From 079ee8833c2e1adcdce6de707f37336339ae9eb3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A2u=20Cao?= <raucao@kosmos.org>
Date: Wed, 14 Feb 2024 11:09:03 +0100
Subject: [PATCH] Implement bitcoin donations via BTCPay

---
 .env.example                                  |   1 +
 .env.test                                     |   1 +
 app/assets/stylesheets/components/buttons.css |   5 +
 .../main_with_tabnav_component.html.erb       |   2 +-
 app/components/modal_component.html.erb       |   2 +-
 app/components/notification_component.rb      |   2 +
 app/controllers/admin/donations_controller.rb |  70 +++---
 .../contributions/donations_controller.rb     | 126 +++++++++-
 app/helpers/application_helper.rb             |   4 -
 app/helpers/btcpay_helper.rb                  |   7 +
 app/jobs/btcpay_check_donation_job.rb         |  24 ++
 app/models/donation.rb                        |  25 +-
 app/models/setting.rb                         |  11 +-
 app/services/btcpay_manager/create_invoice.rb |  21 ++
 .../btcpay_manager/fetch_exchange_rate.rb     |  14 ++
 app/services/btcpay_manager/fetch_invoice.rb  |  14 ++
 app/services/btcpay_manager_service.rb        |   4 +-
 .../admin/donations/_donation.json.jbuilder   |   2 -
 app/views/admin/donations/_form.html.erb      |  18 +-
 app/views/admin/donations/index.html.erb      |  10 +-
 app/views/admin/donations/index.json.jbuilder |   1 -
 app/views/admin/donations/show.html.erb       |  14 +-
 app/views/admin/donations/show.json.jbuilder  |   1 -
 .../contributions/donations/_bitcoin.html.erb |  36 +++
 .../contributions/donations/_list.html.erb    |  24 +-
 .../donations/_opencollective.html.erb        |   6 +
 .../contributions/donations/index.html.erb    |  48 ++--
 .../status_unprocessable_entity.html.erb      |   6 +
 config/routes.rb                              |   6 +-
 ...58_change_donation_amounts_and_currency.rb |   9 +
 .../20240214121049_add_new_donation_fields.rb |   7 +
 ...6124640_add_payment_status_to_donations.rb |   8 +
 db/schema.rb                                  |  10 +-
 spec/features/contributions/donations_spec.rb |  35 +++
 spec/fixtures/btcpay/create_invoice.rb        |  32 +++
 .../btcpay/lightning_eur_settled_invoice.json |  41 +++
 .../lightning_eur_settled_payments.json       |  46 ++++
 .../lightning_sats_settled_invoice.json       |  41 +++
 .../lightning_sats_settled_payments.json      |  46 ++++
 .../onchain_eur_processing_invoice.json       |  42 ++++
 .../onchain_eur_processing_payments.json      |  46 ++++
 .../btcpay/onchain_eur_settled_invoice.json   |  41 +++
 .../btcpay/onchain_eur_settled_payments.json  |  46 ++++
 spec/helpers/application_helper_spec.rb       |   5 -
 spec/jobs/btcpay_check_donation_job_spec.rb   |  63 +++++
 spec/requests/contributions/donations_spec.rb | 233 ++++++++++++++++++
 46 files changed, 1142 insertions(+), 114 deletions(-)
 create mode 100644 app/helpers/btcpay_helper.rb
 create mode 100644 app/jobs/btcpay_check_donation_job.rb
 create mode 100644 app/services/btcpay_manager/create_invoice.rb
 create mode 100644 app/services/btcpay_manager/fetch_exchange_rate.rb
 create mode 100644 app/services/btcpay_manager/fetch_invoice.rb
 delete mode 100644 app/views/admin/donations/_donation.json.jbuilder
 delete mode 100644 app/views/admin/donations/index.json.jbuilder
 delete mode 100644 app/views/admin/donations/show.json.jbuilder
 create mode 100644 app/views/contributions/donations/_bitcoin.html.erb
 create mode 100644 app/views/contributions/donations/_opencollective.html.erb
 create mode 100644 app/views/shared/status_unprocessable_entity.html.erb
 create mode 100644 db/migrate/20240214115058_change_donation_amounts_and_currency.rb
 create mode 100644 db/migrate/20240214121049_add_new_donation_fields.rb
 create mode 100644 db/migrate/20240216124640_add_payment_status_to_donations.rb
 create mode 100644 spec/features/contributions/donations_spec.rb
 create mode 100644 spec/fixtures/btcpay/create_invoice.rb
 create mode 100644 spec/fixtures/btcpay/lightning_eur_settled_invoice.json
 create mode 100644 spec/fixtures/btcpay/lightning_eur_settled_payments.json
 create mode 100644 spec/fixtures/btcpay/lightning_sats_settled_invoice.json
 create mode 100644 spec/fixtures/btcpay/lightning_sats_settled_payments.json
 create mode 100644 spec/fixtures/btcpay/onchain_eur_processing_invoice.json
 create mode 100644 spec/fixtures/btcpay/onchain_eur_processing_payments.json
 create mode 100644 spec/fixtures/btcpay/onchain_eur_settled_invoice.json
 create mode 100644 spec/fixtures/btcpay/onchain_eur_settled_payments.json
 create mode 100644 spec/jobs/btcpay_check_donation_job_spec.rb
 create mode 100644 spec/requests/contributions/donations_spec.rb

diff --git a/.env.example b/.env.example
index 976aaeb..4245a30 100644
--- a/.env.example
+++ b/.env.example
@@ -31,6 +31,7 @@ WEBHOOKS_ALLOWED_IPS='10.1.1.163'
 # Service Integrations
 #
 
+BTCPAY_PUBLIC_URL='https://btcpay.example.com'
 BTCPAY_API_URL='http://localhost:23001/api/v1'
 BTCPAY_STORE_ID=''
 BTCPAY_AUTH_TOKEN=''
diff --git a/.env.test b/.env.test
index c032b0e..aadec95 100644
--- a/.env.test
+++ b/.env.test
@@ -2,6 +2,7 @@ PRIMARY_DOMAIN=kosmos.org
 
 REDIS_URL='redis://localhost:6379/0'
 
+BTCPAY_PUBLIC_URL='https://btcpay.example.com'
 BTCPAY_API_URL='http://btcpay.example.com/api/v1'
 BTCPAY_STORE_ID='123456'
 
diff --git a/app/assets/stylesheets/components/buttons.css b/app/assets/stylesheets/components/buttons.css
index b879634..dde8f3c 100644
--- a/app/assets/stylesheets/components/buttons.css
+++ b/app/assets/stylesheets/components/buttons.css
@@ -32,6 +32,11 @@
            focus:ring-blue-400 focus:ring-opacity-75;
   }
 
+  .btn-emerald {
+    @apply bg-emerald-500 hover:bg-emerald-600 text-white
+           focus:ring-emerald-400 focus:ring-opacity-75;
+  }
+
   .btn-red {
     @apply bg-red-600 hover:bg-red-700 text-white
            focus:ring-red-500 focus:ring-opacity-75;
diff --git a/app/components/main_with_tabnav_component.html.erb b/app/components/main_with_tabnav_component.html.erb
index 6c578a9..60884a5 100644
--- a/app/components/main_with_tabnav_component.html.erb
+++ b/app/components/main_with_tabnav_component.html.erb
@@ -1,5 +1,5 @@
 <main class="w-full max-w-6xl mx-auto pb-12 px-4 md:px-6 lg:px-8">
-  <div class="bg-white rounded-lg shadow">
+  <div class="md:min-h-[50vh] bg-white rounded-lg shadow">
     <div class="px-6 sm:px-12 pt-2 sm:pt-4">
       <%= render partial: @tabnav_partial %>
     </div>
diff --git a/app/components/modal_component.html.erb b/app/components/modal_component.html.erb
index f8d4baf..43f6d10 100644
--- a/app/components/modal_component.html.erb
+++ b/app/components/modal_component.html.erb
@@ -12,7 +12,7 @@
 
     <!-- Modal Container -->
     <div data-modal-target="container"
-         class="max-h-screen w-auto max-w-lg relative
+         class="relative m-4 max-h-screen w-auto max-w-full
                 hidden animate-scale-in fixed inset-0 overflow-y-auto flex items-center justify-center">
       <!-- Modal Card -->
       <div class="m-1 bg-white rounded shadow">
diff --git a/app/components/notification_component.rb b/app/components/notification_component.rb
index 7b3bc84..e753190 100644
--- a/app/components/notification_component.rb
+++ b/app/components/notification_component.rb
@@ -34,6 +34,8 @@ class NotificationComponent < ViewComponent::Base
       'alert-octagon'
     when 'alert'
       'alert-octagon'
+    when 'warning'
+      'alert-octagon'
     else
       'info'
     end
diff --git a/app/controllers/admin/donations_controller.rb b/app/controllers/admin/donations_controller.rb
index 0a90184..449514f 100644
--- a/app/controllers/admin/donations_controller.rb
+++ b/app/controllers/admin/donations_controller.rb
@@ -3,18 +3,16 @@ class Admin::DonationsController < Admin::BaseController
   before_action :set_current_section, only: [:index, :show, :new, :edit]
 
   # GET /donations
-  # GET /donations.json
   def index
-    @pagy, @donations = pagy(Donation.all.order('created_at desc'))
+    @pagy, @donations = pagy(Donation.completed.order('paid_at desc'))
 
     @stats = {
-      overall_sats: @donations.all.sum("amount_sats"),
-      donor_count: Donation.distinct.count(:user_id)
+      overall_sats: @donations.sum("amount_sats"),
+      donor_count: @donations.distinct.count(:user_id)
     }
   end
 
   # GET /donations/1
-  # GET /donations/1.json
   def show
   end
 
@@ -28,54 +26,41 @@ class Admin::DonationsController < Admin::BaseController
   end
 
   # POST /donations
-  # POST /donations.json
   def create
     @donation = Donation.new(donation_params)
 
-    respond_to do |format|
-      if @donation.save
-        format.html do
-          redirect_to admin_donation_url(@donation), flash: {
-            success: 'Donation was successfully created.'
-          }
-        end
-        format.json { render :show, status: :created, location: @donation }
-      else
-        format.html { render :new, status: :unprocessable_entity }
-        format.json { render json: @donation.errors, status: :unprocessable_entity }
-      end
+    if @donation.paid_at == nil
+      @donation.errors.add(:paid_at, message: "is required")
+      render :new, status: :unprocessable_entity and return
+    end
+
+    if @donation.save
+      redirect_to admin_donation_url(@donation), flash: {
+        success: 'Donation was successfully created.'
+      }
+    else
+      render :new, status: :unprocessable_entity
     end
   end
 
-  # PATCH/PUT /donations/1
-  # PATCH/PUT /donations/1.json
+  # PUT /donations/1
   def update
-    respond_to do |format|
-      if @donation.update(donation_params)
-        format.html do
-          redirect_to admin_donation_url(@donation), flash: {
-            success: 'Donation was successfully updated.'
-          }
-        end
-        format.json { render :show, status: :ok, location: @donation }
-      else
-        format.html { render :edit, status: :unprocessable_entity }
-        format.json { render json: @donation.errors, status: :unprocessable_entity }
-      end
+    if @donation.update(donation_params)
+      redirect_to admin_donation_url(@donation), flash: {
+        success: 'Donation was successfully updated.'
+      }
+    else
+      render :edit, status: :unprocessable_entity
     end
   end
 
   # DELETE /donations/1
-  # DELETE /donations/1.json
   def destroy
     @donation.destroy
-    respond_to do |format|
-      format.html do redirect_to admin_donations_url, flash: {
-        success: 'Donation was successfully destroyed.'
-      }
-      end
-      format.json { head :no_content }
-    end
+
+    redirect_to admin_donations_url, flash: {
+      success: 'Donation was successfully destroyed.'
+    }
   end
 
   private
@@ -86,7 +71,10 @@ class Admin::DonationsController < Admin::BaseController
 
     # Only allow a list of trusted parameters through.
     def donation_params
-      params.require(:donation).permit(:user_id, :amount_sats, :amount_eur, :amount_usd, :public_name, :paid_at)
+      params.require(:donation).permit(
+        :user_id, :donation_method,
+        :amount_sats, :fiat_amount, :fiat_currency,
+        :public_name, :paid_at)
     end
 
     def set_current_section
diff --git a/app/controllers/contributions/donations_controller.rb b/app/controllers/contributions/donations_controller.rb
index 1533abb..404f203 100644
--- a/app/controllers/contributions/donations_controller.rb
+++ b/app/controllers/contributions/donations_controller.rb
@@ -1,10 +1,128 @@
 class Contributions::DonationsController < ApplicationController
-  before_action :authenticate_user!
+  include BtcpayHelper
 
-  # GET /donations
-  # GET /donations.json
+  before_action :authenticate_user!
+  before_action :set_donation_methods, only: [:index, :create]
+  before_action :require_donation_method_enabled, only: [:create]
+  before_action :validate_donation_params, only: [:create]
+  before_action :set_donation, only: [:confirm_btcpay]
+
+  # GET /contributions/donations
   def index
-    @donations = current_user.donations.completed
     @current_section = :contributions
+    @donations_completed = current_user.donations.completed.order('paid_at desc')
+    @donations_pending = current_user.donations.processing.order('created_at desc')
+
+    if Setting.lndhub_enabled?
+      begin
+        lndhub_authenticate
+        lndhub_fetch_balance
+      rescue
+        @balance = 0
+      end
+    end
   end
+
+  # POST /contributions/donations
+  def create
+    if params[:currency] == "sats"
+      fiat_amount = nil
+      fiat_currency = nil
+    else
+      fiat_amount = params[:amount].to_i
+      fiat_currency = params[:currency]
+      amount_sats = nil
+    end
+
+    @donation = current_user.donations.create!(
+      donation_method: params[:donation_method],
+      payment_method: nil,
+      paid_at: nil,
+      amount_sats: amount_sats,
+      fiat_amount: (fiat_amount.nil? ? nil : fiat_amount * 100), # store in cents
+      fiat_currency: fiat_currency,
+      public_name: params[:public_name]
+    )
+
+    case params[:donation_method]
+    when "btcpay"
+      res = BtcpayManager::CreateInvoice.call(
+        amount: fiat_amount || (amount_sats.to_f / 100000000),
+        currency: fiat_currency || "BTC",
+        redirect_url: confirm_btcpay_contributions_donation_url(@donation)
+      )
+
+      @donation.update! btcpay_invoice_id: res["id"]
+
+      redirect_to btcpay_checkout_url(res["id"]), allow_other_host: true
+    else
+      redirect_to contributions_donations_url, flash: {
+        error: "Donation method currently not available"
+      }
+    end
+  end
+
+  def confirm_btcpay
+    redirect_to contributions_donations_url and return if @donation.completed?
+
+    invoice = BtcpayManager::FetchInvoice.call(invoice_id: @donation.btcpay_invoice_id)
+
+    if @donation.amount_sats.present?
+      # TODO make default fiat currency configurable and/or determine from user's
+      # i18n browser settings
+      @donation.fiat_currency = "EUR"
+      exchange_rate = BtcpayManager::FetchExchangeRate.call(fiat_currency: @donation.fiat_currency)
+      @donation.fiat_amount = (((@donation.amount_sats.to_f / 100000000) * exchange_rate) * 100).to_i
+    else
+      amt_str = invoice["paymentMethods"].first["amount"]
+      @donation.amount_sats = amt_str.tr(".","").sub(/0*$/, "").to_i
+    end
+
+    case invoice["status"]
+    when "Settled"
+      @donation.paid_at = DateTime.now
+      @donation.payment_status = "settled"
+      @donation.save!
+      flash_message = { success: "Thank you!" }
+    when "Processing"
+      unless @donation.processing?
+        @donation.payment_status = "processing"
+        @donation.save!
+        flash_message = { success: "Thank you! We will send you an email when the payment is confirmed." }
+        BtcpayCheckDonationJob.set(wait: 20.seconds).perform_later(@donation)
+      end
+    when "Expired"
+      flash_message = { warning: "The payment request for this donation has expired" }
+    else
+      flash_message = { warning: "Could not determine status of payment" }
+    end
+
+    redirect_to contributions_donations_url, flash: flash_message
+  end
+
+  private
+
+    def set_donation
+      @donation = current_user.donations.find_by(id: params[:id])
+      http_status :not_found unless @donation.present?
+    end
+
+    def set_donation_methods
+      @donation_methods = []
+      @donation_methods.push :btcpay if Setting.btcpay_enabled?
+      @donation_methods.push :lndhub if Setting.lndhub_enabled?
+      @donation_methods.push :opencollective if Setting.opencollective_enabled?
+    end
+
+    def require_donation_method_enabled
+      http_status :forbidden unless @donation_methods.include?(
+        params[:donation_method].to_sym
+      )
+    end
+
+    def validate_donation_params
+      if !%w[EUR USD sats].include?(params[:currency]) || (params[:amount].to_i <= 0)
+        http_status :unprocessable_entity
+      end
+    end
 end
diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index b4b4f69..50959f6 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -1,10 +1,6 @@
 module ApplicationHelper
   include Pagy::Frontend
 
-  def sats_to_btc(sats)
-    sats.to_f / 100000000
-  end
-
   def main_nav_class(current_section, link_to_section)
     if current_section == link_to_section
       "bg-gray-900/50 text-white px-3 py-2 rounded-md font-medium text-base md:text-sm block md:inline-block"
diff --git a/app/helpers/btcpay_helper.rb b/app/helpers/btcpay_helper.rb
new file mode 100644
index 0000000..a039a50
--- /dev/null
+++ b/app/helpers/btcpay_helper.rb
@@ -0,0 +1,7 @@
+module BtcpayHelper
+
+  def btcpay_checkout_url(invoice_id)
+    "#{Setting.btcpay_public_url}/i/#{invoice_id}"
+  end
+
+end
diff --git a/app/jobs/btcpay_check_donation_job.rb b/app/jobs/btcpay_check_donation_job.rb
new file mode 100644
index 0000000..3d89028
--- /dev/null
+++ b/app/jobs/btcpay_check_donation_job.rb
@@ -0,0 +1,24 @@
+class BtcpayCheckDonationJob < ApplicationJob
+  queue_as :default
+
+  def perform(donation)
+    return if donation.completed?
+
+    invoice = BtcpayManager::FetchInvoice.call(invoice_id: donation.btcpay_invoice_id)
+
+    case invoice["status"]
+    when "Settled"
+      # TODO use time from actual payment confirmation
+      donation.paid_at = DateTime.now
+      donation.payment_status = "settled"
+      donation.save!
+      # TODO send email
+    when "Processing"
+      re_enqueue_job(donation)
+    end
+  end
+
+  def re_enqueue_job(donation)
+    self.class.set(wait: 20.seconds).perform_later(donation)
+  end
+end
diff --git a/app/models/donation.rb b/app/models/donation.rb
index 1a374dd..9799ae6 100644
--- a/app/models/donation.rb
+++ b/app/models/donation.rb
@@ -4,12 +4,25 @@ class Donation < ApplicationRecord
 
   # Validations
   validates_presence_of :user
-  validates_presence_of :amount_sats
-  validates_presence_of :paid_at
-
-  # Hooks
-  # TODO before_create :store_fiat_value
+  validates_presence_of :donation_method,
+    inclusion: { in: %w[ custom btcpay lndhub ] }
+  validates_presence_of :payment_status, allow_nil: true,
+    inclusion: { in: %w[ processing settled ] }
+  validates_presence_of :paid_at, allow_nil: true
+  validates_presence_of :amount_sats, allow_nil: true
+  validates_presence_of :fiat_amount, allow_nil: true
+  validates_presence_of :fiat_currency, allow_nil: true,
+    inclusion: { in: %w[ EUR USD ] }
 
   #Scopes
-  scope :completed, -> { where.not(paid_at: nil) }
+  scope :processing, -> { where(payment_status: "processing") }
+  scope :completed, -> { where(payment_status: "settled") }
+
+  def processing?
+    payment_status == "processing"
+  end
+
+  def completed?
+    payment_status == "settled"
+  end
 end
diff --git a/app/models/setting.rb b/app/models/setting.rb
index daa4b29..4796ab4 100644
--- a/app/models/setting.rb
+++ b/app/models/setting.rb
@@ -51,6 +51,9 @@ class Setting < RailsSettings::Base
   field :btcpay_enabled, type: :boolean,
     default: ENV["BTCPAY_API_URL"].present?
 
+  field :btcpay_public_url, type: :string,
+    default: ENV["BTCPAY_PUBLIC_URL"].presence
+
   field :btcpay_store_id, type: :string,
     default: ENV["BTCPAY_STORE_ID"].presence
 
@@ -157,7 +160,13 @@ class Setting < RailsSettings::Base
   # Nostr
   #
 
-  field :nostr_enabled, type: :boolean, default: true
+  field :nostr_enabled, type: :boolean, default: false
+
+  #
+  # OpenCollective
+  #
+
+  field :opencollective_enabled, type: :boolean, default: true
 
   #
   # RemoteStorage
diff --git a/app/services/btcpay_manager/create_invoice.rb b/app/services/btcpay_manager/create_invoice.rb
new file mode 100644
index 0000000..423576e
--- /dev/null
+++ b/app/services/btcpay_manager/create_invoice.rb
@@ -0,0 +1,21 @@
+module BtcpayManager
+  class CreateInvoice < BtcpayManagerService
+    def initialize(amount:, currency:, redirect_url:)
+      @amount = amount
+      @currency = currency
+      @redirect_url = redirect_url
+    end
+
+    def call
+      post "/invoices", {
+        amount: @amount.to_s,
+        currency: @currency,
+        checkout: {
+          redirectURL: @redirect_url,
+          redirectAutomatically: true,
+          requiresRefundEmail: false
+        }
+      }
+    end
+  end
+end
diff --git a/app/services/btcpay_manager/fetch_exchange_rate.rb b/app/services/btcpay_manager/fetch_exchange_rate.rb
new file mode 100644
index 0000000..2673c78
--- /dev/null
+++ b/app/services/btcpay_manager/fetch_exchange_rate.rb
@@ -0,0 +1,14 @@
+module BtcpayManager
+  class FetchExchangeRate < BtcpayManagerService
+    def initialize(fiat_currency:)
+      @fiat_currency = fiat_currency
+    end
+
+    def call
+      pair_str = "BTC_#{@fiat_currency}"
+      res = get "rates", { currencyPair: pair_str }
+      pair = res.find{|p| p["currencyPair"] == pair_str }
+      rate = pair["rate"].to_f
+    end
+  end
+end
diff --git a/app/services/btcpay_manager/fetch_invoice.rb b/app/services/btcpay_manager/fetch_invoice.rb
new file mode 100644
index 0000000..d7a5682
--- /dev/null
+++ b/app/services/btcpay_manager/fetch_invoice.rb
@@ -0,0 +1,14 @@
+module BtcpayManager
+  class FetchInvoice < BtcpayManagerService
+    def initialize(invoice_id:)
+      @invoice_id = invoice_id
+    end
+
+    def call
+      invoice = get "/invoices/#{@invoice_id}"
+      payment_methods = get "/invoices/#{@invoice_id}/payment-methods"
+      invoice["paymentMethods"] = payment_methods
+      invoice
+    end
+  end
+end
diff --git a/app/services/btcpay_manager_service.rb b/app/services/btcpay_manager_service.rb
index b91e897..4dedb61 100644
--- a/app/services/btcpay_manager_service.rb
+++ b/app/services/btcpay_manager_service.rb
@@ -24,8 +24,8 @@ class BtcpayManagerService < ApplicationService
       "#{base_url}/#{path.gsub(/^\//, '')}"
     end
 
-    def get(path)
-      res = Faraday.get endpoint_url(path), {}, headers
+    def get(path, params = {})
+      res = Faraday.get endpoint_url(path), params, headers
       JSON.parse(res.body)
     end
 
diff --git a/app/views/admin/donations/_donation.json.jbuilder b/app/views/admin/donations/_donation.json.jbuilder
deleted file mode 100644
index 51574aa..0000000
--- a/app/views/admin/donations/_donation.json.jbuilder
+++ /dev/null
@@ -1,2 +0,0 @@
-json.extract! donation, :id, :user_id, :amount_sats, :amount_eur, :amount_usd, :public_name, :created_at, :updated_at
-json.url donation_url(donation, format: :json)
diff --git a/app/views/admin/donations/_form.html.erb b/app/views/admin/donations/_form.html.erb
index f780a2e..67ed69f 100644
--- a/app/views/admin/donations/_form.html.erb
+++ b/app/views/admin/donations/_form.html.erb
@@ -14,14 +14,24 @@
     <%= form.label :user_id %>
     <%= form.collection_select :user_id, User.where(ou: Setting.primary_domain).order(:cn), :id, :cn, {} %>
 
+    <%= form.label :donation_method, "Donation method" %>
+    <%= form.select :donation_method, options_for_select([
+          ["Custom (manual)", "custom"],
+          ["BTCPay", "btcpay"],
+          ["LndHub account", "lndhub"],
+          ["OpenCollective", "opencollective"]
+        ], selected: (donation.donation_method || "custom")) %>
+
     <%= form.label :amount_sats, "Amount BTC (sats)" %>
     <%= form.number_field :amount_sats %>
 
-    <%= form.label :amount_eur, "Amount EUR (cents)" %>
-    <%= form.number_field :amount_eur %>
+    <%= form.label :fiat_amount, "Fiat Amount (cents)" %>
+    <%= form.number_field :fiat_amount %>
 
-    <%= form.label :amount_usd, "Amount USD (cents)"%>
-    <%= form.number_field :amount_usd %>
+    <%= form.label :fiat_currency, "Fiat Currency" %>
+    <%= form.select :fiat_currency, options_for_select([
+          ["EUR", "EUR"], ["USD", "USD"], ["sats", "sats"]
+        ], selected: donation.fiat_currency) %>
 
     <%= form.label :public_name %>
     <%= form.text_field :public_name %>
diff --git a/app/views/admin/donations/index.html.erb b/app/views/admin/donations/index.html.erb
index f13e94b..bbf1a9e 100644
--- a/app/views/admin/donations/index.html.erb
+++ b/app/views/admin/donations/index.html.erb
@@ -25,9 +25,8 @@
       <thead>
         <tr>
           <th>User</th>
-          <th class="text-right">Amount BTC</th>
-          <th class="text-right">in EUR</th>
-          <th class="text-right">in USD</th>
+          <th class="text-right">Sats</th>
+          <th class="text-right">Fiat Amount</th>
           <th class="pl-2">Public name</th>
           <th>Date</th>
           <th></th>
@@ -37,9 +36,8 @@
         <% @donations.each do |donation| %>
           <tr>
             <td><%= link_to donation.user.address, admin_user_path(donation.user.address), class: 'ks-text-link' %></td>
-            <td class="text-right"><%= sats_to_btc donation.amount_sats %></td>
-            <td class="text-right"><% if donation.amount_eur.present? %><%= number_to_currency donation.amount_eur / 100, unit: "" %><% end %></td>
-            <td class="text-right"><% if donation.amount_usd.present? %><%= number_to_currency donation.amount_usd / 100, unit: "" %><% end %></td>
+            <td class="text-right"><% if donation.amount_sats.present? %><%= number_with_delimiter donation.amount_sats %><% end %></td>
+            <td class="text-right"><% if donation.fiat_amount.present? %><%= number_to_currency donation.fiat_amount.to_f / 100, unit: "" %> <%= donation.fiat_currency %><% end %></td>
             <td class="pl-2"><%= donation.public_name %></td>
             <td><%= donation.paid_at ? donation.paid_at.strftime("%Y-%m-%d (%H:%M UTC)") : "" %></td>
             <td class="text-right">
diff --git a/app/views/admin/donations/index.json.jbuilder b/app/views/admin/donations/index.json.jbuilder
deleted file mode 100644
index 9df428c..0000000
--- a/app/views/admin/donations/index.json.jbuilder
+++ /dev/null
@@ -1 +0,0 @@
-json.array! @donations, partial: "donations/donation", as: :donation
diff --git a/app/views/admin/donations/show.html.erb b/app/views/admin/donations/show.html.erb
index bec899d..1853eb2 100644
--- a/app/views/admin/donations/show.html.erb
+++ b/app/views/admin/donations/show.html.erb
@@ -8,17 +8,17 @@
           <th>User</th>
           <td><%= link_to @donation.user.address, admin_user_path(@donation.user.address), class: 'ks-text-link' %></td>
         </tr>
+        <tr>
+          <th>Donation Method</th>
+          <td><%= @donation.donation_method %></td>
+        </tr>
         <tr>
           <th>Amount sats</th>
           <td><%= @donation.amount_sats %></td>
         </tr>
         <tr>
-          <th>Amount EUR</th>
-          <td><%= @donation.amount_eur %></td>
-        </tr>
-        <tr>
-          <th>Amount USD</th>
-          <td><%= @donation.amount_usd %></td>
+          <th>Fiat amount</th>
+          <td><% if @donation.fiat_amount.present? %><%= number_to_currency @donation.fiat_amount.to_f / 100, unit: "" %> <%= @donation.fiat_currency %><% end %></td>
         </tr>
         <tr>
           <th>Public name</th>
@@ -26,7 +26,7 @@
         </tr>
         <tr>
           <th>Date</th>
-          <td><%= @donation.paid_at.strftime("%Y-%m-%d (%H:%M UTC)") %></td>
+          <td><%= @donation.paid_at&.strftime("%Y-%m-%d (%H:%M UTC)") %></td>
         </tr>
       </tbody>
     </table>
diff --git a/app/views/admin/donations/show.json.jbuilder b/app/views/admin/donations/show.json.jbuilder
deleted file mode 100644
index a152e38..0000000
--- a/app/views/admin/donations/show.json.jbuilder
+++ /dev/null
@@ -1 +0,0 @@
-json.partial! "donations/donation", donation: @donation
diff --git a/app/views/contributions/donations/_bitcoin.html.erb b/app/views/contributions/donations/_bitcoin.html.erb
new file mode 100644
index 0000000..6382045
--- /dev/null
+++ b/app/views/contributions/donations/_bitcoin.html.erb
@@ -0,0 +1,36 @@
+<div class="rounded-lg p-6 bg-emerald-50 hover:bg-emerald-100 transition-colors">
+  <h3 class="mb-4 text-lg font-bold">Donate directly with Bitcoin</h3>
+  <p class="mb-6">
+    Open-source money for open-source services.
+  </p>
+  <div data-controller="modal" data-action="keydown.esc->modal#close">
+    <button class="btn-md btn-emerald w-full lg:w-1/2" data-action="click->modal#open">
+      Donate
+    </button>
+    <%= render ModalComponent.new(show_close_button: false) do %>
+      <div>
+        <h3>Your contribution</h3>
+
+        <%= form_with(url: contributions_donations_url, method: :post) do |f| %>
+          <%= f.hidden_field :donation_method, value: "btcpay" %>
+
+          <div class="mb-6 flex gap-2">
+            <%= f.number_field :amount, required: true %>
+            <%= f.select :currency, options_for_select([
+                  ["EUR", "EUR"], ["USD", "USD"], ["sats", "sats"]
+                ], selected: "EUR"), class: "flex-none" %>
+          </div>
+
+          <%= render FormElements::FieldsetComponent.new(tag: "div", title: "Public name") do %>
+            <%= f.text_field :public_name, class: "w-full", placeholder: "Anonymous"  %>
+          <% end %>
+
+          <p class="mt-12">
+            <%= f.submit 'Continue', data: { turbo: false },
+                  class: "btn-md btn-blue w-full" %>
+          </p>
+        <% end %>
+      </div>
+    <% end %>
+  </div>
+</div>
diff --git a/app/views/contributions/donations/_list.html.erb b/app/views/contributions/donations/_list.html.erb
index 8932dd3..16338c9 100644
--- a/app/views/contributions/donations/_list.html.erb
+++ b/app/views/contributions/donations/_list.html.erb
@@ -1,8 +1,12 @@
 <ul class="list-none">
   <% donations.each do |donation| %>
-    <li class="mb-8 grid gap-y-2 gap-x-8 grid-cols-2 items-center">
+    <li class="mb-8 grid gap-y-2 grid-cols-2 items-center">
       <h3 class="mb-0">
+        <% if donation.completed? %>
         <%= donation.paid_at.strftime("%B %d, %Y") %>
+        <% else %>
+        <%= donation.created_at.strftime("%B %d, %Y") %>
+        <% end %>
       </h3>
       <p class="row-span-2 font-mono text-right mb-0">
         <span class="text-xl">
@@ -10,14 +14,22 @@
         </span>
         <br>
         <span class="text-sm text-gray-500">
-          (~ <%= number_to_currency donation.amount_eur / 100, unit: "" %> EUR)
+          (~ <%= number_to_currency donation.fiat_amount.to_f / 100, unit: "" %> <%= donation.fiat_currency %>)
         </span>
       </p>
-      <p class="mb-0">
-        <% if donation.public_name.present? %>
-          Public name: <%= donation.public_name %>
+      <p class="mb-0 text-gray-500">
+        <% if donation.processing? %>
+          Waiting for confirmations
+          <% if donation.donation_method == "btcpay" %>
+            <%= link_to "check status", btcpay_checkout_url(donation.btcpay_invoice_id),
+                  class: "ml-2 btn-sm btn-gray" %>
+          <% end %>
         <% else %>
-          Anonymous
+          <% if donation.public_name.present? %>
+            As: <%= donation.public_name %>
+          <% else %>
+            Anonymous
+          <% end %>
         <% end %>
       </p>
     </li>
diff --git a/app/views/contributions/donations/_opencollective.html.erb b/app/views/contributions/donations/_opencollective.html.erb
new file mode 100644
index 0000000..433b286
--- /dev/null
+++ b/app/views/contributions/donations/_opencollective.html.erb
@@ -0,0 +1,6 @@
+<div class="rounded-lg p-6 bg-zinc-100 hover:bg-zinc-200 transition-colors">
+  <h3 class="mb-4 text-lg font-bold text-gray-500">Donate via OpenCollective</h3>
+  <p class="text-gray-600 text-gray-500">
+    Coming soon.
+  </p>
+</div>
diff --git a/app/views/contributions/donations/index.html.erb b/app/views/contributions/donations/index.html.erb
index 2398fac..3e03617 100644
--- a/app/views/contributions/donations/index.html.erb
+++ b/app/views/contributions/donations/index.html.erb
@@ -6,23 +6,35 @@
       Your financial contributions to the development and upkeep of Kosmos
       software and services.
     </p>
-    <% if @donations.any? %>
-      <%= render partial: "contributions/donations/list",
-                 locals: { donations: @donations } %>
-    <% else %>
-      <div class="text-center">
-        <p class="mt-8 mb-12 inline-flex align-center items-center">
-          <%= image_tag("/img/illustrations/undraw_savings_re_eq4w.svg", class: 'h-48') %>
-        </p>
-        <h3>
-          No donations yet
-        </h3>
-        <p class="text-gray-500">
-          The donation process is not automated yet.<br>Please
-          <a href="https://wiki.kosmos.org/Main_Page#Community_.2F_Getting_in_touch_.2F_Getting_involved" class="ks-text-link" target="_blank">contact us</a>
-          if you'd like to contribute this way right now.
-        </p>
-      </div>
-    <% end %>
   </section>
+
+  <section class="donation-methods">
+    <div class="grid grid-cols-1 sm:grid-cols-2 gap-4 sm:gap-6">
+      <% if @donation_methods.include?(:btcpay) ||
+            @donation_methods.include?(:lndhub) %>
+        <%= render partial: "contributions/donations/bitcoin", locals: {
+          donation_methods: @donation_methods, lndhub_balance: @balance
+        } %>
+      <% end %>
+      <% if @donation_methods.include?(:opencollective) %>
+        <%= render partial: "contributions/donations/opencollective" %>
+      <% end %>
+    </div>
+  </section>
+
+  <% if @donations_pending.any? %>
+  <section class="donation-list">
+    <h2>Pending</h2>
+    <%= render partial: "contributions/donations/list",
+               locals: { donations: @donations_pending } %>
+  </section>
+  <% end %>
+
+  <% if @donations_completed.any? %>
+  <section class="donation-list">
+    <h2>Past contributions</h2>
+    <%= render partial: "contributions/donations/list",
+               locals: { donations: @donations_completed } %>
+  </section>
+  <% end %>
 <% end %>
diff --git a/app/views/shared/status_unprocessable_entity.html.erb b/app/views/shared/status_unprocessable_entity.html.erb
new file mode 100644
index 0000000..47d5f6d
--- /dev/null
+++ b/app/views/shared/status_unprocessable_entity.html.erb
@@ -0,0 +1,6 @@
+<%= render HeaderCompactComponent.new(title: "422") %>
+
+<%= render MainCompactComponent.new do %>
+  <h2>Unprocessable content</h2>
+  <p>The data provided was malformed. Please go back and try again.</p>
+<% end %>
diff --git a/config/routes.rb b/config/routes.rb
index 39e69f2..4307f9e 100644
--- a/config/routes.rb
+++ b/config/routes.rb
@@ -12,8 +12,12 @@ Rails.application.routes.draw do
 
   namespace :contributions do
     root to: 'donations#index'
+    resources :donations, only: ['index', 'create'] do
+      member do
+        get 'confirm_btcpay'
+      end
+    end
     get 'projects', to: 'projects#index'
-    resources :donations, only: ['index']
   end
 
   resources :invitations, only: ['index', 'show', 'create', 'destroy']
diff --git a/db/migrate/20240214115058_change_donation_amounts_and_currency.rb b/db/migrate/20240214115058_change_donation_amounts_and_currency.rb
new file mode 100644
index 0000000..9a14641
--- /dev/null
+++ b/db/migrate/20240214115058_change_donation_amounts_and_currency.rb
@@ -0,0 +1,9 @@
+class ChangeDonationAmountsAndCurrency < ActiveRecord::Migration[7.1]
+  def change
+    rename_column :donations, :amount_usd, :fiat_amount
+    add_column :donations, :fiat_currency, :string, default: "USD"
+    remove_column :donations, :amount_eur, :integer
+
+    Donation.update_all(fiat_currency: 'USD')
+  end
+end
diff --git a/db/migrate/20240214121049_add_new_donation_fields.rb b/db/migrate/20240214121049_add_new_donation_fields.rb
new file mode 100644
index 0000000..1c9873c
--- /dev/null
+++ b/db/migrate/20240214121049_add_new_donation_fields.rb
@@ -0,0 +1,7 @@
+class AddNewDonationFields < ActiveRecord::Migration[7.1]
+  def change
+    add_column :donations, :donation_method, :string
+    add_column :donations, :payment_method, :string, default: nil
+    add_column :donations, :btcpay_invoice_id, :string, default: nil
+  end
+end
diff --git a/db/migrate/20240216124640_add_payment_status_to_donations.rb b/db/migrate/20240216124640_add_payment_status_to_donations.rb
new file mode 100644
index 0000000..613179c
--- /dev/null
+++ b/db/migrate/20240216124640_add_payment_status_to_donations.rb
@@ -0,0 +1,8 @@
+class AddPaymentStatusToDonations < ActiveRecord::Migration[7.1]
+  def change
+    add_column :donations, :payment_status, :string, default: nil
+    add_index :donations, :payment_status
+
+    Donation.completed.update_all payment_status: "settled"
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
index e558da8..dd267df 100644
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_02_07_080515) do
+ActiveRecord::Schema[7.1].define(version: 2024_02_16_124640) do
   create_table "active_storage_attachments", force: :cascade do |t|
     t.string "name", null: false
     t.string "record_type", null: false
@@ -50,12 +50,16 @@ ActiveRecord::Schema[7.1].define(version: 2024_02_07_080515) do
   create_table "donations", force: :cascade do |t|
     t.integer "user_id"
     t.integer "amount_sats"
-    t.integer "amount_eur"
-    t.integer "amount_usd"
+    t.integer "fiat_amount"
     t.string "public_name"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
     t.datetime "paid_at", precision: nil
+    t.string "fiat_currency", default: "USD"
+    t.string "donation_method"
+    t.string "payment_method"
+    t.string "btcpay_invoice_id"
+    t.string "payment_status"
     t.index ["user_id"], name: "index_donations_on_user_id"
   end
 
diff --git a/spec/features/contributions/donations_spec.rb b/spec/features/contributions/donations_spec.rb
new file mode 100644
index 0000000..1bbb475
--- /dev/null
+++ b/spec/features/contributions/donations_spec.rb
@@ -0,0 +1,35 @@
+require 'rails_helper'
+
+RSpec.describe 'Donations page', type: :feature do
+  let(:user) { create :user }
+
+  before do
+    login_as user, :scope => :user
+  end
+
+  describe "Donation methods" do
+    scenario "Only BTCPay enabled" do
+      Setting.btcpay_enabled = true
+      Setting.lndhub_enabled = false
+      Setting.opencollective_enabled = false
+      visit contributions_donations_url
+
+      within ".donation-methods" do
+        expect(page).to have_content("Bitcoin")
+        expect(page).not_to have_content("OpenCollective")
+      end
+    end
+
+    scenario "Only OpenCollective enabled" do
+      Setting.btcpay_enabled = false
+      Setting.lndhub_enabled = false
+      Setting.opencollective_enabled = true
+      visit contributions_donations_url
+
+      within ".donation-methods" do
+        expect(page).not_to have_content("Bitcoin")
+        expect(page).to have_content("OpenCollective")
+      end
+    end
+  end
+end
diff --git a/spec/fixtures/btcpay/create_invoice.rb b/spec/fixtures/btcpay/create_invoice.rb
new file mode 100644
index 0000000..6b9563f
--- /dev/null
+++ b/spec/fixtures/btcpay/create_invoice.rb
@@ -0,0 +1,32 @@
+{
+  "id" => "Q9GBe143MXHkdpZeH4Ftx5",
+  "storeId" => "AxQQ6oH4YX7n5pH1JPBLu97QD6RTybtj8m2W8YzhYr6T",
+  "amount" => "1",
+  "checkoutLink" => "http://10.1.1.163:23001/i/Q9GBe143MXHkdpZeH4Ftx5",
+  "status" => "New",
+  "additionalStatus" => "None",
+  "monitoringExpiration" => 1707995026,
+  "expirationTime" => 1707908626,
+  "createdTime" => 1707907726,
+  "availableStatusesForManualMarking" =>["Settled", "Invalid"],
+  "archived" => false,
+  "type" => "Standard",
+  "currency" => "EUR",
+  "metadata" => {},
+  "checkout" => {
+    "speedPolicy" => "MediumSpeed",
+    "paymentMethods" => ["BTC", "BTC-LightningNetwork"],
+    "defaultPaymentMethod" => "BTC-LightningNetwork",
+    "expirationMinutes" => 15,
+    "monitoringMinutes" => 1440,
+    "paymentTolerance" => 0.0,
+    "redirectURL" => "http://localhost:3000/contributions/donations",
+    "redirectAutomatically" => false,
+    "requiresRefundEmail" => false,
+    "defaultLanguage" => nil,
+    "checkoutType" => nil,
+    "lazyPaymentMethods" => nil},
+    "receipt" => {
+      "enabled" => nil, "showQR" => nil, "showPayments" => nil
+    }
+}
diff --git a/spec/fixtures/btcpay/lightning_eur_settled_invoice.json b/spec/fixtures/btcpay/lightning_eur_settled_invoice.json
new file mode 100644
index 0000000..533b7dc
--- /dev/null
+++ b/spec/fixtures/btcpay/lightning_eur_settled_invoice.json
@@ -0,0 +1,41 @@
+{
+  "id": "MCkDbf2cUgBuuisUCgnRnb",
+  "storeId": "AxQQ6oH4YX7n5pH1JPBLu97QD6RTybtj8m2W8YzhYr6T",
+  "amount": "1",
+  "checkoutLink": "http://10.1.1.163:23001/i/MCkDbf2cUgBuuisUCgnRnb",
+  "status": "Settled",
+  "additionalStatus": "None",
+  "monitoringExpiration": 1708169508,
+  "expirationTime": 1708083108,
+  "createdTime": 1708082208,
+  "availableStatusesForManualMarking": [
+
+  ],
+  "archived": false,
+  "type": "Standard",
+  "currency": "EUR",
+  "metadata": {
+  },
+  "checkout": {
+    "speedPolicy": "MediumSpeed",
+    "paymentMethods": [
+      "BTC",
+      "BTC-LightningNetwork"
+    ],
+    "defaultPaymentMethod": "BTC-LightningNetwork",
+    "expirationMinutes": 15,
+    "monitoringMinutes": 1440,
+    "paymentTolerance": 0.0,
+    "redirectURL": "http://localhost:3000/contributions/donations/27/confirm_btcpay",
+    "redirectAutomatically": true,
+    "requiresRefundEmail": false,
+    "defaultLanguage": null,
+    "checkoutType": null,
+    "lazyPaymentMethods": null
+  },
+  "receipt": {
+    "enabled": null,
+    "showQR": null,
+    "showPayments": null
+  }
+}
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/lightning_eur_settled_payments.json b/spec/fixtures/btcpay/lightning_eur_settled_payments.json
new file mode 100644
index 0000000..483e05f
--- /dev/null
+++ b/spec/fixtures/btcpay/lightning_eur_settled_payments.json
@@ -0,0 +1,46 @@
+[
+  {
+    "activated": true,
+    "destination": "bc1qtvwjguv679lcch9a9zxzxcengq3t3zgd5zm0pd",
+    "paymentLink": "bitcoin:bc1qtvwjguv679lcch9a9zxzxcengq3t3zgd5zm0pd",
+    "rate": "48532.8",
+    "paymentMethodPaid": "0",
+    "totalPaid": "0.00002061",
+    "due": "0",
+    "amount": "0.00002061",
+    "networkFee": "0",
+    "payments": [
+
+    ],
+    "paymentMethod": "BTC",
+    "cryptoCode": "BTC",
+    "additionalData": {
+    }
+  },
+  {
+    "activated": true,
+    "destination": "lnbc20610n1pju73pqpp5rrvhc34tzt3vz70r33c2n2qqtm6hxau2hyl9w23kvrx56vhsfh5sdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp56grmnp2ezj4n323squu2p2e09g5lgncsr7f34084p5dyjgmwcssq9qyyssqfrc9x37qcvvpsx8m4zvu9glvcfcmqzs9ttfsg30g2gjxfkylvp8rdud2yx8gshs2jv0rea0etjrcygrc0hp4vckgsfs4grsnl854ajgpurzzp4",
+    "paymentLink": "lightning:lnbc20610n1pju73pqpp5rrvhc34tzt3vz70r33c2n2qqtm6hxau2hyl9w23kvrx56vhsfh5sdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp56grmnp2ezj4n323squu2p2e09g5lgncsr7f34084p5dyjgmwcssq9qyyssqfrc9x37qcvvpsx8m4zvu9glvcfcmqzs9ttfsg30g2gjxfkylvp8rdud2yx8gshs2jv0rea0etjrcygrc0hp4vckgsfs4grsnl854ajgpurzzp4",
+    "rate": "48532.8",
+    "paymentMethodPaid": "0.00002061",
+    "totalPaid": "0.00002061",
+    "due": "0",
+    "amount": "0.00002061",
+    "networkFee": "0",
+    "payments": [
+      {
+        "id": "18d97c46ab12e2c179e38c70a9a8005ef573778ab93e572a3660cd4d32f04de9",
+        "receivedDate": 1708082214,
+        "value": "0.00002061",
+        "fee": "0.0",
+        "status": "Settled",
+        "destination": "lnbc20610n1pju73pqpp5rrvhc34tzt3vz70r33c2n2qqtm6hxau2hyl9w23kvrx56vhsfh5sdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp56grmnp2ezj4n323squu2p2e09g5lgncsr7f34084p5dyjgmwcssq9qyyssqfrc9x37qcvvpsx8m4zvu9glvcfcmqzs9ttfsg30g2gjxfkylvp8rdud2yx8gshs2jv0rea0etjrcygrc0hp4vckgsfs4grsnl854ajgpurzzp4"
+      }
+    ],
+    "paymentMethod": "BTC-LightningNetwork",
+    "cryptoCode": "BTC",
+    "additionalData": {
+      "paymentHash": "18d97c46ab12e2c179e38c70a9a8005ef573778ab93e572a3660cd4d32f04de9"
+    }
+  }
+]
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/lightning_sats_settled_invoice.json b/spec/fixtures/btcpay/lightning_sats_settled_invoice.json
new file mode 100644
index 0000000..36063c1
--- /dev/null
+++ b/spec/fixtures/btcpay/lightning_sats_settled_invoice.json
@@ -0,0 +1,41 @@
+{
+  "id": "JxjfeJi1TtX8FcWSjEvGxg",
+  "storeId": "AxQQ6oH4YX7n5pH1JPBLu97QD6RTybtj8m2W8YzhYr6T",
+  "amount": "0.0001",
+  "checkoutLink": "http://10.1.1.163:23001/i/JxjfeJi1TtX8FcWSjEvGxg",
+  "status": "Settled",
+  "additionalStatus": "None",
+  "monitoringExpiration": 1708180292,
+  "expirationTime": 1708093892,
+  "createdTime": 1708092992,
+  "availableStatusesForManualMarking": [
+
+  ],
+  "archived": false,
+  "type": "Standard",
+  "currency": "BTC",
+  "metadata": {
+  },
+  "checkout": {
+    "speedPolicy": "MediumSpeed",
+    "paymentMethods": [
+      "BTC",
+      "BTC-LightningNetwork"
+    ],
+    "defaultPaymentMethod": "BTC-LightningNetwork",
+    "expirationMinutes": 15,
+    "monitoringMinutes": 1440,
+    "paymentTolerance": 0.0,
+    "redirectURL": "http://localhost:3000/contributions/donations/32/confirm_btcpay",
+    "redirectAutomatically": true,
+    "requiresRefundEmail": false,
+    "defaultLanguage": null,
+    "checkoutType": null,
+    "lazyPaymentMethods": null
+  },
+  "receipt": {
+    "enabled": null,
+    "showQR": null,
+    "showPayments": null
+  }
+}
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/lightning_sats_settled_payments.json b/spec/fixtures/btcpay/lightning_sats_settled_payments.json
new file mode 100644
index 0000000..a51d272
--- /dev/null
+++ b/spec/fixtures/btcpay/lightning_sats_settled_payments.json
@@ -0,0 +1,46 @@
+[
+  {
+    "activated": true,
+    "destination": "bc1q9fay59qdmtv46d5hpf62vt5eyd7ag98t4h0s3g",
+    "paymentLink": "bitcoin:bc1q9fay59qdmtv46d5hpf62vt5eyd7ag98t4h0s3g",
+    "rate": "1.0",
+    "paymentMethodPaid": "0",
+    "totalPaid": "0.0001",
+    "due": "0",
+    "amount": "0.0001",
+    "networkFee": "0",
+    "payments": [
+
+    ],
+    "paymentMethod": "BTC",
+    "cryptoCode": "BTC",
+    "additionalData": {
+    }
+  },
+  {
+    "activated": true,
+    "destination": "lnbc100u1pju7mjqpp54yt6z4g4j294vta90yn35pwch76a4h47txx4m4njfdqmcsa4w50qdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5gx3wee4c2gsl7lnmx4qkrha3mkxh926j5qpdqz7wyyya04wks7cq9qyyssq4ft7a69c93kr04hamp5ah958ay222dvdrzr3nl599nx0l3ejpqe4ktarkxdymsxgg6v3evat9e9u0fp2vg2r2z860fn0h04znq9c6psqh8s53q",
+    "paymentLink": "lightning:lnbc100u1pju7mjqpp54yt6z4g4j294vta90yn35pwch76a4h47txx4m4njfdqmcsa4w50qdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5gx3wee4c2gsl7lnmx4qkrha3mkxh926j5qpdqz7wyyya04wks7cq9qyyssq4ft7a69c93kr04hamp5ah958ay222dvdrzr3nl599nx0l3ejpqe4ktarkxdymsxgg6v3evat9e9u0fp2vg2r2z860fn0h04znq9c6psqh8s53q",
+    "rate": "1.0",
+    "paymentMethodPaid": "0.0001",
+    "totalPaid": "0.0001",
+    "due": "0",
+    "amount": "0.0001",
+    "networkFee": "0",
+    "payments": [
+      {
+        "id": "a917a15515928b562fa579271a05d8bfb5dadebe598d5dd6724b41bc43b5751e",
+        "receivedDate": 1708093015,
+        "value": "0.0001",
+        "fee": "0.0",
+        "status": "Settled",
+        "destination": "lnbc100u1pju7mjqpp54yt6z4g4j294vta90yn35pwch76a4h47txx4m4njfdqmcsa4w50qdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5gx3wee4c2gsl7lnmx4qkrha3mkxh926j5qpdqz7wyyya04wks7cq9qyyssq4ft7a69c93kr04hamp5ah958ay222dvdrzr3nl599nx0l3ejpqe4ktarkxdymsxgg6v3evat9e9u0fp2vg2r2z860fn0h04znq9c6psqh8s53q"
+      }
+    ],
+    "paymentMethod": "BTC-LightningNetwork",
+    "cryptoCode": "BTC",
+    "additionalData": {
+      "paymentHash": "a917a15515928b562fa579271a05d8bfb5dadebe598d5dd6724b41bc43b5751e"
+    }
+  }
+]
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/onchain_eur_processing_invoice.json b/spec/fixtures/btcpay/onchain_eur_processing_invoice.json
new file mode 100644
index 0000000..ad08b22
--- /dev/null
+++ b/spec/fixtures/btcpay/onchain_eur_processing_invoice.json
@@ -0,0 +1,42 @@
+{
+  "id": "K4e31MhbLKmr3D7qoNYRd3",
+  "storeId": "AxQQ6oH4YX7n5pH1JPBLu97QD6RTybtj8m2W8YzhYr6T",
+  "amount": "100",
+  "checkoutLink": "http://10.1.1.163:23001/i/K4e31MhbLKmr3D7qoNYRd3",
+  "status": "Processing",
+  "additionalStatus": "None",
+  "monitoringExpiration": 1708173683,
+  "expirationTime": 1708087283,
+  "createdTime": 1708086383,
+  "availableStatusesForManualMarking": [
+    "Settled",
+    "Invalid"
+  ],
+  "archived": false,
+  "type": "Standard",
+  "currency": "USD",
+  "metadata": {
+  },
+  "checkout": {
+    "speedPolicy": "MediumSpeed",
+    "paymentMethods": [
+      "BTC",
+      "BTC-LightningNetwork"
+    ],
+    "defaultPaymentMethod": "BTC-LightningNetwork",
+    "expirationMinutes": 15,
+    "monitoringMinutes": 1440,
+    "paymentTolerance": 0.0,
+    "redirectURL": "http://localhost:3000/contributions/donations/28/confirm_btcpay",
+    "redirectAutomatically": true,
+    "requiresRefundEmail": false,
+    "defaultLanguage": null,
+    "checkoutType": null,
+    "lazyPaymentMethods": null
+  },
+  "receipt": {
+    "enabled": null,
+    "showQR": null,
+    "showPayments": null
+  }
+}
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/onchain_eur_processing_payments.json b/spec/fixtures/btcpay/onchain_eur_processing_payments.json
new file mode 100644
index 0000000..5074245
--- /dev/null
+++ b/spec/fixtures/btcpay/onchain_eur_processing_payments.json
@@ -0,0 +1,46 @@
+[
+  {
+    "activated": true,
+    "destination": "bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh",
+    "paymentLink": "bitcoin:bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh",
+    "rate": "52259.2",
+    "paymentMethodPaid": "0.00191354",
+    "totalPaid": "0.00191354",
+    "due": "0",
+    "amount": "0.00191354",
+    "networkFee": "0",
+    "payments": [
+      {
+        "id": "21da85563274d0c3975273c1a2a8551bddeebb68b8f8a3242f63dd4cc238b480-1",
+        "receivedDate": 1708086448,
+        "value": "0.00191354",
+        "fee": "0.0",
+        "status": "Processing",
+        "destination": "bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh"
+      }
+    ],
+    "paymentMethod": "BTC",
+    "cryptoCode": "BTC",
+    "additionalData": {
+    }
+  },
+  {
+    "activated": true,
+    "destination": "lnbc1913540n1pju74r0pp5vpnw6l84ytu5u5evehn00xwsrppg7w45cj4mrwjwng474w7x3ugqdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5sscc8ufdw29lpv9z09c6edhzc2njg0lmspsk8sdunek7yrkeu3mq9qyyssqnzz9xrhpy7sej5k62vcjju253kxx87jveq7vusl2sgaeuyh48ph9ecuud6f329syuut3z8w544c6ynhtx4ratundzmp7fs6sdll8g0spurjhnx",
+    "paymentLink": "lightning:lnbc1913540n1pju74r0pp5vpnw6l84ytu5u5evehn00xwsrppg7w45cj4mrwjwng474w7x3ugqdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5sscc8ufdw29lpv9z09c6edhzc2njg0lmspsk8sdunek7yrkeu3mq9qyyssqnzz9xrhpy7sej5k62vcjju253kxx87jveq7vusl2sgaeuyh48ph9ecuud6f329syuut3z8w544c6ynhtx4ratundzmp7fs6sdll8g0spurjhnx",
+    "rate": "52259.2",
+    "paymentMethodPaid": "0",
+    "totalPaid": "0.00191354",
+    "due": "0",
+    "amount": "0.00191354",
+    "networkFee": "0",
+    "payments": [
+
+    ],
+    "paymentMethod": "BTC-LightningNetwork",
+    "cryptoCode": "BTC",
+    "additionalData": {
+      "paymentHash": "6066ed7cf522f94e532ccde6f799d018428f3ab4c4abb1ba4e9a2beabbc68f10"
+    }
+  }
+]
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/onchain_eur_settled_invoice.json b/spec/fixtures/btcpay/onchain_eur_settled_invoice.json
new file mode 100644
index 0000000..09db36c
--- /dev/null
+++ b/spec/fixtures/btcpay/onchain_eur_settled_invoice.json
@@ -0,0 +1,41 @@
+{
+  "id": "K4e31MhbLKmr3D7qoNYRd3",
+  "storeId": "AxQQ6oH4YX7n5pH1JPBLu97QD6RTybtj8m2W8YzhYr6T",
+  "amount": "100",
+  "checkoutLink": "http://10.1.1.163:23001/i/K4e31MhbLKmr3D7qoNYRd3",
+  "status": "Settled",
+  "additionalStatus": "None",
+  "monitoringExpiration": 1708173683,
+  "expirationTime": 1708087283,
+  "createdTime": 1708086383,
+  "availableStatusesForManualMarking": [
+
+  ],
+  "archived": false,
+  "type": "Standard",
+  "currency": "USD",
+  "metadata": {
+  },
+  "checkout": {
+    "speedPolicy": "MediumSpeed",
+    "paymentMethods": [
+      "BTC",
+      "BTC-LightningNetwork"
+    ],
+    "defaultPaymentMethod": "BTC-LightningNetwork",
+    "expirationMinutes": 15,
+    "monitoringMinutes": 1440,
+    "paymentTolerance": 0.0,
+    "redirectURL": "http://localhost:3000/contributions/donations/28/confirm_btcpay",
+    "redirectAutomatically": true,
+    "requiresRefundEmail": false,
+    "defaultLanguage": null,
+    "checkoutType": null,
+    "lazyPaymentMethods": null
+  },
+  "receipt": {
+    "enabled": null,
+    "showQR": null,
+    "showPayments": null
+  }
+}
\ No newline at end of file
diff --git a/spec/fixtures/btcpay/onchain_eur_settled_payments.json b/spec/fixtures/btcpay/onchain_eur_settled_payments.json
new file mode 100644
index 0000000..aedc453
--- /dev/null
+++ b/spec/fixtures/btcpay/onchain_eur_settled_payments.json
@@ -0,0 +1,46 @@
+[
+  {
+    "activated": true,
+    "destination": "bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh",
+    "paymentLink": "bitcoin:bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh",
+    "rate": "52259.2",
+    "paymentMethodPaid": "0.00191354",
+    "totalPaid": "0.00191354",
+    "due": "0",
+    "amount": "0.00191354",
+    "networkFee": "0",
+    "payments": [
+      {
+        "id": "218652f351508c46cfd99de1c6cdc0dcb66bc1bbfaf38578235d080046a96305-1",
+        "receivedDate": 1708106396,
+        "value": "0.00191354",
+        "fee": "0.0",
+        "status": "Settled",
+        "destination": "bc1qqxm55h6yzych9kg6kquak4c73nyv352070tsmh"
+      }
+    ],
+    "paymentMethod": "BTC",
+    "cryptoCode": "BTC",
+    "additionalData": {
+    }
+  },
+  {
+    "activated": true,
+    "destination": "lnbc1913540n1pju74r0pp5vpnw6l84ytu5u5evehn00xwsrppg7w45cj4mrwjwng474w7x3ugqdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5sscc8ufdw29lpv9z09c6edhzc2njg0lmspsk8sdunek7yrkeu3mq9qyyssqnzz9xrhpy7sej5k62vcjju253kxx87jveq7vusl2sgaeuyh48ph9ecuud6f329syuut3z8w544c6ynhtx4ratundzmp7fs6sdll8g0spurjhnx",
+    "paymentLink": "lightning:lnbc1913540n1pju74r0pp5vpnw6l84ytu5u5evehn00xwsrppg7w45cj4mrwjwng474w7x3ugqdphg3hkuct5d9hkugr5dus8g6r9yp9k7umddaejqcm0dacx2unpw35hvegcqzzsxqyz5vqsp5sscc8ufdw29lpv9z09c6edhzc2njg0lmspsk8sdunek7yrkeu3mq9qyyssqnzz9xrhpy7sej5k62vcjju253kxx87jveq7vusl2sgaeuyh48ph9ecuud6f329syuut3z8w544c6ynhtx4ratundzmp7fs6sdll8g0spurjhnx",
+    "rate": "52259.2",
+    "paymentMethodPaid": "0",
+    "totalPaid": "0.00191354",
+    "due": "0",
+    "amount": "0.00191354",
+    "networkFee": "0",
+    "payments": [
+
+    ],
+    "paymentMethod": "BTC-LightningNetwork",
+    "cryptoCode": "BTC",
+    "additionalData": {
+      "paymentHash": "6066ed7cf522f94e532ccde6f799d018428f3ab4c4abb1ba4e9a2beabbc68f10"
+    }
+  }
+]
\ No newline at end of file
diff --git a/spec/helpers/application_helper_spec.rb b/spec/helpers/application_helper_spec.rb
index 92f8de4..f9a8fb6 100644
--- a/spec/helpers/application_helper_spec.rb
+++ b/spec/helpers/application_helper_spec.rb
@@ -1,9 +1,4 @@
 require 'rails_helper'
 
 describe ApplicationHelper do
-  describe "sats_to_btc" do
-    it "converts satoshis to BTC" do
-      expect(helper.sats_to_btc(120000000)).to eq(1.2)
-    end
-  end
 end
diff --git a/spec/jobs/btcpay_check_donation_job_spec.rb b/spec/jobs/btcpay_check_donation_job_spec.rb
new file mode 100644
index 0000000..9344c46
--- /dev/null
+++ b/spec/jobs/btcpay_check_donation_job_spec.rb
@@ -0,0 +1,63 @@
+require 'rails_helper'
+require 'webmock/rspec'
+
+RSpec.describe BtcpayCheckDonationJob, type: :job do
+  let(:user) { create :user, cn: 'jimmy', ou: 'kosmos.org' }
+
+  let(:donation) do
+    user.donations.create!(
+      donation_method: "btcpay", btcpay_invoice_id: "K4e31MhbLKmr3D7qoNYRd3",
+      paid_at: nil, payment_status: "processing",
+      fiat_amount: 120, fiat_currency: "USD"
+    )
+  end
+
+  after(:each) do
+    clear_enqueued_jobs
+    clear_performed_jobs
+  end
+
+  describe "invoice still processing" do
+    subject(:job) { described_class.perform_later(donation) }
+
+    before do
+      invoice = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_processing_invoice.json")
+      payments = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_processing_payments.json")
+      stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3")
+        .to_return(status: 200, headers: {}, body: invoice)
+      stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3/payment-methods")
+        .to_return(status: 200, headers: {}, body: payments)
+    end
+
+    it "enqueues itself to check again later" do
+      expect_any_instance_of(described_class).to receive(:re_enqueue_job).once
+      perform_enqueued_jobs { job }
+    end
+  end
+
+  describe "invoice settled" do
+    subject(:job) { described_class.perform_later(donation) }
+
+    before do
+      invoice = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_settled_invoice.json")
+      payments = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_settled_payments.json")
+      stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3")
+        .to_return(status: 200, headers: {}, body: invoice)
+      stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3/payment-methods")
+        .to_return(status: 200, headers: {}, body: payments)
+    end
+
+    it "updates the donation record" do
+      perform_enqueued_jobs { job }
+
+      donation.reload
+      expect(donation.paid_at).not_to be_nil
+      expect(donation.payment_status).to eq("settled")
+    end
+
+    it "does not enqueue itself again" do
+      expect_any_instance_of(described_class).not_to receive(:re_enqueue_job)
+      perform_enqueued_jobs { job }
+    end
+  end
+end
diff --git a/spec/requests/contributions/donations_spec.rb b/spec/requests/contributions/donations_spec.rb
new file mode 100644
index 0000000..dc9118f
--- /dev/null
+++ b/spec/requests/contributions/donations_spec.rb
@@ -0,0 +1,233 @@
+require 'rails_helper'
+require 'webmock/rspec'
+
+RSpec.describe "Donations", type: :request do
+  let(:user) { create :user, cn: 'jimmy', ou: 'kosmos.org' }
+
+  before do
+    Warden.test_mode!
+    login_as user, scope: :user
+  end
+
+  after { Warden.test_reset! }
+
+  describe "#create" do
+    describe "with disabled methods" do
+      before do
+        Setting.btcpay_enabled = false
+      end
+
+      it "returns a 403" do
+        post "/contributions/donations", params: { donation_method: "btcpay" }
+        expect(response).to have_http_status(:forbidden)
+      end
+    end
+
+    describe "with fake methods" do
+      it "returns a 403" do
+        post "/contributions/donations", params: { donation_method: "remotestorage" }
+        expect(response).to have_http_status(:forbidden)
+      end
+    end
+
+    describe "with invalid fiat currency" do
+      it "returns a 422" do
+        post "/contributions/donations", params: {
+          donation_method: "btcpay", amount: "10", currency: "GBP"
+        }
+        expect(response).to have_http_status(:unprocessable_entity)
+      end
+    end
+
+    describe "with bad amount" do
+      it "returns a 422" do
+        post "/contributions/donations", params: {
+          donation_method: "btcpay", amount: ""
+        }
+        expect(response).to have_http_status(:unprocessable_entity)
+      end
+    end
+
+    describe "with BTCPay" do
+      before { Setting.btcpay_enabled = true }
+
+      describe "amount in EUR" do
+        before do
+          expect(BtcpayManager::CreateInvoice).to receive(:call)
+            .with(amount: 25, currency: "EUR", redirect_url: "http://www.example.com/contributions/donations/1/confirm_btcpay")
+            .and_return({
+              "id" => "Q9GBe143HJIkdpZeH4Ftx5",
+              "amount" => "25",
+              "currency" => "EUR",
+              "checkoutLink" => "#{Setting.btcpay_api_url}/i/Q9GBe143HJIkdpZeH4Ftx5",
+              "expirationTime" => 1707908626,
+              "checkout" => { "redirectURL" => "http://www.example.com/contributions/donations/1/confirm_btcpay" }
+            })
+
+          post "/contributions/donations", params: {
+            donation_method: "btcpay", amount: "25", currency: "EUR",
+            public_name: "Mickey"
+          }
+        end
+
+        it "creates a new donation record" do
+          expect(user.donations.count).to eq(1)
+          donation = user.donations.first
+          expect(donation.donation_method).to eq("btcpay")
+          expect(donation.payment_method).to be_nil
+          expect(donation.paid_at).to be_nil
+          expect(donation.public_name).to eq("Mickey")
+          expect(donation.amount_sats).to be_nil
+          expect(donation.fiat_amount).to eq(2500)
+          expect(donation.fiat_currency).to eq("EUR")
+          expect(donation.btcpay_invoice_id).to eq("Q9GBe143HJIkdpZeH4Ftx5")
+        end
+
+        it "redirects to the BTCPay checkout page" do
+          expect(response).to redirect_to("https://btcpay.example.com/i/Q9GBe143HJIkdpZeH4Ftx5")
+        end
+      end
+    end
+  end
+
+  describe "#confirm_btcpay" do
+    before { Setting.btcpay_enabled = true }
+
+    describe "with donation of another user" do
+      let(:other_user) { create :user, id: 3, cn: "carl", ou: 'kosmos.org', email: "carl@example.com" }
+
+      before do
+        @donation = other_user.donations.create!(
+          donation_method: "btcpay", btcpay_invoice_id: "123abc",
+          fiat_amount: 25, fiat_currency: "EUR", paid_at: nil
+        )
+        get confirm_btcpay_contributions_donation_path(@donation.id)
+      end
+
+      it "returns a 404" do
+        expect(response).to have_http_status(:not_found)
+      end
+    end
+
+    describe "with confirmed donation" do
+      before do
+        @donation = user.donations.create!(
+          donation_method: "btcpay", btcpay_invoice_id: "123abc",
+          fiat_amount: 25, fiat_currency: "EUR",
+          paid_at: "2024-02-16", payment_status: "settled"
+        )
+        get confirm_btcpay_contributions_donation_path(@donation.id)
+      end
+
+      it "redirects to the donations index" do
+        expect(response).to redirect_to(contributions_donations_url)
+      end
+    end
+
+    describe "settled via Lightning" do
+      describe "amount in EUR" do
+        subject do
+          user.donations.create!(
+            donation_method: "btcpay", btcpay_invoice_id: "MCkDbf2cUgBuuisUCgnRnb",
+            fiat_amount: 25, fiat_currency: "EUR", paid_at: nil
+          )
+        end
+
+        before do
+          invoice = File.read("#{Rails.root}/spec/fixtures/btcpay/lightning_eur_settled_invoice.json")
+          payments = File.read("#{Rails.root}/spec/fixtures/btcpay/lightning_eur_settled_payments.json")
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/MCkDbf2cUgBuuisUCgnRnb")
+            .to_return(status: 200, headers: {}, body: invoice)
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/MCkDbf2cUgBuuisUCgnRnb/payment-methods")
+            .to_return(status: 200, headers: {}, body: payments)
+
+          get confirm_btcpay_contributions_donation_path(subject)
+        end
+
+        it "updates the donation record" do
+          subject.reload
+          expect(subject.paid_at).not_to be_nil
+          expect(subject.amount_sats).to eq(2061)
+        end
+
+        it "redirects to the donations index" do
+          expect(response).to redirect_to(contributions_donations_url)
+        end
+      end
+
+      describe "amount in sats" do
+        subject do
+          user.donations.create!(
+            donation_method: "btcpay", btcpay_invoice_id: "JxjfeJi1TtX8FcWSjEvGxg",
+            amount_sats: 10000, fiat_amount: nil, fiat_currency: nil, paid_at: nil
+          )
+        end
+
+        before do
+          invoice = File.read("#{Rails.root}/spec/fixtures/btcpay/lightning_sats_settled_invoice.json")
+          payments = File.read("#{Rails.root}/spec/fixtures/btcpay/lightning_sats_settled_payments.json")
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/JxjfeJi1TtX8FcWSjEvGxg")
+            .to_return(status: 200, headers: {}, body: invoice)
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/JxjfeJi1TtX8FcWSjEvGxg/payment-methods")
+            .to_return(status: 200, headers: {}, body: payments)
+
+          expect(BtcpayManager::FetchExchangeRate).to receive(:call)
+            .with(fiat_currency: "EUR").and_return(48532.00)
+
+          get confirm_btcpay_contributions_donation_path(subject)
+        end
+
+        it "updates the donation record" do
+          subject.reload
+          expect(subject.paid_at).not_to be_nil
+          expect(subject.amount_sats).to eq(10000)
+          expect(subject.fiat_amount).to eq(485)
+          expect(subject.fiat_currency).to eq("EUR")
+        end
+
+        it "redirects to the donations index" do
+          expect(response).to redirect_to(contributions_donations_url)
+        end
+      end
+    end
+
+    describe "on-chain" do
+      describe "waiting for confirmations" do
+        subject do
+          user.donations.create!(
+            donation_method: "btcpay", btcpay_invoice_id: "K4e31MhbLKmr3D7qoNYRd3",
+            fiat_amount: 120, fiat_currency: "USD", paid_at: nil
+          )
+        end
+
+        before do
+          invoice = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_processing_invoice.json")
+          payments = File.read("#{Rails.root}/spec/fixtures/btcpay/onchain_eur_processing_payments.json")
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3")
+            .to_return(status: 200, headers: {}, body: invoice)
+          stub_request(:get, "http://btcpay.example.com/api/v1/stores/123456/invoices/K4e31MhbLKmr3D7qoNYRd3/payment-methods")
+            .to_return(status: 200, headers: {}, body: payments)
+
+          get confirm_btcpay_contributions_donation_path(subject)
+        end
+
+        it "updates the donation record" do
+          subject.reload
+          expect(subject.paid_at).to be_nil
+          expect(subject.amount_sats).to eq(191354)
+          expect(subject.payment_status).to eq("processing")
+        end
+
+        it "enqueues a job to periodically check the invoice status" do
+          expect(enqueued_jobs.size).to eq(1)
+          expect(enqueued_jobs.first["job_class"]).to eq("BtcpayCheckDonationJob")
+          expect(enqueued_jobs.first['arguments'][0]["_aj_globalid"]).to eq("gid://akkounts/Donation/#{subject.id}")
+        end
+
+        it "redirects to the donations index" do
+          expect(response).to redirect_to(contributions_donations_url)
+        end
+      end
+    end
+  end
+end