#include <stddef.h>
#include <stdint.h>
#include <stdio.h>

#include "cmaybe.h"

MAYBE_TYPE(intmax_t, intmax_t);

MAYBE(intmax_t) average(intmax_t numbers[], size_t length) {
	ENABLE_RETURN(intmax_t);
	if (length == 0)
		RETURN_NOTHING();

	intmax_t sum = 0;
	for (size_t i = 0; i < length; i++) {
		intmax_t num = numbers[i];
		if (num > 0 && INTMAX_MAX - num < sum) {
			RETURN_NOTHING();
		} else if (num < 0 && INTMAX_MIN - num > sum) {
			RETURN_NOTHING();
		} else {
			sum += num;
		}
	}

	RETURN_VALUE(sum/length);
}

int main(void) {
	intmax_t numbers[] = {5, 7, 1, -8, INTMAX_MAX};
	MAYBE(intmax_t) results[6];
	results[0] = average(numbers, 0);
	results[1] = average(numbers, 1);
	results[2] = average(numbers, 2);
	results[3] = average(numbers, 3);
	results[4] = average(numbers, 4);
	results[5] = average(numbers, 5);

	for (size_t i = 0; i < sizeof(results) / sizeof(MAYBE(intmax_t)); i++) {
		IS_VALUE(results[i]) {
			printf("%zu: %jd\n", i, VALUE(results[i]));
		} else {
			printf("%zu: No value\n", i);
		}
	}

	return 0;
}