/*

 * UTF-16 string value functions

 *

 * Copyright (C) 2010-2022, Joachim Metz <joachim.metz@gmail.com>

 *

 * Refer to AUTHORS for acknowledgements.

 *

 * This program 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 3 of the License, or

 * (at your option) any later version.

 *

 * This program 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 General Public License for more details.

 *

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

 * along with this program.  If not, see <https://www.gnu.org/licenses/>.

 */

#include <common.h>

#include <types.h>

#include "libfvalue_libcerror.h"

#include "libfvalue_split_utf16_string.h"

#include "libfvalue_types.h"

/* Splits an UTF-16 string

 * Returns 1 if successful or -1 on error

 */

int libfvalue_utf16_string_split(

     const uint16_t *utf16_string,

     size_t utf16_string_size,

     uint16_t delimiter,

     libfvalue_split_utf16_string_t **split_string,

     libcerror_error_t **error )

{

  uint16_t *segment_start = NULL;

  uint16_t *segment_end   = NULL;

  uint16_t *string_end    = NULL;

  static char *function   = "libfvalue_utf16_string_split";

  size_t string_size      = 0;

  ssize_t segment_length  = 0;

  int number_of_segments  = 0;

  int segment_index       = 0;

  if( utf16_string == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid UTF-16 string.",

     function );

    return( -1 );

  }

  if( utf16_string_size > (size_t) SSIZE_MAX )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_VALUE_EXCEEDS_MAXIMUM,

     "%s: invalid UTF-16 string size value exceeds maximum.",

     function );

    return( -1 );

  }

  if( split_string == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_ARGUMENTS,

     LIBCERROR_ARGUMENT_ERROR_INVALID_VALUE,

     "%s: invalid split string.",

     function );

    return( -1 );

  }

  if( *split_string != NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_ALREADY_SET,

     "%s: invalid split string already set.",

     function );

    return( -1 );

  }

  /* An empty string has no segments

   */

  if( ( utf16_string_size == 0 )

   || ( utf16_string[ 0 ] == 0 ) )

  {

    return( 1 );

  }

  /* Determine the number of segments

   */

  segment_start = (uint16_t *) utf16_string;

  string_end    = (uint16_t *) &( utf16_string[ utf16_string_size - 1 ] );

  do

  {

    segment_end = segment_start;

    while( segment_end <= string_end )

    {

      if( ( segment_end == string_end )

       || ( *segment_end == 0 ) )

      {

        segment_end = NULL;

        break;

      }

      else if( *segment_end == delimiter )

      {

        break;

      }

      segment_end++;

    }

    if( segment_end > string_end )

    {

      break;

    }

    segment_index++;

    if( segment_end == NULL )

    {

      break;

    }

    if( segment_end == segment_start )

    {

      segment_start++;

    }

    else if( segment_end != utf16_string )

    {

      segment_start = segment_end + 1;

    }

  }

  while( segment_end != NULL );

  number_of_segments = segment_index;

  if( libfvalue_split_utf16_string_initialize(

       split_string,

       utf16_string,

       utf16_string_size,

       number_of_segments,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_INITIALIZE_FAILED,

     "%s: unable to initialize split string.",

     function );

    goto on_error;

  }

  if( *split_string == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

     "%s: missing split string.",

     function );

    goto on_error;

  }

  /* Do not bother splitting empty strings

   */

  if( number_of_segments == 0 )

  {

    return( 1 );

  }

  /* Determine the segments

   * empty segments are stored as strings only containing the end of character

   */

  if( libfvalue_split_utf16_string_get_string(

       *split_string,

       &segment_start,

       &string_size,

       error ) != 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_GET_FAILED,

     "%s: unable to retrieve split UTF-16 string.",

     function );

    goto on_error;

  }

  if( segment_start == NULL )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_MISSING,

     "%s: missing segment start.",

     function );

    goto on_error;

  }

  if( string_size < 1 )

  {

    libcerror_error_set(

     error,

     LIBCERROR_ERROR_DOMAIN_RUNTIME,

     LIBCERROR_RUNTIME_ERROR_VALUE_OUT_OF_BOUNDS,

     "%s: invalid string size value out of bounds.",

     function );

    goto on_error;

  }

  string_end = &( segment_start[ string_size - 1 ] );

  for( segment_index = 0;

       segment_index < number_of_segments;

       segment_index++ )

  {

    segment_end = segment_start;

    while( segment_end <= string_end )

    {

      if( ( segment_end == string_end )

       || ( *segment_end == 0 ) )

      {

        segment_end = NULL;

        break;

      }

      else if( *segment_end == delimiter )

      {

        break;

      }

      segment_end++;

    }

    if( segment_end == NULL )

    {

      segment_length = (ssize_t) ( string_end - segment_start );

    }

    else

    {

      segment_length = (ssize_t) ( segment_end - segment_start );

    }

    if( segment_length >= 0 )

    {

      segment_start[ segment_length ] = 0;

      if( libfvalue_split_utf16_string_set_segment_by_index(

           *split_string,

           segment_index,

           segment_start,

           segment_length + 1,

           error ) != 1 )

      {

        libcerror_error_set(

         error,

         LIBCERROR_ERROR_DOMAIN_RUNTIME,

         LIBCERROR_RUNTIME_ERROR_SET_FAILED,

         "%s: unable to set split UTF-16 string segment: %d.",

         function,

         segment_index );

        goto on_error;

      }

    }

    if( segment_end == NULL )

    {

      break;

    }

    if( segment_end == string_end )

    {

      segment_start++;

    }

    if( segment_end != string_end )

    {

      segment_start = segment_end + 1;

    }

  }

  return( 1 );

on_error:

  if( *split_string != NULL )

  {

    libfvalue_split_utf16_string_free(

     split_string,

     NULL );

  }

  return( -1 );

}