/*
 *  This file is part of RawTherapee.
 *
 *  Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
 *
 *  RawTherapee is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 * 
 *  RawTherapee 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 General Public License
 *  along with RawTherapee.  If not, see <http://www.gnu.org/licenses/>.
 */
#include "myfile.h"
#include <cstdarg>
#include <glibmm.h>
#include "safegtk.h"
#ifdef BZIP_SUPPORT
#include <bzlib.h>
#endif

// get mmap() sorted out
#ifdef MYFILE_MMAP

#ifdef WIN32

#include <fcntl.h>
#include <windows.h>

// dummy values
#define MAP_PRIVATE 1
#define PROT_READ 1

void* mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
{
	HANDLE handle = CreateFileMapping((HANDLE)_get_osfhandle(fd), NULL, PAGE_WRITECOPY, 0, 0, NULL);

	if (handle != NULL) {
		start = MapViewOfFile(handle, FILE_MAP_COPY, 0, offset, length);
		CloseHandle(handle);
	}

	return start;
}

int munmap(void *start, size_t length)
{
	UnmapViewOfFile(start);
	return 0;
}

#else // WIN32

#include <fcntl.h>
#include <sys/mman.h>

#endif // WIN32
#endif // MYFILE_MMAP

#ifdef MYFILE_MMAP

IMFILE* fopen (const char* fname)
{
	int fd = safe_open_ReadOnly(fname);
	if ( fd < 0 )
		return 0;

	struct stat stat_buffer;
	if ( fstat(fd,&stat_buffer) < 0 )
	{
		printf("no stat\n");
		close(fd);
		return 0;
	}

	void* data = mmap(0,stat_buffer.st_size,PROT_READ,MAP_PRIVATE,fd,0);
	if ( data == 0 )
	{
		printf("no mmap\n");
		close(fd);
		return 0;
	}

	IMFILE* mf = new IMFILE;

	mf->fd = fd;
	mf->pos = 0;
	mf->size = stat_buffer.st_size;
	mf->data = (char*)data;
	mf->eof = false;

#ifdef BZIP_SUPPORT
	{
	  bool bzip = false;
	  Glib::ustring bname = Glib::path_get_basename(fname);
	  size_t lastdot = bname.find_last_of ('.');
	  if (lastdot!=bname.npos)
	    bzip = bname.substr (lastdot).casefold() == Glib::ustring(".bz2").casefold();
      
	  if (bzip) {
	    int ret;

	    // initialize bzip stream structure
	    bz_stream stream;
	    stream.bzalloc = 0;
	    stream.bzfree = 0;
	    stream.opaque = 0;
	    ret = BZ2_bzDecompressInit(&stream, 0, 0);

	    if (ret != BZ_OK) {
	      printf("bzip initialization failed with error %d\n", ret);
	    }
	    else {
	      // allocate initial buffer for decompressed data
	      unsigned int buffer_out_count = 0; // bytes of decompressed data
	      unsigned int buffer_size = 10*1024*1024; // 10 MB, extended dynamically if needed
	      char* buffer = 0;

	      stream.next_in = mf->data; // input data address
	      stream.avail_in = mf->size;

	      while (ret == BZ_OK) {
		buffer = static_cast<char*>( realloc(buffer, buffer_size)); // allocate/resize buffer
		if (!buffer) free(buffer);

		stream.next_out = buffer + buffer_out_count; // output data adress
		stream.avail_out = buffer_size - buffer_out_count;

		ret = BZ2_bzDecompress(&stream);

		buffer_size *= 2; // increase buffer size for next iteration
		buffer_out_count = stream.total_out_lo32;
		if (stream.total_out_hi32 > 0)
		  printf("bzip decompressed data byte count high byte is nonzero: %d\n", stream.total_out_hi32);
	      }

	      if (ret == BZ_STREAM_END) {
		//delete [] mf->data;
		// close memory mapping, setting fd -1 will ensure deletion of mf->data upon fclose()
		mf->fd = -1;
		munmap((void*)mf->data,mf->size);
		close(mf->fd);

		char* realData = new char [buffer_out_count];
		memcpy(realData, buffer, buffer_out_count);

		mf->data = realData;
		mf->size = buffer_out_count;
	      }
	      else
		printf("bzip decompression failed with error %d\n", ret);

	      // cleanup
	      free(buffer);
	      ret = BZ2_bzDecompressEnd(&stream);
	      if (ret != BZ_OK)
		printf("bzip cleanup failed with error %d\n", ret);
	    }
	  }
	}
#endif // BZIP_SUPPORT

	return mf;
}

IMFILE* gfopen (const char* fname)
{
	return fopen(fname);
}
#else

IMFILE* fopen (const char* fname) {

	FILE* f = g_fopen (fname, "rb");
    if (!f)
        return NULL;
    IMFILE* mf = new IMFILE;
	fseek (f, 0, SEEK_END);
	mf->size = ftell (f);
	mf->data = new char [mf->size];
	fseek (f, 0, SEEK_SET);
	fread (mf->data, 1, mf->size, f);
	fclose (f);
	mf->pos = 0;
	mf->eof = false;

    return mf;
}

IMFILE* gfopen (const char* fname) {

	FILE* f = g_fopen (fname, "rb");
    if (!f)
        return NULL;
    IMFILE* mf = new IMFILE;
	fseek (f, 0, SEEK_END);
	mf->size = ftell (f);
	mf->data = new char [mf->size];
	fseek (f, 0, SEEK_SET);
	fread (mf->data, 1, mf->size, f);
	fclose (f);
	mf->pos = 0;
	mf->eof = false;

#ifdef BZIP_SUPPORT
    {
      bool bzip = false;
      Glib::ustring bname = Glib::path_get_basename(fname);
      size_t lastdot = bname.find_last_of ('.');
      if (lastdot!=bname.npos)
        bzip = bname.substr (lastdot).casefold() == Glib::ustring(".bz2").casefold();
      
      if (bzip) {
	int ret;

	// initialize bzip stream structure
	bz_stream stream;
	stream.bzalloc = 0;
	stream.bzfree = 0;
	stream.opaque = 0;
	ret = BZ2_bzDecompressInit(&stream, 0, 0);

	if (ret != BZ_OK) {
	  printf("bzip initialization failed with error %d\n", ret);
	}
	else {
	  // allocate initial buffer for decompressed data
	  unsigned int buffer_out_count = 0; // bytes of decompressed data
	  unsigned int buffer_size = 10*1024*1024; // 10 MB, extended dynamically if needed
	  char* buffer = 0;

	  stream.next_in = mf->data; // input data address
	  stream.avail_in = mf->size;

	  while (ret == BZ_OK) {
	    buffer = static_cast<char*>( realloc(buffer, buffer_size)); // allocate/resize buffer
	    if (!buffer) free(buffer);

	    stream.next_out = buffer + buffer_out_count; // output data adress
	    stream.avail_out = buffer_size - buffer_out_count;

	    ret = BZ2_bzDecompress(&stream);

	    buffer_size *= 2; // increase buffer size for next iteration
	    buffer_out_count = stream.total_out_lo32;
	    if (stream.total_out_hi32 > 0)
	      printf("bzip decompressed data byte count high byte is nonzero: %d\n", stream.total_out_hi32);
	  }

	  if (ret == BZ_STREAM_END) {
	    delete [] mf->data;
	    char* realData = new char [buffer_out_count];
	    memcpy(realData, buffer, buffer_out_count);

	    mf->data = realData;
	    mf->size = buffer_out_count;
	  }
	  else
	    printf("bzip decompression failed with error %d\n", ret);

	  // cleanup
	  free(buffer);
	  ret = BZ2_bzDecompressEnd(&stream);
	  if (ret != BZ_OK)
	    printf("bzip cleanup failed with error %d\n", ret);
	}
      }
    }
#endif // BZIP_SUPPORT
    return mf;
}
#endif //MYFILE_MMAP

IMFILE* fopen (unsigned* buf, int size) {

	IMFILE* mf = new IMFILE;
	mf->fd = -1;
	mf->size = size;
	mf->data = new char [mf->size];
	memcpy ((void*)mf->data, buf, size);
	mf->pos = 0;
	mf->eof = false;
	return mf;
}

void fclose (IMFILE* f) {
#ifdef MYFILE_MMAP
	if ( f->fd == -1 )
	{
		delete [] f->data;
	}
	else
	{
		munmap((void*)f->data,f->size);
		close(f->fd);
	}
#else
	delete [] f->data;
#endif
	delete f;
}

int fscanf (IMFILE* f, const char* s ...) {
        // fscanf not easily wrapped since we have no terminating \0 at end
        // of file data and vsscanf() won't tell us how many characters that
        // were parsed. However, only dcraw.cc code use it and only for "%f" and
        // "%d", so we make a dummy fscanf here just to support dcraw case.
        char buf[50], *endptr;
        int copy_sz = f->size - f->pos;
        if (copy_sz > sizeof(buf)) {
            copy_sz = sizeof(buf) - 1;
        }
        memcpy(buf, &f->data[f->pos], copy_sz);
        buf[copy_sz] = '\0';
	va_list ap;
        va_start (ap, s);
        if (strcmp(s, "%d") == 0) {
            int i = strtol(buf, &endptr, 10);
            if (endptr == buf) {
                return 0;
            }
            int *pi = va_arg(ap, int*);
            *pi = i;
        } else if (strcmp(s, "%f") == 0) {
            float f = strtof(buf, &endptr);
            if (endptr == buf) {
                return 0;
            }
            float *pf = va_arg(ap, float*);
            *pf = f;
        }
        va_end (ap);
        f->pos += endptr - buf;
        return 1;
}


char* fgets (char* s, int n, IMFILE* f) {

	if (f->pos>=f->size) {
		f->eof = true;
		return NULL;
	}
	int i = 0;
	do s[i++] = f->data[f->pos++];		
	while (i<n && f->pos<f->size);
	return s;
}
