_flags &= ~TIFF_NOBITREV;
}

int
TIFFSetCompressionScheme(TIFF* tif, int scheme)
{
        const TIFFCodec *c = TIFFFindCODEC((uint16) scheme);

        _TIFFSetDefaultCompressionState(tif);
        /*
         * Don't treat an unknown compression scheme as an error.
         * This permits applications to open files with data that
         * the library does not have builtin support for, but which
         * may still be meaningful.
         */
        return (c ? (*c->init)(tif, scheme) : 1);
}

/*
 * Other compression schemes may be registered.  Registered
 * schemes can also override the builtin versions provided
 * by this library.
 */
typedef struct _codec {
        struct _codec*  next;
        TIFFCodec*      info;
} codec_t;
static  codec_t* registeredCODECS = NULL;

const TIFFCodec*
TIFFFindCODEC(uint16 scheme)
{
        const TIFFCodec* c;
        codec_t* cd;

        for (cd = registeredCODECS; cd; cd = cd->next)
                if (cd->info->scheme == scheme)
                        return ((const TIFFCodec*) cd->info);
        for (c = _TIFFBuiltinCODECS; c->name; c++)
                if (c->scheme == scheme)
                        return (c);
        return ((const TIFFCodec*) 0);
}

TIFFCodec*
TIFFRegisterCODEC(uint16 scheme, const char* name, TIFFInitMethod init)
{
        codec_t* cd = (codec_t*)
            _TIFFmalloc(sizeof (codec_t) + sizeof (TIFFCodec) + strlen(name)+1);

        if (cd != NULL) {
                cd->info = (TIFFCodec*) ((tidata_t) cd + sizeof (codec_t));
                cd->info->name = (char*)
                    ((tidata_t) cd->info + sizeof (TIFFCodec));
                strcpy(cd->info->name, name);
                cd->info->scheme = scheme;
                cd->info->init = init;
                cd->next = registeredCODECS;
                registeredCODECS = cd;
        } else
                TIFFError("TIFFRegisterCODEC",
                    "No space to register compression scheme %s", name);
        return (cd->info);
}

void
TIFFUnRegisterCODEC(TIFFCodec* c)
{
        codec_t* cd;
        codec_t** pcd;

        for (pcd = &registeredCODECS; (cd = *pcd); pcd = &cd->next)
                if (cd->info == c) {
                        *pcd = cd->next;
                        _TIFFfree(cd);
                        return;
                }
        TIFFError("TIFFUnRegisterCODEC",
            "Cannot remove compression scheme %s; not registered", c->name);
}
