WeedYears.swift

import Foundation

struct Weed {

	public let birthDate: Date
	private let calendar = Calendar.current
	private let yearLength = 420

	private var today: Date {
		return calendar.startOfDay(for: Date())
	}

	public var birthDays: [Date] {
		var birthDay = 0
		var birthDays = [Int]()

		while birthDay < daysSinceBirth {
			birthDay += yearLength
			birthDays.append(birthDay)
		}

		return birthDays.map { days in
			calendar.date(byAdding: .day, value: days , to: birthDate)!
		}
	}

	public var nextBirthDay: Date {
		return calendar.date(byAdding: .day, value: yearLength, to: birthDays.last!)!
	}

	public var daysSinceBirth: Int {
		return calendar.dateComponents(Set(arrayLiteral: .day), from: birthDate, to: today).day!
	}

	public var age: Int {
		return Int(daysSinceBirth / yearLength)
	}

	init(birhtDate: Date) {
		self.birthDate = calendar.startOfDay(for: birhtDate)
	}

	init(birthDate: String) {
		let dateFormatter = DateFormatter()
		dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
		self.birthDate = dateFormatter.date(from: birthDate)!

	}
}

let weed = Weed(birthDate: "1993-04-10T00:00:00+0000")

print(weed.age)
print(weed.nextBirthDay)

print(weed.birthDate)
weed.birthDays.forEach { birthDay in

	print(birthDay)
}