/***************************************************************
  MPU-UTF8.C

       This file contains UTF-8 <-> UCS-2 conversion and
       character/string stream operations.

       PART OF : MPUIO - library .

       USAGE   : Internal and external .

       NOTE    : UCS-2 is used strictly. Unicode values above
                 U+FFFF and surrogate values are not accepted.

       Copyright (C) 2000 - 2026  by Andrey V.Kosteltsev.
       All Rights Reserved.
 ***************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <libmpuio.h>
#include <mpu-symbols.h>
#include <mpu-libio.h>


static int __mpu_UTF8_continuation( mpu_FILE *stream )
{
  int  c;

  c = __mpu_IO_get_byte_unlocked( stream );
  if( c == mpu_EOF )
  {
    if( stream->_flags & __MPU_IO_EOF_SEEN )
    {
      stream->_flags &= ~__MPU_IO_EOF_SEEN;
      stream->_flags |= __MPU_IO_ERR_SEEN;
      errno = EILSEQ;
    }
    return( mpu_EOF );
  }

  if( (c & 0xc0) != 0x80 )
  {
    stream->_flags |= __MPU_IO_ERR_SEEN;
    errno = EILSEQ;
    return( mpu_EOF );
  }

  return( c );

} /* End of __mpu_UTF8_continuation() */


int __mpu_UTF8_decode_unlocked( mpu_FILE *stream, __mpu_char16_t *wc )
{
  unsigned int  u;
  int           c0;
  int           c1;
  int           c2;
  int           c3;

  c0 = __mpu_IO_get_byte_unlocked( stream );
  if( c0 == mpu_EOF )
     return( mpu_EOF );

  if( c0 < 0x80 )
  {
    *wc = (__mpu_char16_t)c0;
    return( 0 );
  }

  if( c0 >= 0xc2 && c0 <= 0xdf )
  {
    c1 = __mpu_UTF8_continuation( stream );
    if( c1 == mpu_EOF ) return( mpu_EOF );

    u = ((unsigned int)(c0 & 0x1f) << 6) |
         (unsigned int)(c1 & 0x3f);
  }
  else if( c0 >= 0xe0 && c0 <= 0xef )
  {
    c1 = __mpu_UTF8_continuation( stream );
    if( c1 == mpu_EOF ) return( mpu_EOF );

    c2 = __mpu_UTF8_continuation( stream );
    if( c2 == mpu_EOF ) return( mpu_EOF );

    if( (c0 == 0xe0 && c1 < 0xa0) ||
        (c0 == 0xed && c1 >= 0xa0) )
    {
      stream->_flags |= __MPU_IO_ERR_SEEN;
      errno = EILSEQ;
      return( mpu_EOF );
    }

    u = ((unsigned int)(c0 & 0x0f) << 12) |
        ((unsigned int)(c1 & 0x3f) << 6) |
         (unsigned int)(c2 & 0x3f);
  }
  else if( c0 >= 0xf0 && c0 <= 0xf4 )
  {
    c1 = __mpu_UTF8_continuation( stream );
    if( c1 == mpu_EOF ) return( mpu_EOF );

    c2 = __mpu_UTF8_continuation( stream );
    if( c2 == mpu_EOF ) return( mpu_EOF );

    c3 = __mpu_UTF8_continuation( stream );
    if( c3 == mpu_EOF ) return( mpu_EOF );

    if( (c0 == 0xf0 && c1 < 0x90) ||
        (c0 == 0xf4 && c1 > 0x8f) )
    {
      stream->_flags |= __MPU_IO_ERR_SEEN;
      errno = EILSEQ;
      return( mpu_EOF );
    }

    /*
      This is a valid Unicode scalar value above U+FFFF, but
      strict UCS-2 has no representation for it.
     */
    stream->_flags |= __MPU_IO_ERR_SEEN;
    errno = EILSEQ;
    return( mpu_EOF );
  }
  else
  {
    stream->_flags |= __MPU_IO_ERR_SEEN;
    errno = EILSEQ;
    return( mpu_EOF );
  }

  if( u >= 0xd800U && u <= 0xdfffU )
  {
    stream->_flags |= __MPU_IO_ERR_SEEN;
    errno = EILSEQ;
    return( mpu_EOF );
  }

  *wc = (__mpu_char16_t)u;

  return( 0 );

} /* End of __mpu_UTF8_decode_unlocked() */


int __mpu_UTF8_encode_unlocked( __mpu_char16_t wc, mpu_FILE *stream )
{
  unsigned int   u = (unsigned int)wc;
  unsigned char  out[3];
  int            n;
  int            i;

  if( u >= 0xd800U && u <= 0xdfffU )
  {
    errno = EILSEQ;
    stream->_flags |= __MPU_IO_ERR_SEEN;
    return( mpu_EOF );
  }

  if( u < 0x80U )
  {
    out[0] = (unsigned char)u;
    n = 1;
  }
  else if( u < 0x800U )
  {
    out[0] = (unsigned char)(0xc0U | (u >> 6));
    out[1] = (unsigned char)(0x80U | (u & 0x3fU));
    n = 2;
  }
  else
  {
    out[0] = (unsigned char)(0xe0U | (u >> 12));
    out[1] = (unsigned char)(0x80U | ((u >> 6) & 0x3fU));
    out[2] = (unsigned char)(0x80U | (u & 0x3fU));
    n = 3;
  }

  for( i = 0; i < n; ++i )
    if( __mpu_IO_put_byte_unlocked( out[i], stream ) == mpu_EOF )
      return( mpu_EOF );

  return( 0 );

} /* End of __mpu_UTF8_encode_unlocked() */


/***************************************************************
  Read one UCS-2 character from STREAM without acquiring its lock.
 ***************************************************************/
int mpu_fgetc_unlocked( mpu_FILE *stream )
{
  __mpu_char16_t  wc;
  int         ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  ret = __mpu_IO_get_char_unlocked( stream, &wc );

  return( ret == 0 ? (int)wc : mpu_EOF );

} /* End of mpu_fgetc_unlocked() */


int mpu_fgetc( mpu_FILE *stream )
{
  int  ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  pthread_mutex_lock( &stream->_lock );
  ret = mpu_fgetc_unlocked( stream );
  pthread_mutex_unlock( &stream->_lock );

  return( ret );

} /* End of mpu_fgetc() */


/***************************************************************
  Alias of mpu_fgetc_unlocked().
 ***************************************************************/
int mpu_getc_unlocked( mpu_FILE *stream )
{
  return( mpu_fgetc_unlocked( stream ) );

} /* End of mpu_getc_unlocked() */


int mpu_getc( mpu_FILE *stream )
{
  return( mpu_fgetc( stream ) );

} /* End of mpu_getc() */


/***************************************************************
  Push one UCS-2 character back to STREAM.  At least one character
  of pushback is guaranteed.
 ***************************************************************/
int mpu_ungetc( __mpu_char16_t c, mpu_FILE *stream )
{
  int ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  pthread_mutex_lock( &stream->_lock );
  ret = __mpu_IO_unget_char_unlocked( c, stream );
  pthread_mutex_unlock( &stream->_lock );

  return( ret );

} /* End of mpu_ungetc() */


/***************************************************************
  Read one UCS-2 character from mpu_stdin without locking it.
 ***************************************************************/
int mpu_getchar_unlocked( void )
{
  return( mpu_fgetc_unlocked( mpu_stdin ) );

} /* End of mpu_getchar_unlocked() */


int mpu_getchar( void )
{
  return( mpu_fgetc( mpu_stdin ) );

} /* End of mpu_getchar() */


/***************************************************************
  Write one UCS-2 character to STREAM without acquiring its lock.
 ***************************************************************/
int mpu_fputc_unlocked( __mpu_char16_t c, mpu_FILE *stream )
{
  int  ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  ret = __mpu_IO_put_char_unlocked( c, stream );

  return( ret == 0 ? (int)c : mpu_EOF );

} /* End of mpu_fputc_unlocked() */


int mpu_fputc( __mpu_char16_t c, mpu_FILE *stream )
{
  int  ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  pthread_mutex_lock( &stream->_lock );
  ret = mpu_fputc_unlocked( c, stream );
  pthread_mutex_unlock( &stream->_lock );

  return( ret );

} /* End of mpu_fputc() */


/***************************************************************
  Alias of mpu_fputc_unlocked().
 ***************************************************************/
int mpu_putc_unlocked( __mpu_char16_t c, mpu_FILE *stream )
{
  return( mpu_fputc_unlocked( c, stream ) );

} /* End of mpu_putc_unlocked() */


int mpu_putc( __mpu_char16_t c, mpu_FILE *stream )
{
  return( mpu_fputc( c, stream ) );

} /* End of mpu_putc() */


/***************************************************************
  Write one UCS-2 character to mpu_stdout without locking it.
 ***************************************************************/
int mpu_putchar_unlocked( __mpu_char16_t c )
{
  return( mpu_fputc_unlocked( c, mpu_stdout ) );

} /* End of mpu_putchar_unlocked() */


int mpu_putchar( __mpu_char16_t c )
{
  return( mpu_fputc( c, mpu_stdout ) );

} /* End of mpu_putchar() */


/***************************************************************
  Read one UCS-2 line/string from STREAM without acquiring its lock.
 ***************************************************************/
__mpu_char16_t *mpu_fgets_unlocked( __mpu_char16_t *s, int n, mpu_FILE *stream )
{
  int  i;

  if( s == (__mpu_char16_t *)0 || n <= 0 )
  {
    errno = EINVAL;
    return( (__mpu_char16_t *)0 );
  }

  if( !__mpu_IO_valid( stream ) )
    return( (__mpu_char16_t *)0 );

  for( i = 0; i < n - 1; ++i )
  {
    __mpu_char16_t  wc;

    if( __mpu_IO_get_char_unlocked( stream, &wc ) == mpu_EOF )
      break;

    s[i] = wc;
    if( wc == (__mpu_char16_t)'\n' )
    {
      ++i;
      break;
    }
  }

  s[i] = (__mpu_char16_t)0;

  if( i == 0 && (stream->_flags & (__MPU_IO_EOF_SEEN | __MPU_IO_ERR_SEEN)) )
    return( (__mpu_char16_t *)0 );

  return( s );

} /* End of mpu_fgets_unlocked() */


__mpu_char16_t *mpu_fgets( __mpu_char16_t *s, int n, mpu_FILE *stream )
{
  __mpu_char16_t  *ret;

  if( !__mpu_IO_valid( stream ) )
    return( (__mpu_char16_t *)0 );

  pthread_mutex_lock( &stream->_lock );
  ret = mpu_fgets_unlocked( s, n, stream );
  pthread_mutex_unlock( &stream->_lock );

  return( ret );

} /* End of mpu_fgets() */


/***************************************************************
  Write a NUL-terminated UCS-2 string without acquiring STREAM lock.
 ***************************************************************/
int mpu_fputs_unlocked( const __mpu_char16_t *s, mpu_FILE *stream )
{
  if( s == (const __mpu_char16_t *)0 )
  {
    errno = EINVAL;
    return( mpu_EOF );
  }

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  while( *s )
  {
    if( __mpu_IO_put_char_unlocked( *s++, stream ) == mpu_EOF )
      return( mpu_EOF );
  }

  return( 0 );

} /* End of mpu_fputs_unlocked() */


int mpu_fputs( const __mpu_char16_t *s, mpu_FILE *stream )
{
  int  ret;

  if( !__mpu_IO_valid( stream ) )
    return( mpu_EOF );

  pthread_mutex_lock( &stream->_lock );
  ret = mpu_fputs_unlocked( s, stream );
  pthread_mutex_unlock( &stream->_lock );

  return( ret );

} /* End of mpu_fputs() */


int mpu_puts( const __mpu_char16_t *s )
{
  int  ret = 0;

  if( !__mpu_IO_valid( mpu_stdout ) )
    return( mpu_EOF );

  pthread_mutex_lock( &mpu_stdout->_lock );

  if( mpu_fputs_unlocked( s, mpu_stdout ) == mpu_EOF ||
      mpu_fputc_unlocked( (__mpu_char16_t)'\n', mpu_stdout ) == mpu_EOF )
    ret = mpu_EOF;

  pthread_mutex_unlock( &mpu_stdout->_lock );
  return( ret );

} /* End of mpu_puts() */


/***************************************************************
  Read UCS-2 characters through DELIMITER without acquiring the
  stream lock, growing *LINEPTR as required.  The delimiter is
  included in the returned string and a trailing NUL is added.
 ***************************************************************/
ssize_t mpu_getdelim_unlocked( __mpu_char16_t **lineptr, size_t *n,
                               __mpu_char16_t delimiter, mpu_FILE *stream )
{
  __mpu_char16_t  *line;
  size_t           capacity;
  size_t           length = 0;

  if( lineptr == (__mpu_char16_t **)0 || n == (size_t *)0 )
  {
    errno = EINVAL;
    return( (ssize_t)-1 );
  }

  if( delimiter >= (__mpu_char16_t)0xd800 && delimiter <= (__mpu_char16_t)0xdfff )
  {
    errno = EILSEQ;
    return( (ssize_t)-1 );
  }

  if( !__mpu_IO_valid( stream ) )
    return( (ssize_t)-1 );

  line = *lineptr;
  capacity = *n;

  if( line == (__mpu_char16_t *)0 || capacity == 0 )
  {
    capacity = 128;
    line = (__mpu_char16_t *)malloc( capacity * sizeof( __mpu_char16_t ) );
    if( line == (__mpu_char16_t *)0 )
      return( (ssize_t)-1 );
    *lineptr = line;
    *n = capacity;
  }

  for( ;; )
  {
    __mpu_char16_t  wc;

    if( __mpu_IO_get_char_unlocked( stream, &wc ) == mpu_EOF )
    {
      if( length == 0 )
        return( (ssize_t)-1 );
      break;
    }

    if( length == (size_t)SSIZE_MAX )
    {
      errno = EOVERFLOW;
      stream->_flags |= __MPU_IO_ERR_SEEN;
      return( (ssize_t)-1 );
    }

    if( length + 1 >= capacity )
    {
      size_t       new_capacity;
      __mpu_char16_t  *new_line;

      if( capacity > SIZE_MAX / 2 )
      {
        errno = EOVERFLOW;
        stream->_flags |= __MPU_IO_ERR_SEEN;
        return( (ssize_t)-1 );
      }
      new_capacity = capacity * 2;
      if( new_capacity > SIZE_MAX / sizeof( __mpu_char16_t ) )
      {
        errno = EOVERFLOW;
        stream->_flags |= __MPU_IO_ERR_SEEN;
        return( (ssize_t)-1 );
      }
      new_line = (__mpu_char16_t *)realloc( line,
                                        new_capacity * sizeof( __mpu_char16_t ) );
      if( new_line == (__mpu_char16_t *)0 )
      {
        stream->_flags |= __MPU_IO_ERR_SEEN;
        return( (ssize_t)-1 );
      }
      line = new_line;
      capacity = new_capacity;
      *lineptr = line;
      *n = capacity;
    }

    line[length++] = wc;
    if( wc == delimiter )
      break;
  }

  line[length] = (__mpu_char16_t)0;
  return( (ssize_t)length );

} /* End of mpu_getdelim_unlocked() */


/***************************************************************
  Read UCS-2 characters through DELIMITER, growing *LINEPTR as
  required.  This is the locked form of mpu_getdelim_unlocked().
 ***************************************************************/
ssize_t mpu_getdelim( __mpu_char16_t **lineptr, size_t *n,
                      __mpu_char16_t delimiter, mpu_FILE *stream )
{
  ssize_t  ret;

  if( !__mpu_IO_valid( stream ) )
    return( (ssize_t)-1 );

  pthread_mutex_lock( &stream->_lock );
  ret = mpu_getdelim_unlocked( lineptr, n, delimiter, stream );
  pthread_mutex_unlock( &stream->_lock );
  return( ret );

} /* End of mpu_getdelim() */


/***************************************************************
  Read one UCS-2 line without acquiring STREAM lock.  The newline,
  when present, is included in the returned string.
 ***************************************************************/
ssize_t mpu_getline_unlocked( __mpu_char16_t **lineptr, size_t *n,
                              mpu_FILE *stream )
{
  return( mpu_getdelim_unlocked( lineptr, n, (__mpu_char16_t)'\n', stream ) );

} /* End of mpu_getline_unlocked() */


/***************************************************************
  Read one UCS-2 line, growing *LINEPTR as required.
 ***************************************************************/
ssize_t mpu_getline( __mpu_char16_t **lineptr, size_t *n, mpu_FILE *stream )
{
  return( mpu_getdelim( lineptr, n, (__mpu_char16_t)'\n', stream ) );

} /* End of mpu_getline() */


/***************************************************************
  Hide internal symbols:
 ***************************************************************/

__mpu_hidden_decl(__mpu_UTF8_decode_unlocked);
__mpu_hidden_decl(__mpu_UTF8_encode_unlocked);

/*
  End of hide internal symbols.
 ***************************************************************/

/* End of mpu-utf8.c */