chore: one off SMS campaign APIs (#2589)

app/services/twilio/oneoff_sms_campaign_service.rb

@@ -0,0 +1,40 @@
+class Twilio::OneoffSmsCampaignService
+  pattr_initialize [:campaign!]
+
+  def perform
+    raise "Invalid campaign #{campaign.id}" if campaign.inbox.inbox_type != 'Twilio SMS' || !campaign.one_off?
+    raise 'Completed Campaign' if campaign.completed?
+
+    # marks campaign completed so that other jobs won't pick it up
+    campaign.completed!
+
+    audience_label_ids = campaign.audience.select { |audience| audience['type'] == 'Label' }.pluck('id')
+    audience_labels = campaign.account.labels.where(id: audience_label_ids).pluck(:title)
+    process_audience(audience_labels)
+  end
+
+  private
+
+  delegate :inbox, to: :campaign
+  delegate :channel, to: :inbox
+
+  def process_audience(audience_labels)
+    campaign.account.contacts.tagged_with(audience_labels, any: true).each do |contact|
+      next if contact.phone_number.blank?
+
+      send_message(to: contact.phone_number, from: channel.phone_number, content: campaign.message)
+    end
+  end
+
+  def send_message(to:, from:, content:)
+    client.messages.create({
+                             body: content,
+                             from: from,
+                             to: to
+                           })
+  end
+
+  def client
+    ::Twilio::REST::Client.new(channel.account_sid, channel.auth_token)
+  end
+end