akkounts/app/controllers/webhooks_controller.rb

class WebhooksController < ApplicationController
  skip_forgery_protection

  before_action :authorize_request
  before_action :process_payload

  def lndhub
    @user = User.find_by!(ln_account: @payload[:user_login])

    if @zap = @user.zaps.find_by(payment_request: @payload[:payment_request])
      zap_receipt = NostrManager::CreateZapReceipt.call(
        zap: @zap,
        paid_at: Time.parse(@payload[:settled_at]).to_i,
        preimage: @payload[:preimage]
      )
      @zap.update! receipt: zap_receipt.to_h
      NostrManager::PublishZapReceipt.call(zap: @zap)
    end

    send_notifications

    head :ok
  end

  private

  def authorize_request
    if !ENV['WEBHOOKS_ALLOWED_IPS'].split(',').include?(request.remote_ip)
      head :forbidden and return
    end
  end

  def process_payload
    @payload = JSON.parse(request.body.read, symbolize_names: true)
    unless @payload[:type] == "incoming" &&
           @payload[:state] == "settled"
      head :no_content and return
    end
  rescue
    head :unprocessable_entity and return
  end

  def send_notifications
    return if @payload[:amount] < @user.preferences[:lightning_notify_min_sats]

    if @user.preferences[:lightning_notify_only_with_message]
      return if @payload[:memo].blank?
    end

    target = @zap.present? ? @user.preferences[:lightning_notify_zap_received] :
                             @user.preferences[:lightning_notify_sats_received]

    case target
    when "xmpp"
      notify_xmpp
    when "email"
      notify_email
    end
  end

  # TODO refactor into mailer-like generic class/service
  def notify_xmpp
    XmppSendMessageJob.perform_later({
      type: "normal",
      from: Setting.xmpp_notifications_from_address,
      to: @user.address,
      subject: "Sats received!",
      body: "#{helpers.number_with_delimiter @payload[:amount]} sats received in your Lightning wallet:\n> #{@payload[:memo]}"
    })
  end

  def notify_email
    NotificationMailer.with(user: @user, amount_sats: @payload[:amount])
                      .lightning_sats_received.deliver_later
  end
end