using System;

namespace UnityEngine.Localization.SmartFormat.Net.Utilities
{
    /// <summary>
    /// Used for getting DateTime.Now or DateOffset.Now. Time is changeable for unit testing
    /// </summary>
    internal static class SystemTime
    {
        /// <summary>
        /// Normally this is a pass-through to DateTime.Now, but it can be overridden with SetDateTime( .. ) for unit testing and debugging.
        /// </summary>
        public static Func<DateTime> Now = () => DateTime.Now;

        /// <summary>
        /// Set time to return when SystemTime.Now() is called.
        /// </summary>
        public static void SetDateTime(DateTime dateTimeNow)
        {
            Now = () => dateTimeNow;
        }

        /// <summary>
        /// Normally this is a pass-through to DateTimeOffset.Now, but it can be overridden with SetDateTime( .. ) for unit testing and debugging.
        /// </summary>
        public static Func<DateTimeOffset> OffsetNow = () => DateTimeOffset.Now;

        /// <summary>
        /// Set time to return when SystemTime.OffsetNow() is called.
        /// </summary>
        public static void SetDateTimeOffset(DateTimeOffset dateTimeOffset)
        {
            OffsetNow = () => dateTimeOffset;
        }

        /// <summary>
        /// Resets SystemTime.Now() to return DateTime.Now.
        /// </summary>
        public static void ResetDateTime()
        {
            Now = () => DateTime.Now;
            OffsetNow = () => DateTimeOffset.Now;
        }
    }
}