DateAndTimeInterval.swift

//
//  DateAndTimeInterval.swift
//  SwiftUIDevTips
//
//  TimeInterval is the length of time in seconds
//

import SwiftUI

struct DateAndTimeInterval: View {
    var aMinute: TimeInterval = 60.0
    let anHour = 3600.0
    let aDay = 3600.0 * 24.0
    
    var body: some View {
        NavigationStack {
            List {
                // Text("\(aMinute)")
                // Minute
                Text("**Minute**: \(String(format: "%.1f", aMinute)) sec")
                
                // Hour
                Text("**Hour**: \(String(format: "%.1f", anHour)) sec")
                
                // Day
                Text("**Day**: \(String(format: "%.1f", aDay)) sec")
                
                // Today
                Text("**Today**: \(Date.now, format: .dateTime)")
                
                // An hour from now
                Text("**An hour from now**: \(Date(timeIntervalSinceNow: anHour).formatted())")
                
                // An hour ago
                Text("**An hour ago**: \(Date(timeIntervalSinceNow: -anHour), format: .dateTime)")
                
                // Tomorrow but 2 hours from now
                Text("**Tomorrow but 2 hours from now**: \(Date(timeInterval: aDay + anHour, since: Date(timeIntervalSinceNow: anHour)), format: .dateTime)")
                
                // Add a date formatter, change locale
                let targetDate = Date(timeInterval: aDay + anHour, since: Date(timeIntervalSinceNow: anHour))
                let formattedDate = formattedDateString(for: targetDate)
                
                // Tomorrow, 2 hours from now but in Sanfrancisco time zone
                Text("**Tomorrow, 2 hours from now but in Sanfrancisco time zone**: \(formattedDate)")
            }
            .navigationTitle("Date and TimeInterval")
            .navigationBarTitleDisplayMode(.inline)
        }
    }
    
    func formattedDateString(for date: Date) -> String {
        let dateFormatter = DateFormatter()
        dateFormatter.dateStyle = .medium // .short
        dateFormatter.timeStyle = .medium // .short
        /**
         1.    Denmark: da_DK
         2.    Sweden: sv_SE
         3.    Norway: nb_NO
         4.    Finland: fi_FI
         5.    Iceland: is_IS
         **/
        dateFormatter.locale = Locale(identifier: "en_US_POSIX")
        dateFormatter.timeZone = TimeZone(identifier: "America/Los_Angeles") // TimeZone for San Francisco, California
        return dateFormatter.string(from: date)
    }
}

#Preview {
    DateAndTimeInterval()
        .preferredColorScheme(.dark)
}