DateTime Picker with Start & End time - Swift 5

gistfile1.txt

import UIKit

class DateTimePicker: NSObject, UIPickerViewDelegate, UIPickerViewDataSource {

  // Reference from https://stackoverflow.com/questions/40878547/is-it-possible-to-have-uidatepicker-work-with-start-and-end-time
  
  var didSelectDates: ((_ start: Date, _ end: Date) -> Void)?
  
  private lazy var pickerView: UIPickerView = {
    let pickerView = UIPickerView()
    pickerView.delegate = self
    pickerView.dataSource = self
    return pickerView
  }()
  
  private var days = [Date]()
  private var startTimes = [Date]()
  private var endTimes = [Date]()
  
  let dayFormatter = DateFormatter()
  let timeFormatter = DateFormatter()
  
  var inputView: UIView {
    return pickerView
  }
  
  func setup() {
    dayFormatter.dateFormat = "EE d MMM"
    timeFormatter.timeStyle = .short
    days = setDays()
    startTimes = setStartTimes()
    endTimes = setEndTimes()
  }
  
  // MARK: - UIPickerViewDelegate & DateSource
  
  func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 3
  }
  
  func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    switch component {
    case 0:
      return days.count
    case 1:
      return startTimes.count
    case 2:
      return endTimes.count
    default:
      return 0
    }
  }
  
  func pickerView(_ pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusing view: UIView?) -> UIView {
    var label: UILabel
    
    if let view = view as? UILabel {
      label = view
    } else {
      label = UILabel()
    }
    
    label.textColor = .black
    label.textAlignment = .center
    label.font = UIFont.systemFont(ofSize: 15)
    
    var text = ""
    
    switch component {
    case 0:
      text = getDayString(from: days[row])
    case 1:
      text = getTimeString(from: startTimes[row])
    case 2:
      text = getTimeString(from: endTimes[row])
    default:
      break
    }
    
    label.text = text
    
    return label
  }
  
  func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
    
    let dayIndex = pickerView.selectedRow(inComponent: 0)
    let startTimeIndex = pickerView.selectedRow(inComponent: 1)
    let endTimeIndex = pickerView.selectedRow(inComponent: 2)
    
    guard days.indices.contains(dayIndex),
            startTimes.indices.contains(startTimeIndex),
            endTimes.indices.contains(endTimeIndex) else { return }

    let startTime = startTimes[startTimeIndex]
    let endTime = endTimes[endTimeIndex]
    
    didSelectDates?(startTime, endTime)
  }
  
  // MARK: - Private helpers
  
  private func getDays(of date: Date) -> [Date] {
    var dates = [Date]()
    
    let calendar = Calendar.current
    
    // first date
    var currentDate = date
    
    // adding 30 days to current date
    let oneMonthFromNow = calendar.date(byAdding: .day, value: 30, to: currentDate)
    
    // last date
    let endDate = oneMonthFromNow
    
    while currentDate <= endDate! {
      dates.append(currentDate)
      currentDate = calendar.date(byAdding: .day, value: 1, to: currentDate)!
    }
    
    return dates
  }
  
  private func getTimes(of date: Date) -> [Date] {
    var times = [Date]()
    var currentDate = date
    
    currentDate = Calendar.current.date(bySetting: .hour, value: 7, of: currentDate)!
    currentDate = Calendar.current.date(bySetting: .minute, value: 00, of: currentDate)!
    
    let calendar = Calendar.current
    
    let interval = 60
    var nextDiff = interval - calendar.component(.minute, from: currentDate) % interval
    var nextDate = calendar.date(byAdding: .minute, value: nextDiff, to: currentDate) ?? Date()
    
    var hour = Calendar.current.component(.hour, from: nextDate)
    
    while(hour < 23) {
      times.append(nextDate)
      
      nextDiff = interval - calendar.component(.minute, from: nextDate) % interval
      nextDate = calendar.date(byAdding: .minute, value: nextDiff, to: nextDate) ?? Date()
      
      hour = Calendar.current.component(.hour, from: nextDate)
    }
    
    return times
  }
  
  private func setDays() -> [Date] {
    let today = Date()
    return getDays(of: today)
  }
  
  private func setStartTimes() -> [Date] {
    let today = Date()
    return getTimes(of: today)
  }
  
  private func setEndTimes() -> [Date] {
    let today = Date()
    return getTimes(of: today)
  }
  
  private func getDayString(from: Date) -> String {
    return dayFormatter.string(from: from)
  }
  
  private func getTimeString(from: Date) -> String {
    return timeFormatter.string(from: from)
  }
  
}

extension Date {

  static func buildTimeRangeString(startDate: Date, endDate: Date) -> String {
    
    let dayFormatter = DateFormatter()
    dayFormatter.dateFormat = "EEEE, MMM d, yyyy"

    let startTimeFormatter = DateFormatter()
    startTimeFormatter.dateFormat = "h:mm a"
    
    let endTimeFormatter = DateFormatter()
    endTimeFormatter.dateFormat = "h:mm a"
    
    return String(format: "%@ (%@ - %@)",
                  dayFormatter.string(from: startDate),
                  startTimeFormatter.string(from: startDate),
                  endTimeFormatter.string(from: endDate))
  }
}