using System.Diagnostics;
using NBitcoin.Crypto;
using NBitcoin.DataEncoders;
using Xunit;

namespace NBitcoin.Tests
{
    public class hash_tests
    {
        [Fact]
        [Trait("Core", "Core")]
        public void murmurhash3()
        {
            // Test MurmurHash3 with various inputs. Of course this is retested in the
            // bloom filter tests - they would fail if MurmurHash3() had any problems -
            // but is useful for those trying to implement Bitcoin libraries as a
            // source of test data for their MurmurHash3() primitive during
            // development.
            //
            // The magic number 0xFBA4C795 comes from CBloomFilter::Hash()
            T(0x00000000, 0x00000000, "");
            T(0x6a396f08, 0xFBA4C795, "");
            T(0x81f16f39, 0xffffffff, "");

            T(0x514e28b7, 0x00000000, "00");
            T(0xea3f0b17, 0xFBA4C795, "00");
            T(0xfd6cf10d, 0x00000000, "ff");

            T(0x16c6b7ab, 0x00000000, "0011");
            T(0x8eb51c3d, 0x00000000, "001122");
            T(0xb4471bf8, 0x00000000, "00112233");
            T(0xe2301fa8, 0x00000000, "0011223344");
            T(0xfc2e4a15, 0x00000000, "001122334455");
            T(0xb074502c, 0x00000000, "00112233445566");
            T(0x8034d2a0, 0x00000000, "0011223344556677");
            T(0xb4698def, 0x00000000, "001122334455667788");
        }

        /*
   SipHash-2-4 output with
   k = 00 01 02 ...
   and
   in = (empty string)
   in = 00 (1 byte)
   in = 00 01 (2 bytes)
   in = 00 01 02 (3 bytes)
   ...
   in = 00 01 02 ... 3e (63 bytes)
   from: https://131002.net/siphash/siphash24.c
*/
        private ulong[] siphash_4_2_testvec = new ulong[]{
    0x726fdb47dd0e0e31, 0x74f839c593dc67fd, 0x0d6c8009d9a94f5a, 0x85676696d7fb7e2d,
    0xcf2794e0277187b7, 0x18765564cd99a68d, 0xcbc9466e58fee3ce, 0xab0200f58b01d137,
    0x93f5f5799a932462, 0x9e0082df0ba9e4b0, 0x7a5dbbc594ddb9f3, 0xf4b32f46226bada7,
    0x751e8fbc860ee5fb, 0x14ea5627c0843d90, 0xf723ca908e7af2ee, 0xa129ca6149be45e5,
    0x3f2acc7f57c29bdb, 0x699ae9f52cbe4794, 0x4bc1b3f0968dd39c, 0xbb6dc91da77961bd,
    0xbed65cf21aa2ee98, 0xd0f2cbb02e3b67c7, 0x93536795e3a33e88, 0xa80c038ccd5ccec8,
    0xb8ad50c6f649af94, 0xbce192de8a85b8ea, 0x17d835b85bbb15f3, 0x2f2e6163076bcfad,
    0xde4daaaca71dc9a5, 0xa6a2506687956571, 0xad87a3535c49ef28, 0x32d892fad841c342,
    0x7127512f72f27cce, 0xa7f32346f95978e3, 0x12e0b01abb051238, 0x15e034d40fa197ae,
    0x314dffbe0815a3b4, 0x027990f029623981, 0xcadcd4e59ef40c4d, 0x9abfd8766a33735c,
    0x0e3ea96b5304a7d0, 0xad0c42d6fc585992, 0x187306c89bc215a9, 0xd4a60abcf3792b95,
    0xf935451de4f21df2, 0xa9538f0419755787, 0xdb9acddff56ca510, 0xd06c98cd5c0975eb,
    0xe612a3cb9ecba951, 0xc766e62cfcadaf96, 0xee64435a9752fe72, 0xa192d576b245165a,
    0x0a8787bf8ecb74b2, 0x81b3e73d20b49b6f, 0x7fa8220ba3b2ecea, 0x245731c13ca42499,
    0xb78dbfaf3a8d83bd, 0xea1ad565322a1a0b, 0x60e61c23a3795013, 0x6606d7e446282b93,
    0x6ca4ecb15c5f91e1, 0x9f626da15c9625f3, 0xe51b38608ef25f57, 0x958a324ceb064572
};

        [Fact]
        [Trait("Core", "Core")]
        public void siphash()
        {
            var hasher = new Hashes.SipHasher(0x0706050403020100UL, 0x0F0E0D0C0B0A0908UL);
            Assert.Equal(0x726fdb47dd0e0e31UL, hasher.Finalize());
            var t0 = new byte[]{ 0 };
            hasher.Write(t0);
            Assert.Equal(0x74f839c593dc67fdUL, hasher.Finalize());
            var t1 = new byte[] { 1, 2, 3, 4, 5, 6, 7 };
            hasher.Write(t1);
            Assert.Equal(0x93f5f5799a932462UL, hasher.Finalize());
            hasher.Write(0x0F0E0D0C0B0A0908UL);
            Assert.Equal(0x3f2acc7f57c29bdbUL, hasher.Finalize());
            var t2 = new byte[] { 16, 17 };
            hasher.Write(t2);
            Assert.Equal(0x4bc1b3f0968dd39cUL, hasher.Finalize());
            var t3 = new byte[] { 18, 19, 20, 21, 22, 23, 24, 25, 26 };
            hasher.Write(t3);
            Assert.Equal(0x2f2e6163076bcfadUL, hasher.Finalize());
            var t4 = new byte[]{ 27, 28, 29, 30, 31 };
            hasher.Write(t4);
            Assert.Equal(0x7127512f72f27cceUL, hasher.Finalize());
            hasher.Write(0x2726252423222120UL);
            Assert.Equal(0x0e3ea96b5304a7d0UL, hasher.Finalize());
            hasher.Write(0x2F2E2D2C2B2A2928UL);
            Assert.Equal(0xe612a3cb9ecba951UL, hasher.Finalize());

            Assert.Equal(0x7127512f72f27cceUL, Hashes.SipHash(0x0706050403020100UL, 0x0F0E0D0C0B0A0908UL, new uint256("1f1e1d1c1b1a191817161514131211100f0e0d0c0b0a09080706050403020100")));

            // Check test vectors from spec, one byte at a time
            var hasher2 = new Hashes.SipHasher(0x0706050403020100UL, 0x0F0E0D0C0B0A0908UL);
            for(byte x = 0; x < this.siphash_4_2_testvec.Length; ++x)
            {
                Assert.Equal(hasher2.Finalize(), this.siphash_4_2_testvec[x]);
                hasher2.Write(new byte[] { x });
            }
            // Check test vectors from spec, eight bytes at a time
            var hasher3 = new Hashes.SipHasher(0x0706050403020100UL, 0x0F0E0D0C0B0A0908UL);
            for(int x = 0; x < this.siphash_4_2_testvec.Length; x += 8)
            {
                Assert.Equal(hasher3.Finalize(), this.siphash_4_2_testvec[x]);
                hasher3.Write(uint64_t(x) | (uint64_t(x + 1) << 8) | (uint64_t(x + 2) << 16) | (uint64_t(x + 3) << 24) |
                             (uint64_t(x + 4) << 32) | (uint64_t(x + 5) << 40) | (uint64_t(x + 6) << 48) | (uint64_t(x + 7) << 56));
            }
        }

        private ulong uint64_t(int x)
        {
            return (ulong)x;
        }

        [Fact]
        [Trait("UnitTest", "UnitTest")]
        public void hash256()
        {
            Assert.Equal(uint256.Parse("000000000019d6689c085ae165831e934ff763ae46a2a6c172b3f1b60a8ce26f"), Network.Main.GetGenesis().GetHash());
        }

        [Fact]
        [Trait("UnitTest", "UnitTest")]
        public void hash160()
        {
            var data = new byte[] { 1, 2, 3, 4 };
            uint160 result = Hashes.Hash160(data);
            Assert.Equal("706ea1768da7f0c489bf931b362c2d26d8cbd2ec", result.ToString());
        }

        [DebuggerHidden]
        private void T(uint expected, uint seed, string data)
        {
            Assert.Equal(Hashes.MurmurHash3(seed, Encoders.Hex.DecodeData(data)), expected);
        }
    }
}
