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

spec/mailboxes/imap/imap_mailbox_spec.rb

@@ -0,0 +1,93 @@
+require 'rails_helper'
+
+RSpec.describe Imap::ImapMailbox, type: :mailbox do
+  include ActionMailbox::TestHelper
+
+  describe 'add mail as a new conversation in the email inbox' do
+    let(:account) { create(:account) }
+    let(:agent) { create(:user, email: 'agent@example.com', account: account) }
+    let(:channel) do
+      create(:channel_email, imap_enabled: true, imap_address: 'imap.gmail.com',
+                             imap_port: 993, imap_email: 'imap@gmail.com', imap_password: 'password',
+                             account: account)
+    end
+    let(:inbox) { create(:inbox, channel: channel, account: account) }
+    let!(:contact) { create(:contact, email: 'email@gmail.com', phone_number: '+919584546666', account: account, identifier: '123') }
+    let(:conversation) { Conversation.where(inbox_id: channel.inbox).last }
+    let(:class_instance) { described_class.new }
+
+    before do
+      create(:contact_inbox, contact_id: contact.id, inbox_id: channel.inbox.id)
+    end
+
+    context 'when a new email from non existing contact' do
+      let(:inbound_mail) { create_inbound_email_from_mail(from: 'testemail@gmail.com', to: 'imap@gmail.com', subject: 'Hello!') }
+
+      it 'creates the contact and conversation with message' do
+        class_instance.process(inbound_mail.mail, channel)
+        expect(conversation.contact.email).to eq(inbound_mail.mail.from.first)
+        expect(conversation.additional_attributes['source']).to eq('email')
+        expect(conversation.messages.empty?).to be false
+      end
+    end
+
+    context 'when a new email from existing contact' do
+      let(:inbound_mail) { create_inbound_email_from_mail(from: 'email@gmail.com', to: 'imap@gmail.com', subject: 'Hello!') }
+
+      it 'creates a new conversation with message' do
+        class_instance.process(inbound_mail.mail, channel)
+        expect(conversation.contact.email).to eq(contact.email)
+        expect(conversation.additional_attributes['source']).to eq('email')
+        expect(conversation.messages.empty?).to be false
+      end
+    end
+
+    context 'when a reply for existing email conversation' do
+      let(:prev_conversation) { create(:conversation, account: account, inbox: channel.inbox, assignee: agent) }
+      let(:reply_mail) do
+        create_inbound_email_from_mail(from: 'email@gmail.com', to: 'imap@gmail.com', subject: 'Hello!', in_reply_to: 'test-in-reply-to')
+      end
+
+      it 'appends new email to the existing conversation' do
+        create(
+          :message,
+          content: 'Incoming Message',
+          message_type: 'incoming',
+          inbox: inbox,
+          account: account,
+          conversation: prev_conversation
+        )
+        create(
+          :message,
+          content: 'Outgoing Message',
+          message_type: 'outgoing',
+          inbox: inbox,
+          source_id: 'test-in-reply-to',
+          account: account,
+          conversation: prev_conversation
+        )
+
+        expect(prev_conversation.messages.size).to eq(2)
+
+        class_instance.process(reply_mail.mail, channel)
+
+        expect(prev_conversation.messages.size).to eq(3)
+        expect(prev_conversation.messages.last.content_attributes['email']['from']).to eq(reply_mail.mail.from)
+        expect(prev_conversation.messages.last.content_attributes['email']['to']).to eq(reply_mail.mail.to)
+        expect(prev_conversation.messages.last.content_attributes['email']['subject']).to eq(reply_mail.mail.subject)
+        expect(prev_conversation.messages.last.content_attributes['email']['in_reply_to']).to eq(reply_mail.mail.in_reply_to)
+      end
+    end
+
+    context 'when a reply for non existing email conversation' do
+      let(:reply_mail) do
+        create_inbound_email_from_mail(from: 'email@gmail.com', to: 'imap@gmail.com', subject: 'Hello!', in_reply_to: 'test-in-reply-to')
+      end
+
+      it 'creates new email conversation with incoming in-reply-to' do
+        class_instance.process(reply_mail.mail, channel)
+        expect(conversation.additional_attributes['in_reply_to']).to eq(reply_mail.mail.in_reply_to)
+      end
+    end
+  end
+end