using Campaign_Tracker.Server.Municipalities;

namespace Campaign_Tracker.Server.ElectionCycles;

public interface IElectionCycleKanbanReadModel
{
    Task<ElectionCycleKanbanBoard> GetAsync(
        CancellationToken cancellationToken = default);
}

public sealed class ElectionCycleKanbanReadModel : IElectionCycleKanbanReadModel
{
    public const string UnassignedCycleId = "__unassigned__";
    public const string UnassignedCycleName = "Unassigned";
    private readonly IMunicipalityProfileRepository _profiles;
    private readonly IElectionCycleJobRepository _jobs;

    public ElectionCycleKanbanReadModel(
        IMunicipalityProfileRepository profiles,
        IElectionCycleJobRepository jobs)
    {
        _profiles = profiles;
        _jobs = jobs;
    }

    public async Task<ElectionCycleKanbanBoard> GetAsync(
        CancellationToken cancellationToken = default)
    {
        var profiles = await _profiles.GetAllAsync(cancellationToken);
        var activeJobs = (await _jobs.GetAllAsync(cancellationToken))
            .Where(job => job.IsActive)
            .ToArray();

        var jobsByJCode = activeJobs
            .GroupBy(job => job.JCode, StringComparer.OrdinalIgnoreCase)
            .ToDictionary(group => group.Key, group => group.ToArray(), StringComparer.OrdinalIgnoreCase);

        var cardsByCycle = new Dictionary<string, List<ElectionCycleKanbanCard>>(
            StringComparer.OrdinalIgnoreCase);
        var lanesByCycle = activeJobs
            .GroupBy(job => job.CycleId, StringComparer.OrdinalIgnoreCase)
            .ToDictionary(
                group => group.Key,
                group => new ElectionCycleLaneHeader(
                    group.Key,
                    group.Select(job => job.CycleName)
                        .OrderBy(name => name, StringComparer.OrdinalIgnoreCase)
                        .First()),
                StringComparer.OrdinalIgnoreCase);

        var unassignedCards = new List<ElectionCycleKanbanCard>();
        var matchedJobIds = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
        foreach (var profile in profiles)
        {
            if (!jobsByJCode.TryGetValue(profile.Profile.JCode, out var profileJobs))
            {
                unassignedCards.Add(BuildUnassignedCard(profile));
                continue;
            }

            foreach (var job in profileJobs.OrderBy(job => job.CycleName, StringComparer.OrdinalIgnoreCase))
            {
                if (!cardsByCycle.TryGetValue(job.CycleId, out var cycleCards))
                {
                    cycleCards = [];
                    cardsByCycle[job.CycleId] = cycleCards;
                }

                cycleCards.Add(BuildAssignedCard(profile, job));
                matchedJobIds.Add(job.JobId);
            }
        }

        foreach (var orphan in activeJobs.Where(job => !matchedJobIds.Contains(job.JobId)))
        {
            if (!cardsByCycle.TryGetValue(orphan.CycleId, out var cycleCards))
            {
                cycleCards = [];
                cardsByCycle[orphan.CycleId] = cycleCards;
            }

            cycleCards.Add(BuildOrphanedCard(orphan));
        }

        var lanes = cardsByCycle
            .OrderBy(pair => lanesByCycle[pair.Key].CycleName, StringComparer.OrdinalIgnoreCase)
            .Select(pair => new ElectionCycleKanbanLane(
                pair.Key,
                lanesByCycle[pair.Key].CycleName,
                SortCards(pair.Value)))
            .Append(new ElectionCycleKanbanLane(
                UnassignedCycleId,
                UnassignedCycleName,
                SortCards(unassignedCards)))
            .ToArray();

        return new ElectionCycleKanbanBoard(lanes);
    }

    private static IReadOnlyList<ElectionCycleKanbanCard> SortCards(
        IReadOnlyList<ElectionCycleKanbanCard> cards)
        => cards
            .OrderBy(card => card.MunicipalityName, StringComparer.OrdinalIgnoreCase)
            .ThenBy(card => card.JCode, StringComparer.OrdinalIgnoreCase)
            .ToArray();

    private static ElectionCycleKanbanCard BuildAssignedCard(
        MunicipalityProfileView profile,
        ElectionCycleJobAssignment job)
        => new(
            CardId: job.JobId,
            MunicipalityName: MunicipalityName(profile),
            JCode: profile.Profile.JCode,
            CycleId: job.CycleId,
            CycleName: job.CycleName,
            CycleJobStatus: job.Status,
            LegacyJoinKey: profile.Profile.JCode,
            QuickOpenHref: $"/election-cycles/jobs/{job.JobId}");

    private static ElectionCycleKanbanCard BuildOrphanedCard(
        ElectionCycleJobAssignment job)
        => new(
            CardId: job.JobId,
            MunicipalityName: $"(unmapped JCode {job.JCode})",
            JCode: job.JCode,
            CycleId: job.CycleId,
            CycleName: job.CycleName,
            CycleJobStatus: job.Status,
            LegacyJoinKey: job.JCode,
            QuickOpenHref: $"/election-cycles/jobs/{job.JobId}");

    private static ElectionCycleKanbanCard BuildUnassignedCard(
        MunicipalityProfileView profile)
        => new(
            CardId: $"unassigned-{profile.Profile.JCode}",
            MunicipalityName: MunicipalityName(profile),
            JCode: profile.Profile.JCode,
            CycleId: UnassignedCycleId,
            CycleName: UnassignedCycleName,
            CycleJobStatus: UnassignedCycleName,
            LegacyJoinKey: profile.Profile.JCode,
            QuickOpenHref: $"/election-cycles/jobs/new?jCode={Uri.EscapeDataString(profile.Profile.JCode)}");

    private static string MunicipalityName(MunicipalityProfileView profile)
        => profile.Profile.DisplayName
            ?? profile.LegacyName
            ?? profile.Profile.JCode;

    private sealed record ElectionCycleLaneHeader(string CycleId, string CycleName);
}

public sealed record ElectionCycleKanbanBoard(
    IReadOnlyList<ElectionCycleKanbanLane> Lanes);

public sealed record ElectionCycleKanbanLane(
    string CycleId,
    string CycleName,
    IReadOnlyList<ElectionCycleKanbanCard> Cards);

public sealed record ElectionCycleKanbanCard(
    string CardId,
    string MunicipalityName,
    string JCode,
    string CycleId,
    string CycleName,
    string CycleJobStatus,
    string LegacyJoinKey,
    string QuickOpenHref);