Code to display tips submitted on news feed

app/webhooks.rb

@@ -10,6 +10,57 @@ post '/webhooks/paypal' do
   'ok'
 end
 
+def valid_paypal_webhook_source?
+  # https://www.paypal-knowledge.com/infocenter/index?page=content&widgetview=true&id=FAQ1465&viewlocale=en_US&direct=en
+  return true if ['127.0.0.1', '173.0.81.1', '173.0.81.33', '66.211.170.66'].include?(request.ip)
+  false
+end
+
+post '/webhooks/paypal/tipping_notify' do
+  return 403 unless valid_paypal_webhook_source?
+  payload = JSON.parse Base64.strict_decode64(params[:custom]), symbolize_names: true
+
+  site = Site[payload[:site_id]]
+
+  @tip_hash = {
+    message: (params[:memo] ? params[:memo] : nil),
+    amount: params[:mc_gross],
+    currency: params[:mc_currency],
+    fee: params[:mc_fee],
+    actioning_site: (payload[:actioning_site_id] ? Site[payload[:actioning_site_id]] : nil),
+    paypal_payer_email: params[:payer_email],
+    paypal_receiver_email: params[:receiver_email],
+    paypal_txn_id: params[:txn_id],
+    created_at: DateTime.strptime(params[:payment_date], "%H:%M:%S %b %e, %Y %Z").to_time
+  }
+
+  @tip = site.add_tip @tip_hash
+
+  Event.create(
+    site_id: @tip.site.id,
+    actioning_site_id: (@tip.actioning_site ? @tip.actioning_site.id : nil),
+    tip_id: @tip.id
+  )
+
+  if @tip.actioning_site
+    subject = "You received a #{@tip.amount_string} tip from #{@tip.actioning_site.username}!"
+  else
+    subject = "You received a #{@tip.amount_string} tip!"
+  end
+
+  @tip.site.send_email(
+    subject: subject,
+    body: Tilt.new('./views/templates/email/tip_received.erb', pretty: true).render(self)
+  )
+
+  EmailWorker.perform_async({
+    from: 'web@neocities.org',
+    to: params[:payer_email],
+    subject: "You sent a #{@tip.amount_string} tip!",
+    body: Tilt.new('./views/templates/email/tip_sent.erb', pretty: true).render(self)
+  })
+end
+
 post '/webhooks/stripe' do
   event = JSON.parse request.body.read
   if event['type'] == 'customer.created'