using System.Text;
using NewLife;
using Xunit;

namespace XUnitTest.Buffers;

public class SpanHelperTests
{
    [Fact]
    public void ToStr()
    {
        var str = "Hello NewLife";
        var buf = Encoding.UTF8.GetBytes(str);

        var span = new Span<Byte>(buf);
        var str2 = span.ToStr();
        Assert.Equal(str, str2);

        var span3 = new ReadOnlySpan<Byte>(buf);
        var str3 = span3.ToStr();
        Assert.Equal(str, str3);
    }

    [Fact]
    public void GetBytes()
    {
        var str = "Hello NewLife";
        var buf = Encoding.UTF8.GetBytes(str);

        Span<Byte> span = stackalloc Byte[buf.Length];
        var count = Encoding.UTF8.GetBytes(str.AsSpan(), span);
        Assert.Equal(str.Length, count);
        Assert.Equal('H', (Char)span[0]);
        Assert.Equal('e', (Char)span[1]);
        Assert.Equal('l', (Char)span[2]);
        Assert.Equal('l', (Char)span[3]);
        Assert.Equal('o', (Char)span[4]);

        var str3 = Encoding.UTF8.GetString(span);
        Assert.Equal(str, str3);
    }

    [Fact]
    public void ToHex()
    {
        var str = "Hello NewLife";
        var buf = Encoding.UTF8.GetBytes(str);

        Span<Byte> span = stackalloc Byte[buf.Length];
        var count = Encoding.UTF8.GetBytes(str.AsSpan(), span);

        Assert.Equal(buf.ToHex(), span.ToHex());
        Assert.Equal(buf.ToHex(null, 0, 8), span.ToHex(null, 0, 8));
        Assert.Equal(buf.ToHex("-", 0, 8), span.ToHex("-", 0, 8));
        Assert.Equal(buf.ToHex("+&", 5, 8), span.ToHex("+&", 5, 8));

        ReadOnlySpan<Byte> span2 = span;
        Assert.Equal(buf.ToHex(), span2.ToHex());
    }

    [Theory]
    [InlineData("Hello", "Hello")]
    [InlineData(" Hello", "Hello")]
    [InlineData("Hello ", "Hello")]
    [InlineData(" Hello ", "Hello")]
    [InlineData("\tHello\r\n", "Hello")]
    [InlineData("  H e l l o  ", "H e l l o")]
    public void Trim_CharSpan(String input, String expected)
    {
        var span = input.GetBytes().AsSpan();
        var rs = SpanHelper.Trim(span);

        Assert.Equal(expected, rs.ToStr());
    }

    [Fact]
    public void Trim_CharSpan_AllWhitespace()
    {
        var buf = "  \t\r\n ".GetBytes();
        var span = new Span<Byte>(buf);

        var rs = SpanHelper.Trim(span);

        Assert.Equal(String.Empty, rs.ToStr());
        Assert.Equal(0, rs.Length);
    }

    //[Fact]
    //public void Trim_CharSpan_Empty()
    //{
    //    Span<Char> span = [];

    //    var rs = SpanHelper.Trim(span);

    //    Assert.True(rs.IsEmpty);
    //    Assert.Equal(0, rs.Length);
    //}

    [Fact]
    public void Trim_ByteSpan_Empty()
    {
        ReadOnlySpan<Byte> span = [];

        var rs = span.Trim();

        Assert.True(rs.IsEmpty);
        Assert.Equal(0, rs.Length);
    }
}