#include <stdio.h>
#include <wchar.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>

int do_test(int func, const char *name,
	const char *fmt, const wchar_t *wfmt,
	const char *input, int xret, int xlen,
	const void *expect, size_t size, void *obuf)
{
	int consumed = 0;
	int err = 0;
	FILE *f;
	int ret;
	int same;

	if (func&1) {
		f = tmpfile();
		if (!f) {
			printf("%s: cannot create temp file: %s\n",
				name, strerror(errno));
			return 1;
		}
		if (fwrite(input, strlen(input), 1, f)!=1) {
			fclose(f);
			printf("%s: cannot create temp file: %s\n",
				name, strerror(errno));
			return 1;			
		}
		rewind(f);
		if (func&2) ret = fwscanf(f, wfmt, obuf, &consumed);
		else ret = fscanf(f, fmt, obuf, &consumed);
	} else {
		wchar_t winput[1024];
		swprintf(winput, 1024, L"%s", input);
		if (func&2) ret = swscanf(winput, wfmt, obuf, &consumed);
		else ret = sscanf(input, fmt, obuf, &consumed);
	}

	if (func&1) {
		int final = ftell(f);
		if (final != xlen) {
			printf("%s: wrong final position %d, should be %d\n",
				name, final, xlen);
			err = 1;
		}
		fclose(f);
	}

	if (ret != xret) {
		printf("%s: returned %d, expected %d\n", name, ret, xret);
		return 1;
	}

	if (ret <= 0) return err;

	if (consumed != xlen) {
		printf("%s: consumed %d, should have consumed %d\n",
			name, consumed, xlen);
		err = 1;
	}

	/* We assume no padding bits except possibly long double. */
	if (size == sizeof(long double) && strchr(fmt, 'L'))
		same = *(long double *)obuf == *(long double *)expect;
	else
		same = !memcmp(expect, obuf, size);
	if (!same) {
		printf("%s: wrong value: ", name);
		return 2;
	}

	return err;
}


#define TEST_1(func,name,fmt,in,xr,xl,type,ex,ofmt,obuf) do { \
	memset(obuf, 0, sizeof(type)); \
	switch (do_test(func,name,fmt "%n",fmt L"%n",in,xr,xl,(type[]){ex},sizeof ex,obuf)) { \
	case 2: if (#ex[0]=='"' || #ex[0]=='L') \
	printf(ofmt ", expected " ofmt "\n", (type *)obuf, ex); \
	else printf(ofmt ", expected " ofmt "\n", *(type *)obuf, ex); \
	case 1: err++; } } while (0)

#define TEST(fmt,in,xr,xl,type,ex,ofmt) do { \
TEST_1(0,"sscanf(" #in "," #fmt ")",fmt,in,xr,xl,type,ex,ofmt,obuf); \
TEST_1(1,"fscanf(" #in "," #fmt ")",fmt,in,xr,xl,type,ex,ofmt,obuf); \
TEST_1(2,"swscanf(" #in "," #fmt ")",fmt,in,xr,xl,type,ex,ofmt,obuf); \
TEST_1(3,"fwscanf(" #in "," #fmt ")",fmt,in,xr,xl,type,ex,ofmt,obuf); \
} while (0)

/* TEST macro takes 7 arguments:
 * - format string ("%n" is automatically appended to test termination)
 * - input text to scan
 * - expected return value (-1, 0, or 1)
 * - expected number of characters consumed
 * - data type (char or wchar_t for strings) of result
 * - expected result
 * - format for printing result mismatches
 * All arguments should be literals of the correct type, not
 * programmatically generated. The macro does some crazy stuff.
 */

int main()
{
	void *obuf = malloc(256);
	int err=0;

	TEST("%9d", "9999999999", 1, 9, int, 999999999, "%d");
	TEST("%5s", "abcdefg", 1, 5, char, "abcde", "%s");
	TEST("%5[abc]", "ababab", 1, 5, char, "ababa", "%s");
	TEST("%x", "0xq", 0, 2, int, 0, "%d");
	TEST("%Lf", "1.0", 1, 3, long double, 1.0, "%La");
}