using System;

using System.Collections.Generic;

​

public class Program

{

    public static void Main()

    {

        // parameters

        var caseCreateDate = new DateTime(2019, 5, 23, 1, 0, 0);

        var type = "IIPE"; // IIA / IIPE

        // assumes current date time is the same as when case is created

        var escalation = GetEscalationDateTimes(type, caseCreateDate, caseCreateDate);

        // display follow up date times

        foreach(var dt in escalation.FollowUpDateTimes)

        {

            Console.WriteLine("Follow up page on " + dt);

        }

        Console.WriteLine("Due on " + escalation.DueDateTime);

    }

    private static Escalation GetEscalationDateTimes(string type, DateTime currentDate, DateTime caseCreateDate)

    {

        Escalation escalation = new Escalation();

        switch (type)

        {

            case "IIA":

                // first escalation

                escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(5));

                // second escalation

                escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(10));

                // third escalation

                escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(15));

                // due

                escalation.DueDateTime = caseCreateDate.AddMinutes(20);

                break;

            case "IIPE":

                var dayOfWeek = (int)currentDate.DayOfWeek;

                var timeOfDay = currentDate.TimeOfDay;

                if (

                    // Mon-Fri 

                    dayOfWeek >= 1 && dayOfWeek <= 5

                    // Between 8:30am - 5:00pm

                    && timeOfDay >= (new TimeSpan(8, 30, 0)) && timeOfDay < (new TimeSpan(17, 0, 0))

                )

                {

                    // first escalation

                    escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(5));

                    // second escalation

                    escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(10));

                    // third escalation

                    escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(15));

                    // due

                    escalation.DueDateTime = caseCreateDate.AddMinutes(20);

                }

                else if

                    (

                    (

                        // Mon-Fri

                        dayOfWeek >= 1 && dayOfWeek <= 5

                        // Between 5:00pm - 9:00pm

                        && timeOfDay >= (new TimeSpan(17, 0, 0)) && timeOfDay < (new TimeSpan(21, 0, 0))

                    )

                    // Or

                    ||

                    (

                        // Sat/Sun

                        (dayOfWeek == 6 || dayOfWeek == 0)

                        // Between 8:30am - 9:00pm

                        && timeOfDay >= (new TimeSpan(8, 30, 0)) && timeOfDay < (new TimeSpan(21, 0, 0))

                    )

                )

                {

                    // first escalation

                    escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(30));

                    // second escalation

                    escalation.FollowUpDateTimes.Add(caseCreateDate.AddMinutes(35));

                    // due

                    escalation.DueDateTime = caseCreateDate.AddMinutes(37);

                }

                else if

                    (

                    // After 9:00pm or before 8:30am (after hours)

                    timeOfDay >= (new TimeSpan(21, 0, 0)) || timeOfDay < (new TimeSpan(8, 30, 0))

                )

                {

                    // if after 9:00pm, set to next day at 8:30am, else set to current day 8:30am

                    var escalationDate = (timeOfDay >= (new TimeSpan(21, 0, 0)))

                        ? currentDate.Date.AddDays(1).AddHours(8).AddMinutes(30)

                        : currentDate.Date.AddHours(8).AddMinutes(30);

                    if (

                        // Sat/Sun

                        (int)escalationDate.DayOfWeek == 6 || (int)escalationDate.DayOfWeek == 0

                    )

                    {

                        // first escalation at 8:30am

                        escalation.FollowUpDateTimes.Add(escalationDate);

                        // second escalation

                        escalation.FollowUpDateTimes.Add(escalationDate.AddMinutes(30));

                        // third escalation

                        escalation.FollowUpDateTimes.Add(escalationDate.AddMinutes(35));

                        // due

                        escalation.DueDateTime = escalationDate.AddMinutes(37);

                    }

                    else

                    {

                        // first escalation at 8:30am

                        escalation.FollowUpDateTimes.Add(escalationDate);

                        // second escalation

                        escalation.FollowUpDateTimes.Add(escalationDate.AddMinutes(5));

                        // third escalation

                        escalation.FollowUpDateTimes.Add(escalationDate.AddMinutes(10));

                        // fourth escalation

                        escalation.FollowUpDateTimes.Add(escalationDate.AddMinutes(15));

                        // due

                        escalation.DueDateTime = escalationDate.AddMinutes(20);

                    }

                }

                break;

        }

        return escalation;

    }

​

    public class Escalation

    {

        public DateTime? DueDateTime { get; set; }

        public List<DateTime> FollowUpDateTimes { get; set; }

​

        public Escalation()

        {

            FollowUpDateTimes = new List<DateTime>();

        }

    }

}