#include "util/str.h"

static bool match_char(char c, str tokens)
{
	for (size_t t = 0; t < tokens.len; t++)
		if (c == tokens.ptr[t])
			return true;

	return false;
}

size_t str_find(str s, str tokens)
{
	for (size_t i = 0; i < s.len; i++)
		if (match_char(s.ptr[i], tokens))
			return i;

	return s.len;
}

str str_walk(str *s, str sep)
{
	if (s->len == 0)
		return (str) {};

	size_t x = str_find(*s, sep);
	size_t o = x + (x < s->len);

	*s = str_advance(*s, o);

    return (str) { x, s->ptr - o };
}

str str_eat(str s, str tokens)
{
	while (s.len > 0 && match_char(s.ptr[0], tokens))
		s = str_advance(s, 1);
	return s;
}

str str_advance(str s, size_t x)
{
	s.len -= x;
	s.ptr += x;
	return s;
}

bool str_start(str s, str start)
{
	if (s.len < start.len)
		return false;
	s.len = start.len;
	return array_eq(s, start);
}

str str_intro(char *s)
{
    return (str) { strlen(s), s };
}

#include <stdio.h>

#define PARSE_NUM(parse, ...) \
    NULTERM(s, buf) \
    char *end; \
    auto v = parse(buf, &end); \
    if (end != buf+s.len) \
        return false; \
    *x = v; \
    return true;
    

bool str_parse_int(str s, long *x)
{
#define strtol_(start, endp) strtol(start, endp, 0)
    PARSE_NUM(strtol_)
#undef strtol_
}

bool str_parse_double(str s, double *x)
{
    PARSE_NUM(strtod)
}

bool str_split(str s, str sep, str *a, str *b)
{
    size_t x = str_find(s, sep);
    if (x == s.len)
        return false;
    *a = (str) { x, s.ptr };
    *b = str_advance(s, x+1);
    return true;
}