feat: add support to metadata (#20)

* feat: add support to metadata into the sdk init payment method

* feat: serialize metadata object

* chore: fix tests

---------

Co-authored-by: OlegSyng <olegsingaevskii9@gmail.com>

Author: Thrashattack

flizpaysdk/src/androidTest/kotlin/flizpay2/flizpaysdk/FlizpaySDKTest.kt

@@ -30,6 +30,7 @@ class FlizpaySDKTest {
         mockkConstructor(TransactionService::class)
         every {
             anyConstructed<TransactionService>().fetchTransactionInfo(
+                any(),
                 any(),
                 any(),
                 captureLambda()
@@ -62,6 +63,7 @@ class FlizpaySDKTest {
         // Override default success mock with failure
         every {
             anyConstructed<TransactionService>().fetchTransactionInfo(
+                any(),
                 any(),
                 any(),
                 captureLambda()

flizpaysdk/src/main/kotlin/flizpay2/flizpaysdk/FlizpaySDK.kt

@@ -15,17 +15,19 @@ object FlizpaySDK {
      * @param context The Context from which to launch the payment WebView.
      * @param token The JWT token fetched by the host app.
      * @param amount The transaction amount.
+     * @param metadata The metadata object.
      * @param onFailure Optional callback to handle errors (e.g., show alerts).
      */
     fun initiatePayment(
         context: Context,
         token: String,
         amount: String,
+        metadata: Map<String, Any?>? = null,
         onFailure: ((Throwable) -> Unit)? = null,
     ) {
         val transactionService = TransactionService()
 
-        transactionService.fetchTransactionInfo(token, amount) { result ->
+        transactionService.fetchTransactionInfo(token, amount, metadata) { result ->
             if(result.isSuccess) {
                 val redirectUrl = result.getOrNull() ?: Constants.BASE_URL
 

flizpaysdk/src/main/kotlin/flizpay2/flizpaysdk/lib/TransactionService.kt

@@ -7,24 +7,32 @@ import flizpay2.flizpaysdk.Constants
 import okhttp3.MediaType.Companion.toMediaTypeOrNull
 import okhttp3.RequestBody.Companion.toRequestBody
 import org.json.JSONObject
+import org.json.JSONArray
 
 
 class TransactionService {
     private val client = OkHttpClient()
 
+    private fun Map<String, Any?>.toJsonObject(): JSONObject =
+        JSONObject().apply {
+            forEach { (k, v) -> put(k, JSONObject.wrap(v)) }
+        }
+
     /**
      * Calls the /transactions endpoint using the provided token and amount.
      */
     fun fetchTransactionInfo(
         token: String,
         amount: String,
+        metadata: Map<String, Any?>? = null,
         completion: (Result<String>) -> Unit
     ) {
         val url = "${Constants.API_URL}/transactions"
         val requestBody = JSONObject()
             .put("amount", amount)
             .put("currency", "EUR")
             .put("source", "sdk_integration")
+            .put("metadata", metadata?.toJsonObject() ?: JSONObject())
             .toString()
             .toRequestBody("application/json; charset=utf-8".toMediaTypeOrNull())