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

namespace DTS.Common.Utilities
{
    /// <summary>
    /// Convert a DateTime to Unix Time.  No attempt is made to correct for time zone/localities.
    /// </summary>
    public class Time
    {
        public static UInt32 DateTimeToUnixTimestamp(DateTime dateTime)
        {
            var start = new DateTime(1970, 1, 1);
            var span = dateTime - start;

            return (UInt32)span.TotalSeconds;
        }

        public static UInt32 CurrentUtcUnixTimestamp()
        {
            var span = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc));

            return (UInt32)span.TotalSeconds;
        }

        public static UInt32 CurrentLocalUnixTimestamp()
        {
            var span = (DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Local));

            return (UInt32)span.TotalSeconds;
        }

        public static DateTime ToDateTime(UInt32 seconds)
        {
            return new DateTime(1970, 1, 1).AddSeconds(seconds);
        }

        public static UInt32 ToUnixTime(DateTime dateTime)
        {
            var start = new DateTime(1970, 1, 1);
            var span = dateTime - start;

            return (UInt32)span.TotalSeconds;
        }

        public static bool IsBeginningOfTime(DateTime dateTime)
        {
            var start = new DateTime(1970, 1, 1);
            var span = dateTime - start;

            return (0 == span.TotalSeconds);
        }

    }
}