using CsvLib;

namespace CvsLib;

[TestSubject(typeof(ByteArraySearcher))]
public class ByteArraySearcherTests
{
    [Fact]
    public void Contains__EmptyNeedle_ReturnsTrue()
    {
        // --- Arrange
        byte[] haystack = [1, 2, 3, 4, 5,];
        byte[] needle = Array.Empty<byte>();
        ByteArraySearcher searcher = new(needle);

        // --- Act
        bool result = searcher.Contains(haystack);

        // --- Assert
        Assert.True(result);
    }

    [Fact]
    public void Contains__NeedleAtBeginning_ReturnsTrue()
    {
        // --- Arrange
        byte[] haystack = [1, 2, 3, 4, 5,];
        byte[] needle = [1, 2, 3,];
        ByteArraySearcher searcher = new(needle);

        // --- Act
        bool result = searcher.Contains(haystack);

        // --- Assert
        Assert.True(result);
    }

    [Fact]
    public void Contains__NeedleInMiddle_ReturnsTrue()
    {
        // --- Arrange
        byte[] haystack = [1, 2, 3, 4, 5,];
        byte[] needle = [3, 4,];
        ByteArraySearcher searcher = new(needle);

        // --- Act
        bool result = searcher.Contains(haystack);

        // --- Assert
        Assert.True(result);
    }

    [Fact]
    public void Contains__NeedleAtEnd_ReturnsTrue()
    {
        // --- Arrange
        byte[] haystack = [1, 2, 3, 4, 5,];
        byte[] needle = [4, 5,];
        ByteArraySearcher searcher = new(needle);

        // --- Act
        bool result = searcher.Contains(haystack);

        // --- Assert
        Assert.True(result);
    }

    [Fact]
    public void Contains__NeedleNotPresent_ReturnsFalse()
    {
        // --- Arrange
        byte[] haystack = [1, 2, 3, 4, 5,];
        byte[] needle = [5, 6, 7,];
        ByteArraySearcher searcher = new(needle);

        // --- Act
        bool result = searcher.Contains(haystack);

        // --- Assert
        Assert.False(result);
    }
}