/* $Header$ */

/*
 * Copyright (c) 1995-1996 Sam Leffler
 * Copyright (c) 1995-1996 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.
 */

#include "tiffInt.h"

/*
 * TIFF Library.
 *
 * ZIP (aka Deflate) Compression Support
 *
 * This file is simply an interface to the zlib library written by
 * Jean-loup Gailly and Mark Adler.  You must use version 1.0 or later
 * of the library: this code assumes the 1.0 API and also depends on
 * the ability to write the zlib header multiple times (one per strip)
 * which was not possible with versions prior to 0.95.  Note also that
 * older versions of this codec avoided this bug by supressing the header
 * entirely.  This means that files written with the old library cannot
 * be read; they should be converted to a different compression scheme
 * and then reconverted.
 *
 * The data format used by the zlib library is described in the files
 * zlib-3.1.doc, deflate-1.1.doc and gzip-4.1.doc, available in the
 * directory ftp://ftp.uu.net/pub/archiving/zip/doc.  The library was
 * last found at ftp://ftp.uu.net/pub/archiving/zip/zlib/zlib-0.99.tar.gz.
 */

#include "zlibtcl.h"
#include <assert.h>


/*
 * Sigh, ZLIB_VERSION is defined as a string so there's no
 * way to do a proper check here.  Instead we guess based
 * on the presence of defines that were added between the
 * 0.95 and 1.0 distributions.
 */
#if !defined(Z_NO_COMPRESSION) || !defined(Z_DEFLATED)
#error "Antiquated ZLIB software; you must use version 1.0 or later"
#endif

/*
 * State block for each open TIFF
 * file using ZIP compression/decompression.
 */
typedef	struct {
  TIFFPredictorState predict;
  z_stream	stream;
  int		zipquality;		/* compression level */
  int		state;			/* state flags */
#define	ZSTATE_INIT	0x1		/* zlib setup successfully */

  TIFFVGetMethod	vgetparent;		/* super-class method */
  TIFFVSetMethod	vsetparent;		/* super-class method */
} ZIPState;

#define	ZState(tif)		((ZIPState*) (tif)->tif_data)
#define	DecoderState(tif)	ZState(tif)
#define	EncoderState(tif)	ZState(tif)

static int ZIPSetupDecode(TIFF* tif);

static int ZIPSetupDecode(
    TIFF* tif
) {
    ZIPState* sp = DecoderState(tif);
    static char module[] = "ZIPSetupDecode";

    assert(sp != NULL);
    if (inflateInit(&sp->stream) != Z_OK) {
        TIFFError(module, "%s: %s", tif->tif_name, sp->stream.msg);
	return (0);
    } else {
        sp->state |= ZSTATE_INIT;
	return (1);
    }
}

/*
 * Setup state for decoding a strip.
 */

static int ZIPPreDecode(
    TIFF* tif,
    tsample_t s
) {
    ZIPState* sp = DecoderState(tif);

    (void) s;
    assert(sp != NULL);
    sp->stream.next_in = tif->tif_rawdata;
    sp->stream.avail_in = tif->tif_rawcc;
    return (inflateReset(&sp->stream) == Z_OK);
}

static int ZIPDecode(
    TIFF* tif,
    tidata_t op,
    tsize_t occ,
    tsample_t s
) {
    ZIPState* sp = DecoderState(tif);
    static char module[] = "ZIPDecode";

    (void) s;
    assert(sp != NULL);
    sp->stream.next_out = op;
    sp->stream.avail_out = occ;
    do {
        int state = inflate(&sp->stream, Z_PARTIAL_FLUSH);
	if (state == Z_STREAM_END)
	    break;
	if (state == Z_DATA_ERROR) {
	    TIFFError(module,
		      "%s: Decoding error at scanline %d, %s",
		      tif->tif_name, tif->tif_row, sp->stream.msg);
	    if (inflateSync(&sp->stream) != Z_OK)
	        return (0);
	    continue;
	}
	if (state != Z_OK) {
	    TIFFError(module, "%s: zlib error: %s",
		      tif->tif_name, sp->stream.msg);
	    return (0);
	}
    } while (sp->stream.avail_out > 0);
    if (sp->stream.avail_out != 0) {
        TIFFError(module,
		  "%s: Not enough data at scanline %d (short %d bytes)",
		  tif->tif_name, tif->tif_row, sp->stream.avail_out);
	return (0);
    }
    return (1);
}

static int ZIPSetupEncode (
    TIFF* tif
) {
    ZIPState* sp = EncoderState(tif);
    static char module[] = "ZIPSetupEncode";

    assert(sp != NULL);
    if (deflateInit(&sp->stream, sp->zipquality) != Z_OK) {
        TIFFError(module, "%s: %s", tif->tif_name, sp->stream.msg);
        return (0);
    } else {
        sp->state |= ZSTATE_INIT;
        return (1);
    }
}

/*
 * Reset encoding state at the start of a strip.
 */

static int ZIPPreEncode(
    TIFF* tif,
    tsample_t s
) {
    ZIPState *sp = EncoderState(tif);

    (void) s;
    assert(sp != NULL);
    sp->stream.next_out = tif->tif_rawdata;
    sp->stream.avail_out = tif->tif_rawdatasize;
    return (deflateReset(&sp->stream) == Z_OK);
}

/*
 * Encode a chunk of pixels.
 */

static int ZIPEncode(
    TIFF* tif,
    tidata_t bp,
    tsize_t cc,
    tsample_t s
) {
    ZIPState *sp = EncoderState(tif);
    static char module[] = "ZIPEncode";

    (void) s;
    sp->stream.next_in = bp;
    sp->stream.avail_in = cc;
    do {
        if (deflate(&sp->stream, Z_NO_FLUSH) != Z_OK) {
	    TIFFError(module, "%s: Encoder error: %s",
			 tif->tif_name, sp->stream.msg);
	    return (0);
	}
	if (sp->stream.avail_out == 0) {
	    tif->tif_rawcc = tif->tif_rawdatasize;
	    TIFFFlushData1(tif);
	    sp->stream.next_out = tif->tif_rawdata;
	    sp->stream.avail_out = tif->tif_rawdatasize;
	}
    } while (sp->stream.avail_in > 0);
    return (1);
}

/*
 * Finish off an encoded strip by flushing the last
 * string and tacking on an End Of Information code.
 */

static int ZIPPostEncode(
    TIFF* tif
) {
    ZIPState *sp = EncoderState(tif);
    static char module[] = "ZIPPostEncode";
    int state;

    sp->stream.avail_in = 0;
    do {
        state = deflate(&sp->stream, Z_FINISH);
	switch (state) {
	case Z_STREAM_END:
	case Z_OK:
	    if ((int) sp->stream.avail_out != tif->tif_rawdatasize) {
	        tif->tif_rawcc =
		  tif->tif_rawdatasize - sp->stream.avail_out;
		TIFFFlushData1(tif);
		sp->stream.next_out = tif->tif_rawdata;
		sp->stream.avail_out = tif->tif_rawdatasize;
	    }
	    break;
	default:
	    TIFFError(module, "%s: zlib error: %s",
			 tif->tif_name, sp->stream.msg);
	    return (0);
	}
    } while (state != Z_STREAM_END);
    return (1);
}

static void ZIPCleanup(
    TIFF* tif
) {
    ZIPState* sp = ZState(tif);
    if (sp) {
        if (tif->tif_mode == O_RDONLY) {
	    inflateEnd(&sp->stream);
	} else {
	    deflateEnd(&sp->stream);
	}
	TkimgTIFFfree(sp);
	tif->tif_data = NULL;
    }
}

static int ZIPVSetField(
    TIFF* tif,
    ttag_t tag,
    va_list ap
) {
    ZIPState* sp = ZState(tif);
    static char module[] = "ZIPVSetField";

    switch (tag) {
    case TIFFTAG_ZIPQUALITY:
        sp->zipquality = va_arg(ap, int);
	if (tif->tif_mode != O_RDONLY && (sp->state&ZSTATE_INIT)) {
	    if (deflateParams(&sp->stream,
			      sp->zipquality, Z_DEFAULT_STRATEGY) != Z_OK) {
	        TIFFError(module, "%s: zlib error: %s",
			     tif->tif_name, sp->stream.msg);
		return (0);
	    }
	}
	return (1);
    default:
        return (*sp->vsetparent)(tif, tag, ap);
    }
    /*NOTREACHED*/
}

static int
ZIPVGetField(
    TIFF* tif,
    ttag_t tag,
    va_list ap
) {
    ZIPState* sp = ZState(tif);

    switch (tag) {
    case TIFFTAG_ZIPQUALITY:
        *va_arg(ap, int*) = sp->zipquality;
	break;
    default:
        return (*sp->vgetparent)(tif, tag, ap);
    }
    return (1);
}

static const TIFFFieldInfo zipFieldInfo[] = {
    { TIFFTAG_ZIPQUALITY,	 0, 0,	TIFF_ANY,	FIELD_PSEUDO,
      TRUE,	FALSE,	"" },
};
#define	N(a)	(sizeof (a) / sizeof (a[0]))

static voidpf ZipAlloc(
    voidpf opaque,
    uInt items,
    uInt size
) {
    return (voidpf) TkimgTIFFmalloc((tsize_t)(items * size));
}

static void ZipFree(
    voidpf opaque,
    voidpf address
) {
    TkimgTIFFfree((tdata_t) address);
}

int TkimgTIFFInitZip(
    TIFF * handle,
    int scheme
) {
    TIFF* tif = (TIFF *) handle;
    ZIPState* sp;
	assert( (scheme == COMPRESSION_DEFLATE)
		|| (scheme == COMPRESSION_ADOBE_DEFLATE));

    /*
     * We assume here that package zlibtcl is loaded and its stub
     * table initialized. This happens in tiff.c, just before the
     * codec is registered.
     */

    /*
     * Allocate state block so tag methods have storage to record values.
     */

    tif->tif_data = (tidata_t) TkimgTIFFmalloc(sizeof (ZIPState));
    if (tif->tif_data == NULL) {
      goto bad;
    }

    sp = ZState(tif);
    sp->stream.zalloc    = ZipAlloc;
    sp->stream.zfree     = ZipFree;
    sp->stream.opaque    = NULL;
    sp->stream.data_type = Z_BINARY;

    /*
     * Merge codec-specific tag information and
     * override parent get/set field methods.
     */

    _TIFFMergeFieldInfo(tif, (const void *) zipFieldInfo, N(zipFieldInfo));
    sp->vgetparent     = tif->tif_tagmethods.vgetfield;
    tif->tif_tagmethods.vgetfield = ZIPVGetField;	/* hook for codec tags */
    sp->vsetparent     = tif->tif_tagmethods.vsetfield;
    tif->tif_tagmethods.vsetfield = ZIPVSetField;	/* hook for codec tags */

    /*
     * Default values for codec-specific fields
     */

    sp->zipquality = Z_DEFAULT_COMPRESSION;	/* default comp. level */
    sp->state = 0;

    /*
     * Install codec methods.
     */

    tif->tif_setupdecode = ZIPSetupDecode;
    tif->tif_predecode   = ZIPPreDecode;
    tif->tif_decoderow   = ZIPDecode;
    tif->tif_decodestrip = ZIPDecode;
    tif->tif_decodetile  = ZIPDecode;
    tif->tif_setupencode = ZIPSetupEncode;
    tif->tif_preencode   = ZIPPreEncode;
    tif->tif_postencode  = ZIPPostEncode;
    tif->tif_encoderow   = ZIPEncode;
    tif->tif_encodestrip = ZIPEncode;
    tif->tif_encodetile  = ZIPEncode;
    tif->tif_cleanup     = ZIPCleanup;

    /*
     * Setup predictor setup.
     */

    (void) TIFFPredictorInit(tif);
    return (1);
 bad:
    TIFFError("TIFFInitZIP", "No space for ZIP state block");
    return (0);
}
