fix: Update email message_id parsing order (#3073)

Co-authored-by: Pranav Raj S <pranav@chatwoot.com>

app/mailboxes/reply_mailbox.rb

@@ -1,6 +1,4 @@
 class ReplyMailbox < ApplicationMailbox
-  include MailboxHelper
-
   attr_accessor :conversation_uuid, :processed_mail
 
   # Last part is the regex for the UUID
@@ -8,8 +6,8 @@ class ReplyMailbox < ApplicationMailbox
   EMAIL_PART_PATTERN = /^reply\+([0-9a-f]{8}\b-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-\b[0-9a-f]{12})$/i
 
   before_processing :conversation_uuid_from_to_address,
+                    :find_relative_conversation,
                     :verify_decoded_params,
-                    :find_conversation,
                     :decorate_mail
 
   def process
@@ -19,10 +17,18 @@ class ReplyMailbox < ApplicationMailbox
 
   private
 
+  def find_relative_conversation
+    if @conversation_uuid
+      find_conversation_with_uuid
+    elsif mail['In-Reply-To'].try(:value).present?
+      find_conversation_with_in_reply_to
+    end
+  end
+
   def conversation_uuid_from_to_address
     mail.to.each do |email|
       username = email.split('@')[0]
-      match_result = username.match(ApplicationMailbox::REPLY_EMAIL_USERNAME_PATTERN)
+      match_result = username.match(ApplicationMailbox::REPLY_EMAIL_UUID_PATTERN)
       if match_result
         @conversation_uuid = match_result.captures
         break
@@ -35,11 +41,38 @@ class ReplyMailbox < ApplicationMailbox
     raise 'Conversation uuid not found' if conversation_uuid.nil?
   end
 
-  def find_conversation
+  # find conversation uuid from below pattern
+  # reply+<conversation-uuid>@<mailer-domain.com>
+  def find_conversation_with_uuid
     @conversation = Conversation.find_by(uuid: conversation_uuid)
     validate_resource @conversation
   end
 
+  def find_conversation_by_uuid(match_result)
+    @conversation_uuid = match_result.captures[0]
+
+    find_conversation_with_uuid
+  end
+
+  def find_conversation_by_message_id(in_reply_to)
+    @message = Message.find_by(source_id: in_reply_to)
+    @conversation = @message.conversation if @message.present?
+    @conversation_uuid = @conversation.uuid if @conversation.present?
+  end
+
+  # find conversation uuid from below pattern
+  # <conversation/#{@conversation.uuid}/messages/#{@messages&.last&.id}@#{@account.inbound_email_domain}>
+  def find_conversation_with_in_reply_to
+    in_reply_to = mail['In-Reply-To'].try(:value)
+    match_result = in_reply_to.match(ApplicationMailbox::CONVERSATION_MESSAGE_ID_PATTERN) if in_reply_to.present?
+
+    if match_result
+      find_conversation_by_uuid(match_result)
+    else
+      find_conversation_by_message_id(in_reply_to)
+    end
+  end
+
   def validate_resource(resource)
     raise "#{resource.class.name} not found" if resource.nil?