//======================================================================
//
// Project:     XTIDE Universal BIOS, Serial Port Server
//
// File:        Win32File.h - Microsoft Windows file system access.
//
// Routines for accessing the file system under Win32.  It's important
// to use these direct Win32 calls for large files, since FILE * routines,
// in particular ftell() and fseek(), are limited to signed 32-bits (2 GB).
// These are also likely faster since they are more direct.
//

//
// XTIDE Universal BIOS and Associated Tools
// Copyright (C) 2009-2010 by Tomi Tilli, 2011-2013 by XTIDE Universal BIOS Team.
//
// This program 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 2 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.
// Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
//

#include <stdio.h>
#include <errno.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "../library/Library.h"

class FileAccess
{
public:
	int Create( char *p_name )
	{
	  fp = open(p_name, O_CREAT | O_EXCL | O_RDWR, 0666);

		if( fp < 0 )
		{
			if( errno == EEXIST )
			{
				log( 0, "'%s', file already exists", p_name );
				return( 0 );
			}
			else
				log( -1, "'%s', could not create file", p_name );
		}

		name = p_name;

		return( 1 );
	}

	void Open( char *p_name )
	{
		fp = open(p_name, O_RDWR);

		if( fp < 0 )
			log( -1, "'%s', could not open file", p_name );

		name = p_name;
	}

	void Close()
	{
		if( fp )
		{
			if( close( fp ) )
				log( 0, "'%s', could not close file handle", name ? name : "unknown" );
		}
	}

	unsigned long SizeSectors(void)
	{
		struct stat64 st;
		unsigned long i;

		if( fstat64( fp, &st ) )
			log( -1, "'%s', could not retrieve file size (error %i)", name, errno );

		if( st.st_size & 0x1ff )
			log( -1, "'%s', file size is not a multiple of 512 byte sectors", name );

		if( (st.st_size >> 32) > 0x1f )
			log( -1, "'%s', file size greater than LBA28 limit of 137,438,952,960 bytes", name );

		i = st.st_size >> 9;

		return( (unsigned long) i );
	}

	void SeekSectors( unsigned long lba )
	{
		off64_t offset, result;

		offset = lba;
		offset <<= 9;

		result = lseek64(fp, offset, SEEK_SET);
		if( result < 0 || result != offset)
			log( -1, "'%s', Failed to seek to lba=%lu", name, lba );
	}

	void Read( void *buff, unsigned long len )
	{
		unsigned long out_len;

		out_len = read(fp, buff, len);
		if( out_len < 0 || len != out_len )
			log( -1, "'%s', ReadFile failed", name );
	}

	void Write( void *buff, unsigned long len )
	{
		unsigned long out_len;

		out_len = write(fp, buff, len);
		if( out_len < 0 || len != out_len )
			log( -1, "'%s', WriteFile failed", name );
	}

	FileAccess()
	{
		fp = 0;
		name = NULL;
	}

    // LBA 28 limit - 28-bits (could be 1 more, but not worth pushing it)
	const static unsigned long MaxSectors = 0xfffffff;
#define USAGE_MAXSECTORS "137438 MB (LBA28 limit)"

private:
	int fp;
	char *name;
};