Add pdf preview for docx reports [SCI-5601]

app/controllers/reports_controller.rb

@@ -206,7 +206,7 @@ class ReportsController < ApplicationController
       format.json do
         @report.docx_processing!
         log_activity(:generate_docx_report)
-        Reports::DocxJob.perform_later(@report, current_user, root_url)
+        Reports::DocxJob.perform_later(@report.id, current_user, root_url)
         render json: {
           message: I18n.t('projects.reports.index.generation.accepted_message')
         }

app/jobs/reports/docx_job.rb

@@ -51,6 +51,8 @@ module Reports
                           report_link: "<a href='#{report_path}'>#{sanitize_input(report.name)}</a>",
                           team_name: sanitize_input(report.team.name))
         )
+
+        Reports::DocxPreviewJob.perform_later(report.id)
         notification.create_user_notification(user)
       ensure
         file.close

app/jobs/reports/docx_preview_job.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+# Provides asynchronous generation of image previews for ActiveStorage::Blob records.
+module Reports
+  class DocxPreviewJob < ApplicationJob
+    queue_as :reports
+
+    discard_on StandardError do |job, error|
+      report = Report.find_by(id: job.arguments.first)
+      ActiveRecord::Base.no_touching do
+        report&.update(docx_preview_processing: false)
+      end
+      Rails.logger.error("Couldn't generate PDF preview for DOCX Report with id: #{job.arguments.first}. Error:\n #{error}")
+    end
+
+    discard_on ActiveRecord::RecordNotFound
+
+    def perform(report_id)
+      report = Report.find(report_id)
+      blob = report.docx_file.blob
+      blob.open(tmpdir: tempdir) do |input|
+        work_dir = File.dirname(input.path)
+        preview_filename = "#{File.basename(input.path, '.*')}.pdf"
+        preview_file = File.join(work_dir, preview_filename)
+        Rails.logger.info "Starting preparing document preview for file #{blob.filename.sanitized}..."
+
+        ActiveRecord::Base.transaction do
+          success = system(
+            libreoffice_path, '--headless', '--invisible', '--convert-to', 'pdf', '--outdir', work_dir, input.path
+          )
+          unless success && File.file?(preview_file)
+            raise StandardError, "There was an error generating PDF preview, blob id: #{blob.id}"
+          end
+
+          ActiveRecord::Base.no_touching do
+            report.docx_preview_file.attach(io: File.open(preview_file), filename: "#{blob.filename.base}.pdf")
+            report.update(docx_preview_processing: false)
+          end
+          Rails.logger.info("Finished preparing PDF preview for file #{blob.filename.sanitized}.")
+        end
+      ensure
+        File.delete(preview_file) if File.file?(preview_file)
+      end
+    end
+
+    private
+
+    def tempdir
+      Rails.root.join('tmp')
+    end
+
+    def libreoffice_path
+      ENV['LIBREOFFICE_PATH'] || 'soffice'
+    end
+  end
+end

app/models/report.rb

@@ -11,6 +11,7 @@ class Report < ApplicationRecord
   # ActiveStorage configuration
   has_one_attached :pdf_file
   has_one_attached :docx_file
+  has_one_attached :docx_preview_file
 
   auto_strip_attributes :name, :description, nullify: false
   validates :name,
@@ -96,6 +97,16 @@ class Report < ApplicationRecord
     report_elements.order(:position).select { |el| el.parent.blank? }
   end
 
+  def docx_preview_ready?
+    return false if docx_preview_processing
+
+    return true if docx_preview_file.attached?
+
+    Reports::DocxPreviewJob.perform_later(id)
+    ActiveRecord::Base.no_touching { update(docx_preview_processing: true) }
+    false
+  end
+
   # Clean report elements from report
   # the function runs before the report is edit
   def cleanup_report

app/views/reports/_content_document_preview.html.erb

@@ -11,6 +11,8 @@
   <div class="file-preview-container">
     <% if report_type == 'pdf' %>
       <%= render partial: 'shared/pdf_viewer.html.erb', locals: { asset: report.pdf_file, report_document: true } %>
+    <% elsif report_type == 'docx' && report.docx_preview_ready? %>
+      <%= render partial: 'shared/pdf_viewer.html.erb', locals: { asset: report.docx_preview_file, report_document: true } %>
     <% else %>
       <div>
         <i class="fas fa-10x fa-file-word"></i>

db/migrate/20210525143303_add_docx_preview_processing_to_reports.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+class AddDocxPreviewProcessingToReports < ActiveRecord::Migration[6.1]
+  def change
+    add_column :reports, :docx_preview_processing, :boolean, default: false, null: false
+  end
+end

db/structure.sql

@@ -1307,9 +1307,10 @@ CREATE TABLE public.reports (
     updated_at timestamp without time zone NOT NULL,
     last_modified_by_id bigint,
     team_id bigint,
-    pdf_file_status integer DEFAULT 0,
-    docx_file_status integer DEFAULT 0,
-    settings jsonb DEFAULT '{}'::jsonb NOT NULL
+    pdf_file_status integer,
+    docx_file_status integer,
+    settings jsonb DEFAULT '{}'::jsonb NOT NULL,
+    docx_preview_processing boolean DEFAULT false NOT NULL
 );
 
 
@@ -7234,6 +7235,8 @@ INSERT INTO "schema_migrations" (version) VALUES
 ('20210312185911'),
 ('20210325152257'),
 ('20210407143303'),
-('20210506125657');
+('20210410100006'),
+('20210506125657'),
+('20210525143303');