using System.Globalization;

namespace GreenHome.Infrastructure.Extensions;

/// <summary>
/// Helper methods for Persian (Solar Hijri) date calculations.
/// Eliminates duplicate PersianCalendar code across services.
/// </summary>
public static class PersianDateHelper
{
    private static readonly PersianCalendar PersianCalendar = new();

    /// <summary>
    /// Extracts Persian year, month, day from a DateTime and returns the formatted Persian date string (yyyy/MM/dd).
    /// </summary>
    public static (int Year, int Month, int Day, string PersianDate) ToPersianDate(this DateTime dateTime)
    {
        var localDt = dateTime.Kind == DateTimeKind.Utc ? dateTime.ToLocalTime() : dateTime;
        var year = PersianCalendar.GetYear(localDt);
        var month = PersianCalendar.GetMonth(localDt);
        var day = PersianCalendar.GetDayOfMonth(localDt);
        var persianDate = $"{year:0000}/{month:00}/{day:00}";
        return (year, month, day, persianDate);
    }

    /// <summary>
    /// Validates a Persian date string in yyyy/MM/dd format and extracts year, month, day.
    /// </summary>
    public static bool TryParsePersianDate(string? persianDate, out int year, out int month, out int day)
    {
        year = month = day = 0;

        if (string.IsNullOrWhiteSpace(persianDate))
            return false;

        var parts = persianDate.Split('/');
        if (parts.Length != 3)
            return false;

        if (!int.TryParse(parts[0], out year) || year < 1300 || year > 1500)
            return false;

        if (!int.TryParse(parts[1], out month) || month < 1 || month > 12)
            return false;

        if (!int.TryParse(parts[2], out day) || day < 1 || day > 31)
            return false;

        return true;
    }
}