﻿/*
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

namespace DotPulsar.Tests.Internal;

using DotPulsar.Internal;
using FluentAssertions;
using Xunit;

public class Crc32CTests
{
    [Fact]
    public void Calculate_GivenSequenceWithSingleSegment_ShouldReturnExpectedChecksum()
    {
        //Arrange
        var segment = new byte[] { 0x10, 0x01, 0x18, 0xc9, 0xf8, 0x86, 0x94, 0xeb, 0x2c };

        var sequence = new SequenceBuilder<byte>().Append(segment).Build();

        //Act
        var actual = Crc32C.Calculate(sequence);

        //Assert
        const uint expected = 2355953212;
        actual.Should().Be(expected);
    }

    [Fact]
    public void Calculate_GivenSequenceWithMultipleSegments_ShouldReturnExpectedChecksum()
    {
        //Arrange
        var s1 = new byte[]
        {
            0x0a, 0x0f, 0x73, 0x74, 0x61, 0x6e, 0x64, 0x61, 0x6c, 0x6f,
            0x6e, 0x65, 0x2d, 0x33, 0x30, 0x2d, 0x35, 0x10, 0x00, 0x18,
            0xc7, 0xee, 0xa3, 0x93, 0xeb, 0x2c, 0x58, 0x01
        };

        var s2 = new byte[] { 0x10, 0x01, 0x18, 0xc9, 0xf8, 0x86, 0x94, 0xeb, 0x2c };

        var sequence = new SequenceBuilder<byte>().Append(s1).Append(s2).Build();

        //Act
        var actual = Crc32C.Calculate(sequence);

        //Assert
        const uint expected = 1079987866;
        actual.Should().Be(expected);
    }
}