using Nonemm.Contests;
using Nonemm.Core;
using Nonemm.Session;
using Nonemm.Spotting;

namespace Nonemm.App.Windows;

/// The line above the callsign box. N1MM calls it the call frame: it says which
/// spotted station the radio is sitting on, coloured the way the bandmap
/// colours it, or that this is the frequency we are calling CQ on. Space with
/// an empty callsign box takes the station out of the frame and into the box,
/// which is how a station is worked without typing its call.
public sealed partial class EntryWindow
{
    /// Where we last called CQ, so the frame can say so when the radio comes
    /// back to it.
    private Frequency cqFrequency;

    /// What the frame holds, when it holds a callsign. `CQ-Frequency` is not
    /// one, and neither is nothing.
    private string framedCall = "";

    /// How close counts as sitting on a spot, which is a different number for
    /// each mode: a phone signal is wide and a CW one is not.
    private Frequency TuningTolerance =>
        Frequency.FromHertz(Math.Max(
            0,
            session.Settings.TuningToleranceFor(Logging?.Mode.Category ?? ModeCategory.Cw)));

    private void ShowCallFrame()
    {
        framedCall = "";
        if (Logging is null)
        {
            CallFrameText.Text = "";
            return;
        }
        if (cqFrequency.Hertz > 0
            && Math.Abs(Logging.Frequency.Hertz - cqFrequency.Hertz) <= TuningTolerance.Hertz)
        {
            CallFrameText.Text = "CQ-Frequency";
            CallFrameText.Foreground = Verdicts.Cq;
            return;
        }
        if (session.Bandmap.Near(Logging.Frequency, TuningTolerance) is not { } spot)
        {
            CallFrameText.Text = "";
            return;
        }
        // a mark saying the frequency is busy is shown but never taken into the
        // callsign box, because it is not a station
        framedCall = spot.IsStation ? spot.Call.Text : "";
        CallFrameText.Text = spot.IsSplit
            ? $"{spot.Call.Text} — listening on {spot.Qsx.Kilohertz:0.0}"
            : spot.Call.Text;
        CallFrameText.Foreground = spot.IsStation
            ? Verdicts.Colour(VerdictFor(spot))
            : Verdicts.Dupe;
    }

    private Verdict? VerdictFor(Spot spot) => Logging?.Log.Judge(new Qso
    {
        Id = "",
        TimestampUtc = DateTime.UtcNow,
        Call = spot.Call,
        Frequency = spot.Frequency,
        Mode = Logging.Mode,
        ContestName = Logging.Contest.Name,
    });

    /// N1MM only takes the call out of the frame while searching: a running
    /// station is answering callers, not chasing the one it is sitting on.
    private bool TakeFramedCall()
    {
        if (Logging is null || Logging.IsRunning || framedCall.Length == 0
            || Logging.Entry.Call.Trim().Length > 0)
        {
            return false;
        }
        Logging.Entry.Call = framedCall;
        return true;
    }

    /// The frequency a CQ went out on is the one the frame calls ours.
    private void RememberCqFrequency()
    {
        if (Logging is not null)
        {
            cqFrequency = Logging.Frequency;
        }
    }
}