Author: Nishant Rana

(function () {
   'use strict';

   // ---------------------------------------------------------------------
   // Configuration
   // ---------------------------------------------------------------------

   var TURNSTILE_SITE_KEY = 'SITEKEY';
   var TURNSTILE_SCRIPT_URL = 'https://challenges.cloudflare.com/turnstile/v0/api.js?render=explicit';

   var FORM_SELECTOR = 'form.marketingForm';
   var SUBMIT_EVENT = 'd365mkt-formsubmit';
   var AFTER_LOAD_EVENT = 'd365mkt-afterformload';

   // Refresh tokens after four minutes.
   // Cloudflare tokens expire after approximately five minutes.
   var TOKEN_STALE_MS = 4 * 60 * 1000;

   // Hidden unmapped field added through the Customer Insights – Journeys
   // form designer. The generated Turnstile token is copied into this field
   // before the form is submitted.
   var TOKEN_FIELD_NAME = 'cf_token';

   var scriptPromise = null;

   // Stores the Turnstile widget state for each form instance without
   // preventing the form from being garbage collected.
   var widgetState = new WeakMap();

   function loadTurnstileScript() {
      if (scriptPromise) return scriptPromise;

      scriptPromise = new Promise(function (resolve, reject) {

         if (window.turnstile) {
            resolve();
            return;
         }

         var script = document.createElement('script');
         script.src = TURNSTILE_SCRIPT_URL;
         script.async = true;
         script.defer = true;

         script.onload = function () {
            resolve();
         };

         script.onerror = function () {
            scriptPromise = null;
            reject(new Error('[CIJ Turnstile] Failed to load Turnstile script.'));
         };

         document.head.appendChild(script);
      });

      return scriptPromise;
   }

   function renderWidget(formEl) {

      if (widgetState.has(formEl)) {
         return widgetState.get(formEl);
      }

      // The widget container must exist inside the form so that Cloudflare's
      // internally managed hidden field is created within the form element.
      var container = document.createElement('div');
      container.style.display = 'none';
      formEl.appendChild(container);

      var entry = {
         widgetId: null,
         token: null,
         tokenAt: 0,
         resolve: null,
         reject: null
      };

      entry.widgetId = window.turnstile.render(container, {
         sitekey: TURNSTILE_SITE_KEY,

         // Execute Turnstile only when the user submits the form.
         execution: 'execute',

         // Keep the widget completely invisible.
         appearance: 'execute',

         callback: function (token) {
            entry.token = token;
            entry.tokenAt = Date.now();

            if (entry.resolve) {
               entry.resolve(token);
               entry.resolve = null;
               entry.reject = null;
            }
         },

         'error-callback': function (code) {
            console.error('[CIJ Turnstile] Widget error:', code);

            if (entry.reject) {
               entry.reject(new Error('Turnstile error: ' + code));
               entry.resolve = null;
               entry.reject = null;
            }
         },

         'expired-callback': function () {
            entry.token = null;
            entry.tokenAt = 0;
         }
      });

      widgetState.set(formEl, entry);

      return entry;
   }

   function getToken(formEl) {

      return loadTurnstileScript().then(function () {

         var entry = renderWidget(formEl);

         var isFresh =
            entry.token &&
            entry.tokenAt &&
            (Date.now() - entry.tokenAt) < TOKEN_STALE_MS;

         if (isFresh) {
            return Promise.resolve(entry.token);
         }

         return new Promise(function (resolve, reject) {

            entry.resolve = resolve;
            entry.reject = reject;

            window.turnstile.reset(entry.widgetId);
            window.turnstile.execute(entry.widgetId);
         });
      });
   }

   function getFormFromEvent(evt) {

      var target = evt && evt.target;

      if (!target) {
         return null;
      }

      if (target.tagName === 'FORM') {
         return target;
      }

      if (target.querySelector) {
         var nested = target.querySelector('form');

         if (nested) {
            return nested;
         }
      }

      return target.closest ? target.closest('form') : null;
   }

   function setTokenField(formEl, token) {

      var input = formEl.querySelector('[name="' + TOKEN_FIELD_NAME + '"]');

      if (!input) {
         console.error(
            '[CIJ Turnstile] Could not find field "' +
            TOKEN_FIELD_NAME +
            '". Add an unmapped field with this name in the Customer Insights – Journeys form designer.'
         );
         return false;
      }

      input.value = token;

      return true;
   }

   function getSubmitButton(formEl) {
      return formEl.querySelector('button[type="submit"], input[type="submit"]');
   }

   function showWaiting(formEl) {

      var btn = getSubmitButton(formEl);

      if (btn) {
         btn.disabled = true;
         btn.style.opacity = '0.6';
         btn.style.cursor = 'wait';
      }
   }

   function hideWaiting(formEl) {

      var btn = getSubmitButton(formEl);

      if (btn) {
         btn.disabled = false;
         btn.style.opacity = '';
         btn.style.cursor = '';
      }
   }

   function onFormSubmit(evt) {

      var formEl = getFormFromEvent(evt);

      if (!formEl || formEl._cijResubmitting) {
         return;
      }

      // Allow the re-submitted request to continue once a valid token
      // has already been written to the hidden field.
      if (formEl._cijTurnstileReady) {
         formEl._cijTurnstileReady = false;
         return;
      }

      evt.preventDefault();

      if (evt.stopImmediatePropagation) {
         evt.stopImmediatePropagation();
      }

      showWaiting(formEl);

      getToken(formEl)

         .then(function (token) {

            setTokenField(formEl, token);

            formEl._cijTurnstileReady = true;
            formEl._cijResubmitting = true;

            // Re-submit the form after a valid Turnstile token has been obtained.
            if (formEl.requestSubmit) {
               formEl.requestSubmit();
            } else {
               formEl.submit();
            }

            setTimeout(function () {
               formEl._cijResubmitting = false;
            }, 0);
         })

         .catch(function (err) {

            // Do not allow the form to continue without a valid token.
            // The server-side plugin will also reject missing or invalid tokens.
            console.error('[CIJ Turnstile] Could not obtain token. Submission blocked.', err);

            hideWaiting(formEl);
         });
   }

   function wireForm(formEl) {

      if (formEl._cijTurnstileWired) {
         return;
      }

      formEl._cijTurnstileWired = true;

      loadTurnstileScript().then(function () {
         renderWidget(formEl);
      });
   }

   function findAndWireForms(root) {
      (root || document)
      .querySelectorAll(FORM_SELECTOR)
         .forEach(wireForm);
   }

   document.addEventListener(AFTER_LOAD_EVENT, function (evt) {

      var formEl = getFormFromEvent(evt);

      if (formEl) {
         wireForm(formEl);
      } else {
         findAndWireForms(document);
      }
   });

   document.addEventListener(SUBMIT_EVENT, onFormSubmit);

   // Handle forms that were rendered before this script was loaded.
   if (document.readyState !== 'loading') {
      findAndWireForms(document);
   } else {
      document.addEventListener('DOMContentLoaded', function () {
         findAndWireForms(document);
      });
   }

})();

using Microsoft.Xrm.Sdk;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Net.Http;
using System.Runtime.Serialization;
using System.Runtime.Serialization.Json;
using System.Text;

namespace SamplePlugin
{
    /// <summary>
    /// Validates Customer Insights - Journeys form submissions by verifying
    /// the Cloudflare Turnstile token before allowing record creation.
    /// Registered on:
    /// Message: msdynmkt_validateformsubmission
    /// Stage: PostOperation
    /// Mode: Synchronous   
    /// </summary>
    public class ValidateTurnstilePlugin : IPlugin
    {
        private const string TurnstileVerifyUrl =
            "https://challenges.cloudflare.com/turnstile/v0/siteverify";

        private const string TokenFieldName = "tokenfieldname";

        private const string FailureMessage =
            "Captcha validation failed. Please refresh the page and try again.";

        private const string SecretKeyEnvironmentVariableSchemaName =
            "environmentvariablename";

        public void Execute(IServiceProvider serviceProvider)
        {
            var tracing =
                (ITracingService)serviceProvider.GetService(typeof(ITracingService));

            var context =
                (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));

            if (!context.InputParameters.Contains("msdynmkt_formsubmissionrequest"))
            {
                tracing.Trace(
                    "[Turnstile] Input parameter 'msdynmkt_formsubmissionrequest' not found.");
                return;
            }

            var serviceFactory =
                (IOrganizationServiceFactory)serviceProvider.GetService(
                    typeof(IOrganizationServiceFactory));

            var service = serviceFactory.CreateOrganizationService(null);

            string secretKey = GetEnvironmentVariableValue(
                service,
                tracing,
                SecretKeyEnvironmentVariableSchemaName);

            if (string.IsNullOrWhiteSpace(secretKey))
            {
                throw new InvalidPluginExecutionException(
                    $"Environment Variable '{SecretKeyEnvironmentVariableSchemaName}' does not contain a value.");
            }

            var request = Deserialize<FormSubmissionRequest>(
                (string)context.InputParameters["msdynmkt_formsubmissionrequest"]);

            var fields = request?.Fields ?? new List<FormField>();

            string token = fields
                .FirstOrDefault(f => f.Key == TokenFieldName)?
                .Value;

            if (string.IsNullOrWhiteSpace(token))
            {
                tracing.Trace(
                    $"[Turnstile] Token field '{TokenFieldName}' is empty.");

                SetValidationResponse(
                    context,
                    false,
                    FailureMessage);

                return;
            }

            bool isValid = VerifyTurnstile(
                secretKey,
                token,
                tracing);

            tracing.Trace(
                $"[Turnstile] Validation Result = {isValid}");

            SetValidationResponse(
                context,
                isValid,
                isValid ? null : FailureMessage);
        }

        private bool VerifyTurnstile(
            string secretKey,
            string token,
            ITracingService tracing)
        {
            var formContent =
                new FormUrlEncodedContent(
                    new Dictionary<string, string>
                    {
                        { "secret", secretKey },
                        { "response", token }
                    });

            using (var httpClient = new HttpClient())
            {
                string body;

                try
                {
                    var response =
                        httpClient.PostAsync(
                            TurnstileVerifyUrl,
                            formContent).Result;

                    body =
                        response.Content.ReadAsStringAsync().Result;

                    if (!response.IsSuccessStatusCode)
                    {
                        tracing.Trace(
                            $"[Turnstile] siteverify returned HTTP {(int)response.StatusCode}. " +
                            $"Body: {(string.IsNullOrWhiteSpace(body) ? "<empty>" : body)}");

                        return false;
                    }
                }
                catch (Exception ex)
                {
                    tracing.Trace(
                        "[Turnstile] Exception calling siteverify: " +
                        ex);

                    return false;
                }

                var verifyResponse =
                    Deserialize<TurnstileVerifyResponse>(body);

                tracing.Trace(
                    $"[Turnstile] success={verifyResponse.Success}, " +
                    $"hostname={verifyResponse.Hostname}, " +
                    $"errors={(verifyResponse.ErrorCodes == null ? "none" : string.Join(", ", verifyResponse.ErrorCodes))}");

                return verifyResponse.Success;
            }
        }

        private void SetValidationResponse(
    IPluginExecutionContext context,
    bool isValid,
    string error)
        {
            var response = new ValidateFormSubmissionResponse
            {
                IsValid = isValid,
                ValidationOnlyFields = new List<string>
                {
                    TokenFieldName
                },
                Error = error
            };

            context.OutputParameters["msdynmkt_validationresponse"] =
                Serialize(response);
        }

        private string GetEnvironmentVariableValue(
            IOrganizationService service,
            ITracingService tracing,
            string schemaName)
        {
            tracing.Trace(
                "[Turnstile] Retrieving Environment Variable: {0}",
                schemaName);

            var request = new OrganizationRequest(
                "RetrieveEnvironmentVariableValue")
            {
                Parameters =
                {
                    ["DefinitionSchemaName"] = schemaName
                }
            };

            var response = service.Execute(request);

            if (response.Results.Count == 0)
            {
                tracing.Trace(
                    "[Turnstile] Environment Variable '{0}' not found.",
                    schemaName);

                return null;
            }

            var value = response.Results
                .Values
                .FirstOrDefault()
                ?.ToString();

            tracing.Trace(
                "[Turnstile] Environment Variable '{0}' retrieved successfully.",
                schemaName);

            return value;
        }

        private static T Deserialize<T>(string json)
        {
            using (var stream =
                new MemoryStream(Encoding.UTF8.GetBytes(json)))
            {
                return (T)new DataContractJsonSerializer(typeof(T))
                    .ReadObject(stream);
            }
        }

        private static string Serialize<T>(T value)
        {
            using (var stream = new MemoryStream())
            {
                new DataContractJsonSerializer(typeof(T))
                    .WriteObject(stream, value);

                return Encoding.UTF8.GetString(stream.ToArray());
            }
        }

        #region Models

        [DataContract]
        private class FormField
        {
            [DataMember(Name = "Key")]
            public string Key { get; set; }

            [DataMember(Name = "Value")]
            public string Value { get; set; }
        }

        [DataContract]
        private class FormSubmissionRequest
        {
            [DataMember(Name = "Fields")]
            public List<FormField> Fields { get; set; }
        }

        [DataContract]
        private class ValidateFormSubmissionResponse
        {
            [DataMember(Name = "IsValid")]
            public bool IsValid { get; set; }

            [DataMember(Name = "ValidationOnlyFields")]
            public List<string> ValidationOnlyFields { get; set; }

            [DataMember(Name = "Error")]
            public string Error { get; set; }
        }

        [DataContract]
        private class TurnstileVerifyResponse
        {
            [DataMember(Name = "success")]
            public bool Success { get; set; }

            [DataMember(Name = "hostname")]
            public string Hostname { get; set; }

            [DataMember(Name = "error-codes")]
            public string[] ErrorCodes { get; set; }

            [DataMember(Name = "action")]
            public string Action { get; set; }

            [DataMember(Name = "challenge_ts")]
            public string ChallengeTimestamp { get; set; }
        }

        #endregion
    }
}