public DaylightInfo GetDaylight(Location location, string timeZoneId, DateTime commuteStart, DateTime commuteEnd)
{
var sunCalculator = new SunCalculator(location.Longitude, location.Latitude);
var daylightInfo = CalculateDaylightInfo(commuteStart, commuteEnd, sunCalculator, timeZoneId);
return daylightInfo;
}
private DaylightInfo CalculateDaylightInfo(DateTime commuteStart, DateTime commuteEnd, SunCalculator sunCalculator, string timeZoneId)
{
var daylightInfo = new DaylightInfo();
var sunRise = sunCalculator.CalculateSunRise(commuteStart.Date, timeZoneId);
var sunSet = sunCalculator.CalculateSunSet(commuteStart.Date, timeZoneId);
var commuteIsAfterSunrise = commuteStart.TimeOfDay >= sunRise.TimeOfDay;
var commuteIsBeforeSunSet = commuteEnd.TimeOfDay <= sunSet.TimeOfDay;
if (commuteEnd.Date > commuteStart.Date)
{
// Special case; overlapping midnight. Just assume that it's always dark
return daylightInfo;
}
daylightInfo.IsCurrentlyInDaylight = commuteIsAfterSunrise && commuteIsBeforeSunSet;
for (var d = 0; d < DaysInYear; d++)
{
sunRise = sunCalculator.CalculateSunRise(commuteStart.Date.AddDays(d), timeZoneId);
sunSet = sunCalculator.CalculateSunSet(commuteEnd.Date.AddDays(d), timeZoneId);
if (commuteStart.TimeOfDay >= sunRise.TimeOfDay && commuteEnd.TimeOfDay <= sunSet.TimeOfDay)
{
daylightInfo.CommutesInDaylightPerYear++;
}
if (!daylightInfo.TransitionType.HasValue && DaylightTransitionHappened(sunRise, sunSet, commuteStart, commuteEnd, daylightInfo.IsCurrentlyInDaylight))
{
// We need to work out on which edge the transition happened
if (commuteIsAfterSunrise != (commuteStart.TimeOfDay >= sunRise.TimeOfDay))
{
daylightInfo.NextDaylightTransition = sunRise.AddDays(-1);
daylightInfo.TransitionType = DaylightTransition.SunRise;
}
else if (commuteIsBeforeSunSet != (commuteEnd.TimeOfDay <= sunSet.TimeOfDay))
{
daylightInfo.NextDaylightTransition = sunSet.AddDays(-1);
daylightInfo.TransitionType = DaylightTransition.SunSet;
}
else
{
throw new Exception("something went very wrong");
}
}
}
return daylightInfo;
}
