Add LndHub service, lnurl-pay endpoints

Enables the lnurl-pay payment workflow

app/controllers/lnurlpay_controller.rb

@@ -0,0 +1,58 @@
+class LnurlpayController < ApplicationController
+  before_action :find_user_by_address
+
+  def index
+    render json: {
+      status: "OK",
+      callback: "https://accounts.kosmos.org/lnurlpay/#{@user.address}/invoice",
+      tag: "payRequest",
+      maxSendable: 1000000,
+      minSendable: 1000,
+      metadata: metadata(@user.address),
+      commentAllowed: 255
+    }
+  end
+
+  def invoice
+    amount = params[:amount].to_i # msats
+    address = params[:address]
+
+    validate_amount(amount)
+
+    # amount = amount / 1000 # we need sats
+    payment_request = @user.ln_create_invoice({
+      amount: amount,
+      description_hash: Digest::SHA2.hexdigest(metadata(address))
+    })
+
+    render json: {
+      status: "OK",
+      successAction: {
+        tag: "message",
+        message: "Payment received. Thanks!"
+      },
+      routes: [],
+      pr: payment_request
+    }
+  end
+
+  private
+
+  def find_user_by_address
+    address = params[:address].split("@")
+    @user = User.where(cn: address.first, ou: address.last).first
+    http_status :not_found if @user.nil?
+  end
+
+  def metadata(address)
+    "[[\"text/identifier\", \"#{address}\"], [\"text/plain\", \"Sats for #{address}\"]]"
+  end
+
+  def validate_amount(amount)
+    if amount > 1000000 || amount < 1000
+      render json: { status: "ERROR", reason: "Invalid amount" }
+      return
+    end
+  end
+
+end

app/controllers/wallet_controller.rb

@@ -27,27 +27,18 @@ class WalletController < ApplicationController
     if session["ln_auth_token"].present?
       @ln_auth_token = session["ln_auth_token"]
     else
-      res = Faraday.post("#{ENV["LNDHUB_API_URL"]}/auth?type=auth",
+      lndhub = Lndhub.new
-                         { login: current_user.ln_login, password: current_user.ln_password }.to_json,
+      auth_token = lndhub.authenticate(current_user)
-                         "Content-Type" => "application/json",
+      session["ln_auth_token"] = auth_token
-                         "Accept" => "application/json")
+      @ln_auth_token = auth_token
-
-      credentials = JSON.parse(res.body)
-      session["ln_auth_token"] = credentials["access_token"]
-      @ln_auth_token = credentials["access_token"]
     end
   rescue
     # TODO add exception tracking
   end
 
   def fetch_balance
-      res = Faraday.get("#{ENV["LNDHUB_API_URL"]}/balance", {}, {
+    lndhub = Lndhub.new
-        "Content-Type" => "application/json",
+    data = lndhub.balance @ln_auth_token
-        "Accept" => "application/json",
+    data["BTC"]["AvailableBalance"]
-        "Authorization" => "Bearer #{@ln_auth_token}"
-      })
-
-      data = JSON.parse(res.body)
-      data["BTC"]["AvailableBalance"]
   end
 end

app/helpers/lnurlpay_helper.rb

@@ -0,0 +1,2 @@
+module LnurlpayHelper
+end

app/jobs/create_lndhub_wallet_job.rb

@@ -2,14 +2,10 @@ class CreateLndhubWalletJob < ApplicationJob
   queue_as :default
 
   def perform(user)
-    res = Faraday.post("#{ENV["LNDHUB_API_URL"]}/create",
+    lndhub = Lndhub.new
-                       { partnerid: "bluewallet", accounttype: "common" }.to_json,
+    credentials = lndhub.create({ partnerid: user.ou, accounttype: "user" })
-                       "Content-Type" => "application/json")
-
-    credentials = JSON.parse(res.body)
 
     user.update! ln_login: credentials["login"],
                  ln_password: credentials["password"]
   end
-
 end

app/models/user.rb

@@ -56,4 +56,10 @@ class User < ApplicationRecord
     self.valid?
     self.errors[attribute_name].blank?
   end
+
+  def ln_create_invoice(payload)
+    lndhub = Lndhub.new
+    lndhub.authenticate self
+    lndhub.addinvoice payload
+  end
 end

app/services/lndhub.rb

@@ -0,0 +1,57 @@
+class Lndhub
+  attr_accessor :auth_token
+
+  def initialize
+    @base_url = ENV["LNDHUB_API_URL"]
+  end
+
+  def post(endpoint, payload)
+    headers = { "Content-Type" => "application/json" }
+    if auth_token
+      headers.merge!({ "Authorization" => "Bearer #{auth_token}" })
+    end
+
+    res = Faraday.post "#{@base_url}/#{endpoint}", payload.to_json, headers
+
+    if res.status != 200
+      Rails.logger.error "[lndhub] API request failed:"
+      Rails.logger.error res.body
+      #TODO add some kind of exception tracking/notifications
+    end
+
+    JSON.parse(res.body)
+  end
+
+  def get(endpoint, auth_token)
+    res = Faraday.get("#{@base_url}/#{endpoint}", {}, {
+      "Content-Type" => "application/json",
+      "Accept" => "application/json",
+      "Authorization" => "Bearer #{auth_token}"
+    })
+
+    JSON.parse(res.body)
+  end
+
+  def create(payload)
+    post "create", payload
+  end
+
+  def authenticate(user)
+    credentials = post "auth?type=auth", { login: user.ln_login, password: user.ln_password }
+    self.auth_token = credentials["access_token"]
+    self.auth_token
+  end
+
+  def balance(user_token)
+    get "balance", user_token || auth_token
+  end
+
+  def addinvoice(payload)
+    invoice = post "addinvoice", {
+      amt: payload[:amount],
+      description_hash: payload[:description_hash]
+    }
+
+    invoice["payment_request"]
+  end
+end

config/routes.rb

@@ -21,6 +21,9 @@ Rails.application.routes.draw do
 
   get 'wallet', to: 'wallet#index'
 
+  get 'lnurlpay/:address', to: 'lnurlpay#index', constraints: { address: /[^\/]+/}
+  get 'lnurlpay/:address/invoice', to: 'lnurlpay#invoice', constraints: { address: /[^\/]+/}
+
   namespace :admin do
     root to: 'dashboard#index'
     get 'invitations', to: 'invitations#index'

spec/helpers/lnurlpay_helper_spec.rb

@@ -0,0 +1,15 @@
+require 'rails_helper'
+
+# Specs in this file have access to a helper object that includes
+# the LnurlpayHelper. For example:
+#
+# describe LnurlpayHelper do
+#   describe "string concat" do
+#     it "concats two strings with spaces" do
+#       expect(helper.concat_strings("this","that")).to eq("this that")
+#     end
+#   end
+# end
+RSpec.describe LnurlpayHelper, type: :helper do
+  pending "add some examples to (or delete) #{__FILE__}"
+end

spec/jobs/create_lndhub_wallet_job_spec.rb

@@ -16,7 +16,7 @@ RSpec.describe CreateLndhubWalletJob, type: :job do
     perform_enqueued_jobs { job }
 
     expect(WebMock).to have_requested(:post, "http://10.1.1.163:3023/create")
-      .with { |req| req.body == '{"partnerid":"bluewallet","accounttype":"common"}' }
+      .with { |req| req.body == '{"partnerid":"kosmos.org","accounttype":"user"}' }
 
     user.reload
     expect(user.ln_login).to eq("abc123")

spec/requests/lnurlpay_spec.rb

@@ -0,0 +1,7 @@
+require 'rails_helper'
+
+RSpec.describe "Lnurlpays", type: :request do
+  describe "GET /index" do
+    pending "add some examples (or delete) #{__FILE__}"
+  end
+end