Swift:日期格式化

如何将时间显示为“刚刚”“xx分钟前”这种格式呢，话不多少，上代码：

    // 获取当前时间
    let currentDate = Date()
    // 目标时间
    let formatter        = DateFormatter()
    formatter.dateFormat = "yyyy-MM-dd HH:mm:ss"
    guard let targetDate =  formatter.date(from: dateStr) else { return "" }
    
    let calendar = Calendar.current
    let returnFormatter = DateFormatter()
    // 先判断年份
    if calendar.isDate(targetDate, equalTo: currentDate, toGranularity: .year) {
        // 判断是否为今天
        if calendar.isDateInToday(targetDate) {
            let components = calendar.dateComponents([.minute, .hour], from: targetDate, to: currentDate)
            // 判断小时
            if components.hour == 0 {
                // 判断分钟
                if components.minute == 0 {
                    return "刚刚"
                } else {
                    return "\(String(describing: components.hour))分钟前"
                }
            } else {
                return "\(String(describing: components.hour))小时前"
            }
        } else if calendar.isDateInYesterday(targetDate) {
            return "昨天"
        } else {
            returnFormatter.dateFormat = "MM.dd"
            return returnFormatter.string(from: targetDate)
        }
    } else {
        // 直接返回年月日
        returnFormatter.dateFormat = "yyyy.MM.dd";
        return returnFormatter.string(from: targetDate)
    }