using Arch.Core;
using HSchool.Schedule;
using HSchool.Simulation;

namespace HSchool.Server.Game;

/// <summary>
/// Live slice of one school for a diagnostic dump. Built on the worker thread; HTTP never sees
/// the <c>World</c>.
/// </summary>
internal sealed record SchoolLiveDump(
    DateTime GameTime,
    bool Running,
    IReadOnlyList<PresenceSnapshot> Presence,
    IReadOnlyDictionary<string, IReadOnlyDictionary<string, float>> Needs,
    IReadOnlyList<LessonPlacement> Now);

/// <summary>Reads presence and needs from the live school. Call only on that school's worker.</summary>
internal static class SchoolDumpReader
{
    private static readonly QueryDescription IdentityAndNeeds =
        new QueryDescription().WithAll<PersonIdentity, PersonNeeds>();

    public static SchoolLiveDump Read(School school, int weekDays)
    {
        var needs = new Dictionary<string, IReadOnlyDictionary<string, float>>(StringComparer.Ordinal);
        school.World.Query(in IdentityAndNeeds, (ref PersonIdentity identity, ref PersonNeeds live) =>
        {
            needs[identity.Id] = new Dictionary<string, float>(live.Values, StringComparer.Ordinal);
        });

        IReadOnlyList<LessonPlacement> now = [];
        if (school.Timetable is not null && school.Catalog is not null)
        {
            now = TimetableClock.OccurringAt(school.Timetable, school.Catalog, school.Clock.Time, weekDays);
        }

        return new SchoolLiveDump(
            school.Clock.Time,
            school.Clock.IsRunning,
            school.CapturePresence(),
            needs,
            now);
    }
}