package blackwell.testapp

import android.Manifest
import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.content.Intent
import android.telephony.SmsManager
import android.content.IntentFilter
import android.app.Activity
import android.app.PendingIntent.getBroadcast
import android.content.BroadcastReceiver
import android.content.Context
import android.content.pm.PackageManager
import android.support.v4.app.ActivityCompat
import android.support.v4.content.ContextCompat.checkSelfPermission
import android.text.method.ScrollingMovementMethod
import android.view.KeyEvent
import android.view.View
import java.text.SimpleDateFormat
import java.util.*
import android.view.inputmethod.EditorInfo
import android.widget.*
import android.widget.TextView.OnEditorActionListener




var activityReference: Activity? = null

class MainActivity : AppCompatActivity() {

    val PERMISSION_ALL = 1
    val MAX_SMS_LENGTH = 160

    lateinit var textMessage: EditText
    lateinit var phoneNumber: EditText
    lateinit var messageList: TextView
    lateinit var loadCircle: ProgressBar

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

        checkAndRequestPermissions()

        activityReference = this

        messageList = findViewById(R.id.msgList) as TextView
        messageList.movementMethod = ScrollingMovementMethod()

        phoneNumber = findViewById(R.id.phone_no) as EditText
        textMessage = findViewById(R.id.msg) as EditText

        loadCircle = findViewById(R.id.lBar) as ProgressBar
        loadCircle.setVisibility(View.INVISIBLE);

        textMessage.setOnEditorActionListener() { v, actionId, event ->
            if(actionId == EditorInfo.IME_ACTION_SEND){
                sendSMSRequest()
                true
            } else false
        }

        val sendButton = findViewById(R.id.send_btn).setOnClickListener({
            sendSMSRequest()
        })
    }

    private fun sendSMS(phoneNumber: String, message: String) {
        val SENT = "SMS_SENT"
        val DELIVERED = "SMS_DELIVERED"

        val sentPI = getBroadcast(this, 0,
                Intent(SENT), 0)

        val deliveredPI = getBroadcast(this, 0,
                Intent(DELIVERED), 0)

        val timeStamp = SimpleDateFormat("h:mm a").format(Calendar.getInstance().getTime())

        registerReceiver(object : BroadcastReceiver() {
            override fun onReceive(arg0: Context, arg1: Intent) {
                when (resultCode) {
                    Activity.RESULT_OK
                        -> Toast.makeText(baseContext, "SMS Delivered",
                            Toast.LENGTH_SHORT).show()
                    else
                        -> { Toast.makeText(baseContext, "SMS Delivery Error",
                                Toast.LENGTH_SHORT).show()
                             messageList.append("[Message Not Sent]\n")
                    }

                }
                textMessage.text.clear()
                loadCircle.setVisibility(View.INVISIBLE)
            }
        }, IntentFilter(DELIVERED))

        val sms = SmsManager.getDefault()

        if(message.length >= MAX_SMS_LENGTH) {
            val messageList = sms.divideMessage(message)
            sms.sendMultipartTextMessage(phoneNumber, null, messageList, null, null)
        } else {
            sms.sendTextMessage(phoneNumber, null, message, sentPI, deliveredPI)
        }

        messageList.append("[You -> $phoneNumber @ $timeStamp] $message\n")
        loadCircle.setVisibility(View.VISIBLE)
        Toast.makeText(baseContext, "Sending...",
                Toast.LENGTH_SHORT).show()
    }

    private fun sendSMSRequest() {
        if (checkAndRequestPermissions()) {

            val phoneNo = phoneNumber.text.toString()
            val msg = textMessage.text.toString()

            if (!phoneNo.isBlank()) {
                if (!msg.isBlank()) {
                    sendSMS(phoneNo, msg)
                } else {
                    textMessage.error = "Cannot leave message blank"
                }
            } else {
                phoneNumber.error = "Enter A Phone #"
            }

        } else Toast.makeText(baseContext, "SMS Permissions Disabled",
                Toast.LENGTH_SHORT).show()
    }

    private fun checkAndRequestPermissions(): Boolean {
        val listPermissionsNeeded = ArrayList<String>()

        if (checkSelfPermission(this,
                Manifest.permission.SEND_SMS) != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.SEND_SMS)
        }
        if (checkSelfPermission(this,
                Manifest.permission.RECEIVE_SMS) != PackageManager.PERMISSION_GRANTED) {
                    listPermissionsNeeded.add(Manifest.permission.RECEIVE_SMS)
        }

        if (!listPermissionsNeeded.isEmpty()) {
            ActivityCompat.requestPermissions(this, listPermissionsNeeded.toTypedArray(),
                    PERMISSION_ALL)
            return false
        }

        return true
    }

}

package blackwell.testapp

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.os.Build
import android.provider.Telephony
import android.support.annotation.RequiresApi
import android.widget.TextView
import android.widget.Toast
import java.text.SimpleDateFormat
import java.util.*

class SMSReceiver : BroadcastReceiver() {

    @RequiresApi(Build.VERSION_CODES.KITKAT)
    override fun onReceive(context: Context, intent: Intent) {
        val msgs = Telephony.Sms.Intents.getMessagesFromIntent(intent)
        val sms = msgs[0]

        val message = sms.messageBody
        val number = sms.originatingAddress

        val msgList = activityReference!!.findViewById(R.id.msgList) as TextView
        val timeStamp = SimpleDateFormat("h:mm a").format(Calendar.getInstance().getTime())

        msgList.append("[$number @ $timeStamp] $message\n")
    }
}


<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="blackwell.testapp.MainActivity">

    <Button
        android:id="@+id/send_btn"
        style="@android:style/Widget.Holo.Light.Button"
        android:layout_width="146dp"
        android:layout_height="48dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="18dp"
        android:background="@android:drawable/btn_default_small"
        android:text="SEND"
        android:textAppearance="@style/TextAppearance.AppCompat.Body1"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/msgList" />

    <EditText
        android:id="@+id/phone_no"
        android:layout_width="259dp"
        android:layout_height="42dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:background="@android:drawable/editbox_background"
        android:hint="Phone Number"
        android:inputType="phone"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <EditText
        android:id="@+id/msg"
        android:layout_width="327dp"
        android:layout_height="142dp"
        android:layout_marginLeft="0dp"
        android:layout_marginTop="18dp"
        android:background="@android:drawable/editbox_background"
        android:gravity="top|left"
        android:hint="Message"
        android:imeOptions="actionSend"
        android:inputType="textMultiLine"
        app:layout_constraintLeft_toLeftOf="@+id/phone_no"
        app:layout_constraintTop_toBottomOf="@+id/phone_no" />

    <TextView
        android:id="@+id/msgList"
        android:layout_width="327dp"
        android:layout_height="221dp"
        android:layout_marginTop="18dp"
        android:background="@android:drawable/editbox_background"
        android:cacheColorHint="@android:color/transparent"
        android:clickable="true"
        android:fontFamily="sans-serif-smallcaps"
        android:gravity="top|left"
        android:paddingLeft="10dp"
        android:scrollbars="vertical"
        android:textAppearance="@style/TextAppearance.AppCompat"
        app:layout_constraintLeft_toLeftOf="@+id/phone_no"
        app:layout_constraintTop_toBottomOf="@+id/msg" />

    <ProgressBar
        android:id="@+id/lBar"
        style="@android:style/Widget.Holo.Light.ProgressBar.Inverse"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="12dp"
        android:layout_marginLeft="11dp"
        app:layout_constraintBottom_toTopOf="@+id/msg"
        app:layout_constraintLeft_toRightOf="@+id/phone_no" />

</android.support.constraint.ConstraintLayout>

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="blackwell.testapp">

    <uses-permission android:name="android.permission.SEND_SMS" />
    <uses-permission android:name="android.permission.RECEIVE_SMS" />

    <application

        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="Kotlin SMS Demo"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <receiver android:name="blackwell.testapp.SMSReceiver" >
            <intent-filter>
                <action android:name="android.provider.Telephony.SMS_RECEIVED" />
            </intent-filter>
        </receiver>
    </application>


</manifest>