ltc payments

.gitignore

@@ -4,4 +4,5 @@
 vendor/bundle/
 *.log
 tmp/
-logo/
+logo/
+SECRETS.md

Gemfile

@@ -16,6 +16,8 @@ gem 'pg',              '~> 1.5'
 gem 'sequel',          '~> 5.86'
 gem 'prawn',           '~> 2.5'
 gem 'prawn-table',     '~> 0.2'
+gem 'rqrcode',         '~> 2.2'
+gem 'chunky_png',      '~> 1.4'
 gem 'aws-sdk-s3',      '~> 1.170'
 
 group :development do

Gemfile.lock

@@ -22,6 +22,7 @@ GEM
       aws-eventstream (~> 1, >= 1.0.2)
     base64 (0.3.0)
     bigdecimal (3.3.1)
+    chunky_png (1.4.0)
     date (3.5.1)
     dotenv (3.2.0)
     erubi (1.13.1)
@@ -93,6 +94,10 @@ GEM
       ffi (~> 1.0)
     rerun (0.14.0)
       listen (~> 3.0)
+    rqrcode (2.2.0)
+      chunky_png (~> 1.0)
+      rqrcode_core (~> 1.0)
+    rqrcode_core (1.2.0)
     sequel (5.104.0)
       bigdecimal
     sinatra (4.2.1)
@@ -128,6 +133,7 @@ PLATFORMS
 
 DEPENDENCIES
   aws-sdk-s3 (~> 1.170)
+  chunky_png (~> 1.4)
   dotenv (~> 3.1)
   erubi (~> 1.13)
   mail (~> 2.8)
@@ -140,6 +146,7 @@ DEPENDENCIES
   rack-session (~> 2.1)
   rackup (~> 2.3)
   rerun (~> 0.14)
+  rqrcode (~> 2.2)
   sequel (~> 5.86)
   sinatra (~> 4.2)
   sinatra-contrib (~> 4.2)

asxpio.rb

@@ -26,6 +26,8 @@ if ENV['DATABASE_URL']
   DB.connect!
   DB.migrate!
   require_relative 'lib/invoice'
+  require_relative 'lib/ltc_rate'
+  require_relative 'lib/ltc_qr'
   require_relative 'lib/invoice_pdf'
 else
   $logger.warn('DATABASE_URL not set — invoicing disabled')
@@ -152,6 +154,21 @@ class AsxpioWeb < Sinatra::Base
     erb :'admin/invoices/index'
   end
 
+  # Live LTC price for the new-invoice form's "Fetch live" button.
+  # GEL is derived from the gel_rate the operator typed into the form.
+  get '/admin/ltc-rate' do
+    content_type :json
+    currency = params[:currency].to_s.upcase
+    gel_rate = params[:gel_rate].to_s.strip
+    begin
+      rate = LtcRate.fetch(currency, gel_rate: gel_rate.empty? ? nil : gel_rate)
+      { rate: rate.round(8).to_s('F'), currency: currency }.to_json
+    rescue LtcRate::Error => e
+      status 502
+      { error: e.message }.to_json
+    end
+  end
+
   get '/admin/invoices/new' do
     @page_title  = 'New invoice — admin'
     @noindex     = true
@@ -170,6 +187,9 @@ class AsxpioWeb < Sinatra::Base
       issued_on:      params[:issued_on].to_s.strip,
       due_on:         params[:due_on].to_s.strip,
       notes:          params[:notes].to_s.strip,
+      ltc_address:    params[:ltc_address].to_s.strip,
+      ltc_rate:       params[:ltc_rate].to_s.strip,
+      ltc_amount:     params[:ltc_amount].to_s.strip,
       items:          (params[:items] || {}).values
     }
     @form_errors = validate_invoice_params(@form_values)
@@ -247,6 +267,19 @@ class AsxpioWeb < Sinatra::Base
       items = v[:items].select { |i| i.is_a?(Hash) && !i['description'].to_s.strip.empty? }
       errors[:items] = 'At least one line item with a description is required' if items.empty?
       v[:items] = items
+
+      # LTC is optional; validate only when an address is present.
+      unless v[:ltc_address].to_s.strip.empty?
+        errors[:ltc_address] = 'LTC address looks invalid' unless v[:ltc_address] =~ /\A(ltc1|[LM3])[a-zA-HJ-NP-Z0-9]{20,90}\z/
+        %i[ltc_rate ltc_amount].each do |k|
+          next if v[k].to_s.strip.empty?
+          begin
+            raise ArgumentError if BigDecimal(v[k]) <= 0
+          rescue ArgumentError
+            errors[k] = "#{k.to_s.tr('_', ' ').capitalize} must be a positive decimal"
+          end
+        end
+      end
       errors
     end
   end

db/migrations/002_invoice_ltc.rb

@@ -0,0 +1,15 @@
+Sequel.migration do
+  change do
+    alter_table(:invoices) do
+      # LTC payout address captured at issue (defaults from LTC_ADDRESS env in the form).
+      # All three are nullable: LTC payment is opt-in per invoice.
+      add_column :ltc_address, String
+      # LTC price in the invoice currency at issue time (snapshot, like gel_rate).
+      # May be hand-entered or fetched from CoinGecko at form time.
+      add_column :ltc_rate,    BigDecimal, size: [18, 8]
+      # LTC amount due. Normally total / ltc_rate, but can be hand-overridden,
+      # so it is stored explicitly rather than recomputed.
+      add_column :ltc_amount,  BigDecimal, size: [18, 8]
+    end
+  end
+end

lib/invoice.rb

@@ -35,6 +35,19 @@ class Invoice < Sequel::Model(:invoices)
     (total * BigDecimal(gel_rate.to_s)).round(2)
   end
 
+  def ltc?
+    !ltc_address.to_s.strip.empty?
+  end
+
+  # The LTC amount to display / encode in the QR. Returns nil when no amount
+  # is known (address-only invoice).
+  def ltc_amount_due
+    return nil unless ltc?
+    return BigDecimal(ltc_amount.to_s) unless ltc_amount.nil?
+    return nil if ltc_rate.nil? || BigDecimal(ltc_rate.to_s).zero?
+    (total / BigDecimal(ltc_rate.to_s)).round(8)
+  end
+
   class << self
     def allocate_number(year = Date.today.year)
       prefix = "INV-#{year}-"
@@ -64,12 +77,37 @@ class Invoice < Sequel::Model(:invoices)
         pdf_key:        '',
         created_at:     Time.now.utc
       )
+      apply_ltc(invoice, params, subtotal)
       invoice.uuid = SecureRandom.uuid
       invoice
     end
 
     private
 
+    # LTC is opt-in: only populated when an address is given. Rate and amount
+    # are both optional; if amount is blank but rate is present, derive it.
+    def apply_ltc(invoice, params, subtotal)
+      address = params[:ltc_address].to_s.strip
+      return if address.empty?
+
+      invoice.ltc_address = address
+
+      rate = decimal_or_nil(params[:ltc_rate])
+      invoice.ltc_rate = rate
+
+      amount = decimal_or_nil(params[:ltc_amount])
+      amount ||= (subtotal / rate).round(8) if rate && !rate.zero?
+      invoice.ltc_amount = amount
+    end
+
+    def decimal_or_nil(raw)
+      s = raw.to_s.strip
+      return nil if s.empty?
+      BigDecimal(s)
+    rescue ArgumentError
+      nil
+    end
+
     def normalize_currency(c)
       c = c.to_s.upcase
       CURRENCIES.include?(c) or raise ArgumentError, "Unsupported currency: #{c}"

lib/invoice_pdf.rb

@@ -1,6 +1,7 @@
 require 'prawn'
 require 'prawn/table'
 require 'bigdecimal'
+require 'stringio'
 
 class InvoicePdf
   FONTS_DIR = File.join($root, 'public', 'fonts')
@@ -233,6 +234,9 @@ class InvoicePdf
       pdf.text "SWIFT: #{ISSUER[:swift]}"
       pdf.text "Beneficiary: #{ISSUER[:name_latin]}"
     end
+
+    draw_ltc(pdf) if @invoice.respond_to?(:ltc?) && @invoice.ltc?
+
     unless @invoice.notes.to_s.strip.empty?
       pdf.move_down 14
       pdf.fill_color COLOR_MUTED
@@ -243,7 +247,51 @@ class InvoicePdf
     end
   end
 
+  def draw_ltc(pdf)
+    amount  = @invoice.ltc_amount_due
+    qr_size = 78
+
+    pdf.move_down 12
+    pdf.fill_color COLOR_MUTED
+    pdf.font_size(8) { pdf.text 'PAY IN LITECOIN (LTC)', character_spacing: 1.5 }
+    pdf.fill_color COLOR_TEXT
+    pdf.move_down 4
+
+    # Fixed-height row: QR on the right (drawn with float so it doesn't advance
+    # the cursor), text column on the left. The outer bounding_box of height
+    # qr_size leaves the cursor exactly below the row when it ends.
+    qr_bytes = LtcQr.png(@invoice.ltc_address, amount)
+    pdf.bounding_box([0, pdf.cursor], width: pdf.bounds.width, height: qr_size) do
+      pdf.float do
+        pdf.bounding_box([pdf.bounds.right - qr_size, pdf.bounds.top], width: qr_size, height: qr_size) do
+          pdf.image StringIO.new(qr_bytes), width: qr_size, height: qr_size
+        end
+      end
+
+      pdf.bounding_box([0, pdf.bounds.top], width: pdf.bounds.width - qr_size - 16) do
+        pdf.font_size(9) do
+          if amount
+            pdf.text "Amount: #{fmt_ltc(amount)} LTC", style: :bold
+            if @invoice.ltc_rate
+              pdf.fill_color COLOR_MUTED
+              pdf.text "(rate 1 LTC = #{fmt_money(@invoice.ltc_rate)} #{@invoice.currency} at issue)", size: 8
+              pdf.fill_color COLOR_TEXT
+            end
+            pdf.move_down 3
+          end
+          pdf.text 'Address:'
+          pdf.font_size(8) { pdf.text @invoice.ltc_address }
+          pdf.move_down 3
+          pdf.fill_color COLOR_MUTED
+          pdf.font_size(7) { pdf.text 'Scan the QR with any Litecoin wallet to prefill the payment.' }
+          pdf.fill_color COLOR_TEXT
+        end
+      end
+    end
+  end
+
   def draw_footer(pdf)
+    # Static left-side line repeats on every page.
     pdf.repeat(:all) do
       pdf.canvas do
         pdf.fill_color COLOR_MUTED
@@ -252,17 +300,32 @@ class InvoicePdf
             "#{ISSUER[:name_latin]} · Tax ID #{ISSUER[:tax_id]} · Small Business (1% turnover tax)",
             at: [50, 25]
           )
-          pdf.draw_text("Page #{pdf.page_number}", at: [pdf.bounds.right - 50, 25])
         end
         pdf.fill_color COLOR_TEXT
       end
     end
+
+    # Page number must be stamped per page: inside repeat(:all), pdf.page_number
+    # resolves to the final page count for every page. number_pages substitutes
+    # <page>/<total> at finalization, once per actual page.
+    pdf.number_pages(
+      'Page <page> of <total>',
+      at:      [pdf.bounds.right - 90, -25],
+      width:   90,
+      align:   :right,
+      size:    8,
+      color:   COLOR_MUTED
+    )
   end
 
   def fmt_money(value)
     BigDecimal(value.to_s).round(2).to_s('F').then { |s| with_thousands(s) }
   end
 
+  def fmt_ltc(value)
+    BigDecimal(value.to_s).round(8).to_s('F').sub(/(\.\d*?)0+$/, '\\1').sub(/\.$/, '')
+  end
+
   def fmt_qty(value)
     bd = BigDecimal(value.to_s)
     bd.frac.zero? ? bd.to_i.to_s : bd.to_s('F')

lib/ltc_qr.rb

@@ -0,0 +1,30 @@
+require 'rqrcode'
+
+# Renders a Litecoin payment QR as PNG bytes for embedding in the PDF.
+# Encodes a BIP21-style URI: litecoin:<address>?amount=<ltc>
+module LtcQr
+  module_function
+
+  # `amount` is a BigDecimal LTC amount or nil (address-only QR).
+  def uri(address, amount)
+    base = "litecoin:#{address}"
+    return base if amount.nil?
+    # Trim trailing zeros so the wallet shows a clean amount; keep up to 8 dp.
+    amt = amount.round(8).to_s('F').sub(/\.?0+$/, '')
+    "#{base}?amount=#{amt}"
+  end
+
+  # Returns PNG bytes (binary string), sized for a crisp ~120pt PDF placement.
+  def png(address, amount, size: 480)
+    data = uri(address, amount)
+    qr = RQRCode::QRCode.new(data, level: :m)
+    qr.as_png(
+      bit_depth:    1,
+      border_modules: 2,
+      color:        'black',
+      fill:         'white',
+      module_px_size: 6,
+      resize_exactly_to: size
+    ).to_s
+  end
+end

lib/ltc_rate.rb

@@ -0,0 +1,57 @@
+require 'net/http'
+require 'json'
+require 'uri'
+require 'bigdecimal'
+
+# Fetches the current Litecoin price from CoinGecko (free, no API key).
+#
+# CoinGecko's simple/price supports usd and eur directly. GEL is not a
+# CoinGecko vs_currency we rely on, so GEL is derived from the invoice's own
+# captured gel_rate (USD->GEL): ltc_in_gel = ltc_in_usd * gel_rate.
+module LtcRate
+  ENDPOINT = 'https://api.coingecko.com/api/v3/simple/price'.freeze
+  SUPPORTED = %w[USD EUR].freeze
+  TIMEOUT = 6 # seconds
+
+  class Error < StandardError; end
+
+  module_function
+
+  # Returns a BigDecimal: the price of 1 LTC in `currency`.
+  # `gel_rate` (USD->GEL) is required only when currency == 'GEL'.
+  def fetch(currency, gel_rate: nil)
+    currency = currency.to_s.upcase
+
+    if currency == 'GEL'
+      raise Error, 'gel_rate required to derive LTC/GEL' if gel_rate.nil?
+      usd = fetch_simple('usd')
+      (usd * BigDecimal(gel_rate.to_s)).round(8)
+    elsif SUPPORTED.include?(currency)
+      fetch_simple(currency.downcase).round(8)
+    else
+      raise Error, "Unsupported currency: #{currency}"
+    end
+  end
+
+  def fetch_simple(vs)
+    uri = URI(ENDPOINT)
+    uri.query = URI.encode_www_form(ids: 'litecoin', vs_currencies: vs)
+
+    res = Net::HTTP.start(uri.host, uri.port, use_ssl: true,
+                          open_timeout: TIMEOUT, read_timeout: TIMEOUT) do |http|
+      http.get(uri.request_uri, 'Accept' => 'application/json')
+    end
+
+    raise Error, "CoinGecko HTTP #{res.code}" unless res.is_a?(Net::HTTPSuccess)
+
+    data = JSON.parse(res.body)
+    price = data.dig('litecoin', vs)
+    raise Error, "No price for #{vs} in response" if price.nil?
+
+    BigDecimal(price.to_s)
+  rescue JSON::ParserError => e
+    raise Error, "Bad JSON from CoinGecko: #{e.message}"
+  rescue Net::OpenTimeout, Net::ReadTimeout
+    raise Error, 'CoinGecko timed out'
+  end
+end

public/admin-invoice-form.js

@@ -25,4 +25,64 @@
         e.target.closest('tr.item-row').remove();
         reindex();
     });
+
+    // --- Litecoin: live rate fetch + auto amount ------------------------
+    const rateInput = document.getElementById('ltc_rate');
+    const amountInput = document.getElementById('ltc_amount');
+    const fetchBtn = document.getElementById('fetch-ltc-rate');
+    const rateStatus = document.getElementById('ltc-rate-status');
+    const rateCcy = document.getElementById('ltc-rate-ccy');
+    const currencySel = document.getElementById('currency');
+    const gelRateInput = document.getElementById('gel_rate');
+
+    function invoiceTotal() {
+        let total = 0;
+        tbody.querySelectorAll('tr.item-row').forEach((row) => {
+            const inputs = row.querySelectorAll('input');
+            const qty = parseFloat(inputs[1].value) || 0;
+            const unit = parseFloat(inputs[2].value) || 0;
+            total += qty * unit;
+        });
+        return total;
+    }
+
+    // Whether the operator has hand-edited the amount; if so, don't clobber it.
+    let amountTouched = false;
+    if (amountInput) amountInput.addEventListener('input', () => { amountTouched = true; });
+
+    function recomputeAmount() {
+        if (!amountInput || amountTouched) return;
+        const rate = parseFloat(rateInput.value);
+        const total = invoiceTotal();
+        if (rate > 0 && total > 0) {
+            amountInput.value = (total / rate).toFixed(8).replace(/\.?0+$/, '');
+        }
+    }
+
+    function syncCcyLabel() {
+        if (rateCcy && currencySel) rateCcy.textContent = currencySel.value;
+    }
+    syncCcyLabel();
+    if (currencySel) currencySel.addEventListener('change', syncCcyLabel);
+
+    if (rateInput) rateInput.addEventListener('input', recomputeAmount);
+    tbody.addEventListener('input', recomputeAmount);
+
+    if (fetchBtn) {
+        fetchBtn.addEventListener('click', function () {
+            const ccy = currencySel ? currencySel.value : 'USD';
+            const params = new URLSearchParams({ currency: ccy });
+            if (gelRateInput && gelRateInput.value) params.set('gel_rate', gelRateInput.value);
+            rateStatus.textContent = ' fetching…';
+            fetch('/admin/ltc-rate?' + params.toString(), { headers: { Accept: 'application/json' } })
+                .then((r) => r.json().then((j) => ({ ok: r.ok, j })))
+                .then(({ ok, j }) => {
+                    if (!ok) { rateStatus.textContent = ' ' + (j.error || 'failed'); return; }
+                    rateInput.value = j.rate;
+                    rateStatus.textContent = ' ✓ live';
+                    recomputeAmount();
+                })
+                .catch(() => { rateStatus.textContent = ' network error'; });
+        });
+    }
 })();

views/admin/invoices/new.erb

@@ -81,6 +81,29 @@
             <textarea id="notes" name="notes" rows="3" maxlength="1000"><%= @form_values[:notes] %></textarea>
         </div>
 
+        <h2>Litecoin payment <span class="optional">(optional)</span></h2>
+        <p class="optional" style="margin-top:-6px;">Leave the address blank to omit the LTC block and QR from the invoice.</p>
+        <div class="field">
+            <label for="ltc_address">LTC address</label>
+            <input type="text" id="ltc_address" name="ltc_address"
+                   value="<%= @form_values[:ltc_address] || ENV['LTC_ADDRESS'] %>"
+                   placeholder="ltc1..." maxlength="90" />
+        </div>
+        <div class="invoice-grid">
+            <div class="field">
+                <label for="ltc_rate">LTC rate (1 LTC in <span id="ltc-rate-ccy">currency</span>)</label>
+                <input type="text" id="ltc_rate" name="ltc_rate" value="<%= @form_values[:ltc_rate] %>"
+                       placeholder="e.g. 85.20" inputmode="decimal" />
+                <button type="button" id="fetch-ltc-rate" class="link-button">↻ Fetch live</button>
+                <span id="ltc-rate-status" class="optional"></span>
+            </div>
+            <div class="field">
+                <label for="ltc_amount">LTC amount due <span class="optional">(auto from rate; editable)</span></label>
+                <input type="text" id="ltc_amount" name="ltc_amount" value="<%= @form_values[:ltc_amount] %>"
+                       placeholder="auto" inputmode="decimal" />
+            </div>
+        </div>
+
         <button type="submit">Create invoice</button>
     </form>
 </section>

views/admin/invoices/show.erb

@@ -13,6 +13,13 @@
         <% if @invoice.paid_at %>
             <dt>Paid at</dt><dd class="mono"><%= @invoice.paid_at.utc.strftime('%Y-%m-%d %H:%M UTC') %></dd>
         <% end %>
+        <% if @invoice.ltc? %>
+            <dt>LTC</dt>
+            <dd class="mono">
+                <% if (amt = @invoice.ltc_amount_due) %><%= amt.to_s('F').sub(/\.?0+$/, '') %> LTC<% if @invoice.ltc_rate %> @ <%= '%.2f' % @invoice.ltc_rate %> <%= @invoice.currency %><% end %><br /><% end %>
+                <span style="word-break:break-all;"><%= @invoice.ltc_address %></span>
+            </dd>
+        <% end %>
     </dl>
 </section>