REFACTOR: use same code path for handling emails via API and POP

lib/email/processor.rb

@@ -0,0 +1,102 @@
+module Email
+
+  class Processor
+
+    def initialize(mail)
+      @mail = mail
+    end
+
+    def self.process!(mail)
+      Email::Processor.new(mail).process!
+    end
+
+    def process!
+      begin
+        receiver = Email::Receiver.new(@mail)
+        receiver.process!
+      rescue Email::Receiver::BouncedEmailError => e
+        log_email_process_failure(@mail, e)
+        set_incoming_email_rejection_message(receiver.incoming_email, I18n.t("emails.incoming.errors.bounced_email_error"))
+      rescue Email::Receiver::AutoGeneratedEmailReplyError => e
+        log_email_process_failure(@mail, e)
+        set_incoming_email_rejection_message(receiver.incoming_email, I18n.t("emails.incoming.errors.auto_generated_email_reply"))
+      rescue => e
+        log_email_process_failure(@mail, e)
+
+        rejection_message = handle_failure(@mail, e)
+        if rejection_message.present? && receiver && (incoming_email = receiver.incoming_email)
+          set_incoming_email_rejection_message(incoming_email, rejection_message.body.to_s)
+        end
+      end
+    end
+
+    private
+
+    def handle_failure(mail_string, e)
+      message_template = case e
+        when Email::Receiver::EmptyEmailError             then :email_reject_empty
+        when Email::Receiver::NoBodyDetectedError         then :email_reject_empty
+        when Email::Receiver::UserNotFoundError           then :email_reject_user_not_found
+        when Email::Receiver::ScreenedEmailError          then :email_reject_screened_email
+        when Email::Receiver::AutoGeneratedEmailError     then :email_reject_auto_generated
+        when Email::Receiver::InactiveUserError           then :email_reject_inactive_user
+        when Email::Receiver::BlockedUserError            then :email_reject_blocked_user
+        when Email::Receiver::BadDestinationAddress       then :email_reject_bad_destination_address
+        when Email::Receiver::StrangersNotAllowedError    then :email_reject_strangers_not_allowed
+        when Email::Receiver::InsufficientTrustLevelError then :email_reject_insufficient_trust_level
+        when Email::Receiver::ReplyUserNotMatchingError   then :email_reject_reply_user_not_matching
+        when Email::Receiver::TopicNotFoundError          then :email_reject_topic_not_found
+        when Email::Receiver::TopicClosedError            then :email_reject_topic_closed
+        when Email::Receiver::InvalidPost                 then :email_reject_invalid_post
+        when ActiveRecord::Rollback                       then :email_reject_invalid_post
+        when Email::Receiver::InvalidPostAction           then :email_reject_invalid_post_action
+        when Discourse::InvalidAccess                     then :email_reject_invalid_access
+        when RateLimiter::LimitExceeded                   then :email_reject_rate_limit_specified
+      end
+
+      template_args = {}
+      client_message = nil
+
+      # there might be more information available in the exception
+      if message_template == :email_reject_invalid_post && e.message.size > 6
+        message_template = :email_reject_invalid_post_specified
+        template_args[:post_error] = e.message
+      end
+
+      if message_template == :email_reject_rate_limit_specified
+        template_args[:rate_limit_description] = e.description
+      end
+
+      if message_template == :email_reject_auto_generated
+        template_args[:mark_as_reply_to_auto_generated] = true
+      end
+
+      if message_template
+        # inform the user about the rejection
+        message = Mail::Message.new(mail_string)
+        template_args[:former_title] = message.subject
+        template_args[:destination] = message.to
+        template_args[:site_name] = SiteSetting.title
+
+        client_message = RejectionMailer.send_rejection(message_template, message.from, template_args)
+        Email::Sender.new(client_message, message_template).send
+      else
+        Discourse.handle_job_exception(e, error_context(@args, "Unrecognized error type when processing incoming email", mail: mail_string))
+      end
+
+      client_message
+    end
+
+    def set_incoming_email_rejection_message(incoming_email, message)
+      incoming_email.update_attributes!(rejection_message: message)
+    end
+
+    def log_email_process_failure(mail_string, exception)
+      if SiteSetting.log_mail_processing_failures
+        Rails.logger.warn("Email can not be processed: #{exception}\n\n#{mail_string}")
+      end
+    end
+
+  end
+
+end