import math.unsigned

fn test_str() {
    // converting from a string and then back to a string
    // should always give the original string.
    test_strings := [
        '0',
        '1',
        '9',
        '10',
        '11',
        '99',
        '100',
        '101',
        '65534',
        '65535',
        '65536', // 16-bit boundary
        '65537',
        '65538',
        '4294967294',
        '4294967295',
        '4294967296', // 32-bit boundary
        '4294967297',
        '4294967298',
        '281474976710654',
        '281474976710655',
        '281474976710656', // 48-bit boundary,
        '281474976710657',
        '281474976710658',
        '18446744073709551614',
        '18446744073709551615',
        '18446744073709551616', // 64-bit boundary
        '18446744073709551617',
        '18446744073709551618',
        '1208925819614629174706174',
        '1208925819614629174706175',
        '1208925819614629174706176', // 80-bit boundary
        '1208925819614629174706177',
        '1208925819614629174706178',
        '79228162514264337593543950334',
        '79228162514264337593543950335',
        '79228162514264337593543950336', // 96-bit boundary
        '79228162514264337593543950337',
        '79228162514264337593543950338',
        '5192296858534827628530496329220094',
        '5192296858534827628530496329220095',
        '5192296858534827628530496329220096', // 112-bit boundary
        '5192296858534827628530496329220097',
        '5192296858534827628530496329220098',
        '340282366920938463463374607431768211454',
        '340282366920938463463374607431768211455',
        '340282366920938463463374607431768211456', // 128-bit boundary
        '340282366920938463463374607431768211457',
        '340282366920938463463374607431768211458',
        '22300745198530623141535718272648361505980414',
        '22300745198530623141535718272648361505980415',
        '22300745198530623141535718272648361505980416', // 144-bit boundary
        '22300745198530623141535718272648361505980417',
        '22300745198530623141535718272648361505980418',
        '1461501637330902918203684832716283019655932542974',
        '1461501637330902918203684832716283019655932542975',
        '1461501637330902918203684832716283019655932542976', // 160-bit boundary
        '1461501637330902918203684832716283019655932542977',
        '1461501637330902918203684832716283019655932542978',
        '95780971304118053647396689196894323976171195136475134',
        '95780971304118053647396689196894323976171195136475135',
        '95780971304118053647396689196894323976171195136475136', // 176-bit boundary
        '95780971304118053647396689196894323976171195136475137',
        '95780971304118053647396689196894323976171195136475138',
        '6277101735386680763835789423207666416102355444464034512894',
        '6277101735386680763835789423207666416102355444464034512895',
        '6277101735386680763835789423207666416102355444464034512896', // 192-bit boundary
        '6277101735386680763835789423207666416102355444464034512897',
        '6277101735386680763835789423207666416102355444464034512898',
        '411376139330301510538742295639337626245683966408394965837152254',
        '411376139330301510538742295639337626245683966408394965837152255',
        '411376139330301510538742295639337626245683966408394965837152256', // 208-bit boundary
        '411376139330301510538742295639337626245683966408394965837152257',
        '411376139330301510538742295639337626245683966408394965837152258',
        '26959946667150639794667015087019630673637144422540572481103610249214',
        '26959946667150639794667015087019630673637144422540572481103610249215',
        '26959946667150639794667015087019630673637144422540572481103610249216', // 224-bit boundary
        '26959946667150639794667015087019630673637144422540572481103610249217',
        '26959946667150639794667015087019630673637144422540572481103610249218',
        '1766847064778384329583297500742918515827483896875618958121606201292619774',
        '1766847064778384329583297500742918515827483896875618958121606201292619775',
        '1766847064778384329583297500742918515827483896875618958121606201292619776', // 240-bit boundary
        '1766847064778384329583297500742918515827483896875618958121606201292619777',
        '1766847064778384329583297500742918515827483896875618958121606201292619778',
        '115792089237316195423570985008687907853269984665640564039457584007913129639934',
        '115792089237316195423570985008687907853269984665640564039457584007913129639935', // 2^256 - 1
    ]

    for ts in test_strings {
        number := unsigned.uint256_from_dec_str(ts) or {
            assert false, 'invalid Uint256 string ${ts}'
            panic('')
        }

        assert number.str() == ts
    }

    fundamental_constant := unsigned.uint256_from_64(42)
    assert fundamental_constant.str() == '42'
}

fn test_ops() {
    x := unsigned.uint256_from_64(18446744073709551615)
    y := unsigned.uint256_from_64(18446744073709551615)
    z := unsigned.uint256_from_dec_str('340282366920938463426481119284349108225') or {
        assert false
        panic('')
    }
    assert (x * y).str() == '340282366920938463426481119284349108225'
    assert (x + y).str() == '36893488147419103230'
    assert (z / unsigned.uint256_from_64(2)).str() == '170141183460469231713240559642174554112'
    assert (unsigned.uint256_from_dec_str('170141183460469231713240559642174554112') or {
        panic('')
    } - unsigned.uint256_from_64(2)).str() == '170141183460469231713240559642174554110'

    assert x == y
    assert unsigned.uint256_from_dec_str('340282366920938463426481119284349108225') or {
        assert false
        panic('')
    } > y
}

struct LeadingZeros {
    l     unsigned.Uint256
    r     unsigned.Uint256
    zeros int
}

fn new(x unsigned.Uint128, y unsigned.Uint128) unsigned.Uint256 {
    return unsigned.Uint256{x, y}
}

fn test_leading_zeros() {
    tcs := [
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xf000000000000000))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x8000000000000000))
            zeros: 65
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xf000000000000000))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xc000000000000000))
            zeros: 66
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xf000000000000000))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xe000000000000000))
            zeros: 67
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xffff000000000000))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0xff00000000000000))
            zeros: 72
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x000000000000ffff))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x000000000000ff00))
            zeros: 120
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0xf000000000000000), unsigned.uint128_from_64(0x01))
            r:     new(unsigned.uint128_from_64(0x4000000000000000), unsigned.uint128_from_64(0x00))
            zeros: 127
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0xf000000000000000), unsigned.uint128_from_64(0x00))
            r:     new(unsigned.uint128_from_64(0x4000000000000000), unsigned.uint128_from_64(0x00))
            zeros: 192
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0xf000000000000000), unsigned.uint128_from_64(0x00))
            r:     new(unsigned.uint128_from_64(0x8000000000000000), unsigned.uint128_from_64(0x00))
            zeros: 193
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x00))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x00))
            zeros: 256
        },
        LeadingZeros{
            l:     new(unsigned.uint128_from_64(0x01), unsigned.uint128_from_64(0x00))
            r:     new(unsigned.uint128_from_64(0x00), unsigned.uint128_from_64(0x00))
            zeros: 255
        },
    ]

    for tc in tcs {
        zeros := tc.l.xor(tc.r).leading_zeros()
        assert zeros == tc.zeros
    }
}

fn test_separators() {
    // numbers of varying lengths and a random
    // scattering of '_' throughout.
    test_strings := [
        '_',
        '__',
        '_0',
        '0_',
        '_0_',
        '_1',
        '1_',
        '_1_',
        '1_2',
        '_12',
        '12_',
        '12_3',
        '1_23_4',
        '12_345',
        '_123_456_',
        '1_234_567',
        '1234_5678',
        '_123456789',
        '1234567890_',
        '0_123_456_789_0',
        '90_12_345_67890',
        '8901_234_567890_',
        '_7890_123456789_0',
        '678901234_567890',
        '567890_1234567890',
        '4567890123__4567890',
        '_34567890123_4567890',
        '2345678_90123_4567890',
        '123456789_01_234567890',
        '01234567_8901234567890',
        '9012345678901_234567890__',
        '8_90123456_78901234567890',
        '78901234567890_123_4567890',
        '___67890123_4_5_6_78901234567890___',
        '567890123_45678901234567890',
        '45_67890123456789_01234567890',
        '3456789012_345678901234567890',
        '234_567890_1234_5__67890_1234567890_',
        '12345678_90123_456789_0123_4567890',
        '0_123_456_789_012_345_678_901_234_567_890',
        '90_123456__78901__234567_8901_234567890',
        '890123456789012345678901234567_890',
        '7890_1234567_8901234567890_1234567890',
        '67890123_45678_901234567_8901234567890',
        '567890_1234567890_12345678901_234567890',
        '45678_9012345_6789012345678901234567890_',
        '34567890123456_789012345678901234567890',
        '234567_890_1234567890_1234567890_1234567890',
        '334567890_1234567890_1234567890_1234567890',
        '340282360_0000000000_0000000000_0000000000',
        '340282366_9209384634_2648111928_4349108225',
        '340282366_9209384634_6337460743_1768211455',
        '6805_647__338418769269_267492148635_36422912',
        '13611294676837_5385385__34984297_27072845824_',
        '272225893_53675077077_0699685_94_5414569_1648',
        '_5444517_8707350154_1541_3993718908291383296',
        '223007_45198_5306231_4153571_8272648_361505_980416_',
        '146_150_163_733_090_291_820_368_483_271_628_301_965_593_254_297_6',
        '6_27_71_01_7353866807638_35789423207666416_1_0_2355444464034512896',
        '2695994_666715063_979466701508701_9630673637144422_540572481103610249216_',
        '11579208_923731619_5423570985008687_907853269_98_46_656405640__39457584_00791_3129639935',
    ]

    for ts in test_strings {
        with := unsigned.uint256_from_dec_str(ts) or {
            assert false, 'invalid Uint256 string ${ts}'
            panic('')
        }

        without := unsigned.uint256_from_dec_str(ts.replace('_', '')) or {
            assert false, 'invalid Uint256 string ${ts.replace('_', '')}'
            panic('')
        }

        assert with == without
    }
}

fn test_new() {
    assert unsigned.uint256_new(unsigned.uint128_max, unsigned.uint128_max) == unsigned.uint256_max
}

fn test_rsh() {
    a :=
        unsigned.uint256_from_dec_str('115792089237316195423570985008687907853269984665640564039457584007913129639935')!
    assert a.str() == a.rsh(0).str()
    assert '57896044618658097711785492504343953926634992332820282019728792003956564819967' == a.rsh(1).str()
    assert '6277101735386680763835789423207666416102355444464034512895' == a.rsh(64).str()
    assert '91343852333181432387730302044767688728495783935' == a.rsh(100).str()
    assert '340282366920938463463374607431768211455' == a.rsh(128).str()
    assert '170141183460469231731687303715884105727' == a.rsh(129).str()
    assert unsigned.uint256_zero == a.rsh(256)
}

fn test_lsh() {
    a := unsigned.uint256_from_dec_str('123')!
    assert a.lsh(0).str() == a.str()
    assert a.lsh(1).str() == '246'
    assert a.lsh(63).str() == '1134474760533137424384'
    assert a.lsh(64).str() == '2268949521066274848768'
    assert a.lsh(100).str() == '155921023828072216384094494261248'
    assert a.lsh(128).str() == '41854731131275431005995076714107490009088'
    assert a.lsh(200).str() == '197653379443855803891661337357963000110230968235283518742069248'
    assert a.lsh(300) == unsigned.uint256_zero
}

fn test_rotate_left() {
    a :=
        unsigned.uint256_from_dec_str('25514942427378518882041616545065271187265095759155217686057363902268374351523')!
    assert a.rotate_left(182).str() == '88706376393829417451765793453791860419270208590599379720310994108668904859637'
}