feat(dolist): send mail having attachments

app/lib/dolist/api.rb

@@ -1,3 +1,5 @@
+require "support/jsv"
+
 class Dolist::API
   CONTACT_URL = "https://apiv9.dolist.net/v1/contacts/read?AccountID=%{account_id}"
   EMAIL_LOGS_URL = "https://apiv9.dolist.net/v1/statistics/email/sendings/transactional/search?AccountID=%{account_id}"
@@ -6,6 +8,7 @@ class Dolist::API
   EMAIL_MESSAGES_ADRESSES_REPLIES = "https://apiv9.dolist.net/v1/email/messages/addresses/replies?AccountID=%{account_id}"
   EMAIL_MESSAGES_ADRESSES_PACKSENDERS = "https://apiv9.dolist.net/v1/email/messages/addresses/packsenders?AccountID=%{account_id}"
   EMAIL_SENDING_TRANSACTIONAL = "https://apiv9.dolist.net/v1/email/sendings/transactional?AccountID=%{account_id}"
+  EMAIL_SENDING_TRANSACTIONAL_ATTACHMENT = "https://apiv9.dolist.net/v1/email/sendings/transactional/attachment?AccountID=%{account_id}"
   EMAIL_SENDING_TRANSACTIONAL_SEARCH = "https://apiv9.dolist.net/v1/email/sendings/transactional/search?AccountID=%{account_id}"
 
   class_attribute :limit_remaining, :limit_reset_at
@@ -34,39 +37,62 @@ class Dolist::API
   end
 
   def send_email(mail)
-    url = format(EMAIL_SENDING_TRANSACTIONAL, account_id: account_id)
+    if mail.attachments.any? { !_1.inline? }
+      return send_email_with_attachment(mail)
+    end
 
-    body = {
+    body = { "TransactionalSending": prepare_mail_body(mail) }
-      "TransactionalSending": {
-        "Type": "TransactionalService",
-        "Contact": {
-          "FieldList": [
-            {
-              "ID": EMAIL_KEY,
-              "Value": mail.to.first
-            }
-          ]
-        },
-        "Message": {
-          "Name": mail['X-Dolist-Message-Name'].value,
-          "Subject": mail.subject,
-          "SenderID": sender_id,
-          "ForceHttp": true,
-          "Format": "html",
-          "DisableOpenTracking": true,
-          "IsTrackingValidated": true
-        },
-        "MessageContent": {
-          "SourceCode": mail_source_code(mail),
-          "EncodingType": "UTF8",
-          "EnableTrackingDetection": false
-        }
-      }
-    }
 
+    url = format_url(EMAIL_SENDING_TRANSACTIONAL)
     post(url, body.to_json)
   end
 
+  def send_email_with_attachment(mail)
+    uri = URI(format_url(EMAIL_SENDING_TRANSACTIONAL_ATTACHMENT))
+
+    request = Net::HTTP::Post.new(uri)
+
+    default_headers.each do |key, value|
+      next if key.to_s == "Content-Type"
+      request[key] = value
+    end
+
+    boundary = "---011000010111000001101001" # any random string not present in the body
+    request.content_type = "multipart/form-data; boundary=#{boundary}"
+
+    body = "--#{boundary}\r\n"
+
+    base64_files(mail.attachments).each do |file|
+      body << "Content-Disposition: form-data; name=\"#{file.field_name}\"; filename=\"#{file.filename}\"\r\n"
+      body << "Content-Type: #{file.mime_type}\r\n"
+      body << "\r\n"
+      body << file.content
+      body << "\r\n"
+    end
+
+    body << "\r\n--#{boundary}\r\n"
+    body << "Content-Disposition: form-data; name=\"TransactionalSending\"\r\n"
+    body << "Content-Type: text/plain; charset=utf-8\r\n"
+    body << "\r\n"
+    body << prepare_mail_body(mail).to_jsv
+
+    body << "\r\n--#{boundary}--\r\n"
+    body << "\r\n"
+
+    request.body = body
+
+    http = Net::HTTP.new(uri.host, uri.port)
+    http.use_ssl = true
+
+    response = http.request(request)
+
+    if response.body.empty?
+      fail "Dolist API returned an empty response"
+    else
+      JSON.parse(response.body)
+    end
+  end
+
   def sent_mails(email_address)
     contact_id = fetch_contact_id(email_address)
     if contact_id.nil?
@@ -83,23 +109,25 @@ class Dolist::API
   end
 
   def senders
-    url = format(EMAIL_MESSAGES_ADRESSES_PACKSENDERS, account_id: account_id)
+    get format_url(EMAIL_MESSAGES_ADRESSES_PACKSENDERS)
-    get(url)
   end
 
   def replies
-    url = format(EMAIL_MESSAGES_ADRESSES_REPLIES, account_id: account_id)
+    get format_url(EMAIL_MESSAGES_ADRESSES_REPLIES)
-    get(url)
   end
 
   private
 
+  def format_url(base)
+    format(base, account_id: account_id)
+  end
+
   def sender_id
-    senders.dig("ItemList", 0, "Sender", "ID")
+    @sender_id ||= senders.dig("ItemList", 0, "Sender", "ID")
   end
 
   def get(url)
-    response = Typhoeus.get(url, headers:).tap do
+    response = Typhoeus.get(url, headers: default_headers).tap do
       self.class.save_rate_limit_headers(_1.headers)
     end
 
@@ -107,14 +135,18 @@ class Dolist::API
   end
 
   def post(url, body)
-    response = Typhoeus.post(url, body:, headers:).tap do
+    response = Typhoeus.post(url, body:, headers: default_headers).tap do
       self.class.save_rate_limit_headers(_1.headers)
     end
 
-    JSON.parse(response.response_body)
+    if response.response_body.empty?
+      fail "Empty response from Dolist API"
+    else
+      JSON.parse(response.response_body)
+    end
   end
 
-  def headers
+  def default_headers
     {
       "Content-Type": 'application/json',
       "Accept": 'application/json',
@@ -150,6 +182,34 @@ class Dolist::API
     post(url, body)["ItemList"]
   end
 
+  def prepare_mail_body(mail)
+    {
+      "Type": "TransactionalService",
+      "Contact": {
+        "FieldList": [
+          {
+            "ID": EMAIL_KEY,
+            "Value": mail.to.first
+          }
+        ]
+      },
+      "Message": {
+        "Name": mail['X-Dolist-Message-Name'].value,
+        "Subject": mail.subject,
+        "SenderID": sender_id,
+        "ForceHttp": true,
+        "Format": "html",
+        "DisableOpenTracking": true,
+        "IsTrackingValidated": true
+      },
+      "MessageContent": {
+        "SourceCode":  mail_source_code(mail),
+        "EncodingType": "UTF8",
+        "EnableTrackingDetection": false
+      }
+    }
+  end
+
   def to_sent_mail(email_address, contact_id, dolist_message)
     SentMail.new(
       from: ENV['DOLIST_NO_REPLY_EMAIL'],
@@ -180,4 +240,16 @@ class Dolist::API
       mail.html_part.body.decoded
     end
   end
+
+  def base64_files(attachments)
+    attachments.map do |attachment|
+      raise ArgumentError, "Dolist API does not support non PDF attachments. Given #{attachment.filename} which has mime_type=#{attachment.mime_type}" unless attachment.mime_type == "application/pdf"
+
+      field_name = File.basename(attachment.filename, File.extname(attachment.filename))
+      attachment_content = attachment.body.decoded
+      attachment_base64 = Base64.strict_encode64(attachment_content)
+
+      Dolist::Base64File.new(field_name:, filename: attachment.filename, mime_type: attachment.mime_type, content: attachment_base64)
+    end
+  end
 end

app/lib/dolist/base64_file.rb

@@ -0,0 +1,3 @@
+module Dolist
+  Base64File = Struct.new(:field_name, :filename, :mime_type, :content, keyword_init: true)
+end