8 files changed, 194 insertions, 0 deletions
diff --git a/lib/action_mailbox/base.rb b/lib/action_mailbox/base.rb
new file mode 100644
index 0000000000..476c343415
--- /dev/null
+++ b/lib/action_mailbox/base.rb
@@ -0,0 +1,45 @@
+require "active_support/rescuable"
+
+require "action_mailbox/callbacks"
+require "action_mailbox/routing"
+
+class ActionMailbox::Base
+  include ActiveSupport::Rescuable
+  include ActionMailbox::Callbacks, ActionMailbox::Routing
+
+  attr_reader :inbound_email
+  delegate :mail, :bounced!, to: :inbound_email
+
+  def self.receive(inbound_email)
+    new(inbound_email).perform_processing
+  end
+
+  def initialize(inbound_email)
+    @inbound_email = inbound_email
+  end
+
+  def perform_processing
+    run_callbacks :process do
+      track_status_of_inbound_email do
+        process
+      end
+    end
+  rescue => exception
+    # TODO: Include a reference to the inbound_email in the exception raised so error handling becomes easier
+    rescue_with_handler(exception) || raise
+  end
+
+  def process
+    # Overwrite in subclasses
+  end
+  
+  private
+    def track_status_of_inbound_email
+      inbound_email.processing!
+      yield
+      inbound_email.delivered! unless inbound_email.bounced?
+    rescue => exception
+      inbound_email.failed!
+      raise
+    end
+end
diff --git a/lib/action_mailbox/callbacks.rb b/lib/action_mailbox/callbacks.rb
new file mode 100644
index 0000000000..33caaafd2a
--- /dev/null
+++ b/lib/action_mailbox/callbacks.rb
@@ -0,0 +1,26 @@
+require "active_support/callbacks"
+
+module ActionMailbox
+  module Callbacks
+    extend  ActiveSupport::Concern
+    include ActiveSupport::Callbacks
+
+    included do
+      define_callbacks :process
+    end
+
+    module ClassMethods
+      def before_processing(*methods, &block)
+        set_callback(:process, :before, *methods, &block)
+      end
+
+      def after_processing(*methods, &block)
+        set_callback(:process, :after, *methods, &block)
+      end
+
+      def around_processing(*methods, &block)
+        set_callback(:process, :around, *methods, &block)
+      end
+    end
+  end
+end
diff --git a/lib/action_mailbox/engine.rb b/lib/action_mailbox/engine.rb
new file mode 100644
index 0000000000..92852a0fa3
--- /dev/null
+++ b/lib/action_mailbox/engine.rb
@@ -0,0 +1,14 @@
+require "rails/engine"
+
+module ActionMailbox
+  class Engine < Rails::Engine
+    isolate_namespace ActionMailbox
+    config.eager_load_namespaces << ActionMailbox
+
+    initializer "action_mailbox.config" do
+      config.after_initialize do |app|
+        # Configure
+      end
+    end
+  end
+end
diff --git a/lib/action_mailbox/router.rb b/lib/action_mailbox/router.rb
new file mode 100644
index 0000000000..8ba3ad0bae
--- /dev/null
+++ b/lib/action_mailbox/router.rb
@@ -0,0 +1,36 @@
+class ActionMailbox::Router
+  class RoutingError < StandardError; end
+
+  def initialize
+    @routes = []
+  end
+
+  def add_routes(routes)
+    routes.each do |(address, mailbox_name)|
+      add_route address, to: mailbox_name
+    end
+  end
+
+  def add_route(address, to:)
+    routes.append Route.new(address, to: to)
+  end
+
+  def route(inbound_email)
+    if mailbox = match_to_mailbox(inbound_email)
+      mailbox.receive(inbound_email)
+    else
+      inbound_email.bounced!
+
+      raise RoutingError
+    end
+  end
+
+  private
+    attr_reader :routes
+
+    def match_to_mailbox(inbound_email)
+      routes.detect { |route| route.match?(inbound_email) }.try(:mailbox_class)
+    end
+end
+
+require "action_mailbox/router/route"
diff --git a/lib/action_mailbox/router/route.rb b/lib/action_mailbox/router/route.rb
new file mode 100644
index 0000000000..7be4407339
--- /dev/null
+++ b/lib/action_mailbox/router/route.rb
@@ -0,0 +1,31 @@
+class ActionMailbox::Router::Route
+  class InvalidAddressError < StandardError; end
+
+  attr_reader :address, :mailbox_name
+
+  def initialize(address, to:)
+    @address, @mailbox_name = address, to
+  end
+
+  def match?(inbound_email)
+    case address
+    when String
+      recipients_from(inbound_email.mail).include?(address)
+    when Regexp
+      recipients_from(inbound_email.mail).detect { |recipient| address.match?(recipient) }
+    when Proc
+      address.call(inbound_email)
+    else
+      address.try(:match?, inbound_email) || raise(InvalidAddressError)
+    end
+  end
+
+  def mailbox_class
+    "#{mailbox_name.to_s.capitalize}Mailbox".constantize
+  end
+
+  private
+    def recipients_from(mail)
+      Array(mail.to) + Array(mail.cc) + Array(mail.bcc)
+    end
+end
diff --git a/lib/action_mailbox/routing.rb b/lib/action_mailbox/routing.rb
new file mode 100644
index 0000000000..b40e2774e4
--- /dev/null
+++ b/lib/action_mailbox/routing.rb
@@ -0,0 +1,17 @@
+module ActionMailbox
+  module Routing
+    extend ActiveSupport::Concern
+
+    class_methods do
+      attr_reader :router
+
+      def routing(routes)
+        (@router ||= ActionMailbox::Router.new).add_routes(routes)
+      end
+
+      def route(inbound_email)
+        @router.route(inbound_email)
+      end
+    end
+  end
+end
diff --git a/lib/action_mailbox/test_helper.rb b/lib/action_mailbox/test_helper.rb
new file mode 100644
index 0000000000..65a15a1281
--- /dev/null
+++ b/lib/action_mailbox/test_helper.rb
@@ -0,0 +1,22 @@
+require "mail"
+
+module ActionMailbox
+  module TestHelper
+    # Create an InboundEmail record using an eml fixture in the format of message/rfc822
+    # referenced with +fixture_name+ located in +test/fixtures/files/fixture_name+.
+    def create_inbound_email_from_fixture(fixture_name, status: :processing)
+      create_inbound_email file_fixture(fixture_name), filename: fixture_name, status: status
+    end    
+
+    def create_inbound_email_from_mail(status: :processing, **mail_options)
+      raw_email = Tempfile.new.tap { |raw_email| raw_email.write Mail.new(mail_options).to_s }
+      create_inbound_email(raw_email, status: status)
+    end
+
+    def create_inbound_email(io, filename: 'mail.eml', status: :processing)
+      ActionMailbox::InboundEmail.create_and_extract_message_id! \
+        ActionDispatch::Http::UploadedFile.new(tempfile: io, filename: filename, type: 'message/rfc822'),
+        status: status
+    end
+  end
+end
diff --git a/lib/action_mailbox/version.rb b/lib/action_mailbox/version.rb
new file mode 100644
index 0000000000..23c615dbbd
--- /dev/null
+++ b/lib/action_mailbox/version.rb
@@ -0,0 +1,3 @@
+module ActionMailbox
+  VERSION = '0.1.0'
+end