require 'nokogiri'
require 'spec_helper'
require 'misc_shared'

RSpec.describe NewspaperWorks::TextExtractionDerivativeService do
  include_context "shared setup"

  let(:valid_file_set) do
    file_set = FileSet.new
    file_set.save!(validate: false)
    file_set
  end

  let(:work) do
    work = NewspaperPage.create(title: ["Hello"])
    work.members << valid_file_set
    work.save!
  end

  let(:minimal_alto) do
    File.join(fixture_path, 'minimal-alto.xml')
  end

  let(:altoxsd) do
    xsdpath = File.join(fixture_path, 'alto-2-0.xsd')
    Nokogiri::XML::Schema(File.read(xsdpath))
  end

  describe "Creates ALTO derivative" do
    def source_image(name)
      File.join(fixture_path, name)
    end

    def expected_path(file_set, ext)
      Hyrax::DerivativePath.derivative_path_for_reference(file_set, ext)
    end

    def validate_alto(filename)
      altoxsd.validate(filename)
    end

    def derivative_exists(ext)
      path = expected_path(valid_file_set, ext)
      expect(File.exist?(path)).to be true
      expect(File.size(path)).to be > 0
    end

    it "creates, stores valid ALTO and plain-text derivatives" do
      # these are in same test to avoid duplicate OCR operation
      service = described_class.new(valid_file_set)
      service.create_derivatives(source_image('ocr_mono.tiff'))
      # ALTO derivative file exists at expected path and validates:
      altoxsd.validate(expected_path(valid_file_set, 'xml'))
      # Plain text exists as non-empty file:
      derivative_exists('txt')
      derivative_exists('json')
      json_path = expected_path(valid_file_set, 'json')
      loaded_result = JSON.parse(File.read(json_path))
      expect(loaded_result['coords'].length).to be > 1
    end

    it "usually uses OCR, when no existing text" do
      service = described_class.new(valid_file_set)
      # here, service will delegate create_derivatives to OCR impl method:
      expect(service).to receive(:create_derivatives_from_ocr)
      service.create_derivatives(source_image('ocr_mono.tiff'))
    end

    it "defers to existing ALTO sources, when present" do
      # Attach some ALTO to a work
      derivatives = NewspaperWorks::Data::WorkDerivatives.of(
        work,
        valid_file_set
      )
      derivatives.attach(minimal_alto, 'xml')
      # In this case, service will not call the OCR implementation method:
      service = described_class.new(valid_file_set)
      expect(service).not_to receive(:create_derivatives_from_ocr)
      service.create_derivatives(source_image('ocr_mono.tiff'))
    end
  end
end