Add notification mailer, make wallet notifications configurable

app/controllers/webhooks_controller.rb

@@ -12,22 +12,28 @@ class WebhooksController < ApplicationController
     end
 
     user = User.find_by!(ln_account: payload[:user_login])
-
-    # TODO make configurable
+    notify = user.preferences.dig("lightning", "notify_sats_received")
+    case notify
+    when "xmpp"
       notify_xmpp(user.address, payload[:amount], payload[:memo])
+    when "email"
+      NotificationMailer.with(user: user, amount_sats: payload[:amount])
+                        .lightning_sats_received.deliver_later
+    end
 
     head :ok
   end
 
   private
 
+  # TODO refactor into mailer-like generic class/service
   def notify_xmpp(address, amt_sats, memo)
     payload = {
       type: "normal",
       from: "kosmos.org", # TODO domain config
       to: address,
       subject: "Sats received!",
-      body: "#{amt_sats} sats received in your Lightning wallet:\n> #{memo}"
+      body: "#{helpers.number_with_delimiter amt_sats} sats received in your Lightning wallet:\n> #{memo}"
     }
     XmppSendMessageJob.perform_later(payload)
   end

app/mailers/notification_mailer.rb

@@ -0,0 +1,8 @@
+class NotificationMailer < ApplicationMailer
+  def lightning_sats_received
+    @user = params[:user]
+    @amount_sats = params[:amount_sats]
+    @subject = "Sats received"
+    mail to: @user.email, subject: @subject
+  end
+end

app/views/notification_mailer/lightning_sats_received.text.erb

@@ -0,0 +1,3 @@
+You just received <%= number_with_delimiter @amount_sats %> sats in your Lightning account (<%= @user.address %>). Check your wallet app, or open the account page for details:
+
+<%= wallet_transactions_url %>

spec/requests/webhooks_spec.rb

@@ -55,22 +55,51 @@ RSpec.describe "Webhooks", type: :request do
 
       before do
         user.save! #FIXME this should not be necessary
-        post "/webhooks/lndhub", params: payload.to_json
       end
 
       it "returns a 200 status" do
+        post "/webhooks/lndhub", params: payload.to_json
         expect(response).to have_http_status(:ok)
       end
 
+      it "does not send notifications by default" do
+        expect(enqueued_jobs.size).to eq(0)
+      end
+
+      context "notification preference set to 'xmpp'" do
+        before do
+          user.update! preferences: { "lightning" => { "notify_sats_received" => "xmpp" }}
+          post "/webhooks/lndhub", params: payload.to_json
+        end
+
         it "sends an XMPP message to the account owner's JID" do
           expect(enqueued_jobs.size).to eq(1)
+          expect(enqueued_jobs.first["job_class"]).to eq("XmppSendMessageJob")
 
-        msg = enqueued_jobs.first['arguments'].first
-        expect(msg["type"]).to eq('normal')
-        expect(msg["from"]).to eq('kosmos.org')
+          msg = enqueued_jobs.first["arguments"].first
+          expect(msg["type"]).to eq("normal")
+          expect(msg["from"]).to eq("kosmos.org")
           expect(msg["to"]).to eq(user.address)
-        expect(msg["subject"]).to eq('Sats received!')
-        expect(msg["body"]).to match(/^12300 sats received/)
+          expect(msg["subject"]).to eq("Sats received!")
+          expect(msg["body"]).to match(/^12,300 sats received/)
+        end
+      end
+
+      context "notification preference set to 'email'" do
+        before do
+          user.update! preferences: { "lightning" => { "notify_sats_received" => "email" }}
+          post "/webhooks/lndhub", params: payload.to_json
+        end
+
+        it "sends an email notification to the account owner" do
+          expect(enqueued_jobs.size).to eq(1)
+          expect(enqueued_jobs.first["job_class"]).to eq("ActionMailer::MailDeliveryJob")
+          args = enqueued_jobs.first['arguments']
+          expect(args[0]).to eq("NotificationMailer")
+          expect(args[1]).to eq("lightning_sats_received")
+          expect(args[3]["params"]["user"]["_aj_globalid"]).to eq("gid://akkounts/User/1")
+          expect(args[3]["params"]["amount_sats"]).to eq(12300)
+        end
       end
     end
   end