Billing/Billing.Shared/Models/Category.cs

using SQLite;
using System;

namespace Billing.Models
{
    public class Category : IIdItem
    {
        private const string ICON_DEFAULT = "ic_default";
        private const long TRANSPARENT_COLOR = 0x00ffffffL;

        private static Category empty;
        public static Category Empty => empty ??= new() { Id = -1 };

        [PrimaryKey, AutoIncrement]
        public int Id { get; set; }
        public CategoryType Type { get; set; }
        public string Icon { get; set; } = ICON_DEFAULT;
        public string Name { get; set; }
        public long TintColor { get; set; } = TRANSPARENT_COLOR;
        public int? ParentId { get; set; }
        public DateTime? LastUsed { get; set; }
        public int? LastAccountId { get; set; }
    }

    public enum CategoryType
    {
        Spending,
        Income
    }
}