# Copyright 2016 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.


require "google/cloud/errors"
require "google/cloud/dns/version"
require "google/apis/dns_v1"

module Google
  module Cloud
    module Dns
      ##
      # @private
      # Represents the service to DNS, exposing the API calls.
      class Service
        ##
        # Alias to the Google Client API module
        API = Google::Apis::DnsV1

        attr_accessor :project
        attr_accessor :credentials

        ##
        # Creates a new Service instance.
        def initialize project, credentials,
                       retries: nil, timeout: nil, host: nil
          @project = project
          @credentials = credentials
          @service = API::DnsService.new
          @service.client_options.application_name    = "gcloud-ruby"
          @service.client_options.application_version = \
            Google::Cloud::Dns::VERSION
          @service.client_options.open_timeout_sec = timeout
          @service.client_options.read_timeout_sec = timeout
          @service.client_options.send_timeout_sec = timeout
          @service.request_options.retries = retries || 3
          @service.request_options.header ||= {}
          @service.request_options.header["x-goog-api-client"] = \
            "gl-ruby/#{RUBY_VERSION} gccl/#{Google::Cloud::Dns::VERSION}"
          @service.authorization = @credentials.client
          @service.root_url = host if host
        end

        def service
          return mocked_service if mocked_service
          @service
        end
        attr_accessor :mocked_service

        ##
        # Returns Google::Apis::DnsV1::Project
        def get_project project_id = @project
          execute { service.get_project project_id }
        end

        ##
        # Returns Google::Apis::DnsV1::ManagedZone
        def get_zone zone_id
          execute { service.get_managed_zone @project, zone_id }
        end

        ##
        # Returns Google::Apis::DnsV1::ListManagedZonesResponse
        def list_zones token: nil, max: nil
          execute do
            service.list_managed_zones @project, max_results: max,
                                                 page_token: token
          end
        end

        ##
        # Returns Google::Apis::DnsV1::ManagedZone
        def create_zone zone_name, zone_dns, description: nil,
                        name_server_set: nil
          managed_zone = Google::Apis::DnsV1::ManagedZone.new(
            kind: "dns#managedZone",
            name: zone_name,
            dns_name: zone_dns,
            description: (description || ""),
            name_server_set: name_server_set
          )
          execute { service.create_managed_zone @project, managed_zone }
        end

        def delete_zone zone_id
          execute { service.delete_managed_zone @project, zone_id }
        end

        ##
        # Returns Google::Apis::DnsV1::Change
        def get_change zone_id, change_id
          execute { service.get_change @project, zone_id, change_id }
        end

        ##
        # Returns Google::Apis::DnsV1::ListChangesResponse
        def list_changes zone_id, token: nil, max: nil, order: nil, sort: nil
          execute do
            service.list_changes @project, zone_id, max_results: max,
                                                    page_token: token,
                                                    sort_by: sort,
                                                    sort_order: order
          end
        end

        ##
        # Returns Google::Apis::DnsV1::Change
        def create_change zone_id, additions, deletions
          change = Google::Apis::DnsV1::Change.new(
            kind: "dns#change",
            additions: Array(additions),
            deletions: Array(deletions)
          )
          execute { service.create_change @project, zone_id, change }
        end

        ##
        # Returns Google::Apis::DnsV1::ListResourceRecordSetsResponse
        def list_records zone_id, name = nil, type = nil, token: nil, max: nil
          execute do
            service.list_resource_record_sets @project, zone_id,
                                              max_results: max, name: name,
                                              page_token: token, type: type
          end
        end

        ##
        # Fully Qualified Domain Name
        def self.fqdn name, origin_dns
          name = name.to_s.strip
          return name if ip_addr? name
          name = origin_dns if name.empty?
          name = origin_dns if name == "@"
          name = "#{name}.#{origin_dns}" unless name.include? "."
          name = "#{name}." unless name.end_with? "."
          name
        end

        require "ipaddr"

        def self.ip_addr? name
          IPAddr.new name
          true
        rescue IPAddr::Error
          false
        end

        def inspect
          "#{self.class}(#{@project})"
        end

        protected

        def execute
          yield
        rescue Google::Apis::Error => e
          raise Google::Cloud::Error.from_error(e)
        end
      end
    end
  end
end
