namespace IRCSharp.Tests.Tokenization;

public class StatefulDecoder
{
    private IRCTokens.StatefulDecoder _decoder = new();

    [Test]
    public async Task Partial()
    {
        var lines = _decoder.Push("PRIVMSG ");
        await Assert.That(lines).IsEmpty();

        lines = _decoder.Push("#channel hello\r\n");
        await Assert.That(lines).HasCount(1);

        var line = new Line("PRIVMSG #channel hello");
        await Assert.That(lines).Contains(line);
    }

    [Test]
    public async Task Multiple()
    {
        var lines = _decoder.Push("PRIVMSG #channel1 hello\r\nPRIVMSG #channel2 hello\r\n");
        await Assert.That(lines).HasCount(2);

        await Assert.That(lines[0]).IsEqualTo(new Line("PRIVMSG #channel1 hello"));
        await Assert.That(lines[1]).IsEqualTo(new Line("PRIVMSG #channel2 hello"));
    }

    [Test]
    public async Task EncodingIso8859()
    {
        var iso8859 = Encoding.Latin1;
        var decoder = new IRCTokens.StatefulDecoder {Encoding = iso8859};
        var bytes   = iso8859.GetBytes("PRIVMSG #channel :hello Ç\r\n");
        var lines   = decoder.Push(bytes, bytes.Length);
        var line    = new Line("PRIVMSG #channel :hello Ç");
        await Assert.That(lines[0]).IsEqualTo(line);
    }

    [Test]
    public async Task EncodingFallback()
    {
        var latin1  = Encoding.Latin1;
        var decoder = new IRCTokens.StatefulDecoder {Encoding = null, Fallback = latin1};
        var bytes   = latin1.GetBytes("PRIVMSG #channel hélló\r\n");
        var lines   = decoder.Push(bytes, bytes.Length);
        await Assert.That(lines).HasCount(1);
        await Assert.That(lines[0]).IsEqualTo(new Line("PRIVMSG #channel hélló"));
    }

    [Test]
    public async Task Empty()
    {
        var lines = _decoder.Push(string.Empty);
        await Assert.That(lines).IsEmpty();
    }

    [Test]
    public async Task BufferUnfinished()
    {
        _decoder.Push("PRIVMSG #channel hello");
        var lines = _decoder.Push(string.Empty);
        await Assert.That(lines).IsEmpty();
    }

    [Test]
    public async Task Clear()
    {
        _decoder.Push("PRIVMSG ");
        _decoder.Clear();
        await Assert.That(_decoder.Pending).IsEmpty();
    }
}