# Meant to be applied on top of a controller that implements
# Blacklight::SolrHelper. Will inject range limiting behaviors
# to solr parameters creation.
module BlacklightOaiProvider
  module Controller
    extend ActiveSupport::Concern

    included do
      helper_method :oai_config
    end

    # Action method of our own!
    # Delivers a _partial_ that's a display of a single fields range facets.
    # Used when we need a second Solr query to get range facets, after the
    # first found min/max from result set.
    def oai
      body = oai_provider
             .process_request(oai_params.to_h)
             .gsub('<?xml version="1.0" encoding="UTF-8"?>') do |m|
               "#{m}\n<?xml-stylesheet type=\"text/xsl\" href=\"#{ActionController::Base.helpers.asset_path('blacklight_oai_provider/oai2.xsl')}\"?>\n"
             end
      render xml: body, content_type: 'text/xml'
    end

    # Uses Blacklight.config, needs to be modified when
    # that changes to be controller-based. This is the only method
    # in this plugin that accesses Blacklight.config, single point
    # of contact.
    def oai_config
      blacklight_config.oai || {}
    end

    def oai_provider
      @oai_provider ||= BlacklightOaiProvider::SolrDocumentProvider.new(self, oai_config)
    end

    private

    def oai_params
      params.permit(:verb, :identifier, :metadataPrefix, :set, :from, :until, :resumptionToken)
    end
  end
end