Disable calculating winners during balloting

Calculating winners before the balloting is over is useless (results
aren't published at that point) and can lead to the wrong results since
users are still voting and results might change.

And we were showing the button to calculate winners even when a budget
had finished. However, in this case the action to calculate winners did
nothing, which resulted in administrators seeing nothing happened after
pressing the button.

spec/components/admin/budgets/calculate_winners_button_component_spec.rb

@@ -0,0 +1,65 @@
+require "rails_helper"
+
+describe Admin::Budgets::CalculateWinnersButtonComponent, controller: Admin::BaseController do
+  let(:budget) { create(:budget) }
+  let(:component) { Admin::Budgets::CalculateWinnersButtonComponent.new(budget) }
+  before { sign_in(create(:administrator).user) }
+
+  it "renders when reviewing ballots" do
+    budget.update!(phase: "reviewing_ballots")
+
+    render_inline component
+
+    expect(page).to have_button "Calculate Winner Investments"
+    expect(page).not_to have_button "Recalculate Winner Investments"
+  end
+
+  it "does not render before balloting has finished" do
+    budget.update!(phase: "balloting")
+
+    render_inline component
+
+    expect(page).not_to have_button "Calculate Winner Investments"
+    expect(page).not_to have_button "Recalculate Winner Investments"
+  end
+
+  it "does not render after the budget process has finished" do
+    budget.update!(phase: "finished")
+
+    render_inline component
+
+    expect(page).not_to have_button "Calculate Winner Investments"
+    expect(page).not_to have_button "Recalculate Winner Investments"
+  end
+
+  context "budget with winners" do
+    before { create(:budget_investment, :winner, budget: budget) }
+
+    it "renders when reviewing ballots" do
+      budget.update!(phase: "reviewing_ballots")
+
+      render_inline component
+
+      expect(page).to have_button "Recalculate Winner Investments"
+      expect(page).not_to have_button "Calculate Winner Investments"
+    end
+
+    it "does not render before balloting has finished" do
+      budget.update!(phase: "balloting")
+
+      render_inline component
+
+      expect(page).not_to have_button "Calculate Winner Investments"
+      expect(page).not_to have_button "Recalculate Winner Investments"
+    end
+
+    it "does not render after the budget process has finished" do
+      budget.update!(phase: "finished")
+
+      render_inline component
+
+      expect(page).not_to have_button "Calculate Winner Investments"
+      expect(page).not_to have_button "Recalculate Winner Investments"
+    end
+  end
+end