feat: Add support for template variables in messages content (#6215)

Fixes: #6078

Co-authored-by: Sojan <sojan@pepalo.com>

app/drops/contact_drop.rb

@@ -0,0 +1,17 @@
+class ContactDrop < BaseDrop
+  def email
+    @obj.try(:email)
+  end
+
+  def phone_number
+    @obj.try(:phone_number)
+  end
+
+  def first_name
+    @obj.try(:name).try(:split).try(:first)
+  end
+
+  def last_name
+    @obj.try(:name).try(:split).try(:last) if @obj.try(:name).try(:split).try(:size) > 1
+  end
+end

app/drops/user_drop.rb

@@ -2,4 +2,12 @@ class UserDrop < BaseDrop
   def available_name
     @obj.try(:available_name)
   end
+
+  def first_name
+    @obj.try(:name).try(:split).try(:first)
+  end
+
+  def last_name
+    @obj.try(:name).try(:split).try(:last) if @obj.try(:name).try(:split).try(:size) > 1
+  end
 end

app/models/concerns/liquidable.rb

@@ -0,0 +1,36 @@
+module Liquidable
+  extend ActiveSupport::Concern
+
+  included do
+    acts_as_taggable_on :labels
+    before_create :process_liquid_in_content
+  end
+
+  private
+
+  def message_drops
+    {
+      'contact' => ContactDrop.new(conversation.contact),
+      'agent' => UserDrop.new(sender),
+      'conversation' => ConversationDrop.new(conversation),
+      'inbox' => InboxDrop.new(inbox)
+    }
+  end
+
+  def liquid_processable_message?
+    content.present? && message_type == 'outgoing'
+  end
+
+  def process_liquid_in_content
+    return unless liquid_processable_message?
+
+    template = Liquid::Template.parse(modified_liquid_content)
+    self.content = template.render(message_drops)
+  end
+
+  def modified_liquid_content
+    # This regex is used to match the code blocks in the content
+    # We don't want to process liquid in code blocks
+    content.gsub(/`(.*?)`/m, '{% raw %}`\\1`{% endraw %}')
+  end
+end

app/models/message.rb

@@ -32,6 +32,7 @@
 
 class Message < ApplicationRecord
   include MessageFilterHelpers
+  include Liquidable
   NUMBER_OF_PERMITTED_ATTACHMENTS = 15
 
   before_validation :ensure_content_type

spec/drops/contact_drop_spec.rb

@@ -0,0 +1,26 @@
+require 'rails_helper'
+
+describe ::ContactDrop do
+  subject(:contact_drop) { described_class.new(contact) }
+
+  let!(:contact) { create(:contact) }
+
+  context 'when first name' do
+    it 'returns first name' do
+      contact.update!(name: 'John Doe')
+      expect(subject.first_name).to eq 'John'
+    end
+  end
+
+  context 'when last name' do
+    it 'returns the last name' do
+      contact.update!(name: 'John Doe')
+      expect(subject.last_name).to eq 'Doe'
+    end
+
+    it 'returns empty when last name not present' do
+      contact.update!(name: 'John')
+      expect(subject.last_name).to be_nil
+    end
+  end
+end

spec/drops/user_drop_spec.rb

@@ -0,0 +1,26 @@
+require 'rails_helper'
+
+describe ::UserDrop do
+  subject(:user_drop) { described_class.new(user) }
+
+  let!(:user) { create(:user) }
+
+  context 'when first name' do
+    it 'returns first name' do
+      user.update!(name: 'John Doe')
+      expect(subject.first_name).to eq 'John'
+    end
+  end
+
+  context 'when last name' do
+    it 'returns the last name' do
+      user.update!(name: 'John Doe')
+      expect(subject.last_name).to eq 'Doe'
+    end
+
+    it 'returns empty when last name not present' do
+      user.update!(name: 'John')
+      expect(subject.last_name).to be_nil
+    end
+  end
+end

spec/models/concerns/liquidable_shared.rb

@@ -0,0 +1,58 @@
+require 'rails_helper'
+
+shared_examples_for 'liqudable' do
+  context 'when liquid is present in content' do
+    let(:contact) { create(:contact, name: 'john', phone_number: '+912883') }
+    let(:conversation) { create(:conversation, id: 1, contact: contact) }
+
+    context 'when message is incoming' do
+      let(:message) { build(:message, conversation: conversation, message_type: 'incoming') }
+
+      it 'will not process liquid in content' do
+        message.content = 'hey {{contact.name}} how are you?'
+        message.save!
+        expect(message.content).to eq 'hey {{contact.name}} how are you?'
+      end
+    end
+
+    context 'when message is outgoing' do
+      let(:message) { build(:message, conversation: conversation, message_type: 'outgoing') }
+
+      it 'set replaces liquid variables in message' do
+        message.content = 'hey {{contact.name}} how are you?'
+        message.save!
+        expect(message.content).to eq 'hey john how are you?'
+      end
+
+      it 'process liquid operators like default value' do
+        message.content = 'Can we send you an email at {{ contact.email | default: "default"  }} ?'
+        message.save!
+        expect(message.content).to eq 'Can we send you an email at default ?'
+      end
+
+      it 'return empty string when value is not available' do
+        message.content = 'Can we send you an email at {{contact.email}}?'
+        message.save!
+        expect(message.content).to eq 'Can we send you an email at ?'
+      end
+
+      it 'will not process liquid tags in multiple code blocks' do
+        message.content = 'hey {{contact.name}} how are you? ```code: {{contact.name}}``` ``` code: {{contact.name}} ``` test `{{contact.name}}`'
+        message.save!
+        expect(message.content).to eq 'hey john how are you? ```code: {{contact.name}}``` ``` code: {{contact.name}} ``` test `{{contact.name}}`'
+      end
+
+      it 'will not process liquid tags in single ticks' do
+        message.content = 'hey {{contact.name}} how are you? ` code: {{contact.name}} ` ` code: {{contact.name}} ` test'
+        message.save!
+        expect(message.content).to eq 'hey john how are you? ` code: {{contact.name}} ` ` code: {{contact.name}} ` test'
+      end
+
+      it 'will not throw error for broken quotes' do
+        message.content = 'hey {{contact.name}} how are you? ` code: {{contact.name}} ` ` code: {{contact.name}} test'
+        message.save!
+        expect(message.content).to eq 'hey john how are you? ` code: {{contact.name}} ` ` code: john test'
+      end
+    end
+  end
+end

spec/models/message_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 require 'rails_helper'
+require Rails.root.join 'spec/models/concerns/liquidable_shared.rb'
 
 RSpec.describe Message, type: :model do
   context 'with validations' do
@@ -9,6 +10,10 @@ RSpec.describe Message, type: :model do
     it { is_expected.to validate_presence_of(:account_id) }
   end
 
+  describe 'concerns' do
+    it_behaves_like 'liqudable'
+  end
+
   describe '#reopen_conversation' do
     let(:conversation) { create(:conversation) }
     let(:message) { build(:message, message_type: :incoming, conversation: conversation) }