Dynamically render Dashboard stats from CSV data

config.rb

@@ -1,5 +1,6 @@
 require 'govuk_tech_docs'
 require 'lib/api_catalogue'
+require 'lib/dashboard_stats'
 require 'lib/url_helpers'
 
 GovukTechDocs.configure(self)
@@ -11,7 +12,9 @@
 helpers UrlHelpers
 
 csv_path = File.expand_path("data/inputs/apic.csv", __dir__)
-ApiCatalogue.from_csv(csv_path).organisations_apis.each do |organisation, apis|
+api_catalogue = ApiCatalogue.from_csv(csv_path)
+
+api_catalogue.organisations_apis.each do |organisation, apis|
   proxy(
     UrlHelpers.organisation_path(organisation),
     "organisation_index.html",
@@ -30,3 +33,10 @@
     )
   end
 end
+
+proxy(
+  "/dashboard/index.html",
+  "dashboard.html",
+  locals: { dashboard_stats: DashboardStats.new(api_catalogue) },
+  ignore: true,
+)

lib/api_catalogue.rb

@@ -18,12 +18,10 @@ def self.from_csv(csv_path)
     new(data)
   end
 
-  def initialize(data)
-    @data = data
-  end
+  attr_reader :organisations_apis
 
-  def organisations_apis
-    data.each
+  def initialize(organisations_apis)
+    @organisations_apis = organisations_apis
   end
 
   private

lib/dashboard_stats.rb

@@ -0,0 +1,44 @@
+class DashboardStats
+  OrganisationStats = Struct.new(
+    :organisation, :api_count, :first_added, :last_updated, keyword_init: true
+  )
+
+  def initialize(api_catalogue)
+    @api_catalogue = api_catalogue
+  end
+
+  def total_apis
+    api_catalogue.organisations_apis.sum do |_, apis|
+      apis.count
+    end
+  end
+
+  def total_organisations
+    api_catalogue.organisations_apis.count
+  end
+
+  def by_organisation
+    @_by_organsation ||= calculate_stats_by_organisation
+  end
+
+  private
+
+  attr_reader :api_catalogue
+
+  def calculate_stats_by_organisation
+    api_catalogue
+      .organisations_apis
+      .map(&method(:build_organisation_stats))
+      .sort_by(&:api_count)
+      .reverse
+  end
+
+  def build_organisation_stats(organisation, apis)
+    OrganisationStats.new(
+      organisation: organisation,
+      api_count: apis.count,
+      first_added: apis.min_by(&:date_added)&.date_added,
+      last_updated: apis.max_by(&:date_updated)&.date_updated,
+    )
+  end
+end

source/dashboard.html.erb

@@ -0,0 +1,47 @@
+---
+title: API Catalogue Contents
+weight: 1000
+hide_in_navigation: true
+---
+
+<h2>API Catalogue Contents</h2>
+
+<table>
+  <thead>
+    <tr>
+      <th>Total APIs:</th>
+      <th>Departments Represented:</th>
+    </tr>
+  </thead>
+
+  <tbody>
+    <tr>
+      <td><%= dashboard_stats.total_apis %></td>
+      <td><%= dashboard_stats.total_organisations %></td>
+    </tr>
+  </tbody>
+</table>
+
+<table>
+  <thead>
+    <tr>
+      <th>Department:</th>
+      <th>Number of APIs:</th>
+      <th>First Added:</th>
+      <th>Last Update:</th>
+      <th>Link:</th>
+    </tr>
+  </thead>
+
+  <tbody>
+    <% dashboard_stats.by_organisation.each do |stats| %>
+      <tr>
+        <td><%= stats.organisation.name %></td>
+        <td><%= stats.api_count %></td>
+        <td><%= stats.first_added&.to_formatted_s(:iso8601) %></td>
+        <td><%= stats.last_updated&.to_formatted_s(:iso8601) %></td>
+        <td><%= link_to(stats.organisation.alternate_name, organisation_path(stats.organisation)) %></td>
+      </tr>
+    <% end %>
+  </tbody>
+</table>

spec/lib/dashboard_stats_spec.rb

@@ -0,0 +1,43 @@
+require "api_catalogue"
+require "dashboard_stats"
+
+RSpec.describe DashboardStats do
+  let(:csv_path) { File.expand_path("../../data/inputs/apic.csv", __dir__) }
+  let(:api_catalogue) { ApiCatalogue.from_csv(csv_path) }
+
+  subject { described_class.new(api_catalogue) }
+
+  describe "#total_apis" do
+    it "sums the APIs across each organisation" do
+      expect(subject.total_apis).to be > 100
+    end
+  end
+
+  describe "#total_organisations" do
+    it "sums the number of organisations" do
+      expect(subject.total_organisations).to be > 10
+      expect(subject.total_organisations).to be < subject.total_apis
+    end
+  end
+
+  describe "#by_organisation" do
+    it "provides stats per organisation" do
+      nhs_stats = subject.by_organisation.detect do |stats|
+        stats.organisation.name.casecmp?("National Health Service")
+      end
+
+      expect(nhs_stats).to have_attributes(
+        organisation: have_attributes(name: "National Health Service"),
+        api_count: (a_value > 30),
+        first_added: be_a(Date),
+        last_updated: be_a(Date),
+      )
+    end
+
+    it "orders the organisations by number of APIs" do
+      subject.by_organisation.each_cons(2) do |org1, org2|
+        expect(org1.api_count).to be >= org2.api_count
+      end
+    end
+  end
+end