using Nonemm.Core;

namespace Nonemm.Contests.Rules;

/// The Oceania DX contest, CW and phone. Only contacts with Oceania count for
/// a station outside it, and they are worth more the lower the band: 20 points
/// on 160 metres, 10 on 80, 5 on 40 and 1 on the higher bands. Each prefix
/// worked counts once per band.
public sealed class OceaniaDx : Contest
{
    private readonly ModeCategory mode;

    public OceaniaDx(ModeCategory mode) => this.mode = mode;

    public string Name => mode == ModeCategory.Cw ? "OceaniaCW" : "OceaniaSSB";

    public string DisplayName => $"Oceania DX {ModeLabel()}";

    public string CabrilloName => mode == ModeCategory.Cw ? "Oceania-DX-CW" : "Oceania-DX-SSB";

    public IReadOnlyList<ExchangeField> ExchangeFieldsFor(StationInfo me) =>
    [
        new ExchangeField("Snt", ExchangeSlot.SentReport, ExchangeFieldKind.Report, IsRequired: false),
        new ExchangeField("SntNR", ExchangeSlot.SentNumber, ExchangeFieldKind.Number, IsRequired: false),
        new ExchangeField("Rcv", ExchangeSlot.ReceivedReport, ExchangeFieldKind.Report),
        new ExchangeField("RcvNR", ExchangeSlot.SerialNumber, ExchangeFieldKind.Number),
    ];

    public IReadOnlyList<string> MultiplierNamesFor(StationInfo me) => ["Prefixes"];

    public DupeScope DupeScope => DupeScope.PerBand;

    public bool HasSerialNumbers => true;

    public IReadOnlyList<ModeCategory> Modes => [mode];

    public string SentExchangeFor(StationInfo me) => "001";

    public int PointsFor(QsoContext qso) =>
        IsWorkable(qso) ? PointsOn(qso.Band) : 0;

    public IReadOnlyList<Multiplier> MultipliersFor(QsoContext qso) =>
        IsWorkable(qso) && qso.Qso.Call.WpxPrefix() is { } prefix
            ? [new Multiplier(1, prefix, qso.Band?.Name ?? "")]
            : [];

    public int TotalScore(ScoreTally tally, ContestEntry entry) =>
        tally.Points * tally.TotalMultipliers;

    public CabrilloExchange CabrilloExchange(Qso qso, StationInfo me, ContestEntry entry) =>
        new(
            [
                new CabrilloField(me.Callsign, 13),
                new CabrilloField(qso.SentReport, 3),
                new CabrilloField($"{qso.SentNumber:000}", 4),
            ],
            [
                new CabrilloField(qso.Call.Text, 13),
                new CabrilloField(qso.ReceivedReport, 3),
                new CabrilloField($"{qso.ReceivedNumber:000}", 4),
            ]);

    /// One side of every contact has to be in Oceania.
    public bool IsWorkable(QsoContext qso) =>
        qso.Continent == "OC" || qso.Me.Continent == "OC";

    /// What a contact is worth on each of the contest's six bands. The high
    /// bands pay more than 20 metres, which is the other way round from most
    /// contests: from Oceania they are the hard ones. A band that is not in
    /// this table is not in the contest — the WARC bands and 6 metres — and
    /// scores nothing, which is how N1MM's `COceania.ComputePoints` ends as
    /// well.
    private static int PointsOn(Band? band) => band?.Name switch
    {
        "160M" => 20,
        "80M" => 10,
        "40M" => 5,
        "20M" => 1,
        "15M" => 2,
        "10M" => 3,
        _ => 0,
    };

    private string ModeLabel() => mode == ModeCategory.Cw ? "CW" : "SSB";
}