using Nonemm.Core;

namespace Nonemm.Contests.Rules;

/// The EU DX Contest. Its "Europe" is the European Union: the member states,
/// their outermost regions and their overseas territories, and nothing else.
/// The exchange is the country and district code of the other station.
///
/// A contact with a station in that list is worth 10 points, or 2 inside your
/// own country. Everything else is 3 points on your own continent and 5 from
/// another.
public sealed class EuDxContest : Contest
{
    /// The member states, and the entities that are legally part of one: the
    /// Azores and Madeira, the Canaries, Ceuta and Melilla, the French overseas
    /// departments, Cyprus, and the Dutch and Danish territories.
    private static readonly IReadOnlySet<string> Union = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
    {
        "9A", "9H", "CT", "CU", "DL", "EA", "EA6", "EI", "ES", "F", "HA", "I", "IS", "IT9",
        "LX", "LY", "LZ", "OE", "OH", "OH0", "OJ0", "OK", "OM", "ON", "OX", "OZ", "PA", "S5",
        "SM", "SP", "SV", "SV5", "SV9", "TK", "YL", "YO",
        "5B", "CT3", "EA8", "EA9", "FO", "FP", "FY", "IG9", "IH9", "P4",
        "PJ0", "PJ2", "PJ4", "PJ5", "PJ6", "PJ7", "PJ8",
    };

    public string Name => "EUDXC";

    public string DisplayName => "EU DX Contest";

    public string CabrilloName => "EUDXC";

    public IReadOnlyList<ExchangeField> ExchangeFieldsFor(StationInfo me) =>
    [
        new ExchangeField("Snt", ExchangeSlot.SentReport, ExchangeFieldKind.Report, IsRequired: false),
        new ExchangeField("Rcv", ExchangeSlot.ReceivedReport, ExchangeFieldKind.Report),
        new ExchangeField("Exch", ExchangeSlot.Exchange1, ExchangeFieldKind.Text) { Width = 5 },
    ];

    /// A station in the union sends a district code, which goes in the section
    /// column; everyone else sends a CQ zone, which goes in the zone column.
    public Qso FromExchange1(Qso qso, string typed) =>
        IsUnion(qso.CountryPrefix)
            ? qso with { Section = typed.Trim().ToUpperInvariant() }
            : qso with { Zone = int.TryParse(typed, out int zone) ? zone : 0 };

    public IReadOnlyList<string> MultiplierNames => ["Codes", "Countries"];

    public DupeScope DupeScope => DupeScope.PerBandAndMode;

    public bool HasSerialNumbers => false;

    public IReadOnlyList<ModeCategory> Modes => [ModeCategory.Cw, ModeCategory.Phone];

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

    public int PointsFor(QsoContext qso)
    {
        if (IsUnion(qso.CountryPrefix))
        {
            return qso.IsSameCountry ? 2 : 10;
        }
        if (!qso.IsSameContinent)
        {
            return 5;
        }
        return IsUnion(qso.Me.CountryPrefix) || !qso.IsSameCountry ? 3 : 2;
    }

    /// The district code and the country each count once per band. Only a
    /// station in the union sends a code; everyone else sends a CQ zone, which
    /// counts for nothing.
    public IReadOnlyList<Multiplier> MultipliersFor(QsoContext qso)
    {
        string band = qso.Band?.Name ?? "";
        List<Multiplier> found = [];
        string code = qso.Qso.Section.Trim().ToUpperInvariant();
        if (IsUnion(qso.CountryPrefix) && code.Length > 0)
        {
            found.Add(new Multiplier(1, code, band));
        }
        if (qso.CountryPrefix.Length > 0)
        {
            found.Add(new Multiplier(2, qso.CountryPrefix, band));
        }
        return found;
    }

    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(entry.SentExchange, 5),
            ],
            [
                new CabrilloField(qso.Call.Text, 13),
                new CabrilloField(qso.ReceivedReport, 3),
                new CabrilloField(qso.Section.Length > 0 ? qso.Section : qso.Exchange1, 5),
            ]);

    private static bool IsUnion(string countryPrefix) => Union.Contains(countryPrefix);
}