package com.pantos27.hamburgersforbreakfast

import android.app.Activity
import android.os.Bundle
/**
 *   A utility class to keep track if your app is in the foreground or background
 *   without any special permission or API restrictions
 *   Note that if your app has any activities that run on a different
 *   process (through the process attribute in your manifest) this utility might not be persistent
 *
 */
object ApplicationWatcher : android.app.Application.ActivityLifecycleCallbacks {
    private var started : Int? = null
    private var resumed : Int? = null

    override fun onActivityCreated(activity: Activity, savedInstanceState: Bundle?) {
    }

    override fun onActivityStarted(activity: Activity) {
        started = activity.hashCode()
    }

    override fun onActivityResumed(activity: Activity) {
        resumed = activity.hashCode()
    }

    override fun onActivityPaused(activity: Activity) {
        if (resumed==activity.hashCode()){
            resumed=null
        }
    }

    override fun onActivityStopped(activity: Activity) {
        if (started==activity.hashCode()){
            started=null
        }
    }

    override fun onActivitySaveInstanceState(activity: Activity, outState: Bundle?) {
    }

    override fun onActivityDestroyed(activity: Activity) {
    }

    public fun isAppStarted() = started!=null
    public fun isAppResumed() = resumed!=null
}