TD-4086-Adds tableau JWT token helper class and settings

Author: kevwhitt-hee

DigitalLearningSolutions.Data/Extensions/ConfigurationExtensions.cs

@@ -49,6 +49,11 @@ public static class ConfigurationExtensions
 
         private const string LearningHubUserAPIUserAPIUrl = "LearningHubUserApi:UserApiUrl";
         private const string UserResearchUrlName = "UserResearchUrl";
+        private const string TableauSectionKey = "TableauDashboards";
+        private const string TableauClientId = "ClientId";
+        private const string TableauClientSecret = "ClientSecret";
+        private const string TableauUsername = "Username";
+        private const string TableauClientName = "ClientName";
 
         public static string GetAppRootPath(this IConfiguration config)
         {
@@ -218,5 +223,21 @@ public static string GetUserResearchUrl(this IConfiguration config)
         {
             return config[UserResearchUrlName]!;
         }
+        public static string GetTableauClientName(this IConfiguration config)
+        {
+            return config[$"{TableauSectionKey}:{TableauClientName}"]!;
+        }
+        public static string GetTableauClientId(this IConfiguration config)
+        {
+            return config[$"{TableauSectionKey}:{TableauClientId}"]!;
+        }
+        public static string GetTableauClientSecret(this IConfiguration config)
+        {
+            return config[$"{TableauSectionKey}:{TableauClientSecret}"]!;
+        }
+        public static string GetTableauUser(this IConfiguration config)
+        {
+            return config[$"{TableauSectionKey}:{TableauUsername}"]!;
+        }
     }
 }

DigitalLearningSolutions.Web/Helpers/ExternalApis/FilteredApiHelper.cs

@@ -6,12 +6,10 @@
     using System.Net.Http;
     using System.Security.Claims;
     using System.Text;
-    using System.Text.Json;
     using System.Threading.Tasks;
     using Newtonsoft.Json;
     using System.Net.Http.Headers;
     using DigitalLearningSolutions.Data.Models.External.Filtered;
-    using System.Collections;
     using System.Collections.Generic;
     using System.Linq;
     using DigitalLearningSolutions.Data.Utilities;

DigitalLearningSolutions.Web/Helpers/ExternalApis/TableauConnectionHelper.cs

@@ -0,0 +1,61 @@
+namespace DigitalLearningSolutions.Web.Helpers.ExternalApis
+{
+    using Microsoft.IdentityModel.Tokens;
+    using System.Collections.Generic;
+    using System.IdentityModel.Tokens.Jwt;
+    using System.Security.Claims;
+    using System.Text;
+    using System;
+    using Microsoft.Extensions.Configuration;
+    using DigitalLearningSolutions.Data.Extensions;
+
+    public interface ITableauConnectionHelperService
+        {
+         string GetToken(string email);
+        }
+    public class TableauConnectionHelper : ITableauConnectionHelperService
+    {
+        private readonly string connectedAppClient;
+        private readonly string connectedAppSecretKey;
+        private readonly string connectedAppClientId;
+        private readonly string user;
+        public TableauConnectionHelper(IConfiguration config)
+        {
+            connectedAppClient = config.GetTableauClientName();
+            connectedAppClientId = config.GetTableauClientId();
+            connectedAppSecretKey = config.GetTableauClientSecret();
+            user = config.GetTableauUser();
+        }
+        public string GetToken(string email)
+        {
+            var tokenHandler = new JwtSecurityTokenHandler();
+            var key = Encoding.ASCII.GetBytes(connectedAppSecretKey);
+
+            var tokenDescriptor = new SecurityTokenDescriptor
+            {
+                Issuer = connectedAppClientId,
+                Audience = "tableau",
+                Subject = new ClaimsIdentity(new[]
+                {
+                new Claim(JwtRegisteredClaimNames.Sub, user),
+                new Claim(JwtRegisteredClaimNames.Jti, Guid.NewGuid().ToString()),
+                new Claim("scp", "tableau:views:embed"),
+                new Claim("scp", "tableau:metrics:embed")
+            }),
+                Expires = DateTime.UtcNow.AddMinutes(5),
+                SigningCredentials = new SigningCredentials(new SymmetricSecurityKey(key), SecurityAlgorithms.HmacSha256Signature),
+                Claims = new Dictionary<string, object>
+            {
+                { "kid", connectedAppClientId },
+                { "iss", connectedAppClient }
+            }
+            };
+
+            var token = tokenHandler.CreateToken(tokenDescriptor);
+            var tokenString = tokenHandler.WriteToken(token);
+
+            return tokenString;
+        }
+
+    }
+}

DigitalLearningSolutions.Web/Startup.cs

@@ -560,6 +560,7 @@ private static void RegisterHttpClients(IServiceCollection services)
             services.AddHttpClient<ILearningHubReportApiClient, LearningHubReportApiClient>();
             services.AddScoped<IFreshdeskApiClient, FreshdeskApiClient>();
             services.AddScoped<ILearningHubUserApiClient, LearningHubUserApiClient>();
+            services.AddScoped<ITableauConnectionHelperService, TableauConnectionHelper>();
         }
 
         private static void RegisterWebServiceFilters(IServiceCollection services)

DigitalLearningSolutions.Web/appsettings.json

@@ -78,5 +78,14 @@
   "LearningHubUserApi": {
     "UserApiUrl": "https://userapi.learninghub.nhs.uk/api/"
   },
+  "TableauDashboards": {
+    "SiteUrl": "https://tabuat.data.england.nhs.uk",
+    "CompetencyDashboardUrl": "https://tabuat.data.england.nhs.uk/#/workbooks/7839/views",
+    "Username": "SVC_default_TEL",
+    "Password": "",
+    "ClientName":  "tel_dls",
+    "ClientId": "a7906ce3-e0c9-403e-a169-8eb78d858f8a",
+    "ClientSecret":  ""
+  },
   "UserResearchUrl": "https://forms.office.com/e/nKcK8AdHRX"
 }