require_relative '../http'

module Spectre::Http
  class SpectreHttpRequest
    def keystone url, username, password, project, domain, cert=nil
      @__req['keystone'] = {} unless @__req.key? 'keystone'

      @__req['keystone']['url'] = url
      @__req['keystone']['username'] = username
      @__req['keystone']['password'] = password
      @__req['keystone']['project'] = project
      @__req['keystone']['domain'] = domain
      @__req['keystone']['cert'] = cert

      @__req['auth'] = 'keystone'
    end
  end

  module Keystone
    @@cache = {}

    def self.on_req _http, net_req, req
      return unless req.key? 'keystone' and req['auth'] == 'keystone'

      keystone_cfg = req['keystone']

      if @@cache.key? keystone_cfg
        token = @@cache[keystone_cfg]
      else
        token, _ = authenticate(
          keystone_cfg['url'],
          keystone_cfg['username'],
          keystone_cfg['password'],
          keystone_cfg['project'],
          keystone_cfg['domain'],
          keystone_cfg['cert'],
        )

        @@cache[keystone_cfg] = token
      end

      net_req['X-Auth-Token'] = token
    end

    private

    def self.authenticate keystone_url, username, password, project, domain, cert
      auth_data = {
        auth: {
          identity: {
            methods: ['password'],
            password: {
              user: {
                name: username,
                password: password,
                domain: {
                  name: domain,
                },
              },
            },
          },
          scope: {
            project: {
              name: project,
              domain: {
                name: domain,
              },
            },
          },
        },
      }

      keystone_url = keystone_url + '/' unless keystone_url.end_with? '/'

      base_uri = URI(keystone_url)
      uri = URI.join(base_uri, 'auth/tokens?nocatalog=true')

      http = Net::HTTP.new(base_uri.host, base_uri.port)

      if cert
        http.use_ssl = true
        http.ca_file = cert
      end

      req = Net::HTTP::Post.new(uri)
      req.body = JSON.pretty_generate(auth_data)
      req.content_type = 'application/json'

      res = http.request(req)

      raise "error while authenticating: #{res.code} #{res.message}\n#{res.body}" if res.code != '201'

      [
        res['X-Subject-Token'],
        JSON.parse(res.body),
      ]
    end

    Spectre::Http.register(self)
  end
end