using Nonemm.Session;

namespace Nonemm.Session.Tests;

/// The decoded text as the modem sends it, one character at a time.
public class DigitalReceiverTests
{
    private static List<string> CallsIn(string text)
    {
        DigitalReceiver receiver = new();
        List<string> heard = [];
        receiver.CallHeard += (_, call) => heard.Add(call);
        foreach (char c in text)
        {
            receiver.Receive(c.ToString());
        }
        return heard;
    }

    [Fact]
    public void ACallsignIsReportedWhenTheWordEnds()
    {
        Assert.Equal(["OM5M"], CallsIn("CQ DE OM5M "));
    }

    [Fact]
    public void AWordThatIsStillBeingSentIsNotReportedYet()
    {
        Assert.Empty(CallsIn("CQ DE OM5"));
    }

    [Fact]
    public void ALineBreakEndsAWordTheSameWayASpaceDoes()
    {
        Assert.Equal(["OM5M"], CallsIn("DE OM5M\r\n"));
    }

    [Fact]
    public void NoiseThatIsNotShapedLikeACallIsPassedOver()
    {
        Assert.Empty(CallsIn("RYRY ????? +.+. \r\n"));
    }

    [Fact]
    public void TheTextIsKeptAsItArrived()
    {
        DigitalReceiver receiver = new();

        receiver.Receive("CQ TEST ");
        receiver.Receive("OM5M");

        Assert.Equal("CQ TEST OM5M", receiver.Text);
    }

    /// A callsign has at most three characters after its number, so that is
    /// where a word that ran into the next one is cut.
    [Fact]
    public void AWordRunTogetherWithTheNextIsCutBackToTheCall()
    {
        Assert.Equal("OM5MTE", DigitalReceiver.TrimToCall("OM5MTESTTEST"));
        Assert.Equal("OM5M", DigitalReceiver.TrimToCall("OM5M"));
    }

    [Fact]
    public void APortableCallIsLeftAlone()
    {
        Assert.Equal("OM5M/P", DigitalReceiver.TrimToCall("OM5M/P"));
    }

    [Fact]
    public void TheWordUnderThePointerIsTheOneAroundIt()
    {
        Assert.Equal("OM5M", DigitalReceiver.WordAt("CQ DE OM5M K", 7));
        Assert.Equal("", DigitalReceiver.WordAt("CQ DE OM5M K", 5));
    }
}