/*

 * TIFF Common Routines

 * Copyright (c) 2013 Thilo Borgmann <thilo.borgmann _at_ mail.de>

 *

 * This file is part of FFmpeg.

 *

 * FFmpeg is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * FFmpeg is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with FFmpeg; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

/**

 * @file

 * TIFF Common Routines

 * @author Thilo Borgmann <thilo.borgmann _at_ mail.de>

 */

#include "libavutil/bprint.h"

#include "libavutil/mem.h"

#include "tiff_common.h"

int ff_tis_ifd(unsigned tag)

{

    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(ifd_tags); i++) {

        if (ifd_tags[i] == tag) {

            return i + 1;

        }

    }

    return 0;

}

unsigned ff_tget_short(GetByteContext *gb, int le)

{

    return le ? bytestream2_get_le16(gb) : bytestream2_get_be16(gb);

}

unsigned ff_tget_long(GetByteContext *gb, int le)

{

    return le ? bytestream2_get_le32(gb) : bytestream2_get_be32(gb);

}

double ff_tget_double(GetByteContext *gb, int le)

{

    av_alias64 i = { .u64 = le ? bytestream2_get_le64(gb) : bytestream2_get_be64(gb)};

    return i.f64;

}

unsigned ff_tget(GetByteContext *gb, int type, int le)

{

    switch (type) {

    case AV_TIFF_BYTE:  return bytestream2_get_byte(gb);

    case AV_TIFF_SHORT: return ff_tget_short(gb, le);

    case AV_TIFF_LONG:  return ff_tget_long(gb, le);

    default:         return UINT_MAX;

    }

}

static const char *auto_sep(int count, const char *sep, int i, int columns)

{

    if (sep)

        return i ? sep : "";

    if (i && i%columns) {

        return ", ";

    } else

        return columns < count ? "\n" : "";

}

static int bprint_to_avdict(AVBPrint *bp, const char *name,

                            AVDictionary **metadata)

{

    char *ap;

    int ret;

    if (!av_bprint_is_complete(bp)) {

        av_bprint_finalize(bp, NULL);

        return AVERROR(ENOMEM);

    }

    if ((ret = av_bprint_finalize(bp, &ap)) < 0)

        return ret;

    return av_dict_set(metadata, name, ap, AV_DICT_DONT_STRDUP_VAL);

}

int ff_tadd_doubles_metadata(int count, const char *name, const char *sep,

                             GetByteContext *gb, int le, AVDictionary **metadata)

{

    AVBPrint bp;

    int i;

    if (count >= INT_MAX / sizeof(int64_t) || count <= 0)

        return AVERROR_INVALIDDATA;

    if (bytestream2_get_bytes_left(gb) < count * sizeof(int64_t))

        return AVERROR_INVALIDDATA;

    av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);

    for (i = 0; i < count; i++) {

        av_bprintf(&bp, "%s%.15g", auto_sep(count, sep, i, 4), ff_tget_double(gb, le));

    }

    return bprint_to_avdict(&bp, name, metadata);

}

int ff_tadd_shorts_metadata(int count, const char *name, const char *sep,

                            GetByteContext *gb, int le, int is_signed, AVDictionary **metadata)

{

    AVBPrint bp;

    int i;

    if (count >= INT_MAX / sizeof(int16_t) || count <= 0)

        return AVERROR_INVALIDDATA;

    if (bytestream2_get_bytes_left(gb) < count * sizeof(int16_t))

        return AVERROR_INVALIDDATA;

    av_bprint_init(&bp, 0, AV_BPRINT_SIZE_UNLIMITED);

    for (i = 0; i < count; i++) {

        int v = is_signed ? (int16_t)ff_tget_short(gb, le) :  ff_tget_short(gb, le);

        av_bprintf(&bp, "%s%5i", auto_sep(count, sep, i, 8), v);

    }

    return bprint_to_avdict(&bp, name, metadata);

}

int ff_tadd_string_metadata(int count, const char *name,

                            GetByteContext *gb, int le, AVDictionary **metadata)

{

    char *value;

    if (bytestream2_get_bytes_left(gb) < count || count < 0)

        return AVERROR_INVALIDDATA;

    value = av_malloc(count + 1);

    if (!value)

        return AVERROR(ENOMEM);

    bytestream2_get_bufferu(gb, value, count);

    value[count] = 0;

    av_dict_set(metadata, name, value, AV_DICT_DONT_STRDUP_VAL);

    return 0;

}

int ff_tdecode_header(GetByteContext *gb, int *le, int *ifd_offset)

{

    if (bytestream2_get_bytes_left(gb) < 8) {

        return AVERROR_INVALIDDATA;

    }

    *le = bytestream2_get_le16u(gb);

    if (*le == AV_RB16("II")) {

        *le = 1;

    } else if (*le == AV_RB16("MM")) {

        *le = 0;

    } else {

        return AVERROR_INVALIDDATA;

    }

    if (ff_tget_short(gb, *le) != 42) {

        return AVERROR_INVALIDDATA;

    }

    *ifd_offset = ff_tget_long(gb, *le);

    return 0;

}

int ff_tread_tag(GetByteContext *gb, int le, unsigned *tag, unsigned *type,

                 unsigned *count, int *next)

{

    int ifd_tag;

    int valid_type;

    *tag    = ff_tget_short(gb, le);

    *type   = ff_tget_short(gb, le);

    *count  = ff_tget_long (gb, le);

    ifd_tag    = ff_tis_ifd(*tag);

    valid_type = *type != 0 && *type < FF_ARRAY_ELEMS(type_sizes);

    *next = bytestream2_tell(gb) + 4;

    // check for valid type

    if (!valid_type) {

        return AVERROR_INVALIDDATA;

    }

    // seek to offset if this is an IFD-tag or

    // if count values do not fit into the offset value

    if (ifd_tag || (*count > 4 || !(type_sizes[*type] * (*count) <= 4 || *type == AV_TIFF_STRING))) {

        bytestream2_seek(gb, ff_tget_long (gb, le), SEEK_SET);

    }

    return 0;

}