sms-receiver-class-sms-verirication-api.kt

package com.shishirthedev.smsretriverapi
import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import com.google.android.gms.auth.api.phone.SmsRetriever
import com.google.android.gms.common.api.CommonStatusCodes
import com.google.android.gms.common.api.Status
import java.util.regex.Pattern

class SMSReceiver : BroadcastReceiver() {
    private var otpListener: OTPReceiveListener? = null

    fun setOTPListener(otpListener: OTPReceiveListener?) {
        this.otpListener = otpListener
    }

    override fun onReceive(context: Context, intent: Intent) {
        if (intent.action == SmsRetriever.SMS_RETRIEVED_ACTION) {
            val extras = intent.extras
            val status = extras!![SmsRetriever.EXTRA_STATUS] as Status?
            when (status!!.statusCode) {
                CommonStatusCodes.SUCCESS -> {
                    val sms = extras[SmsRetriever.EXTRA_SMS_MESSAGE] as String?
                    sms?.let {
                        // val p = Pattern.compile("[0-9]+") check a pattern with only digit
                        val p = Pattern.compile("\\d+")
                        val m = p.matcher(it)
                        if (m.find()) {
                            val otp = m.group()
                            if (otpListener != null) {
                                otpListener!!.onOTPReceived(otp)
                            }
                        }
                    }
                }
            }
        }
    }

    interface OTPReceiveListener {
        fun onOTPReceived(otp: String?)
    }
}