package random_test;

import random;

@test fn seq() void = {
	let r: random.random = random.init(1234567u64);
	assert(!(random.next(&r) != 6457827717110365317u64));
	assert(!(random.next(&r) != 3203168211198807973u64));
	assert(!(random.next(&r) != 9817491932198370423u64));
	assert(!(random.next(&r) != 4593380528125082431u64));
	assert(!(random.next(&r) != 16408922859458223821u64));
};

@test fn deterministic() void = {
	let a: random.random = random.init(42u64);
	let b: random.random = random.init(42u64);
	let i: i32 = 0;
	for (i < 32) {
		assert(!(random.next(&a) != random.next(&b)));
		i += 1;
	};
};

@test fn u32n_inrange() void = {
	let r: random.random = random.init(7u64);
	let i: i32 = 0;
	for (i < 200) {
		let v: u32 = random.u32n(&r, 17u32);
		// v stored as u64 with possible high bits — mask before compare.
		let vv: u64 = (v: u64) & 0xFFFFFFFFu64;
		assert(!(vv >= 17u64));
		i += 1;
	};
};

@test fn u64n_pow2() void = {
	let r: random.random = random.init(99u64);
	let i: i32 = 0;
	for (i < 200) {
		let v: u64 = random.u64n(&r, 16u64);
		assert(!(v >= 16u64));
		i += 1;
	};
};

@test fn u64n_nonpow2() void = {
	let r: random.random = random.init(123u64);
	let i: i32 = 0;
	for (i < 200) {
		let v: u64 = random.u64n(&r, 100u64);
		assert(!(v >= 100u64));
		i += 1;
	};
};