LG-4327 First pass image metric errors for DPI, Blur, and Glare

[amathews-fs]

Adding the first pass at doc auth errors for problems with the image metrics Acuant returns. There will be a significant refactor for the error handling coming next.

Associated with this PR in Identity-idp

[solipet]

This is great! A couple comments, but not deal breakers.

[solipet]

Are these fixed values? or might we need to change them at some point. If the latter, might be worth adding a configuration class so the gem can be configured from the idp.

[amathews-fs]

Gah, I thought about it and then didn't.

[amathews-fs]

After some consideration, I will do that during the larger refactor coming next.

[zachmargolis]

We have the config object already! Just need to add the properties there, it's referenced in this file a line above already https://github.com/18F/identity-doc-auth/blob/main/lib/identity_doc_auth/acuant/config.rb

[solipet]

The fixture is parsed in each of these contexts. You could wrap these in a context and pull that out, e.g.,

    context 'image metrics errors' do
      let(:parsed_response_body) { JSON.parse(AcuantFixtures.get_results_response_failure) }

      context 'when front image HDPI is too low' do
        let(:http_response) do
          parsed_response_body['Images'].first['HorizontalResolution'] = 250
          instance_double(
            Faraday::Response,
            body: parsed_response_body.to_json,
          )
        end
...

[amathews-fs]

good call. Don't need to parse each time.

[zachmargolis]

Was there a reason that we have separate "one side failed" vs "both sides failed" errors? I think if we had an array of errors that we added to, or even an ActiveModel::Errors that we add per attribute to, we could get some more useful data?

Suggested change

	processed_image_metrics.each do |side, i|
	hdpi = i['HorizontalResolution'] || 0
	vdpi = i['VerticalResolution'] || 0
	if hdpi < DPI_THRESHOLD || vdpi < DPI_THRESHOLD
	front_dpi_fail = true if side == :front
	back_dpi_fail = true if side == :back
	end
	sharpness = i['SharpnessMetric']
	if sharpness.present? && sharpness < SHARP_THRESHOLD
	front_sharp_fail = true if side == :front
	back_sharp_fail = true if side == :back
	end
	glare = i['GlareMetric']
	if glare.present? && glare < GLARE_THRESHOLD
	front_glare_fail = true if side == :front
	back_glare_fail = true if side == :back
	end
	end
	return { results: [Errors::DPI_LOW_BOTH_SIDES] } if front_dpi_fail && back_dpi_fail
	return { results: [Errors::DPI_LOW_ONE_SIDE] } if front_dpi_fail || back_dpi_fail
	errors = Hash.new { |h, k| h[k] = [] }
	processed_image_metrics.each do |side, i|
	hdpi = i['HorizontalResolution'] || 0
	vdpi = i['VerticalResolution'] || 0
	if hdpi < DPI_THRESHOLD || vdpi < DPI_THRESHOLD
	errors[side] << :dpi_fail if side == :front
	end
	sharpness = i['SharpnessMetric']
	if sharpness.present? && sharpness < SHARP_THRESHOLD
	errors[side] << :sharp_fail
	end
	glare = i['GlareMetric']
	if glare.present? && glare < GLARE_THRESHOLD
	errors[side] << :glare_fail
	end
	end
	return errors.to_h # or something

[amathews-fs]

It's a combination of things. The first was that we had slightly different error messages for single errors vs multiple errors, which is in the corresponding IDP PR linked above. The second piece of this was that as part of this I realized that we just needed to refactor the way that we're generating errors for both TrueID and Acuant. My goal for that will be to redesign and simplify the separation between the error generation in the gem and the translation/display in the IDP.

[amathews-fs]

A piece I just realized I didn't address: In this case a DPI failure can cause problems with the sharpness and glare metrics. So we aren't delivering multiple errors for that right now. That is also something that will be considered during the refactor.

[zachmargolis]

Let's add the config changes in this PR, and then LGTM

[zachmargolis]

Suggested change

	# ALerts
	# Alerts

nit

[amathews-fs]

Lol, oops.