lettermint mail dispatcher

mixtape/Mails/Dispatchers/Lettermint/LettermintDispatcher.cs

@@ -0,0 +1,157 @@
+using System.IO;
+using System.Net.Http;
+using System.Net.Http.Json;
+using System.Net.Mail;
+using System.Text.Json;
+using Microsoft.AspNetCore.Hosting;
+using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
+using Attachment = System.Net.Mail.Attachment;
+
+namespace Mixtape.Mails.Dispatchers.Lettermint;
+
+public class LettermintDispatcher : IMailDispatcher
+{
+  protected Queue<Mail> Queue { get; } = new();
+
+  protected MailOptions Options { get; set; }
+
+  protected IWebHostEnvironment Env { get; set; }
+
+  protected HttpClient Http { get; }
+
+  protected JsonSerializerOptions JsonSerializerOptions { get; }
+
+  protected ILogger<LettermintDispatcher> Logger { get; }
+
+
+  public LettermintDispatcher(IOptionsMonitor<MailOptions> monitor, IWebHostEnvironment env, HttpClient http, ILogger<LettermintDispatcher> logger)
+  {
+    Options = monitor.CurrentValue;
+    Env = env;
+    Http = http;
+    Http.DefaultRequestHeaders.Add("x-lettermint-token", Options.Lettermint.Token);
+    JsonSerializerOptions = new JsonSerializerOptions
+    {
+      PropertyNamingPolicy = JsonNamingPolicy.SnakeCaseLower
+    };
+    Logger = logger;
+
+    monitor.OnChange(opts => Options = opts);
+  }
+
+
+  /// <inheritdoc />
+  public Task<bool> IsSenderSupported(string email, CancellationToken token = default)
+  {
+    return Task.FromResult(true);
+  }
+
+
+  /// <inheritdoc />
+  public async Task Send(Mail message, CancellationToken token = default)
+  {
+    string uri = Options.Lettermint.ApiUrl + $"/v1/send";
+
+    // add app name as tag
+    if (message.Metadata.TryGetValue("application", out string value) && !message.Tag.HasValue())
+    {
+      message.Tag = value;
+      message.Metadata.Remove("application");
+    }
+
+    LettermintRequest.SendEmail data = new()
+    {
+      // to addresses
+      To = Convert(message.To),
+      ReplyTo = Convert(message.ReplyToList),
+      Cc = Convert(message.CC),
+      Bcc = Convert(message.Bcc),
+
+      // from address
+      From = message.From!.ToString(),
+
+      // subject
+      Subject = message.Subject,
+
+      // tag/group
+      Tag = message.Tag,
+
+      // metadata
+      Metadata = message.Metadata,
+      Route = Options.Lettermint.Route
+    };
+
+    // set attachments
+    foreach (Attachment attachment in message.Attachments)
+    {
+      data.Attachments.Add(Convert(attachment));
+    }
+
+    // set body
+    if (!message.IsBodyHtml)
+    {
+      data.Text = message.Body;
+    }
+    else
+    {
+      data.Html = message.Body;
+    }
+
+    try
+    {
+      using HttpResponseMessage responseMessage = await Http.PostAsJsonAsync(uri, data, JsonSerializerOptions, token);
+      LettermintResponse.SendEmail response = await responseMessage.Content.ReadFromJsonAsync<LettermintResponse.SendEmail>(JsonSerializerOptions, token);
+
+      if (!responseMessage.IsSuccessStatusCode)
+      {
+        throw new Exception($"Could not send message via Lettermint API. Status code: {responseMessage.StatusCode}, Message: {response.ErrorMessage}");
+      }
+
+      Logger.LogDebug("Email {id} sent via Lettermint API", response.MessageId);
+    }
+    catch (Exception ex)
+    {
+      Logger.LogError(ex, "Could not send message via Lettermint API");
+    }
+  }
+
+
+  /// <inheritdoc />
+  public void Dispose() { }
+
+
+  /// <summary>
+  /// Convert a collection of addresses to a Lettermint email addresses
+  /// </summary>
+  protected string[] Convert(MailAddressCollection addresses)
+  {
+    return addresses
+      .Select(address => address.ToString())
+      .ToArray();
+  }
+
+
+  /// <summary>
+  /// Convert an attachment to a Lettermint email attachment
+  /// </summary>
+  protected LettermintRequest.EmailAttachment Convert(Attachment attachment)
+  {
+    byte[] buffer = new byte[8067];
+    using MemoryStream memoryStream = new();
+    int count;
+    while ((count = attachment.ContentStream.Read(buffer, 0, buffer.Length)) > 0)
+    {
+      memoryStream.Write(buffer, 0, count);
+    }
+    string base64String = System.Convert.ToBase64String(memoryStream.ToArray());
+
+    return new()
+    {
+      Filename = attachment.Name,
+      ContentType = attachment.ContentType.MediaType,
+      Content = base64String,
+      ContentId = attachment.ContentId
+    };
+  }
+}

mixtape/Mails/Dispatchers/Lettermint/LettermintOptions.cs

@@ -0,0 +1,10 @@
+namespace Mixtape.Mails.Dispatchers.Lettermint;
+
+public class LettermintOptions
+{
+  public string ApiUrl { get; set; } = "https://api.lettermint.co";
+
+  public string Token { get; set; }
+
+  public string Route { get; set; } = "outgoing";
+}

mixtape/Mails/Dispatchers/Lettermint/LettermintRequest.cs

@@ -0,0 +1,56 @@
+using System.Text.Json.Serialization;
+
+namespace Mixtape.Mails.Dispatchers.Lettermint;
+
+public class LettermintRequest
+{
+  public class SendEmail
+  {
+    public string From { get; set; }
+
+    public string[] To { get; set; } = [];
+
+    public string[] Cc { get; set; } = [];
+
+    public string[] Bcc { get; set; } = [];
+
+    public string[] ReplyTo { get; set; }
+
+    public string Subject { get; set; }
+
+    public string Text { get; set; }
+
+    public string Html { get; set; }
+
+    public string Route { get; set; }
+
+    public string Tag { get; set; }
+
+    public List<EmailAttachment> Attachments { get; set; } = [];
+
+    public Dictionary<string, string> Metadata { get; set; } = new();
+  }
+
+  public class EmailAttachment
+  {
+    /// <summary>
+    /// Filename of the attachment.
+    /// </summary>
+    public string Filename { get; set; }
+
+    /// <summary>
+    /// MIME type of the attachment.
+    /// </summary>
+    public string ContentType { get; set; }
+
+    /// <summary>
+    /// Content of the attachment encoded in base64.
+    /// </summary>
+    public string Content { get; set; }
+
+    /// <summary>
+    /// Content ID for inline attachments, referenced via cid: in HTML body
+    /// </summary>
+    public string ContentId { get; set; }
+  }
+}

mixtape/Mails/Dispatchers/Lettermint/LettermintResponse.cs

@@ -0,0 +1,16 @@
+using System.Text.Json.Serialization;
+
+namespace Mixtape.Mails.Dispatchers.Lettermint;
+
+public class LettermintResponse
+{
+  public class SendEmail
+  {
+    public string MessageId { get; set; }
+
+    public string Status { get; set; }
+
+    [JsonPropertyName("message")]
+    public string ErrorMessage { get; set; }
+  }
+}

mixtape/Mails/MailOptions.cs

@@ -1,4 +1,5 @@
-using Mixtape.Mails.Dispatchers.Postmark;
+using Mixtape.Mails.Dispatchers.Lettermint;
+using Mixtape.Mails.Dispatchers.Postmark;
 using Mixtape.Mails.Dispatchers.Scaleway;
 
 namespace Mixtape.Mails;
@@ -25,5 +26,7 @@ public class MailOptions
 
   public ScalewayOptions Scaleway { get; set; }
 
+  public LettermintOptions Lettermint { get; set; }
+
   public Func<Mail, string> BuildViewPath { get; set; }
 }

mixtape/Mails/MixtapeMailModule.cs

@@ -3,6 +3,7 @@ using Mixtape.Mails.Dispatchers.Postmark;
 using Mixtape.Mails.Dispatchers.Scaleway;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
+using Mixtape.Mails.Dispatchers.Lettermint;
 
 namespace Mixtape.Mails;
 
@@ -11,6 +12,8 @@ internal class MixtapeMailModule : MixtapeModule
   public override void ConfigureServices(IServiceCollection services, IConfiguration configuration)
   {
     services.AddHttpClient<ScalewayDispatcher>().RemoveAllLoggers();
+    services.AddHttpClient<LettermintDispatcher>().RemoveAllLoggers();
+
     services.AddScoped<IMailProvider, MailProvider>();
 
     // use logger mail dispatcher as default implementation

mixtape/mixtape.csproj

@@ -18,7 +18,7 @@
         <PackageReference Include="Microsoft.Extensions.DependencyModel" Version="10.0.7" />
         <PackageReference Include="FluentValidation" Version="12.1.1" />
         <PackageReference Include="Postmark" Version="5.3.0" />
-        <PackageReference Include="PowCapServer.Core" Version="2.0.2" />
+        <PackageReference Include="PowCapServer.Core" Version="2.0.1" />
         <PackageReference Include="Seq.Extensions.Logging" Version="9.0.0" />
         <PackageReference Include="SixLabors.ImageSharp.Web" Version="3.2.0" />
     </ItemGroup>