using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;

namespace JiShe.CollectBus.Common.Extensions
{
    public static class DateTimeOffsetExtensions
    {
         
        /// <summary>
        /// 获取当前时间毫秒级时间戳
        /// </summary>
        /// <returns></returns>
        public static long GetCurrentTimeMillis()
        {
            return DateTimeOffset.UtcNow.ToUnixTimeMilliseconds();
        }

        /// <summary>
        /// 将Unix时间戳转换为日期时间
        /// </summary>
        /// <param name="millis"></param>
        /// <returns></returns>
        public static DateTime FromUnixMillis(long millis)
        {
            return DateTimeOffset.FromUnixTimeMilliseconds(millis).DateTime;
        }

        /// <summary>
        /// 采集时间节点计算
        /// </summary>
        /// <param name="referenceTime">待采集时间</param>
        /// <param name="interval"></param>
        /// <returns></returns>
        public static DateTime CalculateNextCollectionTime(this DateTime referenceTime, int interval)
        {
            // 计算精确到分钟的基准时间
            var baseTime = new DateTime(
                referenceTime.Year,
                referenceTime.Month,
                referenceTime.Day,
                referenceTime.Hour,
                referenceTime.Minute,
                0);

            // 计算总分钟数和下一个间隔点
            int totalMinutes = baseTime.Hour * 60 + baseTime.Minute;
            int nextTotalMinutes = ((totalMinutes / interval) + 1) * interval;

            // 处理跨天情况
            int daysToAdd = nextTotalMinutes / (24 * 60);
            int remainingMinutes = nextTotalMinutes % (24 * 60);
            int hours = remainingMinutes / 60;
            int minutes = remainingMinutes % 60;

            return baseTime.Date
                .AddDays(daysToAdd)
                .AddHours(hours)
                .AddMinutes(minutes);
        }


        /// <summary>
        /// 将 DateTime 时间转换为 DateTimeOffset 时间
        /// </summary>
        /// <param name="rawDateTime"></param>
        /// <returns></returns>
        public static DateTimeOffset GetDateTimeOffset(this DateTime rawDateTime)
        {
            //确保 Kind 为 Local（如果是 Unspecified）
            DateTime localDateTime = rawDateTime.Kind == DateTimeKind.Unspecified
                ? DateTime.SpecifyKind(rawDateTime, DateTimeKind.Local)
                : rawDateTime;

            // 转换为 DateTimeOffset（自动应用本地时区偏移）
            return new DateTimeOffset(localDateTime);
        }

        private static readonly long UnixEpochTicks = new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).Ticks;

        /// <summary>
        /// 获取当前 DateTimeOffset 距离 Unix 纪元（1970-01-01）的微秒数
        /// </summary>
        public static long ToUnixTimeMicroseconds(this DateTimeOffset dateTimeOffset)
        {
            // Ticks 单位是 100 纳秒，转换为微秒需除以 10
            long elapsedTicks = dateTimeOffset.Ticks - UnixEpochTicks;
            return elapsedTicks / 10; // 1 微秒 = 1000 纳秒 = 10 Ticks
        }

        /// <summary>
        /// 获取当前 DateTimeOffset 距离 Unix 纪元（1970-01-01）的纳秒数
        /// </summary>
        public static long ToUnixTimeNanoseconds(this DateTimeOffset dateTimeOffset)
        {
            long nanoseconds = (dateTimeOffset.Ticks - UnixEpochTicks) * 100;
            return nanoseconds;
        }
    }
}