var rnd = std.rand.DefaultPrng.init(0);

        const magic = randLowZero();

        const magic = rnd.next() & rnd.next() & rnd.next();

}
fn randLowZero() u64 {
    return rand() & rand() & rand();
}
var random_state: u32 = 1804289383;
fn rand32() u32 {
    var number = random_state;
    // XOR shift algorithm
    number ^= number << 13;
    number ^= number >> 17;
    number ^= number << 5;
    // update random number state
    random_state = number;
    // return random number
    return number;

fn rand() u64 {
    const r1 = @intCast(u64, rand32()) & 0xFFFF;
    const r2 = @intCast(u64, rand32()) & 0xFFFF;
    const r3 = @intCast(u64, rand32()) & 0xFFFF;
    const r4 = @intCast(u64, rand32()) & 0xFFFF;

    return r1 | (r2 << 16) | (r3 << 32) | (r4 << 48);
}

test "BishopMagicNumbers" {
    if (true) return error.SkipZigTest; // slow

test "MagicNumbers" {

    var rook_magic: [64]Chess.BoardType = undefined;

    }
    const expected_bishop_magic: [64]Chess.BoardType = .{ 9241390835893862432, 9234710240556097536, 1227239730261824640, 577604527957049348, 6918659473418780672, 351888113804529668, 2328924575914001472, 4614013701991826049, 2331927815258656, 9016004274033184, 2305860618585916944, 648597650767120384, 577061163230053010, 579277706207166480, 4614220409926336512, 580964498095089664, 4616199239888937985, 1126041776325888, 616996207142899796, 10141929783173120, 5630608183136385, 36873230555873632, 181275456685879328, 576743335520240152, 2603115769260982529, 2380875882396914688, 2289189183030272, 171145581949894664, 1153203048319827969, 2305913930985283584, 72657961755345152, 1127003718435328, 148904939935000608, 282608955041792, 1153062518049211400, 10378688279935975552, 290279660069376, 290279660069376, 6922619801915492428, 6922619801915492428, 1158067358212916246, 2328924575914001472, 36319360414908928, 4611703757044990977, 1224980203021800448, 4521260535005248, 290561443953836160, 2310347987528229122, 2328924575914001472, 564053894369288, 1585408924206502016, 4675139272704, 144185593598050818, 7440091971840, 4612816883383795840, 9234710240556097536, 4614013701991826049, 580964498095089664, 83334186434036744, 648597650767120384, 17592766972164, 9439545093914103944, 2331927815258656, 9241390835893862432 };
    try std.testing.expectEqualSlices(Chess.BoardType, &expected_bishop_magic, &bishop_magic);
}
test "RookMagicNumbers" {
    if (true) return error.SkipZigTest; // slow
    var rook_magic: [64]Chess.BoardType = undefined;
    for (std.enums.values(Chess.Square)) |square, idx| {

    // std.debug.print("{any}\n{any}\n", .{ bishop_magic, rook_magic });

    const expected_rook_magic: [64]Chess.BoardType = .{ 9259401108760043536, 594475563268280320, 144124055069409314, 72068610631143424, 72076285769418752, 108090789187420288, 324265770315940096, 9367487500631408770, 2305983747248373760, 14051934662285148160, 4612249107028804096, 72198881416318976, 9223653529145639440, 4648277836300289160, 1153204079162360320, 167055404054872320, 4791830278402211904, 13511073762115648, 10090880114674926608, 18332157638541321, 4902733343504729120, 141287311278592, 876517475657892112, 573945342918788, 35804994879488, 9223688714458236480, 72906490033217536, 844463587201024, 290486580455932032, 144117389246857344, 18295937913061888, 5406589228312428673, 9223442407754825769, 4503874543034369, 48431846559596576, 9295438429141602308, 18018869587216385, 3377768473690120, 2233852801025, 4785075694604450, 36030189125550082, 9227875774059790342, 9223407221495332992, 18332157638541321, 1155182100580696192, 35201820918080, 4612820723034226768, 45041495719411716, 603668391936256, 18084767791612032, 4612249107028804096, 15276649741245483264, 288371148000592256, 14628817498200408128, 1127068272296960, 4657003602455658752, 88510690829569, 2535612326510617, 144124055069409314, 2377918195506874625, 4611967527763988485, 1181631959278293026, 9232412290735146116, 261213468561048706 };
    try std.testing.expectEqualSlices(Chess.BoardType, &expected_rook_magic, &rook_magic);

    { // bishop

    { // bishop d4

    { // rook

    { // rook d4

    { // rook

    { // rook h8