/*
 * Utility functions for NANP number validation.
 */

#include <stdbool.h>

#include <themwi/nanp/number_utils.h>

bool is_nanp_valid_prefix(const char *s)
{
	/* validate NPA part */
	if (s[0] < '2')
		return false;
	if (s[1] == '1' && s[2] == '1')
		return false;
	/* validate exchange part */
	if (s[3] < '2')
		return false;
	if (s[4] == '1' && s[5] == '1')
		return false;
	/* all checks passed */
	return true;
}