require 'grouper-rest-client'
require "delegate"

module Ddr::Auth
  class GrouperGateway < SimpleDelegator

    SUBJECT_ID_RE = Regexp.new('[^@]+(?=@duke\.edu)')
    DEFAULT_TIMEOUT = 5

    def self.repository_groups(*args)
      new.repository_groups(*args)
    end

    def self.user_groups(*args)
      new.user_groups(*args)
    end

    def initialize
      super Grouper::Rest::Client::Resource.new(ENV["GROUPER_URL"],
                                                user: ENV["GROUPER_USER"],
                                                password: ENV["GROUPER_PASSWORD"],
                                                timeout: ENV.fetch("GROUPER_TIMEOUT", DEFAULT_TIMEOUT).to_i)
    end

    # List of all grouper groups for the repository
    def repository_groups(raw = false)
      repo_groups = groups(Ddr::Auth.repository_group_filter)
      if ok?
        return repo_groups if raw
        repo_groups.map do |g|
          Group.new(g["name"], label: g["displayExtension"])
        end
      else
        []
      end
    end

    def user_groups(user, raw = false)
      groups = []
      subject_id = user.principal_name.scan(SUBJECT_ID_RE).first
      return groups unless subject_id
      begin
        request_body = {
          "WsRestGetGroupsRequest" => {
            "subjectLookups" => [{"subjectIdentifier" => subject_id}]
          }
        }
        # Have to use :call b/c grouper-rest-client :subjects method doesn't support POST
        response = call("subjects", :post, request_body)
        if ok?
          result = response["WsGetGroupsResults"]["results"].first
          # Have to manually filter results b/c Grouper WS version 1.5 does not support filter parameter
          if result && result["wsGroups"]
            groups = result["wsGroups"].select { |g| g["name"] =~ /^#{REPOSITORY_GROUP_FILTER}/ }
          end
        end
      rescue StandardError => e
        # XXX Should we raise a custom exception?
        Rails.logger.error e
      end
      return groups if raw
      groups.map do |g|
        Group.new(g["name"], label: g["displayExtension"])
      end
    end

  end
end