#include <string.h>
//#include <stdio.h>
typedef unsigned int size_t;
#define NULL ((void*)0)

typedef int conv_t;
typedef unsigned int ucs4_t;

typedef int iconv_t;


/* Return code if invalid input after a shift sequence of n bytes was read.
   (xxx_mbtowc) */
#define RET_SHIFT_ILSEQ(n)  (-1-2*(n))
/* Return code if invalid. (xxx_mbtowc) */
#define RET_ILSEQ           RET_SHIFT_ILSEQ(0)
/* Return code if only a shift sequence of n bytes was read. (xxx_mbtowc) */
#define RET_TOOFEW(n)       (-2-2*(n))

/* Return code if invalid. (xxx_wctomb) */
#define RET_ILUNI      -1
/* Return code if output buffer is too small. (xxx_wctomb, xxx_reset) */
#define RET_TOOSMALL   -2


#define CP866 0
#define CP1251 1
#define CP1252 2
#define KOI8_RU 3
#define ISO8859_5 4
#define UTF_8 5

#include "cp866.h"
#include "cp1251.h"
#include "cp1252.h"
#include "koi8_ru.h"
#include "iso8859_5.h"
#include "utf8.h"

int encoding(char *what) {

	/* Ignore //TRANSLIT or //IGNORE for now. */
	int i;
	for(i = 0; i < strlen(what); i++) {
	  if(what[i] == '/') {
		what[i] = '\0';
		break;
	  }
	}

	if (!strcasecmp(what,"CP866")) return CP866;
	if (!strcasecmp(what,"CP1251")) return CP1251;
	if (!strcasecmp(what,"windows-1252")) return CP1252;
	if (!strcasecmp(what,"CP1252")) return CP1252;
	if (!strcasecmp(what,"KOI8-RU")) return KOI8_RU;
	if (!strcasecmp(what,"ISO8859-5")) return ISO8859_5;
	if (!strcasecmp(what,"UTF-8")) return UTF_8;
	return -1;
}


iconv_t iconv_open(const char *tocode, const char *fromcode) {
	int to, from;

	if ((to=encoding(tocode))==-1) return -1;
	if ((from=encoding(fromcode))==-1) return -1;

	to=to<<16&0xFFFF0000;
	from=from&0xFFFF;
	return to+from;
}

int iconv_close(iconv_t icd)
{
  return 0;
}

size_t iconv(iconv_t cd, const char **inbuf, size_t *inbytesleft,
	char **outbuf, size_t *outbytesleft)
{
	int n, to, from, count1,count2;
	int pwc, converted,written;
	int (*mbtowc)(conv_t, ucs4_t *, const unsigned char *, int);
	int (*wctomb)(conv_t, ucs4_t *, const unsigned char *, int);
	
	char *str;
	str=*outbuf;
	
	from=cd>>16;
	to=cd&0xFFFF;
			
	switch (from)
	{
		case CP866: mbtowc=cp866_mbtowc; break;
		case CP1251: mbtowc=cp1251_mbtowc; break;
		case CP1252: mbtowc=cp1252_mbtowc; break;
		case ISO8859_5: mbtowc=iso8859_5_mbtowc; break;
		case KOI8_RU: mbtowc=koi8_ru_mbtowc; break;
		case UTF_8: mbtowc=utf8_mbtowc; break;
		default: return -2;
	}
		
	switch (to)
	{
		case CP866: wctomb=cp866_wctomb; break;
		case CP1251: wctomb=cp1251_wctomb; break;
		case CP1252: wctomb=cp1252_wctomb; break;
		case ISO8859_5: wctomb=iso8859_5_wctomb; break;
		case KOI8_RU: wctomb=koi8_ru_wctomb; break;
		case UTF_8: wctomb=utf8_wctomb; break;
		default: return -3;
	}

    if(from == to) {
      int oc=0,ic=0;

      while(*inbytesleft > 0 && *outbytesleft > 0) {
        str[oc]=(*inbuf)[ic];
        ++ic;
        ++oc;
        (*inbytesleft)--;
        (*outbytesleft)--;
        (*outbuf)++;
      }

      return 0;
    }
	
	count1=0;
	count2=0;
		
	while ( *inbytesleft>0 && *outbytesleft>1)
	{
		n=1;
		
		do {
		//converted= (utf8_mbtowc)(0,&pwc,((*inbuf)+count1),n);
		//	printf("%d\n",n);
		converted= (mbtowc)(0,&pwc,((*inbuf)+count1),n);
		
		n++;
		}	while (converted==RET_TOOFEW(0));
		
		if (converted<0) return -10; 
		//written=  (cp866_wctomb)(0,str+count2,pwc,1);
		written=  (wctomb)(0,str+count2,pwc,1);
		if (written<0) written=0;//return -11; 
				
		//printf("Conv:%d Wri:%d In:%d Out:%d UTF:%x UCS:%x 866:%s\n",converted, written, *inbytesleft,*outbytesleft,*((*inbuf)+count1),pwc, str);
		
		(*inbytesleft)-=converted;
		(*outbytesleft)-=written;
		(*outbuf)+=written;
		count1+=converted;
		count2+=written;
	}
	*(str+count2)='\0';
			
	if (*inbytesleft>0 && *outbytesleft==0) return -12;
	return 0;
}


/*
int main()
{
	char *s;// ="вертолет";
	char *z;
	//unsigned int pwc;
	iconv_t cd;
	int in, out;
	
		FILE *infile; 
		char *fname = "file.txt";
	   
		infile = fopen(fname,"r");
	
	fseek(infile, 0, SEEK_END);
	size_t file_size = ftell(infile);
	rewind(infile);

	//printf ("LOL\n");

	char *buffer = (char*)malloc(file_size * sizeof(char));
	if (buffer == NULL)
	{
		fclose(infile);
		printf("Error allocating %d bytes.\n", file_size * sizeof(char));
		return -1;
	}
	size_t bytes_read = fread(buffer, sizeof(char), file_size, infile);
	if (bytes_read != file_size)
	{
		printf("Have read only %d bytes of %d.\n", bytes_read, file_size);
		free(buffer);
		fclose(infile);
		return -1;
	}
	
	in=strlen(buffer);
	z=malloc(in+1);
	
	out=in+1;
	cd=iconv_open("CP1251","CP866");
//	printf("%x\n",cd);
	int t;
	t=iconv(cd, &buffer, &in, &z, &out);
	printf("\nResult: %d", t);
	puts(z);
	//for (;s<s+strlen(s);s++) {cp866_mbtowc (0,  &pwc, s, 1);printf("%c=%u\n",*s,pwc);}
}
*/


typedef struct
{
	char *name;
	void *f;
} export_t;

char szStart[]           = "START";
char szVersion[]         = "version";
char sziconv_open[]    = "iconv_open";
char sziconv[]   = "iconv";

export_t EXPORTS[] __asm__("EXPORTS") =
{
	{ szStart,       (void*)0x0 },
	{ szVersion,     (void*)0x00010001 },
	{ sziconv_open,  iconv_open    },
	{ sziconv,       iconv   },
	{ NULL,          NULL },
};