DRY up btcpay and lndhub services

Removing initialize methods from the main/manager class also allows for
different iniitalizers in specific task services

app/services/btcpay_manager/fetch_lightning_wallet_balance.rb

@@ -1,7 +1,7 @@
 module BtcpayManager
   class FetchLightningWalletBalance < BtcpayManagerService
     def call
-      res = get "stores/#{store_id}/lightning/BTC/balance"
+      res = get "/lightning/BTC/balance"
 
       {
         confirmed_balance: res["offchain"]["local"].to_i / 1000 # msats to sats

app/services/btcpay_manager/fetch_onchain_wallet_balance.rb

@@ -1,7 +1,7 @@
 module BtcpayManager
   class FetchOnchainWalletBalance < BtcpayManagerService
     def call
-      res = get "stores/#{store_id}/payment-methods/onchain/BTC/wallet"
+      res = get "/payment-methods/onchain/BTC/wallet"
 
       {
         balance: (res["balance"].to_f * 100000000).to_i, # BTC to sats

app/services/btcpay_manager_service.rb

@@ -2,23 +2,35 @@
 # API Docs: https://docs.btcpayserver.org/API/Greenfield/v1/
 #
 class BtcpayManagerService < ApplicationService
-  attr_reader :base_url, :store_id, :auth_token
-
-  def initialize
-    @base_url   = Setting.btcpay_api_url
-    @store_id   = Setting.btcpay_store_id
-    @auth_token = Setting.btcpay_auth_token
-  end
-
   private
 
-    def get(endpoint)
-      res = Faraday.get("#{base_url}/#{endpoint}", {}, {
+    def base_url
+      @base_url ||= "#{Setting.btcpay_api_url}/stores/#{Setting.btcpay_store_id}"
+    end
+
+    def auth_token
+      @auth_token ||= Setting.btcpay_auth_token
+    end
+
+    def headers
+      {
         "Content-Type" => "application/json",
         "Accept" => "application/json",
         "Authorization" => "token #{auth_token}"
-      })
+      }
+    end
 
+    def endpoint_url(path)
+      "#{base_url}/#{path.gsub(/^\//, '')}"
+    end
+
+    def get(path)
+      res = Faraday.get endpoint_url(path), {}, headers
+      JSON.parse(res.body)
+    end
+
+    def post(path, payload)
+      res = Faraday.post endpoint_url(path), payload.to_json, headers
       JSON.parse(res.body)
     end
 end

app/services/lndhub.rb

@@ -1,24 +1,20 @@
-class Lndhub
+class Lndhub < ApplicationService
   attr_accessor :auth_token
 
-  def initialize
-    @base_url = ENV["LNDHUB_API_URL"]
-  end
-
-  def post(endpoint, payload)
+  def post(path, 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
+    res = Faraday.post endpoint_url(path), payload.to_json, headers
     log_error(res) if res.status != 200
 
     JSON.parse(res.body)
   end
 
-  def get(endpoint, auth_token)
-    res = Faraday.get("#{@base_url}/#{endpoint}", {}, {
+  def get(path, auth_token)
+    res = Faraday.get(endpoint_url(path), {}, {
       "Content-Type" => "application/json",
       "Accept" => "application/json",
       "Authorization" => "Bearer #{auth_token}"
@@ -42,7 +38,7 @@ class Lndhub
     self.auth_token
   end
 
-  def balance(user_token=nil)
+  def fetch_balance(user_token=nil)
     get "balance", user_token || auth_token
   end
 
@@ -72,4 +68,14 @@ class Lndhub
       Sentry.capture_message("Lndhub API request failed: #{res.body}")
     end
   end
+
+  private
+
+    def base_url
+      @base_url ||= Setting.lndhub_api_url
+    end
+
+    def endpoint_url(path)
+      "#{base_url}/#{path.gsub(/^\//, '')}"
+    end
 end

app/services/lndhub_v2.rb

@@ -1,13 +1,13 @@
 class LndhubV2 < Lndhub
 
-  def post(endpoint, payload, options={})
+  def post(path, payload, options={})
     headers = { "Content-Type" => "application/json" }
     if auth_token
       headers.merge!({ "Authorization" => "Bearer #{auth_token}" })
     elsif options[:admin_token]
       headers.merge!({ "Authorization" => "Bearer #{options[:admin_token]}" })
     end
-    res = Faraday.post "#{@base_url}/#{endpoint}", payload.to_json, headers
+    res = Faraday.post endpoint_url(path), payload.to_json, headers
     log_error(res) if res.status != 200
 
     JSON.parse(res.body)