HumanTime

HumanTime.swift

class HumanTime: NSObject {
    let minute  = 1
    let hour    = 60
    let day     = 60 * 24
    let week    = 60 * 24 * 7
    
    let now: Date
    
    convenience override init() {
        self.init(now: Date())
    }
    
    init(now: Date) {
        self.now = now
    }
    
    func ageInWords(_ time: Date) -> String {
        let mins = Int(round(now.timeIntervalSince(time) / 60.0))
        
        switch mins {
        case 0:
            return "just now"
        case 1..<hour:
            return formatMinutes(mins, withUnit: "min", divisor: minute)
        case hour..<day:
            return formatMinutes(mins, withUnit: "hour", divisor: hour)
        case day..<week:
            return formatMinutes(mins, withUnit: "day", divisor: day)
        default:
            return formatMinutes(mins, withUnit: "week", divisor: week)
        }
    }
    
    func formatMinutes(_ minutes: Int, withUnit unit: String, divisor: Int) -> String {
        let units = (minutes + divisor / 2) / divisor
        let plural = (units != 1)
        return "\(units) \(unit)\(plural ? "s" : "")"
    }
}