5dplomacy/MultiversalDiplomacy/Model/Season.cs

using System.Text.Json.Serialization;

namespace MultiversalDiplomacy.Model;

/// <summary>
/// Represents a state of the map produced by a set of move orders on a previous season.
/// </summary>
public class Season(string? past, int turn, string timeline)
{
    /// <summary>
    /// The first turn number. This is defined to reduce confusion about whether the first turn is 0 or 1.
    /// </summary>
    public const int FIRST_TURN = 0;

    /// <summary>
    /// The designation of the season immediately preceding this season.
    /// If this season is an alternate timeline root, the past is from the origin timeline.
    /// The initial season does not have a past.
    /// </summary>
    public string? Past { get; } = past;

    /// <summary>
    /// The current turn, beginning at 0. Each season (spring and fall) is one turn.
    /// Phases that only occur after the fall phase occur when Turn % 2 == 1.
    /// The current year is (Turn / 2) + 1901.
    /// </summary>
    public int Turn { get; } = turn;

    /// <summary>
    /// The timeline to which this season belongs.
    /// </summary>
    public string Timeline { get; } = timeline;

    /// <summary>
    /// The multiversal designation of this season.
    /// </summary>
    [JsonIgnore]
    public string Key => $"{this.Timeline}{this.Turn}";

    public override string ToString() => Key;
}