How to format time and check "working hours" in Swift - swift

Question

I've been playing with NSDate() but I hit a bump and need help. I need to check working hours and if user is using an app during open hours some green dot will appear.
I work with firebase and data for working hours is:
main
---> key
----> working hours
-------------->
Mon: 12:00-18:00
Tue: 11:30-21:00
etc.
I get the logic. Grab day in week. Grab correct line in Firebase. Grab user current time and see if it is given range. I'm still beginner but I would love to learn how to do this.
Can somebody direct me a little bit?
Here is only code I have for now:
// Check current time
let userTime = NSDate()
let formatter = NSDateFormatter();
formatter.dateFormat = "HH:mm"
let now = formatter.stringFromDate(userTime)
print(now)

Answer 1

Since no question should go unanswered ;)
Since your pattern is stable you can use Regular Expressions with named groups. Keep the regex pattern outside the function.
let regex = try! NSRegularExpression(pattern: "(?<day>\\w{3}):\\s(?<openHour>\\d{2}):(?<openMin>\\d{2})-(?<closeHour>\\d{2}):(?<closeMin>\\d{2})",
options: .caseInsensitive)
Here is a function that takes your input "Mon: 12:00-18:00", you can select the right now based on the correct day, or move the day checking into the function too.
func isOfficeOpenNow(input: String) -> Bool {
let range = NSRange(location: 0, length: input.utf8.count)
guard let match = regex.firstMatch(in: input, options: [], range: range) else {
assert(false, "Epic Fail!")
}
guard let dayRange = Range(match.range(withName: "day"), in: input),
let openHourRange = Range(match.range(withName: "openHour"), in: input),
let openMinRange = Range(match.range(withName: "openMin"), in: input),
let closeHourRange = Range(match.range(withName: "closeHour"), in: input),
let closeMinRange = Range(match.range(withName: "closeMin"), in: input) else {
assert(false, "Did not find the named groups")
}
let day = String(input[dayRange])
guard let openHour = Int(input[openHourRange]),
let openMin = Int(input[openMinRange]),
let closeHour = Int(input[closeHourRange]),
let closeMin = Int(input[closeMinRange]) else {
assert(false, "Failed to convert to ints")
}
print("day: \(day) Opens at: \(openHour):\(openMin) and closes at \(closeHour):\(closeMin)")
// Lets check if its now open (not checking the day....sorry)
let tz = NSTimeZone.default
let now = NSCalendar.current.dateComponents(in: tz, from: Date())
guard let hour = now.hour,
let minute = now.minute else {
assert(false, "this should never happen")
}
let rightNowInMinutes = hour * 60 + minute
let opensAt = openHour * 60 + openMin
let closesAt = closeHour * 60 + closeMin
assert(opensAt < closesAt, "Opening after closing does not make sense")
return rightNowInMinutes > opensAt &&
rightNowInMinutes < closesAt
}
Here is how you could use it
if isOfficeOpenNow(input: "Mon: 12:00-18:00") {
print("Store open")
} else {
print("Store closed")
}