using System;
using System.Linq;
using StardewValley;
namespace StardewModdingAPI.Utilities
{
/// <summary>Represents a Stardew Valley date.</summary>
public class SDate : IEquatable<SDate>
{
/*********
** Properties
*********/
/// <summary>The internal season names in order.</summary>
private readonly string[] Seasons = { "spring", "summer", "fall", "winter" };
/// <summary>The number of seasons in a year.</summary>
private int SeasonsInYear => this.Seasons.Length;
/// <summary>The number of days in a season.</summary>
private readonly int DaysInSeason = 28;
/*********
** Accessors
*********/
/// <summary>The day of month.</summary>
public int Day { get; }
/// <summary>The season name.</summary>
public string Season { get; }
/// <summary>The year.</summary>
public int Year { get; }
/*********
** Public methods
*********/
/// <summary>Construct an instance.</summary>
/// <param name="day">The day of month.</param>
/// <param name="season">The season name.</param>
/// <exception cref="ArgumentException">One of the arguments has an invalid value (like day 35).</exception>
public SDate(int day, string season)
: this(day, season, Game1.year) { }
/// <summary>Construct an instance.</summary>
/// <param name="day">The day of month.</param>
/// <param name="season">The season name.</param>
/// <param name="year">The year.</param>
/// <exception cref="ArgumentException">One of the arguments has an invalid value (like day 35).</exception>
public SDate(int day, string season, int year)
{
// validate
if (season == null)
throw new ArgumentNullException(nameof(season));
if (!this.Seasons.Contains(season))
throw new ArgumentException($"Unknown season '{season}', must be one of [{string.Join(", ", this.Seasons)}].");
if (day < 1 || day > this.DaysInSeason)
throw new ArgumentException($"Invalid day '{day}', must be a value from 1 to {this.DaysInSeason}.");
if (year < 1)
throw new ArgumentException($"Invalid year '{year}', must be at least 1.");
// initialise
this.Day = day;
this.Season = season;
this.Year = year;
}
/// <summary>Get the current in-game date.</summary>
public static SDate Now()
{
return new SDate(Game1.dayOfMonth, Game1.currentSeason, Game1.year);
}
/// <summary>Get a new date with the given number of days added.</summary>
/// <param name="offset">The number of days to add.</param>
/// <returns>Returns the resulting date.</returns>
/// <exception cref="ArithmeticException">The offset would result in an invalid date (like year 0).</exception>
public SDate AddDays(int offset)
{
// simple case
int day = this.Day + offset;
string season = this.Season;
int year = this.Year;
// handle season transition
if (day > this.DaysInSeason || day < 1)
{
// get season index
int curSeasonIndex = this.GetSeasonIndex();
// get season offset
int seasonOffset = day / this.DaysInSeason;
if (day < 1)
seasonOffset -= 1;
// get new date
day = this.GetWrappedIndex(day, this.DaysInSeason);
season = this.Seasons[this.GetWrappedIndex(curSeasonIndex + seasonOffset, this.Seasons.Length)];
year += seasonOffset / this.Seasons.Length;
}
// validate
if (year < 1)
throw new ArithmeticException($"Adding {offset} days to {this} would result in invalid date {day:00} {season} {year}.");
// return new date
return new SDate(day, season, year);
}
/// <summary>Get a string representation of the date. This is mainly intended for debugging or console messages.</summary>
public override string ToString()
{
return $"{this.Day:00} {this.Season} Y{this.Year}";
}
/****
** IEquatable
****/
/// <summary>Get whether this instance is equal to another.</summary>
/// <param name="other">The other value to compare.</param>
public bool Equals(SDate other)
{
return this == other;
}
/// <summary>Get whether this instance is equal to another.</summary>
/// <param name="obj">The other value to compare.</param>
public override bool Equals(object obj)
{
return obj is SDate other && this == other;
}
/// <summary>Get a hash code which uniquely identifies a date.</summary>
public override int GetHashCode()
{
// return the number of days since 01 spring Y1
int yearIndex = this.Year - 1;
return
yearIndex * this.DaysInSeason * this.SeasonsInYear
+ this.GetSeasonIndex() * this.DaysInSeason
+ this.Day;
}
/****
** Operators
****/
/// <summary>Get whether one date is equal to another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
/// <returns>The equality of the dates</returns>
public static bool operator ==(SDate date, SDate other)
{
return date?.GetHashCode() == other?.GetHashCode();
}
/// <summary>Get whether one date is not equal to another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
public static bool operator !=(SDate date, SDate other)
{
return date?.GetHashCode() != other?.GetHashCode();
}
/// <summary>Get whether one date is more than another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
public static bool operator >(SDate date, SDate other)
{
return date?.GetHashCode() > other?.GetHashCode();
}
/// <summary>Get whether one date is more than or equal to another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
public static bool operator >=(SDate date, SDate other)
{
return date?.GetHashCode() >= other?.GetHashCode();
}
/// <summary>Get whether one date is less than or equal to another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
public static bool operator <=(SDate date, SDate other)
{
return date?.GetHashCode() <= other?.GetHashCode();
}
/// <summary>Get whether one date is less than another.</summary>
/// <param name="date">The base date to compare.</param>
/// <param name="other">The other date to compare.</param>
public static bool operator <(SDate date, SDate other)
{
return date?.GetHashCode() < other?.GetHashCode();
}
/*********
** Private methods
*********/
/// <summary>Get the current season index.</summary>
/// <exception cref="InvalidOperationException">The current season wasn't recognised.</exception>
private int GetSeasonIndex()
{
int index = Array.IndexOf(this.Seasons, this.Season);
if (index == -1)
throw new InvalidOperationException($"The current season '{this.Season}' wasn't recognised.");
return index;
}
/// <summary>Get the real index in an array which should be treated as a two-way loop.</summary>
/// <param name="index">The index in the looped array.</param>
/// <param name="length">The number of elements in the array.</param>
private int GetWrappedIndex(int index, int length)
{
int wrapped = index % length;
if (wrapped < 0)
wrapped += length;
return wrapped;
}
}
}