Private Email Service Support (#1028)

* Added ServerSettingKey's for SMTP and moved email service code to Kavita. Nothing integrated in the UI yet.

* Undo all the custom SMTP stuff and prepare for custom email service url.

* Foundation for email service to use a custom url is setup.

* Implemented the ability to hook up custom email url

API/Services/EmailService.cs

@@ -1,10 +1,11 @@
 using System;
-using System.Net.Http;
 using System.Threading.Tasks;
+using API.Data;
 using API.DTOs.Email;
-using API.Services.Tasks;
+using API.Entities.Enums;
 using Flurl.Http;
 using Kavita.Common.EnvironmentInfo;
+using Kavita.Common.Helpers;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 
@@ -16,25 +17,39 @@ public interface IEmailService
     Task<bool> CheckIfAccessible(string host);
     Task SendMigrationEmail(EmailMigrationDto data);
     Task SendPasswordResetEmail(PasswordResetEmailDto data);
+    Task<bool> TestConnectivity(string emailUrl);
 }
 
 public class EmailService : IEmailService
 {
     private readonly ILogger<EmailService> _logger;
-    private const string ApiUrl = "https://email.kavitareader.com";
+    private readonly IUnitOfWork _unitOfWork;
 
-    public EmailService(ILogger<EmailService> logger)
+    /// <summary>
+    /// This is used to initially set or reset the ServerSettingKey. Do not access from the code, access via UnitOfWork
+    /// </summary>
+    public const string DefaultApiUrl = "https://email.kavitareader.com";
+
+    public EmailService(ILogger<EmailService> logger, IUnitOfWork unitOfWork)
     {
         _logger = logger;
+        _unitOfWork = unitOfWork;
 
-        FlurlHttp.ConfigureClient(ApiUrl, cli =>
+        FlurlHttp.ConfigureClient(DefaultApiUrl, cli =>
             cli.Settings.HttpClientFactory = new UntrustedCertClientFactory());
     }
 
+    public async Task<bool> TestConnectivity(string emailUrl)
+    {
+        FlurlHttp.ConfigureClient(emailUrl, cli =>
+            cli.Settings.HttpClientFactory = new UntrustedCertClientFactory());
+
+        return await SendEmailWithGet(emailUrl + "/api/email/test");
+    }
+
     public async Task SendConfirmationEmail(ConfirmationEmailDto data)
     {
-
-        var success = await SendEmailWithPost(ApiUrl + "/api/email/confirm", data);
+        var success = await SendEmailWithPost(DefaultApiUrl + "/api/email/confirm", data);
         if (!success)
         {
             _logger.LogError("There was a critical error sending Confirmation email");
@@ -43,17 +58,20 @@ public class EmailService : IEmailService
 
     public async Task<bool> CheckIfAccessible(string host)
     {
-        return await SendEmailWithGet(ApiUrl + "/api/email/reachable?host=" + host);
+        // This is the only exception for using the default because we need an external service to check if the server is accessible for emails
+        return await SendEmailWithGet(DefaultApiUrl + "/api/email/reachable?host=" + host);
     }
 
     public async Task SendMigrationEmail(EmailMigrationDto data)
     {
-        await SendEmailWithPost(ApiUrl + "/api/email/email-migration", data);
+        var emailLink = (await _unitOfWork.SettingsRepository.GetSettingAsync(ServerSettingKey.EmailServiceUrl)).Value;
+        await SendEmailWithPost(emailLink + "/api/email/email-migration", data);
     }
 
     public async Task SendPasswordResetEmail(PasswordResetEmailDto data)
     {
-        await SendEmailWithPost(ApiUrl + "/api/email/email-password-reset", data);
+        var emailLink = (await _unitOfWork.SettingsRepository.GetSettingAsync(ServerSettingKey.EmailServiceUrl)).Value;
+        await SendEmailWithPost(emailLink + "/api/email/email-password-reset", data);
     }
 
     private static async Task<bool> SendEmailWithGet(string url)
@@ -106,4 +124,5 @@ public class EmailService : IEmailService
         }
         return true;
     }
+
 }

API/Services/Tasks/StatsService.cs

@@ -7,6 +7,7 @@ using API.DTOs.Stats;
 using API.Entities.Enums;
 using Flurl.Http;
 using Kavita.Common.EnvironmentInfo;
+using Kavita.Common.Helpers;
 using Microsoft.AspNetCore.Http;
 using Microsoft.Extensions.Logging;
 

API/Services/Tasks/VersionUpdaterService.cs

@@ -1,14 +1,13 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
-using System.Net.Http;
 using System.Threading.Tasks;
 using API.DTOs.Update;
 using API.SignalR;
 using API.SignalR.Presence;
 using Flurl.Http;
-using Flurl.Http.Configuration;
 using Kavita.Common.EnvironmentInfo;
+using Kavita.Common.Helpers;
 using MarkdownDeep;
 using Microsoft.AspNetCore.SignalR;
 using Microsoft.Extensions.Hosting;
@@ -44,15 +43,6 @@ internal class GithubReleaseMetadata
     public string Published_At { get; init; }
 }
 
-public class UntrustedCertClientFactory : DefaultHttpClientFactory
-{
-    public override HttpMessageHandler CreateMessageHandler() {
-        return new HttpClientHandler {
-            ServerCertificateCustomValidationCallback = (_, _, _, _) => true
-        };
-    }
-}
-
 public interface IVersionUpdaterService
 {
     Task<UpdateNotificationDto> CheckForUpdate();