// Copyright (C) 2004-2021 Artifex Software, Inc.

//

// This file is part of MuPDF.

//

// MuPDF is free software: you can redistribute it and/or modify it under the

// terms of the GNU Affero General Public License as published by the Free

// Software Foundation, either version 3 of the License, or (at your option)

// any later version.

//

// MuPDF 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 Affero General Public License for more

// details.

//

// You should have received a copy of the GNU Affero General Public License

// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>

//

// Alternative licensing terms are available from the licensor.

// For commercial licensing, see <https://www.artifex.com/> or contact

// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,

// CA 94129, USA, for further information.

#include "mupdf/fitz.h"

#include <string.h>

#include <zlib.h>

#if !defined (INT32_MAX)

#define INT32_MAX 2147483647L

#endif

#define ZIP_LOCAL_FILE_SIG 0x04034b50

#define ZIP_CENTRAL_DIRECTORY_SIG 0x02014b50

#define ZIP_END_OF_CENTRAL_DIRECTORY_SIG 0x06054b50

struct fz_zip_writer

{

  fz_output *output;

  fz_buffer *central;

  int count;

  int closed;

};

void

fz_write_zip_entry(fz_context *ctx, fz_zip_writer *zip, const char *name, fz_buffer *buf, int compress)

{

  int offset = fz_tell_output(ctx, zip->output);

  int sum;

  sum = crc32(0, NULL, 0);

  sum = crc32(sum, buf->data, (uInt)buf->len);

  /* bit 11 of general purpose bit flag indicates UTF-8. */

  fz_append_int32_le(ctx, zip->central, ZIP_CENTRAL_DIRECTORY_SIG);

  fz_append_int16_le(ctx, zip->central, 0); /* version made by: MS-DOS */

  fz_append_int16_le(ctx, zip->central, 20); /* version to extract: 2.0 */

  fz_append_int16_le(ctx, zip->central, 1<<11); /* general purpose bit flag */

  fz_append_int16_le(ctx, zip->central, 0); /* compression method: store */

  fz_append_int16_le(ctx, zip->central, 0); /* TODO: last mod file time */

  fz_append_int16_le(ctx, zip->central, 0); /* TODO: last mod file date */

  fz_append_int32_le(ctx, zip->central, sum); /* crc-32 */

  fz_append_int32_le(ctx, zip->central, (int)buf->len); /* csize */

  fz_append_int32_le(ctx, zip->central, (int)buf->len); /* usize */

  fz_append_int16_le(ctx, zip->central, (int)strlen(name)); /* file name length */

  fz_append_int16_le(ctx, zip->central, 0); /* extra field length */

  fz_append_int16_le(ctx, zip->central, 0); /* file comment length */

  fz_append_int16_le(ctx, zip->central, 0); /* disk number start */

  fz_append_int16_le(ctx, zip->central, 0); /* internal file attributes */

  fz_append_int32_le(ctx, zip->central, 0); /* external file attributes */

  fz_append_int32_le(ctx, zip->central, offset); /* relative offset of local header */

  fz_append_string(ctx, zip->central, name);

  fz_write_int32_le(ctx, zip->output, ZIP_LOCAL_FILE_SIG);

  fz_write_int16_le(ctx, zip->output, 20); /* version to extract: 2.0 */

  fz_write_int16_le(ctx, zip->output, 1<<11); /* general purpose bit flag */

  fz_write_int16_le(ctx, zip->output, 0); /* compression method: store */

  fz_write_int16_le(ctx, zip->output, 0); /* TODO: last mod file time */

  fz_write_int16_le(ctx, zip->output, 0); /* TODO: last mod file date */

  fz_write_int32_le(ctx, zip->output, sum); /* crc-32 */

  fz_write_int32_le(ctx, zip->output, (int)buf->len); /* csize */

  fz_write_int32_le(ctx, zip->output, (int)buf->len); /* usize */

  fz_write_int16_le(ctx, zip->output, (int)strlen(name)); /* file name length */

  fz_write_int16_le(ctx, zip->output, 0); /* extra field length */

  fz_write_data(ctx, zip->output, name, strlen(name));

  fz_write_data(ctx, zip->output, buf->data, buf->len);

  ++zip->count;

}

void

fz_close_zip_writer(fz_context *ctx, fz_zip_writer *zip)

{

  int64_t offset = fz_tell_output(ctx, zip->output);

  fz_write_data(ctx, zip->output, zip->central->data, zip->central->len);

  fz_write_int32_le(ctx, zip->output, ZIP_END_OF_CENTRAL_DIRECTORY_SIG);

  fz_write_int16_le(ctx, zip->output, 0); /* number of this disk */

  fz_write_int16_le(ctx, zip->output, 0); /* number of disk where central directory starts */

  fz_write_int16_le(ctx, zip->output, zip->count); /* entries in central directory in this disk */

  fz_write_int16_le(ctx, zip->output, zip->count); /* entries in central directory in total */

  fz_write_int32_le(ctx, zip->output, (int)zip->central->len); /* size of the central directory */

  fz_write_int32_le(ctx, zip->output, (int)offset); /* offset of the central directory */

  fz_write_int16_le(ctx, zip->output, 5); /* zip file comment length */

  fz_write_data(ctx, zip->output, "MuPDF", 5);

  fz_close_output(ctx, zip->output);

  zip->closed = 1;

}

void

fz_drop_zip_writer(fz_context *ctx, fz_zip_writer *zip)

{

  if (!zip)

    return;

  if (!zip->closed)

    fz_warn(ctx, "dropping unclosed zip writer");

  fz_drop_output(ctx, zip->output);

  fz_drop_buffer(ctx, zip->central);

  fz_free(ctx, zip);

}

fz_zip_writer *

fz_new_zip_writer_with_output(fz_context *ctx, fz_output *out)

{

  fz_zip_writer *zip = NULL;

  fz_var(zip);

  fz_try(ctx)

  {

    zip = fz_malloc_struct(ctx, fz_zip_writer);

    zip->output = out;

    zip->central = fz_new_buffer(ctx, 0);

  }

  fz_catch(ctx)

  {

    fz_drop_output(ctx, out);

    if (zip)

      fz_drop_buffer(ctx, zip->central);

    fz_free(ctx, zip);

    fz_rethrow(ctx);

  }

  return zip;

}

fz_zip_writer *

fz_new_zip_writer(fz_context *ctx, const char *filename)

{

  fz_output *out = fz_new_output_with_path(ctx, filename, 0);

  fz_zip_writer *zip = NULL;

  fz_try(ctx)

    zip = fz_new_zip_writer_with_output(ctx, out);

  fz_catch(ctx)

  {

    fz_drop_output(ctx, out);

    fz_rethrow(ctx);

  }

  return zip;

}