/*
 * Copyright (c) 1999
 * Silicon Graphics Computer Systems, Inc.
 *
 * Copyright (c) 1999 
 * Boris Fomitchev
 *
 * This material is provided "as is", with absolutely no warranty expressed
 * or implied. Any use is at your own risk.
 *
 * Permission to use or copy this software for any purpose is hereby granted 
 * without fee, provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 *
 */ 

#ifndef _STLP_SSTREAM_C
#define _STLP_SSTREAM_C

#ifndef _STLP_SSTREAM_H
# include <stl/_sstream.h>
#endif

# if defined (_STLP_EXPOSE_STREAM_IMPLEMENTATION)

# if defined ( _STLP_NESTED_TYPE_PARAM_BUG )
// no wint_t is supported for this mode
# define __BSB_int_type__ int
# define __BSB_pos_type__ streampos
# else
# define __BSB_int_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_stringbuf<_CharT, _Traits, _Alloc>::int_type
# define __BSB_pos_type__ _STLP_TYPENAME_ON_RETURN_TYPE basic_stringbuf<_CharT, _Traits, _Alloc>::pos_type
# endif

_STLP_BEGIN_NAMESPACE

//----------------------------------------------------------------------
// Non-inline stringbuf member functions.

// Constructors.  Note that the base class constructor sets all of the
// get and area pointers to null.

template <class _CharT, class _Traits, class _Alloc>
basic_stringbuf<_CharT, _Traits, _Alloc>
  ::basic_stringbuf(ios_base::openmode __mode)
    : basic_streambuf<_CharT, _Traits>(), _M_mode(__mode), _M_str()
{}

template <class _CharT, class _Traits, class _Alloc>
basic_stringbuf<_CharT, _Traits, _Alloc>
  ::basic_stringbuf(const basic_string<_CharT, _Traits, _Alloc>& __s, ios_base::openmode __mode)
    : basic_streambuf<_CharT, _Traits>(), _M_mode(__mode), _M_str(__s)
{
  _M_set_ptrs();
}

template <class _CharT, class _Traits, class _Alloc>
basic_stringbuf<_CharT, _Traits, _Alloc>::~basic_stringbuf()
{}

// Set the underlying string to a new value.
template <class _CharT, class _Traits, class _Alloc>
void 
basic_stringbuf<_CharT, _Traits, _Alloc>::str(const basic_string<_CharT, _Traits, _Alloc>& __s)
{
  _M_str = __s;
  _M_set_ptrs();
}

template <class _CharT, class _Traits, class _Alloc>
void 
basic_stringbuf<_CharT, _Traits, _Alloc>::_M_set_ptrs() {
  _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
  _CharT* __data_end = __data_ptr + _M_str.size();
  // The initial read position is the beginning of the string.
  if (_M_mode & ios_base::in)
    this->setg(__data_ptr, __data_ptr, __data_end);
  
  // The initial write position is the beginning of the string.
  if (_M_mode & ios_base::out) {
    if (_M_mode & ios_base::app)
      this->setp(__data_end, __data_end);
    else
      this->setp(__data_ptr, __data_end);
  }
}

// Precondition: gptr() >= egptr().  Returns a character, if one is available.
template <class _CharT, class _Traits, class _Alloc>
__BSB_int_type__
basic_stringbuf<_CharT, _Traits, _Alloc>::underflow()
{
  return this->gptr() != this->egptr()
    ? _Traits::to_int_type(*this->gptr())
    : _Traits::eof();
}

// Precondition: gptr() >= egptr().
template <class _CharT, class _Traits, class _Alloc>
__BSB_int_type__
basic_stringbuf<_CharT, _Traits, _Alloc>::uflow()
{
  if (this->gptr() != this->egptr()) {
    int_type __c = _Traits::to_int_type(*this->gptr());
    this->gbump(1);
    return __c;
  }
  else
    return _Traits::eof();
}

template <class _CharT, class _Traits, class _Alloc>
__BSB_int_type__
basic_stringbuf<_CharT, _Traits, _Alloc>::pbackfail(int_type __c)
{
  if (this->gptr() != this->eback()) {
    if (!_Traits::eq_int_type(__c, _Traits::eof())) {
      if (_Traits::eq(_Traits::to_char_type(__c), this->gptr()[-1])) {
        this->gbump(-1);
        return __c;
      }
      else if (_M_mode & ios_base::out) {
        this->gbump(-1);
        *this->gptr() = __c;
        return __c;
      }
      else
        return _Traits::eof();
    }
    else {
      this->gbump(-1);
      return _Traits::not_eof(__c);
    }
  }
  else
    return _Traits::eof();
}

template <class _CharT, class _Traits, class _Alloc>
__BSB_int_type__
basic_stringbuf<_CharT, _Traits, _Alloc>::overflow(int_type __c)
{
  // fbp : reverse order of "ifs" to pass Dietmar's test.
  // Apparently, standard allows overflow with eof even for read-only streams.
  if (!_Traits::eq_int_type(__c, _Traits::eof())) {
    if (_M_mode & ios_base::out) {
      if (!(_M_mode & ios_base::in)) {
        // It's a write-only streambuf, so we can use special append buffer.
        if (this->pptr() == this->epptr())
          this->_M_append_buffer();
      
        if (this->pptr() != this->epptr()) {
          *this->pptr() = _Traits::to_char_type(__c);
          this->pbump(1);
          return __c;
        }
        else
          return _Traits::eof();
      }

      else {
        // We're not using a special append buffer, just the string itself.
        if (this->pptr() == this->epptr()) {
          ptrdiff_t __offset = this->gptr() - this->eback();
          _M_str.push_back(_Traits::to_char_type(__c));

	  _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
	  size_t __data_size = _M_str.size();

          this->setg(__data_ptr, __data_ptr + __offset, __data_ptr+__data_size);
          this->setp(__data_ptr, __data_ptr + __data_size);
          this->pbump((int)__data_size);
          return __c;
        }
        else {
          *this->pptr() = _Traits::to_char_type(__c);
          this->pbump(1);
          return __c;
        }
      }
    }
    else                          // Overflow always fails if it's read-only 
      return _Traits::eof();
  }
  else                        // __c is EOF, so we don't have to do anything
    return _Traits::not_eof(__c);
}

template <class _CharT, class _Traits, class _Alloc>
streamsize 
basic_stringbuf<_CharT, _Traits, _Alloc>::xsputn(const char_type* __s,
                                                 streamsize __n)
{
  streamsize __nwritten = 0;

  if ((_M_mode & ios_base::out) && __n > 0) {
    // If the put pointer is somewhere in the middle of the string,
    // then overwrite instead of append.
    if (this->pbase() == _M_str.data() ) {
      ptrdiff_t __avail = _M_str.data() + _M_str.size() - this->pptr();
      if (__avail > __n) {
        _Traits::copy(this->pptr(), __s, __n);
        this->pbump((int)__n);
        return __n;
      }
      else {
        _Traits::copy(this->pptr(), __s, __avail);
        __nwritten += __avail;
        __n -= __avail;
        __s += __avail;
        this->setp(_M_Buf, _M_Buf + __STATIC_CAST(int,_S_BufSiz));
      }
    }

    // At this point we know we're appending.
    if (_M_mode & ios_base::in) {
      ptrdiff_t __get_offset = this->gptr() - this->eback();
      _M_str.append(__s, __s + __n);
      
      _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
      size_t __data_size = _M_str.size();

      this->setg(__data_ptr, __data_ptr + __get_offset, __data_ptr+__data_size);
      this->setp(__data_ptr, __data_ptr + __data_size);
      this->pbump((int)__data_size);
    }
    else {
      _M_append_buffer();
      _M_str.append(__s, __s + __n);
    }

    __nwritten += __n;
  }

  return __nwritten;
}

template <class _CharT, class _Traits, class _Alloc>
streamsize 
basic_stringbuf<_CharT, _Traits, _Alloc>::_M_xsputnc(char_type __c,
                                                     streamsize __n)
{
  streamsize __nwritten = 0;

  if ((_M_mode & ios_base::out) && __n > 0) {
    // If the put pointer is somewhere in the middle of the string,
    // then overwrite instead of append.
    if (this->pbase() == _M_str.data()) {
      ptrdiff_t __avail = _M_str.data() + _M_str.size() - this->pptr();
      if (__avail > __n) {
        _Traits::assign(this->pptr(), __n, __c);
        this->pbump((int)__n);
        return __n;
      }
      else {
        _Traits::assign(this->pptr(), __avail, __c);
        __nwritten += __avail;
        __n -= __avail;
        this->setp(_M_Buf, _M_Buf + __STATIC_CAST(int,_S_BufSiz));
      }
    }

    // At this point we know we're appending.
    if (this->_M_mode & ios_base::in) {
      ptrdiff_t __get_offset = this->gptr() - this->eback();
      _M_str.append(__n, __c);

      _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
      size_t __data_size = _M_str.size();

      this->setg(__data_ptr, __data_ptr + __get_offset, __data_ptr+__data_size);
      this->setp(__data_ptr, __data_ptr + __data_size);
      this->pbump((int)__data_size);

    }
    else {
      _M_append_buffer();
      _M_str.append(__n, __c);      
    }

    __nwritten += __n;
  }

  return __nwritten;
}

// According to the C++ standard the effects of setbuf are implementation
// defined, except that setbuf(0, 0) has no effect.  In this implementation,
// setbuf(<anything>, n), for n > 0, calls reserve(n) on the underlying
// string.
template <class _CharT, class _Traits, class _Alloc>
basic_streambuf<_CharT, _Traits>*
basic_stringbuf<_CharT, _Traits, _Alloc>::setbuf(_CharT*, streamsize __n)
{
  if (__n > 0) {
    bool __do_get_area = false;
    bool __do_put_area = false;
    ptrdiff_t __offg = 0;
    ptrdiff_t __offp = 0;

    if (this->pbase() == _M_str.data()) {
      __do_put_area = true;
      __offp = this->pptr() - this->pbase();
    }

    if (this->eback() == _M_str.data()) {
      __do_get_area = true;
      __offg = this->gptr() - this->eback();
    }

    if ((_M_mode & ios_base::out) && !(_M_mode & ios_base::in))
      _M_append_buffer();

    _M_str.reserve(__n);

    _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
    size_t __data_size = _M_str.size();

    if (__do_get_area) {
      this->setg(__data_ptr, __data_ptr + __offg, __data_ptr+__data_size);
    }

    if (__do_put_area) {
      this->setp(__data_ptr, __data_ptr+__data_size);
      this->pbump((int)__offp);
    }
  }

  return this;
}

template <class _CharT, class _Traits, class _Alloc>
__BSB_pos_type__
basic_stringbuf<_CharT, _Traits, _Alloc>::seekoff(off_type __off, 
            ios_base::seekdir __dir,
            ios_base::openmode __mode)
{
  bool __in  = false;
  bool __out = false;
  
  if ((__mode & (ios_base::in | ios_base::out)) == (ios_base::in | ios_base::out) ) {
    if (__dir == ios_base::beg || __dir == ios_base::end)
      __in = __out = true;
  }
  else if (__mode & ios_base::in)
    __in = true;
  else if (__mode & ios_base::out)
    __out = true;

  if (!__in && !__out)
    return pos_type(off_type(-1));
  else if ((__in  && (!(_M_mode & ios_base::in) || this->gptr() == 0)) ||
           (__out && (!(_M_mode & ios_base::out) || this->pptr() == 0)))
    return pos_type(off_type(-1));

  if ((_M_mode & ios_base::out) && !(_M_mode & ios_base::in))
    _M_append_buffer();

  streamoff __newoff;
  switch(__dir) {
  case ios_base::beg:
    __newoff = 0;
    break;
  case ios_base::end:
    __newoff = _M_str.size();
    break;
  case ios_base::cur:
    __newoff = __in ? this->gptr() - this->eback() 
                    : this->pptr() - this->pbase();
    break;
  default:
    return pos_type(off_type(-1));
  }

  __off += __newoff;

  if (__in) {
    ptrdiff_t __n = this->egptr() - this->eback();

    if (__off < 0 || __off > __n)
      return pos_type(off_type(-1));
    else
      this->setg(this->eback(), this->eback() + __off, this->eback() + __n);
  }

  if (__out) {
    ptrdiff_t __n = this->epptr() - this->pbase();

    if (__off < 0 || __off > __n)
      return pos_type(off_type(-1));
    else {
      this->setp(this->pbase(), this->pbase() + __n);
      this->pbump((int)__off);
    }
  }

  return pos_type(__off);
}

template <class _CharT, class _Traits, class _Alloc>
__BSB_pos_type__
basic_stringbuf<_CharT, _Traits, _Alloc>
  ::seekpos(pos_type __pos, ios_base::openmode __mode)
{
  bool __in  = (__mode & ios_base::in) != 0;
  bool __out = (__mode & ios_base::out) != 0;

  if ((__in  && (!(_M_mode & ios_base::in) || this->gptr() == 0)) ||
      (__out && (!(_M_mode & ios_base::out) || this->pptr() == 0)))
    return pos_type(off_type(-1));

  const off_type __n = __pos - pos_type(off_type(0));
  if ((_M_mode & ios_base::out) && !(_M_mode & ios_base::in))
    _M_append_buffer();

  if (__in) {
    if (__n < 0 || __n > this->egptr() - this->eback())
      return pos_type(off_type(-1));
    this->setg(this->eback(), this->eback() + __n, this->egptr());
  }

  if (__out) {
    if (__n < 0 || size_t(__n) > _M_str.size())
      return pos_type(off_type(-1));

    _CharT* __data_ptr = __CONST_CAST(_CharT*,_M_str.data());
    size_t __data_size = _M_str.size();
    
    this->setp(__data_ptr, __data_ptr+__data_size);
    this->pbump((int)__n);
  }

  return __pos;
}

// This is declared as a const member function because it is 
// called by basic_stringbuf<>::str().  Precondition: this is a
// write-only stringbuf.  We can't use an output buffer for read-
// write stringbufs.  Postcondition: pptr is reset to the beginning
// of the buffer.
template <class _CharT, class _Traits, class _Alloc>
void basic_stringbuf<_CharT, _Traits, _Alloc>::_M_append_buffer() const

{
  // Do we have a buffer to append?
  if (this->pbase() == this->_M_Buf && this->pptr() != this->_M_Buf) {
    basic_stringbuf<_CharT, _Traits, _Alloc>* __this = __CONST_CAST(_Self*,this);
    __this->_M_str.append((const _CharT*)this->pbase(), (const _CharT*)this->pptr());
    __this->setp(__CONST_CAST(_CharT*,_M_Buf),
                 __CONST_CAST(_CharT*,_M_Buf + __STATIC_CAST(int,_S_BufSiz)));
  }

  // Have we run off the end of the string?
  else if (this->pptr() == this->epptr()) {
    basic_stringbuf<_CharT, _Traits, _Alloc>* __this = __CONST_CAST(_Self*,this);
    __this->setp(__CONST_CAST(_CharT*,_M_Buf),
                 __CONST_CAST(_CharT*,_M_Buf + __STATIC_CAST(int,_S_BufSiz)));
  }
}

//----------------------------------------------------------------------
// Non-inline istringstream member functions.

template <class _CharT, class _Traits, class _Alloc>
basic_istringstream<_CharT, _Traits, _Alloc>
  ::basic_istringstream(ios_base::openmode __mode)
    : basic_istream<_CharT, _Traits>(0),
      _M_buf(__mode | ios_base::in)
{
  this->init(&_M_buf);
}

template <class _CharT, class _Traits, class _Alloc>
basic_istringstream<_CharT, _Traits, _Alloc>
  ::basic_istringstream(const _String& __str,ios_base::openmode __mode)
    : basic_istream<_CharT, _Traits>(0),
      _M_buf(__str, __mode | ios_base::in)
{
  this->init(&_M_buf);
}

template <class _CharT, class _Traits, class _Alloc>
basic_istringstream<_CharT, _Traits, _Alloc>::~basic_istringstream()
{}

//----------------------------------------------------------------------
// Non-inline ostringstream member functions.

template <class _CharT, class _Traits, class _Alloc>
basic_ostringstream<_CharT, _Traits, _Alloc>
  ::basic_ostringstream(ios_base::openmode __mode)
    : basic_ostream<_CharT, _Traits>(0),
      _M_buf(__mode | ios_base::out)
{
  this->init(&_M_buf);
}
  
template <class _CharT, class _Traits, class _Alloc>
basic_ostringstream<_CharT, _Traits, _Alloc>
  ::basic_ostringstream(const _String& __str, ios_base::openmode __mode)
    : basic_ostream<_CharT, _Traits>(0),
      _M_buf(__str, __mode | ios_base::out)
{
  this->init(&_M_buf);
}

template <class _CharT, class _Traits, class _Alloc>
basic_ostringstream<_CharT, _Traits, _Alloc>::~basic_ostringstream()
{}

//----------------------------------------------------------------------
// Non-inline stringstream member functions.

template <class _CharT, class _Traits, class _Alloc>
basic_stringstream<_CharT, _Traits, _Alloc>
  ::basic_stringstream(ios_base::openmode __mode)
    : basic_iostream<_CharT, _Traits>(0), _M_buf(__mode)
{
   this->init(&_M_buf);
}

template <class _CharT, class _Traits, class _Alloc>
basic_stringstream<_CharT, _Traits, _Alloc>
  ::basic_stringstream(const _String& __str, ios_base::openmode __mode)
    : basic_iostream<_CharT, _Traits>(0), _M_buf(__str, __mode)
{
  this->init(&_M_buf);
}

template <class _CharT, class _Traits, class _Alloc>
basic_stringstream<_CharT, _Traits, _Alloc>::~basic_stringstream()
{}

_STLP_END_NAMESPACE

# undef __BSB_int_type__
# undef __BSB_pos_type__

# endif /* EXPOSE */

#endif /* _STLP_SSTREAM_C */
