using System.Text;
using System.Net.Http.Headers;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.Functions.Worker;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;

namespace My.Function
{
    public class GetXsollaPaymentToken
    {
        private readonly ILogger<GetXsollaPaymentToken> _logger;

        private const int PROJECT_ID = ""; // Your Xsolla project ID
        private const string API_KEY = ""; // Your Xsolla API key

        public GetXsollaPaymentToken(ILogger<GetXsollaPaymentToken> logger)
        {
            _logger = logger;
        }

        [Function("GetXsollaPaymentToken")]
        public async Task<IActionResult> Run([HttpTrigger(AuthorizationLevel.Anonymous, "get", "post")] HttpRequest req)
        {
            _logger.LogInformation("GetXsollaPaymentToken function processed a request.");

            // Reading the request body
            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            _logger.LogInformation("Request body: " + requestBody);

            // Deserializing request body JSON
            dynamic data = JsonConvert.DeserializeObject(requestBody);

            // Extracting necessary data from JSON
            string uid = data.FunctionArgument.uid;
            string sku = data.FunctionArgument.sku;
            string returnUrl = data.FunctionArgument.returnUrl;

            // Creating payload for Xsolla API
            var payload = new
            {
                user = new
                {
                    id = new { value = uid },
                    country = new { value = "US", allow_modify = false }
                },
                purchase = new
                {
                    items = new[]
                    {
                        new { sku = sku, quantity = 1 }
                    }
                },
                sandbox = true,
                settings = new
                {
                    language = "en",
                    currency = "USD",
                    return_url = returnUrl,
                    ui = new { theme = "63295aab2e47fab76f7708e3" }
                }
            };

            // Constructing Xsolla API URL
            string url = $"https://store.xsolla.com/api/v3/project/{PROJECT_ID}/admin/payment/token";

            // Sending request to Xsolla API
            using (HttpClient client = new HttpClient())
            {
                // Adding authorization header
                string headerValue = Convert.ToBase64String(Encoding.UTF8.GetBytes($"{PROJECT_ID}:{API_KEY}"));
                client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Basic", headerValue);

                // Serializing payload to JSON
                var jsonPayload = JsonConvert.SerializeObject(payload);
                var content = new StringContent(jsonPayload, Encoding.UTF8, "application/json");

                // Making POST request to Xsolla API
                var xsollaRes = await client.PostAsync(url, content);

                // Checking response from Xsolla API
                if (xsollaRes.IsSuccessStatusCode)
                {
                    // Reading successful response content
                    string responseContent = await xsollaRes.Content.ReadAsStringAsync();
                    return new OkObjectResult(responseContent);
                }
                else
                {
                    // Returning status code in case of failure
                    return new StatusCodeResult((int)xsollaRes.StatusCode);
                }
            }
        }
    }
}

{

 "FunctionArgument": {

   "uid": "1D384D9EF12EAB8B",

   "sku": "booster_max_1",

   "returnUrl": "https://login.xsolla.com/api/blank"

 }

}

{"token":"xsnpCF8tS4ox7quoibgTgPFVFxG9gTvS_lc_en_bg_2C2640_tb_6E7BF7","order_id":90288613}

using System;
using PlayFab;
using PlayFab.ClientModels;
using PlayFab.CloudScriptModels;
using UnityEngine;
using Xsolla.Core;

public class XsollaPlayfabSample : MonoBehaviour
{
    private void Start()
    {
        // Logging in anonymously
        LoginAnonymous(
            // Callback function invoked after successful login
            userId => {
                // Requesting Xsolla payment token
                GetXsollaPaymentToken(
                    userId, // PlayFab user ID received after login
                    "booster_max_1", // SKU of the product
                    orderData => {
                        // Creating Xsolla token and opening purchase UI
                        XsollaToken.Create(orderData.token);
                        XsollaWebBrowser.OpenPurchaseUI(orderData.token);

                        // Adding order for tracking
                        OrderTrackingService.AddOrderForTracking(
                            orderData.order_id,
                            true,
                            () => Debug.Log("Payment completed"),
                            onError => Debug.LogError(onError.errorMessage));
                    });
            });
    }

    private static void LoginAnonymous(Action<string> onSuccess)
    {
        // Logging in with custom ID
        PlayFabClientAPI.LoginWithCustomID(
            new LoginWithCustomIDRequest {
                CustomId = SystemInfo.deviceUniqueIdentifier, // Unique ID generated based on the device
                CreateAccount = true
            },
            result => {
                // Logging the result
                Debug.Log("Logged with playfab id: " + result.PlayFabId);

                // Invoking onSuccess callback with PlayFab ID
                onSuccess?.Invoke(result.PlayFabId);
            },
            error => { Debug.LogError(error.GenerateErrorReport()); }); // Handling login error
    }

    private static void GetXsollaPaymentToken(string userId, string sku, Action<OrderData> onSuccess)
    {
        // Creating request data for Xsolla payment token
        var tokenRequestData = new PaymentTokenRequestData {
            uid = userId, // User ID
            sku = sku, // Product SKU
            returnUrl = $"app://xpayment.{Application.identifier}" // Return URL
        };

        // Executing a function in the PlayFab cloud to get payment token
        PlayFabCloudScriptAPI.ExecuteFunction(
            new ExecuteFunctionRequest {
                FunctionName = "GetXsollaPaymentToken", // Name of Azure function
                FunctionParameter = tokenRequestData, // Data passed to the function
                GeneratePlayStreamEvent = false // Setting true if call should show up in PlayStream
            },
            result => {
                // Logging the result
                Debug.Log($"GetXsollaPaymentToken result: {result.FunctionResult}");

                // Parsing JSON result to OrderData object
                OrderData orderData = JsonUtility.FromJson<OrderData>(result.FunctionResult.ToString());

                // Invoking onSuccess callback with order data
                onSuccess?.Invoke(orderData);
            },
            error => Debug.LogError($"Error: {error.GenerateErrorReport()}")); // Handling error
    }

    // Class for payment token request data
    public class PaymentTokenRequestData
    {
        public string uid; // User ID
        public string sku; // Product SKU
        public string returnUrl; // Return URL
    }
}