using Nonemm.Contests.Rules;
using Nonemm.Contests.Udc;
using Nonemm.Core;

namespace Nonemm.Contests;

/// The contests on offer: the ones written into the program, plus whatever
/// `.udc` files the operator has put in the user-defined contests folder.
public sealed class ContestRegistry
{
    private static readonly IReadOnlyList<ContestChoice> BuiltIn =
    [
        new("CQWW", "CQ World Wide DX", [ModeCategory.Cw, ModeCategory.Phone, ModeCategory.Digital], m => new CqWorldWide(m)),
        new("CQWPX", "CQ WPX", [ModeCategory.Cw, ModeCategory.Phone, ModeCategory.Digital], m => new CqWpx(m)),
        new("ARRLDX", "ARRL International DX", [ModeCategory.Cw, ModeCategory.Phone], m => new ArrlDx(m)),
        new("IARU", "IARU HF World Championship", [ModeCategory.Cw, ModeCategory.Phone], _ => new IaruHf()),
        new("SS", "ARRL Sweepstakes", [ModeCategory.Cw, ModeCategory.Phone], m => new Sweepstakes(m)),
        new("WAE", "Worked All Europe DX", [ModeCategory.Cw, ModeCategory.Phone, ModeCategory.Digital], m => new Wae(m)),
        new("ARRLRTTY", "ARRL RTTY Roundup", [ModeCategory.Digital], _ => new RttyRoundup()),
        new("NAQP", "North American QSO Party", [ModeCategory.Cw, ModeCategory.Phone, ModeCategory.Digital], m => new NorthAmericanQsoParty(m)),
        new("OKOMDX", "Czech and Slovak Republics DX", [ModeCategory.Cw], _ => new OkOmDx()),
        new("YOTA", "YOTA Contest", [ModeCategory.Cw, ModeCategory.Phone], _ => new Yota()),
        new("IOTA", "RSGB Islands On The Air", [ModeCategory.Cw, ModeCategory.Phone], _ => new Iota()),
        new("EUDXC", "EU DX Contest", [ModeCategory.Cw, ModeCategory.Phone], _ => new EuDxContest()),
        new("CQ160", "CQ World-Wide 160 Metre", [ModeCategory.Cw, ModeCategory.Phone], m => new CqOneSixty(m)),
        new("XERTTY", "Mexico RTTY Contest", [ModeCategory.Digital], _ => new MexicoRtty()),
        new("REF", "French REF DX contest", [ModeCategory.Cw, ModeCategory.Phone], m => new FrenchRef(m)),
        new("UKRAINDX", "Ukrainian DX", [ModeCategory.Cw, ModeCategory.Phone], _ => new UkrainianDx()),
        new("BARTGRTTYS", "BARTG RTTY Sprint", [ModeCategory.Digital], _ => new BartgSprint()),
        new("ARRL10M", "ARRL 10 Metre Contest", [ModeCategory.Cw, ModeCategory.Phone], _ => new Arrl10Metre()),
        new("RUSDXRTTY", "Russian DX RTTY", [ModeCategory.Digital], _ => new RussianDxRtty()),
        new("RDAC", "Russian District Award Contest", [ModeCategory.Cw, ModeCategory.Phone], _ => new RussianDistrictAward()),
        new("YOHFDX", "YO DX HF", [ModeCategory.Cw, ModeCategory.Phone], _ => new YoDxHf()),
        new("OCEANIA", "Oceania DX", [ModeCategory.Cw, ModeCategory.Phone], m => new OceaniaDx(m)),
        new("FDREG1", "IARU Region 1 Field Day", [ModeCategory.Cw, ModeCategory.Phone], _ => new FieldDayRegionOne()),
        new("SARTGRTTY", "SARTG World Wide RTTY", [ModeCategory.Digital], _ => new SartgRtty()),
        new("ALLASIA", "All Asian DX", [ModeCategory.Cw, ModeCategory.Phone], m => new AllAsian(m)),
        new("DX", "General logging", [], _ => new GeneralLogging()),
    ];

    private readonly Dictionary<string, ContestChoice> byName;

    private ContestRegistry(Dictionary<string, ContestChoice> byName) => this.byName = byName;

    public static ContestRegistry Create(IEnumerable<UdcFile>? userDefined = null)
    {
        Dictionary<string, ContestChoice> byName = BuiltIn.ToDictionary(
            c => c.Name,
            StringComparer.OrdinalIgnoreCase);
        foreach (UdcFile file in userDefined ?? [])
        {
            UserDefinedContest contest = new(file);
            byName[contest.Name] = new ContestChoice(
                contest.Name,
                contest.DisplayName,
                contest.Modes,
                _ => new UserDefinedContest(file));
        }
        return new ContestRegistry(byName);
    }

    /// Reads every `.udc` file in the folder. Published files come with the
    /// extension in either case, and a file that will not parse is reported
    /// rather than silently left out.
    public static ContestRegistry FromFolder(string folder, out IReadOnlyList<string> problems)
    {
        List<UdcFile> files = [];
        List<string> failures = [];
        if (Directory.Exists(folder))
        {
            IEnumerable<string> found = Directory.EnumerateFiles(folder)
                .Where(f => Path.GetExtension(f).Equals(".udc", StringComparison.OrdinalIgnoreCase));
            foreach (string path in found)
            {
                try
                {
                    files.Add(UdcFile.Parse(File.ReadAllText(path)));
                }
                catch (Exception e) when (e is FormatException or IOException)
                {
                    failures.Add($"{path}: {e.Message}");
                }
            }
        }
        problems = failures;
        return Create(files);
    }

    public IReadOnlyList<ContestChoice> Choices =>
        byName.Values.OrderBy(c => c.DisplayName, StringComparer.Ordinal).ToList();

    public Contest Create(string name, ModeCategory mode)
    {
        ContestChoice choice = Find(name, ref mode)
            ?? throw new KeyNotFoundException($"no contest named '{name}'");
        return choice.Create(mode);
    }

    public bool Has(string name)
    {
        ModeCategory ignored = ModeCategory.Cw;
        return Find(name, ref ignored) is not null;
    }

    /// A name N1MM wrote carries the mode, and that is better than whatever the
    /// log's mode column says, so it wins when the name resolves that way.
    private ContestChoice? Find(string name, ref ModeCategory mode)
    {
        if (byName.TryGetValue(name, out ContestChoice? choice))
        {
            return choice;
        }
        if (N1mmContestNames.TryResolve(name, out string family, out ModeCategory named)
            && byName.TryGetValue(family, out ContestChoice? resolved))
        {
            mode = named;
            return resolved;
        }
        return null;
    }
}