namespace HSchool.People;

/// <summary>
/// Whether a generated or loaded roster still fills this map. A mismatch means the file is stale
/// relative to the layout — the school must not start and the file must stay untouched.
/// Staff openings are the player's to fill; only pupil seats have to be occupied.
/// </summary>
public static class RosterFit
{
    public static bool Matches(Roster roster, SchoolDemand demand)
    {
        if (roster.Classes.Count != demand.Classes.Count || roster.People.Count(person => person.IsStudent) != demand.Seats.Count)
        {
            return false;
        }

        var classesByRoom = roster.Classes.ToDictionary(schoolClass => schoolClass.RoomId, StringComparer.Ordinal);
        foreach (var expected in demand.Classes)
        {
            if (!classesByRoom.TryGetValue(expected.RoomId, out var actual)
                || actual.Capacity != expected.Capacity
                || actual.PupilIds.Count != expected.Capacity)
            {
                return false;
            }
        }

        return true;
    }
}