#include "stringfile.h"
#include <stdio.h>
#include <errno.h> //EINVAL

int StringFILE::Vread(void *ptr, size_t size, size_t nmemb)
{
int have=str.len()-pos;
if (have<=0) return 0;
int need=size*nmemb;
if (need>have) {nmemb=have/size; need=size*nmemb;}
memcpy(ptr,((const char*)str)+pos,need);
pos+=need;
return nmemb;
}

int StringFILE::Vgetc()
{
if (pos >= str.len()) //...i znowu byl bug roku! :O
	return EOF;
else
	return str[pos++];
}

char *StringFILE::Vgets(char *s, int size)
{
int have=str.len()-pos;
if (have<=0) return 0;
if (size<0) size=0;
if (have>size) have=size-1;
const char* src=((const char*)str)+pos;
char *dest=s;
while(have-- > 0)
	{
	*(dest++) = *(src++); pos++;
	if (dest[-1]=='\n') break;
	}
*dest=0;
return s;
}

int StringFILE::Vprintf(const char *format, va_list args)
{
char *buf=str.directAppend(10000);
vsnprintf(buf,10000,format,args);
int n=strlen(buf); // todo: strlen moze wyjsc poza siebie jezeli printf nie da 0S
str.endAppend(n);
return n;
}

int StringFILE::Vseek(long offset, int whence)
{
switch(whence)
	{
	case SEEK_SET: pos=offset; break;
	case SEEK_CUR: pos+=offset; break;
	case SEEK_END: pos=str.len()-offset; break;
	default: return EINVAL;
	}
if (pos < 0) pos=0; else if (pos>str.len()) pos=str.len();
return 0;
}

const char StringFileSystem::PREFIX[]="string://";

bool StringFileSystem::isStringPath(const char* path)
{
return !strncmp(path,PREFIX,sizeof(PREFIX)-1);
}

VirtFILE *StringFileSystem::Vfopen(const char* path,const char*mode)
{
if ((*mode=='r') && isStringPath(path))
	{
	return new StringFILE2(SString(path+sizeof(PREFIX)-1));
	}
return chain->Vfopen(path,mode);
}

int StringFileSystem::Vfexists(const char* path)
{ return chain->Vfexists(path); }

VirtDIR *StringFileSystem::Vopendir(const char* path)
{ return chain->Vopendir(path); }