using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SteamWare
{

  /// <summary>
  /// Singolo dettaglio evento
  /// </summary>
  public class EventDetail
  {
    /// <summary>
    /// Data di riferimento
    /// </summary>
    public DateTime when { get; set; }
    /// <summary>
    /// Nome evento
    /// </summary>
    public string what { get; set; } = "";
  }
  /// <summary>
  /// Classe gestione procedure Calendario (es festività)
  /// </summary>
  public class calendarMan
  {
    /// <summary>
    /// Calculate Easter Sunday for any given year.
    /// src.: https://stackoverflow.com/a/2510411/1233379
    /// </summary>
    /// <param name="year">The year to calcolate Easter against.</param>
    /// <returns>a DateTime object containing the Easter month and day for the given year</returns>
    public static DateTime GetEasterSunday(int year)
    {
      int day = 0;
      int month = 0;

      int g = year % 19;
      int c = year / 100;
      int h = (c - (int)(c / 4) - (int)((8 * c + 13) / 25) + 19 * g + 15) % 30;
      int i = h - (int)(h / 28) * (1 - (int)(h / 28) * (int)(29 / (h + 1)) * (int)((21 - g) / 11));

      day = i - ((year + (int)(year / 4) + i + 2 - c + (int)(c / 4)) % 7) + 28;
      month = 3;

      if (day > 31)
      {
        month++;
        day -= 31;
      }

      return new DateTime(year, month, day);
    }
    /// <summary>
    /// Elenco festività per l'anno indicato
    /// </summary>
    /// <param name="anno"></param>
    /// <returns></returns>
    public  static List<EventDetail> elencoFestAnno(int anno)
    {
      List<EventDetail> answ = new List<EventDetail>();
      // aggiungo le feste comandate...
      answ.Add(new EventDetail() { what = "Capodanno", when = new DateTime(anno, 1, 1) });
      answ.Add(new EventDetail() { what = "Epifania", when = new DateTime(anno, 1, 6) });
      answ.Add(new EventDetail() { what = "Lavoro", when = new DateTime(anno, 5, 1) });
      answ.Add(new EventDetail() { what = "Ferragosto", when = new DateTime(anno, 8, 15) });
      answ.Add(new EventDetail() { what = "Ognissanti", when = new DateTime(anno, 11, 1) });
      answ.Add(new EventDetail() { what = "Immacolata", when = new DateTime(anno, 12, 8) });
      answ.Add(new EventDetail() { what = "Natale", when = new DateTime(anno, 12, 25) });
      answ.Add(new EventDetail() { what = "S.Stefano", when = new DateTime(anno, 12, 26) });
      // Pasqua + Pasquetta
      answ.Add(new EventDetail() { what = "Pasqua", when = GetEasterSunday(anno) });
      answ.Add(new EventDetail() { what = "Pasquetta", when = GetEasterSunday(anno).AddDays(1) });
      // feste ITA
      answ.Add(new EventDetail() { what = "Liberazione", when = new DateTime(anno, 4, 25) });
      answ.Add(new EventDetail() { what = "Repubblica", when = new DateTime(anno, 6, 2) });

      return answ;
    }

  }
}