Billing Class

class MyBillingImpl(private val activity: Activity) :
    PurchasesUpdatedListener, ConsumeResponseListener, BillingProcessor.IBillingHandler {

    var billingClient: BillingClient = BillingClient.newBuilder(activity)
        .enablePendingPurchases()
        .setListener(this)
        .build()
    private var list: MutableList<SkuDetails>? = null

    init {
        //billingClient = BillingClient.newBuilder(activity).setListener(this).build()
        billingClient.startConnection(object : BillingClientStateListener {
            override fun onBillingSetupFinished(p0: BillingResult) {
                if (p0.responseCode == BillingClient.BillingResponseCode.OK) {
                    Log.v("baglanti kuruldu", "kuruldu")
                    Toast.makeText(activity, "baglanti kuruldu", Toast.LENGTH_SHORT).show()
                    val purchases: MutableList<Purchase> =
                        billingClient.queryPurchases(BillingClient.SkuType.INAPP).purchasesList!!
                    Toast.makeText(activity, "${purchases.toString()}", Toast.LENGTH_SHORT).show()
                    handeItemAlreadyPuchase(purchases)
                    Log.v("purchase", purchases.toString())
                }
            }

            override fun onBillingServiceDisconnected() {
                Log.v("disconnect billing", "kuruldu")
            }
        })
    }

    //premium icin
    private fun handeItemAlreadyPuchase(purchases: MutableList<Purchase>) {
        val pyrchasedItem: StringBuilder = StringBuilder("premium")
        purchases.forEach {
            Toast.makeText(activity, "${it.sku}", Toast.LENGTH_SHORT).show()
            if (it.sku == "utku") {
                val consumeParams: ConsumeParams = ConsumeParams.newBuilder()
                    .setPurchaseToken(it.purchaseToken)
                    .build()
                billingClient.consumeAsync(consumeParams, this)
            }
            pyrchasedItem.append("\n ${it.sku}")
        }
    }

    override fun onPurchasesUpdated(p0: BillingResult, purchases: MutableList<Purchase>?) {
        if (p0.responseCode == BillingClient.BillingResponseCode.OK && purchases != null) {
            purchases
        }
    }

    fun skuParams() {
        val params =
            SkuDetailsParams.newBuilder().setSkusList(listOf("test", "test3","birthchart","test2"))
                .setType(BillingClient.SkuType.INAPP).build()
        billingClient.querySkuDetailsAsync(params, object : SkuDetailsResponseListener {
            override fun onSkuDetailsResponse(p0: BillingResult, p1: MutableList<SkuDetails>?) {
                if (p0.responseCode == BillingClient.BillingResponseCode.OK) {
                    Toast.makeText(activity, "baglanti kuruldu SkuParams", Toast.LENGTH_SHORT)
                        .show()
                    loadProduct(p1)
                } else {
                    Toast.makeText(activity, "baglanti kurulamadı SkuParams", Toast.LENGTH_SHORT)
                        .show()
                }
            }

        })
    }

    fun loadProduct(p1: MutableList<SkuDetails>?) {
        list = p1
    }

    fun returnList(): MutableList<SkuDetails>? {
        return list
    }

    fun consumePurchase(purchaseToken: String) {
        val consumeParams = ConsumeParams
            .newBuilder()
            .setPurchaseToken(purchaseToken)
            .build()
    }

    override fun onConsumeResponse(p0: BillingResult, p1: String) {
        // Handle consumption
    }