package com.example.sergey.notify

import android.app.Notification
import android.app.NotificationManager
import android.app.PendingIntent
import android.content.Intent
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.support.v4.app.NotificationCompat
import android.view.View
import android.app.NotificationChannel
import android.content.Context
import android.graphics.Color
import android.provider.Settings
import android.util.Log


class MainActivity : AppCompatActivity() {

    var notificationID = 1
    var channelId : String = "" // set in createChannel, only used in API >= 26

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        createChannel()
    }

    fun onClick(view: View) {
        displayNotification()
    }

    private fun displayNotification()
    {
        // Intent to launch another activity if the user clicks
        //   this notification. To be wrapped in a PendingIntent, because
        //   it will be sent from whatever activity manages notifications;
        //   this activity may not even be running.

        // ---So I had a weird bug that took me hours to understand.
        // These do NOT work, because they produce an _implicit_ intent with the string
        //   argument taken to be the name of the action! E.g.,
        //      Intent { act=class com.example.sergey.notify.NotificationActivity }
        // This intent simply gets lost, the intended activity never gets called.
        //
        // val i : Intent = Intent( NotificationActivity::class.toString() )
        // val i : Intent = Intent( NotificationActivity::class.java.toString() )
        //
        // This was a sneaky typo, because it made this intent look explicit, although it wasn't!
        // ---end bug

        // This creates an explicit intent and works:
        //   Note that we need to pass a Java class, not a Kotlin class, to match the API's signature,
        //    which requires a Java class
        val i : Intent = Intent(this, NotificationActivity::class.java )

        // This works too, and produces Intent { cmp=com.example.sergey.notify/.NotificationActivity }
        //val i : Intent = Intent()
        //i.setClass(this, NotificationActivity::class.java)

        // If we wanted to send an implicit intent, we'd need to match the intent-filter
        //   of NotificationActivity in the Manifest. This would result in many apps
        //   being offered up, because this implicit intent matches almost any app's filters.
        //val i = Intent()
        //i.setAction(Intent.ACTION_MAIN)
        //i.addCategory(Intent.CATEGORY_DEFAULT)

        Log.d("INTENT", i.toString())

        i.putExtra("notificationID", notificationID)

        val pendingIntent : PendingIntent =
                PendingIntent.getActivity(this,
                        0, // on some SDK versions, the code should NOT be 0, or else it won't work
                        i,
                        0) // flags are important, see https://developer.android.com/reference/android/app/PendingIntent.html

        val nm : NotificationManager = getSystemService(NOTIFICATION_SERVICE) as NotificationManager

        // Using the approved constructor for 26, which mandates that Channels be used;
        //   the older channel-less constructor is deprecated.
        val notiBuilder = if ( android.os.Build.VERSION.SDK_INT >= 26 )
            Notification.Builder(this, channelId) else  Notification.Builder(this)

        notiBuilder.setSmallIcon(R.mipmap.ic_launcher)
                    .setContentTitle("Meeting Reminder")
                    .setContentText("Reminder: Meeting starts in 5 minutes")
                    .setContentIntent(pendingIntent)
                    // .setAutoCancel(true)  --if not set, the notification needs to be
                    //   cancelled explicitly, or else it sticks in the notification bar.
                    //   See cancellation logic in NotificationActivity.

        val n = notiBuilder.build() // API >= 16, otherwise use NotificationCompat

        // Sound & vibration:
        //  This is deprecated, but works on API < 26 to vibrate & chime.
        //   For API >= 26, these settings belong on the Channel, not on the Notification or Builder;
        //    see createChannel() below.
        n.defaults = n.defaults or Notification.DEFAULT_VIBRATE
        n.defaults = n.defaults or Notification.DEFAULT_SOUND

        // OR these, also deprecated:
        //notiBuilder.setVibrate(longArrayOf(100, 200, 300, 400, 500, 400, 300, 200, 400))
        //notiBuilder.setSound(Settings.System.DEFAULT_NOTIFICATION_URI);

        nm.notify(notificationID, n)
    }

    // https://stackoverflow.com/questions/45668079/notificationchannel-issue-in-android-o
    // http://www.vogella.com/tutorials/AndroidNotifications/article.html
    private fun createChannel() {

        if (android.os.Build.VERSION.SDK_INT >= 26) {

            val mNotificationManager = getSystemService(Context.NOTIFICATION_SERVICE) as NotificationManager

            // The id of the channel.
            channelId = "my_channel_01"

            // The user-visible name of the channel. Look for it in Android's configs!
            val name = getString(R.string.channel_name)
            // The user-visible description of the channel.
            val description = getString(R.string.channel_description)

            val importance = NotificationManager.IMPORTANCE_LOW
            val mChannel = NotificationChannel(channelId, name, importance)

            // Configure the notification channel.
            mChannel.description = description

            mChannel.enableLights(true)

            // Sets the notification light color for notifications posted to this
            // channel, if the device supports this feature.
            mChannel.lightColor = Color.RED

            // Sets vibration if the device supports it
            mChannel.enableVibration(true)
            mChannel.vibrationPattern = longArrayOf(100, 200, 300, 400, 500, 400, 300, 200, 400)

            mNotificationManager.createNotificationChannel(mChannel)
        }
    }
}