Add script for PDF attachment report

This script produces a CSV of counts of published PDF attachemnts per
organisation owning the associated manual. This was produced for the
Content Operating Model team.

bin/content_model_pdf_report

@@ -0,0 +1,84 @@
+#!/usr/bin/env ruby
+
+require File.expand_path("../../config/environment", __FILE__)
+require 'csv'
+
+POST_PUBLICATION_STATES = %w(published archived).freeze
+
+first_period_start_date = ENV.fetch('FIRST_PERIOD_START_DATE', Date.parse('2016-01-01'))
+last_time_period_days = ENV.fetch('LAST_TIME_PERIOD_DAYS', 30)
+last_time_period_start_date = last_time_period_days.days.ago
+
+manual_records = ManualRecord.all
+unique_owning_organisation_slugs = manual_records.map(&:organisation_slug).uniq
+
+organisation_published_pdfs_total_counts_hash = Hash[unique_owning_organisation_slugs.map { |o| [o, 0] }]
+organisation_published_pdfs_since_first_period_counts_hash = Hash[unique_owning_organisation_slugs.map { |o| [o, 0] }]
+organisation_published_pdfs_since_second_period_counts_hash = Hash[unique_owning_organisation_slugs.map { |o| [o, 0] }]
+
+def document_published_after_date?(document_edition, date)
+  (document_edition.exported_at || document_edition.updated_at) >= date
+end
+
+def document_edition_never_published?(document_edition)
+  !POST_PUBLICATION_STATES.include?(document_edition.state)
+end
+
+def all_unique_document_ids_for_manual(manual)
+  manual.editions.map(&:document_ids).flatten.uniq
+end
+
+manual_records.to_a.each do |manual|
+  next unless manual.has_ever_been_published?
+
+  unique_pdf_attachment_file_ids_for_manual = Set.new
+
+  # Rather than examine each manual edition and its set of document editions and attachments in turn,
+  # we instead get all unique document ids associated with this manual, then walk through
+  # the editions of these documents in version order to find unique PDF attachments and their
+  # publication times.
+  all_unique_document_ids_for_manual(manual).each do |document_id|
+    document_editions = SpecialistDocumentEdition.where(document_id: document_id).order(:version_number)
+
+    document_editions.each do |document_edition|
+      next if document_edition_never_published?(document_edition)
+
+      document_edition.attachments.each do |attachment|
+        next if unique_pdf_attachment_file_ids_for_manual.include? attachment.file_id
+        next unless /.*\.pdf$/ =~ attachment.filename
+
+        organisation_published_pdfs_total_counts_hash[manual.organisation_slug] += 1
+
+        if document_published_after_date?(document_edition, first_period_start_date)
+          organisation_published_pdfs_since_first_period_counts_hash[manual.organisation_slug] += 1
+        end
+
+        if document_published_after_date?(document_edition, last_time_period_start_date)
+          organisation_published_pdfs_since_second_period_counts_hash[manual.organisation_slug] += 1
+        end
+
+        unique_pdf_attachment_file_ids_for_manual << attachment.file_id
+      end
+    end
+  end
+end
+
+document_report_filename = Rails.root.join("content-operating-report-for-pdf-documents-#{Time.zone.today.strftime('%Y-%m-%d')}.csv")
+
+CSV.open(document_report_filename, 'w') do |document_csv|
+  document_csv << [
+    "Organisation",
+    "Total published PDF attachments",
+    "#{first_period_start_date} - present PDF attachments",
+    "Last #{last_time_period_days} days PDF attachments"
+  ]
+
+  unique_owning_organisation_slugs.each do |organisation_slug|
+    document_csv << [
+      organisation_slug.titleize,
+      organisation_published_pdfs_total_counts_hash[organisation_slug],
+      organisation_published_pdfs_since_first_period_counts_hash[organisation_slug],
+      organisation_published_pdfs_since_second_period_counts_hash[organisation_slug]
+    ]
+  end
+end