DateUtils #swift #date

DateUtil.swift

//
//  DateUtil.swift
//  DrinkSum
//
//  Created by Greg Eales on 5/11/20.
//

import Foundation
struct DateUtil {
    static func getModifiedDate(date: Date, currentDate: Date) -> String {

        let dateFormatter = DateFormatter()
        let difference = Calendar.current.dateComponents([.day], from: currentDate, to: date)
        if abs(difference.day!) == 0 || abs(difference.day!) == 1 {
            let relativeDateFormatter = RelativeDateTimeFormatter()
            relativeDateFormatter.dateTimeStyle = .named
            relativeDateFormatter.formattingContext = .beginningOfSentence
            let relativePortion =  relativeDateFormatter.localizedString(for: date, relativeTo: currentDate)
          
            dateFormatter.setLocalizedDateFormatFromTemplate("MMMMd")
            let datePortion = dateFormatter.string(from: date)
            return "\(relativePortion) \(difference.day! == 0 ? "" : ", " + datePortion)"
        } else {
            dateFormatter.setLocalizedDateFormatFromTemplate("MMMMdEEEE")
            return dateFormatter.string(from: date)
        }
    }
    
    static func getTodaysDateString() -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.setLocalizedDateFormatFromTemplate("MMMMdEEEE")
        return dateFormatter.string(from: Date())
    }
    
    static func getWeekDayShort(from: Date = Date()) -> String {
        
        let dateFormatter = DateFormatter()
        dateFormatter.setLocalizedDateFormatFromTemplate("ccccc")
        return dateFormatter.string(from: from)
    }
    
    static func datePlusDays(forDate: Date, days: Int) -> Date {
        return Calendar.current.date(byAdding: DateComponents(day: days), to: forDate)!
    }
    
    static func getMonthString() -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.setLocalizedDateFormatFromTemplate("MMMMyyyy")
        return dateFormatter.string(from: Date())
    }
}

extension Date {
    public func removeTimeStamp() -> Date {
        guard let date = Calendar.current.date(
                from: Calendar.current.dateComponents([.year, .month, .day], from: self)) else {
            fatalError("Failed to strip time from Date object")
        }
        return date
    }
    
    public func beginningOfDay() -> Date {
        return self.removeTimeStamp()
    }
    
    public func endOfDay() -> Date {
        return (Calendar.current.date(
                    byAdding: .day, value: 1, to: self)?.removeTimeStamp().addingTimeInterval(TimeInterval(-1)))!
    }
    
    public var hour: Int {
         get {
             return Calendar.current.component(.hour, from: self)
         }
     }
    
    public var minute: Int {
        get {
            return Calendar.current.component(.minute, from: self)
        }
    }
    
    public var second: Int {
        get {
            return Calendar.current.component(.second, from: self)
        }
    }
    
    public func toString() -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = "yyyy-MM-dd'T'HH:mm:ssZ"
        return dateFormatter.string(from: self)
    }
    
    public func toStringWithFormat(format: String = "yyyy-MM-dd'T'HH:mm:ssZ") -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.dateFormat = format
        return dateFormatter.string(from: self)
    }
    
    func interval(ofComponent comp: Calendar.Component, fromDate date: Date) -> Int {

        let currentCalendar = Calendar.current

        guard let start = currentCalendar.ordinality(of: comp, in: .era, for: date) else { return 0 }
        guard let end = currentCalendar.ordinality(of: comp, in: .era, for: self) else { return 0 }

        return end - start
    }
    
    public var monthString: String {
        get {
            return DateUtil.getMonthString()
        }
    }
  
    private func monthsInCalendar() -> [String] {
        let formatter = DateFormatter()
        let monthComponents = formatter.shortMonthSymbols!
        return monthComponents
    }
  
    private func getDayRangeForMonth(monthNumber: Int, yearNumber: Int) {
        
        let dateComponents = DateComponents(
            year: yearNumber,
            month: monthNumber,
            day: 1)
        
        let tmpDate = Calendar.current.date(from: dateComponents)!
        let daysInMonth = (Calendar.current.range(of: .day, in: .month, for: tmpDate)?.max())!
        return Array(1...daysInMonth)
    }
  
    private func getMonthNumberFromName(name: String) -> Int {
        return monthsInCalendar().firstIndex(of: month)! + 1
    }
    
    private func getMonthNameFromNumber(monthNumber: Int) -> String {
        let months = monthsInCalendar()
        return months[monthNumber - 1]
    }
}