Make credit pricing configurable (#9326)

* Add credit prices to SiteConfig

* Add credit prices to /internal/config

* Fix spec and transform values on update

app/controllers/credits_controller.rb

@@ -99,14 +99,17 @@ class CreditsController < ApplicationController
   end
 
   def cost_per_credit
-    if @number_to_purchase < 10
-      500
-    elsif @number_to_purchase < 100
-      400
-    elsif @number_to_purchase < 1000
-      300
+    prices = SiteConfig.credit_prices_in_cents
+
+    case @number_to_purchase
+    when ..9
+      prices[:small]
+    when 10..99
+      prices[:medium]
+    when 100..999
+      prices[:large]
     else
-      250
+      prices[:xlarge]
     end
   end
 end

app/controllers/internal/configs_controller.rb

@@ -56,6 +56,7 @@ module Internal
         social_media_handles: SiteConfig.social_media_handles.keys,
         email_addresses: SiteConfig.email_addresses.keys,
         meta_keywords: SiteConfig.meta_keywords.keys,
+        credit_prices_in_cents: SiteConfig.credit_prices_in_cents.keys,
       )
     end
 
@@ -70,6 +71,7 @@ module Internal
       %i[sidebar_tags suggested_tags suggested_users].each do |param|
         config[param] = config[param].downcase.delete(" ") if config[param]
       end
+      config[:credit_prices_in_cents]&.transform_values!(&:to_i)
     end
 
     def bust_relevant_caches

app/models/site_config.rb

@@ -138,4 +138,12 @@ class SiteConfig < RailsSettings::Base
 
   # Broadcast
   field :welcome_notifications_live_at, type: :date
+
+  # Credits
+  field :credit_prices_in_cents, type: :hash, default: {
+    small: 500,
+    medium: 400,
+    large: 300,
+    xlarge: 250
+  }
 end

app/views/internal/configs/show.html.erb

@@ -248,6 +248,49 @@
           </div>
         </div>
 
+        <div class="card mt-3">
+          <%= render partial: "card_header",
+                     locals: {
+                       header: "Credits",
+                       state: "collapse",
+                       target: "creditsBodyContainer",
+                       expanded: "false"
+                     } %>
+
+          <div id="creditsBodyContainer" class="card-body collapse hide" aria-labelledby="creditsBodyContainer">
+            <%= f.fields_for :credit_prices_in_cents do |price_field| %>
+              <div class="form-group">
+                <%= price_field.label "Credit price in cents (S)" %>
+                <%= price_field.number_field :small,
+                                             class: "form-control",
+                                             value: SiteConfig.credit_prices_in_cents[:small] %>
+                <div class="alert alert-info">Price for small credit purchase (< 10 credits).</div>
+              </div>
+              <div class="form-group">
+                <%= price_field.label "Credit price in cents (M)" %>
+                <%= price_field.number_field :medium,
+                                             class: "form-control",
+                                            value: SiteConfig.credit_prices_in_cents[:medium] %>
+                <div class="alert alert-info">Price for medium credit purchase (10 - 99 credits).</div>
+              </div>
+              <div class="form-group">
+                <%= price_field.label "Credit price in cents (L)" %>
+                <%= price_field.number_field :large,
+                                             class: "form-control",
+                                             value: SiteConfig.credit_prices_in_cents[:large] %>
+                <div class="alert alert-info">Price for large credit purchase (100 - 999 credits).</div>
+              </div>
+              <div class="form-group">
+                <%= price_field.label "Credit price in cents (XL)" %>
+                <%= price_field.number_field :xlarge,
+                                             class: "form-control",
+                                             value: SiteConfig.credit_prices_in_cents[:xlarge] %>
+                <div class="alert alert-info">Price for extra large credit purchase (1000 credits or more).</div>
+              </div>
+            <% end %>
+          </div>
+        </div>
+ 
         <div class="card mt-3">
           <%= render partial: "card_header",
                      locals: {

spec/requests/internal/configs_spec.rb

@@ -513,6 +513,26 @@ RSpec.describe "/internal/config", type: :request do
           expect(SiteConfig.public).to eq(is_public)
         end
       end
+
+      describe "Credits" do
+        it "updates the credit prices", :aggregate_failures do
+          original_prices = {
+            small: 500,
+            medium: 400,
+            large: 300,
+            xlarge: 250
+          }
+          SiteConfig.credit_prices_in_cents = original_prices
+
+          SiteConfig.credit_prices_in_cents.each_key do |size|
+            new_prices = original_prices.merge(size => 123)
+            expect do
+              post "/internal/config", params: { site_config: { credit_prices_in_cents: new_prices },
+                                                 confirmation: confirmation_message }
+            end.to change { SiteConfig.credit_prices_in_cents[size] }.from(original_prices[size.to_sym]).to(123)
+          end
+        end
+      end
     end
   end
   # rubocop:enable RSpec/NestedGroups