# File lib/chef_zero/endpoints/environment_cookbook_versions_endpoint.rb, line 10
      def post(request)
        cookbook_names = list_data(request, request.rest_path[0..1] + ['cookbooks'])

        # Get the list of cookbooks and versions desired by the runlist
        desired_versions = {}
        run_list = FFI_Yajl::Parser.parse(request.body, :create_additions => false)['run_list']
        run_list.each do |run_list_entry|
          if run_list_entry =~ /(.+)::.+\@(.+)/ || run_list_entry =~ /(.+)\@(.+)/
            raise RestErrorResponse.new(412, "No such cookbook: #{$1}") if !cookbook_names.include?($1)
            raise RestErrorResponse.new(412, "No such cookbook version for cookbook #{$1}: #{$2}") if !list_data(request, request.rest_path[0..1] + ['cookbooks', $1]).include?($2)
            desired_versions[$1] = [ $2 ]
          else
            desired_cookbook = run_list_entry.split('::')[0]
            raise RestErrorResponse.new(412, "No such cookbook: #{desired_cookbook}") if !cookbook_names.include?(desired_cookbook)
            desired_versions[desired_cookbook] = list_data(request, request.rest_path[0..1] + ['cookbooks', desired_cookbook])
          end
        end

        # Filter by environment constraints
        environment = FFI_Yajl::Parser.parse(get_data(request, request.rest_path[0..3]), :create_additions => false)
        environment_constraints = environment['cookbook_versions'] || {}

        desired_versions.each_key do |name|
          desired_versions = filter_by_constraint(desired_versions, name, environment_constraints[name])
        end

        # Depsolve!
        solved = depsolve(request, desired_versions.keys, desired_versions, environment_constraints)
        if !solved
          if @last_missing_dep && !cookbook_names.include?(@last_missing_dep)
            return raise RestErrorResponse.new(412, "No such cookbook: #{@last_missing_dep}")
          elsif @last_constraint_failure
            return raise RestErrorResponse.new(412, "Could not satisfy version constraints for: #{@last_constraint_failure}")
          else

            return raise RestErrorResponse.new(412, "Unsolvable versions!")
          end
        end

        result = {}
        solved.each_pair do |name, versions|
          cookbook = FFI_Yajl::Parser.parse(get_data(request, request.rest_path[0..1] + ['cookbooks', name, versions[0]]), :create_additions => false)
          result[name] = DataNormalizer.normalize_cookbook(self, request.rest_path[0..1], cookbook, name, versions[0], request.base_uri, 'MIN')
        end
        json_response(200, result)
      end