using System;

namespace DataModel.Helpers
{
    /// <summary>
    /// JDE date/time conversion helpers
    /// </summary>
    public static class DateTimeHelpers
    {
        /// <summary>
        /// Strips time component from datetime
        /// </summary>
        /// <param name="source">Datetime to strip time component from</param>
        /// <returns>Date component of source datetime</returns>
        public static int ToJDEDate(this DateTime source)
        {
            return (source.Year < 2000 ? 0 : 100000) + (source.Year % 100) * 1000 + source.DayOfYear;
        }

        public static DateTime FromJDEDate(this int sourceDate)
        {
            if (sourceDate == 0) { return new DateTime(1900, 1, 1); }

            DateTime baseDate = new DateTime(1900, 1, 1);
            try
            {
                string strSource = sourceDate.ToString();

                if (strSource.Length < 5 || strSource.Length > 6) { throw new Exception($"invalid source date length ({strSource.Length})"); }

                if (strSource.StartsWith("1"))
                {
                    baseDate = new DateTime(2000, 1, 1);
                }

                baseDate = baseDate.AddYears(int.Parse(strSource.Substring(1, 2)));
                baseDate = baseDate.AddDays(int.Parse(strSource.Substring(3)) - 1);
            }
            catch
            {
                //Do nothing
            }

            return baseDate;
        }

        /// <summary>
        /// Strips date component from datetime
        /// </summary>
        /// <param name="source">Datetime to strip date component from</param>
        /// <returns>Time component of source datetime</returns>
        public static int ToJDETime(this DateTime source)
        {
            return source.Hour * 10000 + source.Minute * 100 + source.Second;
        }

        /// <summary>
        /// Converts the JDE date + time components into a datetime
        /// </summary>
        /// <param name="sourceDate">JDE date component</param>
        /// <param name="sourceTime">JDE time component</param>
        /// <returns>Combined datetime from source JDE date/time components</returns>
        public static DateTime FromJDEDateTime(this DateTime sourceDate, int sourceTime)
        {
            try
            {
                int hours = sourceTime / 10000;
                int minutes = (sourceTime % 10000) / 100;
                int seconds = sourceTime % 100;

                return sourceDate.Date.AddHours(hours).AddMinutes(minutes).AddSeconds(seconds);
            }
            catch
            {
                return sourceDate;

            }
        }
    }
}