FEATURE: Switch to new methods of pageview measurement and reporting (#28729)

### UI changes

All of the UI changes described are gated behind the `use_legacy_pageviews`
site setting.

This commit changes the admin dashboard pageviews report to
use the "Consolidated Pageviews with Browser Detection" report
introduced in 2f2da7274732cba30d03b6c5c3a4194652cb6783 with
the following changes:

* The report name is changed to "Site traffic"
* The pageview count on the dashboard is counting only using the new method
* The old "Consolidated Pageviews" report is renamed as "Consolidated Legacy Pageviews"
* By default "known crawlers" and "other" sources of pageviews are hidden on the report

When `use_legacy_pageviews` is `true`, we do not show or allow running
the "Site traffic" report for admins. When `use_legacy_pageviews` is `false`,
we do not show or allow running the following legacy reports:

* consolidated_page_views
* consolidated_page_views_browser_detection
* page_view_anon_reqs
* page_view_logged_in_reqs

### Historical data changes

Also part of this change is that, since we introduced our new "Consolidated
Pageviews with Browser Detection" report, some admins are confused at either:

* The lack of data before a certain date , which didn’t exist before
  we started collecting it
* Comparing this and the current "Consolidated Pageviews" report data,
  which rolls up "Other Pageviews" into "Anonymous Browser" and so it
  appears inaccurate

All pageview data in the new report before the date where the _first_
anon or logged in browser pageview was recorded is now hidden.

spec/requests/admin/reports_controller_spec.rb

@@ -5,6 +5,52 @@ RSpec.describe Admin::ReportsController do
   fab!(:moderator)
   fab!(:user)
 
+  describe "#index" do
+    before { sign_in(admin) }
+
+    it "excludes page view mobile reports" do
+      get "/admin/reports.json"
+      expect(response.parsed_body["reports"].map { |r| r[:type] }).not_to include(
+        "page_view_anon_browser_mobile_reqs",
+        "page_view_logged_in_browser_mobile_reqs",
+        "page_view_anon_mobile_reqs",
+        "page_view_logged_in_mobile_reqs",
+      )
+    end
+
+    it "excludes about and storage stats reports" do
+      get "/admin/reports.json"
+      expect(response.parsed_body["reports"].map { |r| r[:type] }).not_to include(
+        "report_about",
+        "report_storage_stats",
+      )
+    end
+
+    context "when use_legacy_pageviews is true" do
+      before { SiteSetting.use_legacy_pageviews = true }
+
+      it "excludes the site_traffic report and includes legacy pageview reports" do
+        get "/admin/reports.json"
+        expect(response.parsed_body["reports"].map { |r| r[:type] }).not_to include("site_traffic")
+        expect(response.parsed_body["reports"].map { |r| r[:type] }).to include(
+          *Admin::ReportsController::HIDDEN_LEGACY_PAGEVIEW_REPORTS,
+        )
+      end
+    end
+
+    context "when use_legacy_pageviews is false" do
+      before { SiteSetting.use_legacy_pageviews = false }
+
+      it "includes the site_traffic report and excludes legacy pageview reports" do
+        get "/admin/reports.json"
+        expect(response.parsed_body["reports"].map { |r| r[:type] }).to include("site_traffic")
+        expect(response.parsed_body["reports"].map { |r| r[:type] }).not_to include(
+          *Admin::ReportsController::HIDDEN_LEGACY_PAGEVIEW_REPORTS,
+        )
+      end
+    end
+  end
+
   describe "#bulk" do
     context "when logged in as an admin" do
       before { sign_in(admin) }
@@ -128,6 +174,84 @@ RSpec.describe Admin::ReportsController do
         expect(response.parsed_body["errors"]).to include(I18n.t("not_found"))
       end
     end
+
+    context "when use_legacy_pageviews is true" do
+      before do
+        SiteSetting.use_legacy_pageviews = true
+        sign_in(admin)
+      end
+
+      it "marks the site_traffic report as not_found and does not run it" do
+        get "/admin/reports/bulk.json",
+            params: {
+              reports: {
+                site_traffic: {
+                  limit: 10,
+                },
+                consolidated_page_views: {
+                  limit: 10,
+                },
+                consolidated_page_views_browser_detection: {
+                  limit: 10,
+                },
+                page_view_anon_reqs: {
+                  limit: 10,
+                },
+                page_view_logged_in_reqs: {
+                  limit: 10,
+                },
+              },
+            }
+
+        expect(response.status).to eq(200)
+        expect(response.parsed_body["reports"].count).to eq(5)
+        expect(response.parsed_body["reports"][0]).to include("error" => "not_found", "data" => nil)
+        expect(response.parsed_body["reports"][1]["type"]).to eq("consolidated_page_views")
+        expect(response.parsed_body["reports"][2]["type"]).to eq(
+          "consolidated_page_views_browser_detection",
+        )
+        expect(response.parsed_body["reports"][3]["type"]).to eq("page_view_anon_reqs")
+        expect(response.parsed_body["reports"][4]["type"]).to eq("page_view_logged_in_reqs")
+      end
+    end
+
+    context "when use_legacy_pageviews is false" do
+      before do
+        SiteSetting.use_legacy_pageviews = false
+        sign_in(admin)
+      end
+
+      it "marks the legacy pageview reports as not_found and does not run them" do
+        get "/admin/reports/bulk.json",
+            params: {
+              reports: {
+                site_traffic: {
+                  limit: 10,
+                },
+                consolidated_page_views: {
+                  limit: 10,
+                },
+                consolidated_page_views_browser_detection: {
+                  limit: 10,
+                },
+                page_view_anon_reqs: {
+                  limit: 10,
+                },
+                page_view_logged_in_reqs: {
+                  limit: 10,
+                },
+              },
+            }
+
+        expect(response.status).to eq(200)
+        expect(response.parsed_body["reports"].count).to eq(5)
+        expect(response.parsed_body["reports"][0]["type"]).to eq("site_traffic")
+        expect(response.parsed_body["reports"][1]).to include("error" => "not_found", "data" => nil)
+        expect(response.parsed_body["reports"][2]).to include("error" => "not_found", "data" => nil)
+        expect(response.parsed_body["reports"][3]).to include("error" => "not_found", "data" => nil)
+        expect(response.parsed_body["reports"][4]).to include("error" => "not_found", "data" => nil)
+      end
+    end
   end
 
   describe "#show" do
@@ -228,5 +352,35 @@ RSpec.describe Admin::ReportsController do
         expect(response.parsed_body["errors"]).to include(I18n.t("not_found"))
       end
     end
+
+    context "when use_legacy_pageviews is true" do
+      before do
+        SiteSetting.use_legacy_pageviews = true
+        sign_in(admin)
+      end
+
+      it "does not allow running site_traffic report" do
+        Admin::ReportsController::HIDDEN_PAGEVIEW_REPORTS.each do |report_type|
+          get "/admin/reports/#{report_type}.json"
+          expect(response.status).to eq(404)
+          expect(response.parsed_body["errors"]).to include(I18n.t("not_found"))
+        end
+      end
+    end
+
+    context "when use_legacy_pageviews is false" do
+      before do
+        SiteSetting.use_legacy_pageviews = false
+        sign_in(admin)
+      end
+
+      it "does not allow running legacy pageview reports" do
+        Admin::ReportsController::HIDDEN_LEGACY_PAGEVIEW_REPORTS.each do |report_type|
+          get "/admin/reports/#{report_type}.json"
+          expect(response.status).to eq(404)
+          expect(response.parsed_body["errors"]).to include(I18n.t("not_found"))
+        end
+      end
+    end
   end
 end