Store country band details in database

app/controllers/country_bands_controller.rb

@@ -10,7 +10,7 @@ def index
 
   def edit
     @number = id_from_params
-    unless CountryBand::BANDS.keys.include?(@number)
+    unless CountryBandDetail.distinct.pluck(:number).include?(@number)
       flash[:danger] = "Unknown band number"
       return redirect_to country_bands_path
     end

app/models/country_band.rb

@@ -1,46 +1,10 @@
 # frozen_string_literal: true
 
 class CountryBand < ApplicationRecord
-  BANDS = {
-    0 => {
-      value: 0.00,
-    },
-    1 => {
-      value: 0.19,
-    },
-    2 => {
-      value: 0.32,
-    },
-    3 => {
-      value: 0.45,
-    },
-    4 => {
-      value: 2.28,
-    },
-    5 => {
-      value: 3.00,
-    },
-  }.freeze
-
-  # According to WCA's current dues policy, the due amount per competitor is equivalent
-  # to this percent of registration fee. Only used if this due amount per competitor is
-  # larger than the due amount per competitor calculated from the competition's country band.
-  PERCENT_REGISTRATION_FEE_USED_FOR_DUE_AMOUNT = 0.15
-
-  def self.percent_registration_fee_used_for_due_amount(country_band)
-    return 0 if country_band.nil?
-    if country_band >= 3
-      0.15
-    elsif country_band >= 1
-      0.05
-    else
-      0.00
-    end
-  end
-
   belongs_to :country, foreign_key: :iso2, primary_key: :iso2
   validates_inclusion_of :iso2, in: Country::WCA_COUNTRY_ISO_CODES
-  validates_inclusion_of :number, in: BANDS.keys.freeze
+
+  validates :number, presence: true, inclusion: { in: CountryBandDetail.distinct.pluck(:number) }
 
   def country
     Country.find_by_iso2(self.iso2)

app/models/country_band_detail.rb

@@ -0,0 +1,6 @@
+# frozen_string_literal: true
+
+class CountryBandDetail < ApplicationRecord
+  scope :active, -> { where(end_date: nil).or(inactive.invert_where) }
+  scope :inactive, -> { where(end_date: ..Date.today) }
+end

app/views/country_bands/_show_band.html.erb

@@ -1,12 +1,12 @@
 <div class="row list-group-item country-band">
   <div class="col-xs-12 text-center title">
-    <%= t("country_bands.band_title", number: number) %>
-    (<%= t("country_bands.due_value", value: data[:value]) %>)
+    <%= t("country_bands.band_title", number: country_band_detail.number) %>
+    (<%= t("country_bands.due_value", value: country_band_detail.due_amount_per_competitor_in_cents.to_f / 100) %>)
     <% if current_user&.can_admin_finances? %>
-      <%= link_to(ui_icon("pencil alt"), edit_country_band_path(id: number)) %>
+      <%= link_to(ui_icon("pencil alt"), edit_country_band_path(id: country_band_detail.number)) %>
     <% end %>
   </div>
-  <% (@country_bands_by_number[number] || []).map(&:country).sort_by(&:name).each do |c| %>
+  <% (@country_bands_by_number[country_band_detail.number] || []).map(&:country).sort_by(&:name).each do |c| %>
     <div class="col-xs-6 col-sm-4 col-md-3 col">
       <div class="country continent-<%= continent_id_as_class(c.continent.id) %>">
         <div class="flag"><%= flag_icon c.iso2 %></div>

app/views/country_bands/index.html.erb

@@ -14,8 +14,8 @@
     </div>
   </div>
   <div class="list-group">
-    <% CountryBand::BANDS.each do |number, data| %>
-      <%= render "show_band", number: number, data: data %>
+    <% CountryBandDetail.active.order(:number).each do |country_band_detail| %>
+      <%= render "show_band", country_band_detail: country_band_detail %>
     <% end %>
   </div>
 </div>

db/migrate/20241225030959_create_country_band_details.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+class CreateCountryBandDetails < ActiveRecord::Migration[7.2]
+  def change
+    create_table :country_band_details do |t|
+      t.integer "number", null: false
+      t.date "start_date", null: false
+      t.date "end_date"
+      t.integer "due_amount_per_competitor_in_cents", null: false
+      t.integer "due_percent_registration_fee", null: false
+      t.timestamps
+    end
+  end
+end

db/migrate/20241225031242_populate_country_band_details.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+class PopulateCountryBandDetails < ActiveRecord::Migration[7.2]
+  def change
+    CountryBandDetail.create!(
+      number: 0,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 0,
+      due_percent_registration_fee: 0,
+    )
+    CountryBandDetail.create!(
+      number: 1,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 19,
+      due_percent_registration_fee: 5,
+    )
+    CountryBandDetail.create!(
+      number: 2,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 32,
+      due_percent_registration_fee: 5,
+    )
+    CountryBandDetail.create!(
+      number: 3,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 45,
+      due_percent_registration_fee: 15,
+    )
+    CountryBandDetail.create!(
+      number: 4,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 228,
+      due_percent_registration_fee: 15,
+    )
+    CountryBandDetail.create!(
+      number: 5,
+      start_date: '2018-01-01',
+      due_amount_per_competitor_in_cents: 300,
+      due_percent_registration_fee: 15,
+    )
+  end
+end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.2].define(version: 2024_11_24_050607) do
+ActiveRecord::Schema[7.2].define(version: 2024_12_25_031242) do
   create_table "Competitions", id: { type: :string, limit: 32, default: "" }, charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.string "name", limit: 50, default: "", null: false
     t.string "cityName", limit: 50, default: "", null: false
@@ -665,6 +665,16 @@
     t.datetime "updated_at", null: false
   end
 
+  create_table "country_band_details", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
+    t.integer "number", null: false
+    t.date "start_date", null: false
+    t.date "end_date"
+    t.integer "due_amount_per_competitor_in_cents", null: false
+    t.integer "due_percent_registration_fee", null: false
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+  end
+
   create_table "country_bands", charset: "utf8mb4", collation: "utf8mb4_unicode_ci", force: :cascade do |t|
     t.integer "number", null: false
     t.string "iso2", limit: 2, null: false

lib/dues_calculator.rb

@@ -24,10 +24,12 @@ def self.dues_per_competitor_in_usd(country_iso2, base_entry_fee_lowest_denomina
     DuesCalculator.update_exchange_rates_if_needed
     input_money_us_dollars = Money.new(base_entry_fee_lowest_denomination, currency_code).exchange_to("USD")
 
-    registration_fee_dues_us_dollars = input_money_us_dollars * CountryBand.percent_registration_fee_used_for_due_amount(country_band)
-    country_band_dues_us_dollars = country_band.present? && country_band > 0 ? CountryBand::BANDS[country_band][:value] : 0
-    # times 100 because Money require lowest currency subunit, which is cents for USD
-    country_band_dues_us_dollars_money = Money.new(country_band_dues_us_dollars * 100, "USD")
+    country_band_detail = CountryBandDetail.find_by(number: country_band)
+    return nil unless country_band_detail
+
+    registration_fee_dues_us_dollars = input_money_us_dollars * country_band_detail.due_percent_registration_fee.to_f/100
+    # cent is given directly because Money require lowest currency subunit, which is cents for USD
+    country_band_dues_us_dollars_money = Money.new(country_band_detail.due_amount_per_competitor_in_cents, "USD")
 
     [registration_fee_dues_us_dollars, country_band_dues_us_dollars_money].max
   rescue Money::Currency::UnknownCurrency, CurrencyUnavailable