using CelticCalendarCalculator.Model;
using CelticCalendarCalculator.Model.Constants;
using System.Text;

namespace CelticCalendarCalculator.Control {
    internal class Ics {

        public static void createIcs() {
            //some variables for demo purposes
            DateTime DateStart = DateTime.Now;
            DateTime DateEnd = DateStart.AddMinutes(105);
            string Summary = "Small summary text";
            string Location = "Event location";
            string Description = "Lorem ipsum dolor sit amet, consectetuer adipiscing elit.";
            string FileName = "CalendarItem";

            //create a new stringbuilder instance
            StringBuilder sb = new StringBuilder();

            //start the calendar item
            sb.AppendLine("BEGIN:VCALENDAR");
            sb.AppendLine("VERSION:2.0");
            sb.AppendLine("PRODID:stackoverflow.com");
            sb.AppendLine("CALSCALE:GREGORIAN");
            sb.AppendLine("METHOD:PUBLISH");

            //create a time zone if needed, TZID to be used in the event itself
            sb.AppendLine("BEGIN:VTIMEZONE");
            sb.AppendLine("TZID:Europe/Amsterdam");
            sb.AppendLine("BEGIN:STANDARD");

            // oh no....
            CreateTimezoneIndicator();

            sb.AppendLine(IcaConstants.offset + CreateTimezoneIndicator());
            sb.AppendLine(IcaConstants.offsetfrom + CreateTimezoneIndicator());

            sb.AppendLine("END:STANDARD");
            sb.AppendLine("END:VTIMEZONE");

            //add the event
            sb.AppendLine("BEGIN:VEVENT");

            //with time zone specified
            sb.AppendLine("DTSTART;TZID=Europe/Amsterdam:" + DateStart.ToString("yyyyMMddTHHmm00"));
            sb.AppendLine("DTEND;TZID=Europe/Amsterdam:" + DateEnd.ToString("yyyyMMddTHHmm00"));
            //or without
            sb.AppendLine("DTSTART:" + DateStart.ToString("yyyyMMddTHHmm00"));
            sb.AppendLine("DTEND:" + DateEnd.ToString("yyyyMMddTHHmm00"));

            sb.AppendLine("SUMMARY:" + Summary + "");
            sb.AppendLine("LOCATION:" + Location + "");
            sb.AppendLine("DESCRIPTION:" + Description + "");
            sb.AppendLine("PRIORITY:3");
            sb.AppendLine("END:VEVENT");

            //end calendar item
            sb.AppendLine("END:VCALENDAR");

            //create a string from the stringbuilder
            string CalendarItem = sb.ToString();

        }


        private static string CreateTimezoneIndicator() {

            String result = ":";
            string operatorstr = Config.timeOffset >= 0 ? "+" : "-";
            result += operatorstr;

            if (Config.timeOffset <= 9) {
                result += "0";
            }

            result += Config.timeOffset.ToString();
            result += IcaConstants.postfix;

            return result;
        }
    }
}