/* mz_strm_zlib.c -- Stream for zlib inflate/deflate

   part of the minizip-ng project

   Copyright (C) Nathan Moinvaziri

      https://github.com/zlib-ng/minizip-ng

   This program is distributed under the terms of the same license as zlib.

   See the accompanying LICENSE file for the full text of the license.

*/

#include "mz.h"

#include "mz_strm.h"

#include "mz_strm_zlib.h"

#if !defined(ZLIB_COMPAT)

#  include "zlib-ng.h"

#else

#  include "zlib.h"

#endif

/***************************************************************************/

#if !defined(ZLIB_COMPAT)

#  define ZLIB_PREFIX(x) zng_##x

typedef zng_stream zlib_stream;

#else

#  define ZLIB_PREFIX(x) x

typedef z_stream zlib_stream;

#endif

#if !defined(DEF_MEM_LEVEL)

#  if MAX_MEM_LEVEL >= 8

#    define DEF_MEM_LEVEL 8

#  else

#    define DEF_MEM_LEVEL MAX_MEM_LEVEL

#  endif

#endif

/***************************************************************************/

static mz_stream_vtbl mz_stream_zlib_vtbl = {

    mz_stream_zlib_open,   mz_stream_zlib_is_open, mz_stream_zlib_read,           mz_stream_zlib_write,

    mz_stream_zlib_tell,   mz_stream_zlib_seek,    mz_stream_zlib_close,          mz_stream_zlib_error,

    mz_stream_zlib_create, mz_stream_zlib_delete,  mz_stream_zlib_get_prop_int64, mz_stream_zlib_set_prop_int64};

/***************************************************************************/

typedef struct mz_stream_zlib_s {

    mz_stream stream;

    zlib_stream zstream;

    uint8_t buffer[INT16_MAX];

    int32_t buffer_len;

    int64_t total_in;

    int64_t total_out;

    int64_t max_total_in;

    int8_t initialized;

    int16_t level;

    int32_t window_bits;

    int32_t mode;

    int32_t error;

} mz_stream_zlib;

/***************************************************************************/

int32_t mz_stream_zlib_open(void *stream, const char *path, int32_t mode) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    MZ_UNUSED(path);

    zlib->zstream.data_type = Z_BINARY;

    zlib->zstream.zalloc = Z_NULL;

    zlib->zstream.zfree = Z_NULL;

    zlib->zstream.opaque = Z_NULL;

    zlib->zstream.total_in = 0;

    zlib->zstream.total_out = 0;

    zlib->total_in = 0;

    zlib->total_out = 0;

    if (mode & MZ_OPEN_MODE_WRITE) {

#ifdef MZ_ZIP_NO_COMPRESSION

        return MZ_SUPPORT_ERROR;

#else

        zlib->zstream.next_out = zlib->buffer;

        zlib->zstream.avail_out = sizeof(zlib->buffer);

        zlib->error = ZLIB_PREFIX(deflateInit2)(&zlib->zstream, (int8_t)zlib->level, Z_DEFLATED, zlib->window_bits,

                                                DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY);

#endif

    } else if (mode & MZ_OPEN_MODE_READ) {

#ifdef MZ_ZIP_NO_DECOMPRESSION

        return MZ_SUPPORT_ERROR;

#else

        zlib->zstream.next_in = zlib->buffer;

        zlib->zstream.avail_in = 0;

        zlib->error = ZLIB_PREFIX(inflateInit2)(&zlib->zstream, zlib->window_bits);

#endif

    }

    if (zlib->error != Z_OK)

        return MZ_OPEN_ERROR;

    zlib->initialized = 1;

    zlib->mode = mode;

    return MZ_OK;

}

int32_t mz_stream_zlib_is_open(void *stream) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    if (zlib->initialized != 1)

        return MZ_OPEN_ERROR;

    return MZ_OK;

}

int32_t mz_stream_zlib_read(void *stream, void *buf, int32_t size) {

#ifdef MZ_ZIP_NO_DECOMPRESSION

    MZ_UNUSED(stream);

    MZ_UNUSED(buf);

    MZ_UNUSED(size);

    return MZ_SUPPORT_ERROR;

#else

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    uint64_t total_in_before = 0;

    uint64_t total_in_after = 0;

    uint64_t total_out_before = 0;

    uint64_t total_out_after = 0;

    uint32_t total_in = 0;

    uint32_t total_out = 0;

    uint32_t in_bytes = 0;

    uint32_t out_bytes = 0;

    int32_t bytes_to_read = sizeof(zlib->buffer);

    int32_t read = 0;

    int32_t err = Z_OK;

    zlib->zstream.next_out = (Bytef *)buf;

    zlib->zstream.avail_out = (uInt)size;

    do {

        if (zlib->zstream.avail_in == 0) {

            if (zlib->max_total_in > 0) {

                if ((int64_t)bytes_to_read > (zlib->max_total_in - zlib->total_in))

                    bytes_to_read = (int32_t)(zlib->max_total_in - zlib->total_in);

            }

            read = mz_stream_read(zlib->stream.base, zlib->buffer, bytes_to_read);

            if (read < 0)

                return read;

            zlib->zstream.next_in = zlib->buffer;

            zlib->zstream.avail_in = read;

        }

        total_in_before = zlib->zstream.avail_in;

        total_out_before = zlib->zstream.total_out;

        err = ZLIB_PREFIX(inflate)(&zlib->zstream, Z_SYNC_FLUSH);

        if ((err >= Z_OK) && (zlib->zstream.msg)) {

            zlib->error = Z_DATA_ERROR;

            break;

        }

        total_in_after = zlib->zstream.avail_in;

        total_out_after = zlib->zstream.total_out;

        in_bytes = (uint32_t)(total_in_before - total_in_after);

        out_bytes = (uint32_t)(total_out_after - total_out_before);

        total_in += in_bytes;

        total_out += out_bytes;

        zlib->total_in += in_bytes;

        zlib->total_out += out_bytes;

        if (err == Z_STREAM_END)

            break;

        if (err != Z_OK) {

            zlib->error = err;

            break;

        }

    } while (zlib->zstream.avail_out > 0);

    MZ_UNUSED(total_in);

    if (zlib->error != 0) {

        /* Zlib errors are compatible with MZ */

        return zlib->error;

    }

    return total_out;

#endif

}

#ifndef MZ_ZIP_NO_COMPRESSION

static int32_t mz_stream_zlib_flush(void *stream) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    if (mz_stream_write(zlib->stream.base, zlib->buffer, zlib->buffer_len) != zlib->buffer_len)

        return MZ_WRITE_ERROR;

    return MZ_OK;

}

static int32_t mz_stream_zlib_deflate(void *stream, int flush) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    uint64_t total_out_before = 0;

    uint64_t total_out_after = 0;

    int32_t out_bytes = 0;

    int32_t err = Z_OK;

    do {

        if (zlib->zstream.avail_out == 0) {

            err = mz_stream_zlib_flush(zlib);

            if (err != MZ_OK)

                return err;

            zlib->zstream.avail_out = sizeof(zlib->buffer);

            zlib->zstream.next_out = zlib->buffer;

            zlib->buffer_len = 0;

        }

        total_out_before = zlib->zstream.total_out;

        err = ZLIB_PREFIX(deflate)(&zlib->zstream, flush);

        total_out_after = zlib->zstream.total_out;

        out_bytes = (uint32_t)(total_out_after - total_out_before);

        zlib->buffer_len += out_bytes;

        zlib->total_out += out_bytes;

        if (err == Z_STREAM_END)

            break;

        if (err != Z_OK) {

            zlib->error = err;

            return MZ_DATA_ERROR;

        }

    } while ((zlib->zstream.avail_in > 0) || (flush == Z_FINISH && err == Z_OK));

    return MZ_OK;

}

#endif

int32_t mz_stream_zlib_write(void *stream, const void *buf, int32_t size) {

#ifdef MZ_ZIP_NO_COMPRESSION

    MZ_UNUSED(stream);

    MZ_UNUSED(buf);

    MZ_UNUSED(size);

    return MZ_SUPPORT_ERROR;

#else

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    int32_t err = MZ_OK;

    zlib->zstream.next_in = (Bytef *)(intptr_t)buf;

    zlib->zstream.avail_in = (uInt)size;

    err = mz_stream_zlib_deflate(stream, Z_NO_FLUSH);

    if (err != MZ_OK) {

        return err;

    }

    zlib->total_in += size;

    return size;

#endif

}

int64_t mz_stream_zlib_tell(void *stream) {

    MZ_UNUSED(stream);

    return MZ_TELL_ERROR;

}

int32_t mz_stream_zlib_seek(void *stream, int64_t offset, int32_t origin) {

    MZ_UNUSED(stream);

    MZ_UNUSED(offset);

    MZ_UNUSED(origin);

    return MZ_SEEK_ERROR;

}

int32_t mz_stream_zlib_close(void *stream) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    if (zlib->mode & MZ_OPEN_MODE_WRITE) {

#ifdef MZ_ZIP_NO_COMPRESSION

        return MZ_SUPPORT_ERROR;

#else

        mz_stream_zlib_deflate(stream, Z_FINISH);

        mz_stream_zlib_flush(stream);

        ZLIB_PREFIX(deflateEnd)(&zlib->zstream);

#endif

    } else if (zlib->mode & MZ_OPEN_MODE_READ) {

#ifdef MZ_ZIP_NO_DECOMPRESSION

        return MZ_SUPPORT_ERROR;

#else

        ZLIB_PREFIX(inflateEnd)(&zlib->zstream);

#endif

    }

    zlib->initialized = 0;

    if (zlib->error != Z_OK)

        return MZ_CLOSE_ERROR;

    return MZ_OK;

}

int32_t mz_stream_zlib_error(void *stream) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    return zlib->error;

}

int32_t mz_stream_zlib_get_prop_int64(void *stream, int32_t prop, int64_t *value) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    switch (prop) {

    case MZ_STREAM_PROP_TOTAL_IN:

        *value = zlib->total_in;

        break;

    case MZ_STREAM_PROP_TOTAL_IN_MAX:

        *value = zlib->max_total_in;

        break;

    case MZ_STREAM_PROP_TOTAL_OUT:

        *value = zlib->total_out;

        break;

    case MZ_STREAM_PROP_HEADER_SIZE:

        *value = 0;

        break;

    case MZ_STREAM_PROP_COMPRESS_WINDOW:

        *value = zlib->window_bits;

        break;

    default:

        return MZ_EXIST_ERROR;

    }

    return MZ_OK;

}

int32_t mz_stream_zlib_set_prop_int64(void *stream, int32_t prop, int64_t value) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)stream;

    switch (prop) {

    case MZ_STREAM_PROP_COMPRESS_LEVEL:

        if (value == MZ_COMPRESS_LEVEL_DEFAULT)

            zlib->level = Z_DEFAULT_COMPRESSION;

        else

            zlib->level = (int16_t)value;

        break;

    case MZ_STREAM_PROP_TOTAL_IN_MAX:

        zlib->max_total_in = value;

        break;

    case MZ_STREAM_PROP_COMPRESS_WINDOW:

        zlib->window_bits = (int32_t)value;

        break;

    default:

        return MZ_EXIST_ERROR;

    }

    return MZ_OK;

}

void *mz_stream_zlib_create(void) {

    mz_stream_zlib *zlib = (mz_stream_zlib *)calloc(1, sizeof(mz_stream_zlib));

    if (zlib) {

        zlib->stream.vtbl = &mz_stream_zlib_vtbl;

        zlib->level = Z_DEFAULT_COMPRESSION;

        zlib->window_bits = -MAX_WBITS;

    }

    return zlib;

}

void mz_stream_zlib_delete(void **stream) {

    mz_stream_zlib *zlib = NULL;

    if (!stream)

        return;

    zlib = (mz_stream_zlib *)*stream;

    free(zlib);

    *stream = NULL;

}

void *mz_stream_zlib_get_interface(void) {

    return (void *)&mz_stream_zlib_vtbl;

}