using Aberwyn.Data;

namespace Aberwyn.Data
{
    public class PayoutService
    {
    }


    public static class SwedishHolidays
    {
        public static bool IsRedDay(DateTime date)
        {
            var year = date.Year;

            var fixedHolidays = new[]
            {
            new DateTime(year, 1, 1),   // Nyårsdagen
            new DateTime(year, 1, 6),   // Trettondedag jul
            new DateTime(year, 5, 1),   // Första maj
            new DateTime(year, 6, 6),   // Nationaldagen
            new DateTime(year, 12, 25), // Juldagen
            new DateTime(year, 12, 26), // Annandag jul
        };

            if (fixedHolidays.Contains(date.Date))
                return true;

            // Rörliga helgdagar
            var easter = GetEasterSunday(year);

            var movable = new[]
            {
            easter.AddDays(-2), // Långfredagen
            easter,             // Påskdagen
            easter.AddDays(1),  // Annandag påsk
            easter.AddDays(39), // Kristi himmelsfärd
            easter.AddDays(49), // Pingstdagen
            GetMidsummerDay(year),
        };

            return movable.Contains(date.Date);
        }

        private static DateTime GetMidsummerDay(int year)
        {
            // Lördag mellan 20–26 juni
            for (int day = 20; day <= 26; day++)
            {
                var d = new DateTime(year, 6, day);
                if (d.DayOfWeek == DayOfWeek.Saturday)
                    return d;
            }
            throw new Exception("Midsummer not found");
        }


        private static DateTime GetEasterSunday(int year)
        {
            // Meeus/Jones/Butcher
            int a = year % 19;
            int b = year / 100;
            int c = year % 100;
            int d = b / 4;
            int e = b % 4;
            int f = (b + 8) / 25;
            int g = (b - f + 1) / 3;
            int h = (19 * a + b - d - g + 15) % 30;
            int i = c / 4;
            int k = c % 4;
            int l = (32 + 2 * e + 2 * i - h - k) % 7;
            int m = (a + 11 * h + 22 * l) / 451;
            int month = (h + l - 7 * m + 114) / 31;
            int day = ((h + l - 7 * m + 114) % 31) + 1;

            return new DateTime(year, month, day);
        }
    }


}
public static class SalaryDateService
{
    public static DateTime GetSalaryPayDate(int year, int month)
    {
        var payDate = new DateTime(year, month, 25);

        while (payDate.DayOfWeek == DayOfWeek.Saturday ||
               payDate.DayOfWeek == DayOfWeek.Sunday ||
               SwedishHolidays.IsRedDay(payDate))
        {
            payDate = payDate.AddDays(-1);
        }

        return payDate;
    }
}