feat: IMAP Email Channel (#3298)

This change allows the user to configure both IMAP and SMTP for an email inbox. IMAP enables the user to see emails in Chatwoot. And user can use SMTP to reply to an email conversation.

Users can use the default settings to send and receive emails for email inboxes if both IMAP and SMTP are disabled.

Fixes #2520

app/mailboxes/imap/imap_mailbox.rb

@@ -0,0 +1,79 @@
+class Imap::ImapMailbox
+  include MailboxHelper
+  attr_accessor :channel, :account, :inbox, :conversation, :processed_mail
+
+  def process(mail, channel)
+    @inbound_mail = mail
+    @channel = channel
+    load_account
+    load_inbox
+    decorate_mail
+
+    # prevent loop from chatwoot notification emails
+    return if notification_email_from_chatwoot?
+
+    ActiveRecord::Base.transaction do
+      find_or_create_contact
+      find_or_create_conversation
+      create_message
+      add_attachments_to_message
+    end
+  end
+
+  private
+
+  def load_account
+    @account = @channel.account
+  end
+
+  def load_inbox
+    @inbox = @channel.inbox
+  end
+
+  def decorate_mail
+    @processed_mail = MailPresenter.new(@inbound_mail, @account)
+  end
+
+  def find_conversation_by_in_reply_to
+    return if in_reply_to.blank?
+
+    message = @inbox.messages.find_by(source_id: in_reply_to)
+    if message.nil?
+      @inbox.conversations.where("additional_attributes->>'in_reply_to' = ?", in_reply_to).first
+    else
+      @inbox.conversations.find(message.conversation_id)
+    end
+  end
+
+  def in_reply_to
+    @inbound_mail.in_reply_to
+  end
+
+  def find_or_create_conversation
+    @conversation = find_conversation_by_in_reply_to || ::Conversation.create!({ account_id: @account.id,
+                                                                                 inbox_id: @inbox.id,
+                                                                                 contact_id: @contact.id,
+                                                                                 contact_inbox_id: @contact_inbox.id,
+                                                                                 additional_attributes: {
+                                                                                   source: 'email',
+                                                                                   in_reply_to: in_reply_to,
+                                                                                   mail_subject: @processed_mail.subject,
+                                                                                   initiated_at: {
+                                                                                     timestamp: Time.now.utc
+                                                                                   }
+                                                                                 } })
+  end
+
+  def find_or_create_contact
+    @contact = @inbox.contacts.find_by(email: @processed_mail.original_sender)
+    if @contact.present?
+      @contact_inbox = ContactInbox.find_by(inbox: @inbox, contact: @contact)
+    else
+      create_contact
+    end
+  end
+
+  def identify_contact_name
+    processed_mail.sender_name || processed_mail.from.first.split('@').first
+  end
+end

app/mailboxes/mailbox_helper.rb

@@ -29,6 +29,21 @@ module MailboxHelper
     @message.save!
   end
 
+  def create_contact
+    @contact_inbox = ::ContactBuilder.new(
+      source_id: "email:#{processed_mail.message_id}",
+      inbox: @inbox,
+      contact_attributes: {
+        name: identify_contact_name,
+        email: processed_mail.original_sender,
+        additional_attributes: {
+          source_id: "email:#{processed_mail.message_id}"
+        }
+      }
+    ).perform
+    @contact = @contact_inbox.contact
+  end
+
   def notification_email_from_chatwoot?
     # notification emails are send via mailer sender email address. so it should match
     @processed_mail.original_sender == Mail::Address.new(ENV.fetch('MAILER_SENDER_EMAIL', 'Chatwoot <accounts@chatwoot.com>')).address

app/mailboxes/support_mailbox.rb

@@ -78,21 +78,6 @@ class SupportMailbox < ApplicationMailbox
     end
   end
 
-  def create_contact
-    @contact_inbox = ::ContactBuilder.new(
-      source_id: "email:#{processed_mail.message_id}",
-      inbox: @inbox,
-      contact_attributes: {
-        name: identify_contact_name,
-        email: @processed_mail.original_sender,
-        additional_attributes: {
-          source_id: "email:#{processed_mail.message_id}"
-        }
-      }
-    ).perform
-    @contact = @contact_inbox.contact
-  end
-
   def identify_contact_name
     processed_mail.sender_name || processed_mail.from.first.split('@').first
   end