/*
Copyright (c) 2001, Loki software, inc.
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, 
are permitted provided that the following conditions are met:

Redistributions of source code must retain the above copyright notice, this list 
of conditions and the following disclaimer.

Redistributions in binary form must reproduce the above copyright notice, this
list of conditions and the following disclaimer in the documentation and/or
other materials provided with the distribution.

Neither the name of Loki software nor the names of its contributors may be used 
to endorse or promote products derived from this software without specific prior 
written permission. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' 
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY 
DIRECT,INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON 
ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 
*/

//
// File class, can be a memory file or a regular disk file.
// Originally from LeoCAD, used with permission from the author. :)
//
// Leonardo Zide (leo@lokigames.com)
//

#include "stdafx.h"

#include <stdio.h>
#include <memory.h>
#include <stdlib.h>
#include <string.h>


IDataStream::IDataStream()
{ }
  
IDataStream::~IDataStream()
{ }

/////////////////////////////////////////////////////////////////////////////
// File construction/destruction

MemStream::MemStream()
{
  m_nGrowBytes = 1024;
  m_nPosition = 0;
  m_nBufferSize = 0;
  m_nFileSize = 0;
  m_pBuffer = NULL;
  m_bAutoDelete = true;
}

MemStream::MemStream(unsigned long nLen)
{
  m_nGrowBytes = 1024;
  m_nPosition = 0;
  m_nBufferSize = 0;
  m_nFileSize = 0;
  m_pBuffer = NULL;
  m_bAutoDelete = true;

  GrowFile (nLen);
}

FileStream::FileStream()
{
  m_hFile = NULL;
  m_bCloseOnDelete = false;
}

MemStream::~MemStream()
{
  if (m_pBuffer)
    Close();

  m_nGrowBytes = 0;
  m_nPosition = 0;
  m_nBufferSize = 0;
  m_nFileSize = 0;
}

FileStream::~FileStream()
{
  if (m_hFile != NULL && m_bCloseOnDelete)
    Close();
}

/////////////////////////////////////////////////////////////////////////////
// File operations

char* MemStream::ReadString(char* pBuf, unsigned long nMax)
{
  int nRead = 0;
  unsigned char ch;

  if (nMax <= 0)
    return NULL;
  if (m_nPosition >= m_nFileSize)
    return NULL;

  while ((--nMax))
  {
    if (m_nPosition == m_nFileSize)
      break;

    ch = m_pBuffer[m_nPosition];
    m_nPosition++;
    pBuf[nRead++] = ch;

    if (ch == '\n')
      break;
  }

  pBuf[nRead] = '\0';
  return pBuf;
}

char* FileStream::ReadString(char* pBuf, unsigned long nMax)
{
  return fgets(pBuf, nMax, m_hFile);
}

unsigned long MemStream::Read(void* pBuf, unsigned long nCount)
{
  if (nCount == 0)
    return 0;

  if (m_nPosition > m_nFileSize)
    return 0;

  unsigned long nRead;
  if (m_nPosition + nCount > m_nFileSize)
    nRead = (unsigned long)(m_nFileSize - m_nPosition);
  else
    nRead = nCount;

  memcpy((unsigned char*)pBuf, (unsigned char*)m_pBuffer + m_nPosition, nRead);
  m_nPosition += nRead;

  return nRead;
}

unsigned long FileStream::Read(void* pBuf, unsigned long nCount)
{
  return fread(pBuf, 1, nCount, m_hFile);
}

int MemStream::GetChar()
{
  if (m_nPosition > m_nFileSize)
    return 0;

  unsigned char* ret = (unsigned char*)m_pBuffer + m_nPosition;
  m_nPosition++;

  return *ret;
}

int FileStream::GetChar()
{
  return fgetc(m_hFile);
}

unsigned long MemStream::Write(const void* pBuf, unsigned long nCount)
{
  if (nCount == 0)
    return 0;

  if (m_nPosition + nCount > m_nBufferSize)
    GrowFile(m_nPosition + nCount);

  memcpy((unsigned char*)m_pBuffer + m_nPosition, (unsigned char*)pBuf, nCount);

  m_nPosition += nCount;

  if (m_nPosition > m_nFileSize)
    m_nFileSize = m_nPosition;

  return nCount;
}

unsigned long FileStream::Write(const void* pBuf, unsigned long nCount)
{
  return fwrite(pBuf, 1, nCount, m_hFile);
}

int MemStream::PutChar(int c)
{
  if (m_nPosition + 1 > m_nBufferSize)
    GrowFile(m_nPosition + 1);

  unsigned char* bt = (unsigned char*)m_pBuffer + m_nPosition;
  *bt = c;

  m_nPosition++;

  if (m_nPosition > m_nFileSize)
    m_nFileSize = m_nPosition;

  return 1;
}

/*!\todo SPoG suggestion: replace printf with operator >> using c++ iostream and strstream */
void FileStream::printf(const char* s, ...)
{
  va_list args;

  va_start (args, s);
  vfprintf(m_hFile, s, args);
  va_end (args);
}

/*!\todo SPoG suggestion: replace printf with operator >> using c++ iostream and strstream */
void MemStream::printf(const char* s, ...)
{
  va_list args;

  char buffer[4096];
  va_start (args, s);
  vsprintf(buffer, s, args);
  va_end (args);
  Write(buffer, strlen(buffer));
}

int FileStream::PutChar(int c)
{
  return fputc(c, m_hFile);
}

bool FileStream::Open(const char *filename, const char *mode)
{
  m_hFile = fopen(filename, mode);
  m_bCloseOnDelete = true;

  return (m_hFile != NULL);
}

void MemStream::Close()
{
  m_nGrowBytes = 0;
  m_nPosition = 0;
  m_nBufferSize = 0;
  m_nFileSize = 0;
  if (m_pBuffer && m_bAutoDelete)
    free(m_pBuffer);
  m_pBuffer = NULL;
}

void FileStream::Close()
{
  if (m_hFile != NULL)
    fclose(m_hFile);

  m_hFile = NULL;
  m_bCloseOnDelete = false;
}

unsigned long MemStream::Seek(long lOff, int nFrom)
{
  unsigned long lNewPos = m_nPosition;

  if (nFrom == SEEK_SET)
    lNewPos = lOff;
  else if (nFrom == SEEK_CUR)
    lNewPos += lOff;
  else if (nFrom == SEEK_END)
    lNewPos = m_nFileSize + lOff;
  else
    return (unsigned long)-1;

  m_nPosition = lNewPos;

  return m_nPosition;
}

unsigned long FileStream::Seek(long lOff, int nFrom)
{
  fseek (m_hFile, lOff, nFrom);

  return ftell(m_hFile);
}

unsigned long MemStream::GetPosition() const
{
    return m_nPosition;
}

unsigned long FileStream::GetPosition() const
{
  return ftell(m_hFile);
}

void MemStream::GrowFile(unsigned long nNewLen)
{
  if (nNewLen > m_nBufferSize)
  {
    // grow the buffer
    unsigned long nNewBufferSize = m_nBufferSize;

    // determine new buffer size
    while (nNewBufferSize < nNewLen)
      nNewBufferSize += m_nGrowBytes;

    // allocate new buffer
    unsigned char* lpNew;
    if (m_pBuffer == NULL)
      lpNew = static_cast<unsigned char*>(malloc(nNewBufferSize));
    else
      lpNew = static_cast<unsigned char*>(realloc(m_pBuffer, nNewBufferSize));

    m_pBuffer = lpNew;
    m_nBufferSize = nNewBufferSize;
  }
}

void MemStream::Flush()
{
  // Nothing to be done
}

void FileStream::Flush()
{
  if (m_hFile == NULL)
    return;

  fflush(m_hFile);
}

void MemStream::Abort()
{
  Close();
}

void FileStream::Abort()
{
  if (m_hFile != NULL)
  {
    // close but ignore errors
    if (m_bCloseOnDelete)
      fclose(m_hFile);
    m_hFile = NULL;
    m_bCloseOnDelete = false;
  }
}

void MemStream::SetLength(unsigned long nNewLen)
{
  if (nNewLen > m_nBufferSize)
    GrowFile(nNewLen);

  if (nNewLen < m_nPosition)
    m_nPosition = nNewLen;

  m_nFileSize = nNewLen;
}

void FileStream::SetLength(unsigned long nNewLen)
{
  fseek(m_hFile, nNewLen, SEEK_SET);
}

unsigned long MemStream::GetLength() const
{
  return m_nFileSize;
}

unsigned long FileStream::GetLength() const
{
  unsigned long nLen, nCur;

  // Seek is a non const operation
  nCur = ftell(m_hFile);
  fseek(m_hFile, 0, SEEK_END);
  nLen = ftell(m_hFile);
  fseek(m_hFile, nCur, SEEK_SET);

  return nLen;
}