#include "util.h"

void*
checkp(void *p)
{
	if (!p) die("pointer assertion failed, OOM?\n");
	return p;
}

void*
die(const char *fmtstr, ...)
{
	va_list ap;

	va_start(ap, fmtstr);
	vprintf(fmtstr, ap);
	va_end(ap);

	exit(EXIT_FAILURE);
}

char*
aprintf(const char *fmtstr, ...)
{
	va_list ap, cpy;
	size_t nb;
	char *str;

	va_copy(cpy, ap);

	va_start(cpy, fmtstr);
	nb = vsnprintf(NULL, 0, fmtstr, cpy);
	va_end(cpy);

	if (nb < 0) die("Invalid fmtstr!\n");
	str = checkp(malloc(nb+1));

	va_start(ap, fmtstr);
	nb = vsnprintf(str, nb+1, fmtstr, ap);
	va_end(ap);

	return str;
}

const char*
mhash(const char *str, int len)
{
	static char buf[MHASHLEN + 1];
	int i, k, v;
	char c, *bp;

	if (!str || !*str) str = ".";
	if (len == -1) len = strlen(str);

	for (v = 0, i = 0; i < len; i++) v += str[i];

	srand(v);
	for (bp = buf, i = 0; i < MHASHLEN / 2; i++)
		bp += sprintf(bp, "%02x", str[i % len] ^ (rand() % 256));

	return buf;
}

int
checkalph(const char *str, const char *alph)
{
	const char *c;

	for (c = str; *c; c++)
		if (!strchr(alph, *c)) return FAIL;

	return OK;
}

void
freadstr(FILE *f, char **dst)
{
	size_t start, len, tmp;
	char c;

	start = ftell(f);
	for (len = 0; (c = fgetc(f)) != EOF && c; len++);
	fseek(f, start, SEEK_SET);

	*dst = checkp(calloc(1, len + 1));
	tmp = fread(*dst, len, 1, f);
	fgetc(f);
}

void
fputstr(FILE *f, char *s)
{
	fprintf(f, "%s", s);
	fputc(0, f);
}

const char*
ask(const char *fmtstr, ...)
{
	static char linebuf[256];
	va_list ap;
	int fail;

	va_start(ap, fmtstr);
	vprintf(fmtstr, ap);
	va_end(ap);

	fail = !fgets(linebuf, sizeof(linebuf), stdin);

	if (!fail && *linebuf) {
		if (linebuf[strlen(linebuf)-1] == '\n')
			linebuf[strlen(linebuf)-1] = '\0';
		if (echo) printf("%s\n", linebuf);
	}

	if (fail) errno = EBADMSG;

	return fail ? "" : linebuf;
}

void
dump(const char *filename)
{
	char buf[256];
	FILE *f;
	int nb;

	if (!(f = fopen(filename, "r"))) return;

	while ((nb = fread(buf, 1, sizeof(buf) - 1, f)))
		printf("%.*s", nb, buf);

	fclose(f);
}

int
strpfcmp(const char *prefix, const char *str)
{
	return strncmp(prefix, str, strlen(prefix));
}