TimerViewViewModel.swift

//
//  TimerViewViewModel.swift
//  group_app
//
//  Created by Emily Markova on 8/2/23.
//

import SwiftUI
import Foundation

class TimerViewViewModel: NSObject, ObservableObject, UNUserNotificationCenterDelegate {
    //timer properties
    @Published var progress: CGFloat = 0.0
    @Published var timerStringValue: String = "00:00"
    @Published var isStarted: Bool = false
    @Published var addNewTimer: Bool = false
    
    @Published var hour: Int = 0
    @Published var minutes: Int = 0
    @Published var seconds: Int = 0
    
    //total seconds
    @Published var totalSeconds: Int = 0
    @Published var staticTotalSeconds: Int = 0
    
    //post timer properties
    @Published var isFinished: Bool = false
    
    //since its NSobject
    override init(){
        super.init()
        self.authorizationNotification()
    }
    //request notification access
    func authorizationNotification(){
        UNUserNotificationCenter.current().requestAuthorization(options: [.sound,.alert,.badge]){
            _, _ in
            
        }
        //show in app notification
        UNUserNotificationCenter.current().delegate = self
    }
    func userNotificationCenter(_ center: UNUserNotificationCenter, willPresent notification: UNNotification, withCompletionHandler completionHandler: @escaping (UNNotificationPresentationOptions) -> Void) {
        completionHandler([.sound,.banner])
    }
    func startTimer(){
        withAnimation(.easeInOut(duration: 0.25)){isStarted = true}
        timerStringValue = "\(hour == 0 ? "" : "\(hour):")\(minutes >= 10 ? "\(minutes)":"0\(minutes)"):\(seconds >= 10 ? "\(seconds)":"0\(seconds)")"
        //calculating total seconds for timer animation
        totalSeconds = (hour*3600) + (minutes * 60)  + seconds
        staticTotalSeconds = totalSeconds
    }
    
    func stopTimer(){
        withAnimation{
            isStarted = false
            hour = 0
            minutes = 0
            seconds = 0
            progress = 1
        }
        totalSeconds = 0
        staticTotalSeconds = 0
        timerStringValue = "00:00"
    }

    func updateTimer(){
        totalSeconds -= 1
        progress = CGFloat(totalSeconds) / CGFloat(staticTotalSeconds)
        progress = (progress < 0 ? 0 : progress)
        hour = totalSeconds / 3600
        minutes = (totalSeconds / 60) % 60
        seconds = (totalSeconds % 60)
        timerStringValue = "\(hour == 0 ? "" : "\(hour):")\(minutes >= 10 ? "\(minutes)" : "0\(minutes)"):\(seconds >= 10 ? "\(seconds)" : "0\(seconds)")"
        if hour == 0 && seconds == 0 && minutes == 0 {
            isStarted = false
            isFinished = true
        }
    }
    
    func addNotification(){
        let content = UNMutableNotificationContent()
        content.title = "Pomodoro Timer"
        content.subtitle = "Woohoo! You finished it!!"
        content.sound = UNNotificationSound.default
        
        let request = UNNotificationRequest(identifier: UUID().uuidString, content: content, trigger: UNTimeIntervalNotificationTrigger(timeInterval: TimeInterval(staticTotalSeconds), repeats: false))
        
        UNUserNotificationCenter.current().add(request)
    }
}