# frozen_string_literal: true

module Spandx
  module Gateways
    # https://api.nuget.org/v3-flatcontainer/#{name}/#{version}/#{name}.nuspec
    # https://api.nuget.org/v3-flatcontainer/#{package.name}/index.json
    # https://docs.microsoft.com/en-us/nuget/api/package-base-address-resource
    class Nuget
      def initialize(http: Spandx.http, catalogue:)
        @http = http
        @catalogue = catalogue
        @guess = Guess.new(catalogue)
      end

      def licenses_for(name, version)
        document = nuspec_for(name, version)

        extract_licenses_from(document) ||
          guess_licenses_from(document)
      end

      private

      attr_reader :http, :catalogue, :guess

      def nuspec_url_for(name, version)
        "https://api.nuget.org/v3-flatcontainer/#{name}/#{version}/#{name}.nuspec"
      end

      def nuspec_for(name, version)
        response = http.get(nuspec_url_for(name, version))
        from_xml(response.body) if http.ok?(response)
      end

      def from_xml(xml)
        Nokogiri::XML(xml).tap(&:remove_namespaces!)
      end

      def extract_licenses_from(document)
        licenses = document.search('//package/metadata/license')
        licenses.map(&:text) if licenses.any?
      end

      def guess_licenses_from(document)
        document
          .search('//package/metadata/licenseUrl')
          .map { |node| guess_license_for(node.text) }
          .compact
      end

      def guess_license_for(url)
        response = http.get(url)

        guess.license_for(response.body) if http.ok?(response)
      end
    end
  end
end