module std::math::random;

struct Xorshiro128PPRandom (Random)
{
	uint[4] state;
}

<*
 @require seed.len > 0
*>
fn void Xorshiro128PPRandom.set_seed(&self, char[] seed) @dynamic
{
	self.state = random::make_seed(uint[4], seed);
}

// Xorshiro128++ implementation
fn uint Xorshiro128PPRandom.next_int(&self) @dynamic
{
	uint result = (self.state[0] + self.state[3]).rotl(7) + self.state[0];

	uint t  = self.state[1] << 9U;

	self.state[2] ^= self.state[0];
	self.state[3] ^= self.state[1];
	self.state[1] ^= self.state[2];
	self.state[0] ^= self.state[3];

	self.state[2] ^= t;

	self.state[3] = self.state[3].rotl(11);

	return result;
}

<*
 @require bytes.len > 0
*>
fn void Xorshiro128PPRandom.next_bytes(&self, char[] bytes) @dynamic => @random_value_to_bytes(self.next_int, bytes);
fn uint128 Xorshiro128PPRandom.next_int128(&self) @dynamic => @long_to_int128(self.next_long());
fn ulong Xorshiro128PPRandom.next_long(&self) @dynamic => @int_to_long(self.next_int());
fn ushort Xorshiro128PPRandom.next_short(&self) @dynamic => (ushort)self.next_int();
fn char Xorshiro128PPRandom.next_byte(&self) @dynamic => (char)self.next_int();