# Copyright 2017 Google Inc. All rights reserved.
#
# 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
#
#     http://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/env"
require "google/cloud/error_reporting/service"
require "google/cloud/error_reporting/credentials"
require "google/cloud/error_reporting/error_event"

module Google
  module Cloud
    module ErrorReporting
      ##
      # Project
      #
      # Projects are top-level containers in Google Cloud Platform. They store
      # information about billing and authorized users, and they control access
      # to Stackdriver ErrorReporting. Each project has a friendly name and a
      # unique ID. Projects can be created only in the [Google Developers
      # Console](https://console.developers.google.com).
      #
      # @example
      #   require "google/cloud/error_reporting"
      #
      #   error_reporting = Google::Cloud::ErrorReporting.new
      #   error_event = error_reporting.error_event "Error with Backtrace",
      #                                             event_time: Time.now,
      #                                             service_name: "my_app_name"
      #   error_reporting.report error_event
      #
      # See {Google::Cloud::ErrorReporting.new}
      #
      class Project
        ##
        # Find default project_id from `ERROR_REPORTING_RPOJECT`,
        # `GOOGLE_CLOUD_PROJECT`, `GCLOUD_PROJECT` environment varaibles, or
        # query from GCE meta service.
        #
        # @return [String] default valid GCP project_id
        #
        def self.default_project
          ENV["ERROR_REPORTING_PROJECT"] ||
            ENV["GOOGLE_CLOUD_PROJECT"] ||
            Google::Cloud.env.project_id
        end

        ##
        # Find default service_name from `ERROR_REPORTING_SERVICE`,
        # `GAE_SERVICE` environment Variables, or just "ruby".
        #
        # @return [String] default GCP service_name
        #
        def self.default_service_name
          ENV["ERROR_REPORTING_SERVICE"] ||
            Google::Cloud.env.app_engine_service_id ||
            "ruby"
        end

        ##
        # Find default service_version from `ERROR_REPORTING_VERSION` or
        # `GAE_VERSION` environment varaibles.
        #
        # @return [String] default GCP service_version
        #
        def self.default_service_version
          ENV["ERROR_REPORTING_VERSION"] ||
            Google::Cloud.env.app_engine_service_version
        end

        ##
        # @private The Service object
        attr_accessor :service

        ##
        # @private Create a new Project instance.
        #
        # @param [Google::Cloud::ErrorReporting::Service] service The underlying
        #   Service object
        #
        # @return [Google::Cloud::ErrorReporting::Project] A new Project
        #   instance
        #
        def initialize service
          @service = service
        end

        ##
        # Get the name of current project_id from underneath gRPC Service
        # object.
        #
        # @return [String] The current project_id
        #
        def project
          service.project
        end

        ##
        # Report a {Google::Cloud::ErrorReporting::ErrorEvent} to Stackdriver
        # Error Reporting service.
        #
        # @example
        #   require "google/cloud/error_reporting"
        #
        #   error_reporting = Google::Cloud::ErrorReporting.new
        #
        #   error_event = error_reporting.error_event "Error with Backtrace"
        #   error_reporting.report error_event
        #
        def report *args, &block
          service.report *args, &block
        end

        ##
        # Create a {Google::Cloud::ErrorReporting::ErrorEvent} from the
        # given exception, and report this ErrorEvent to Stackdriver Error
        # Reporting service.
        #
        # @param [Exception] exception A Ruby exception
        # @param [String] service_name The service's name.
        #   Default to {default_service_name}
        # @param [String] service_version The service's version.
        #   Default to {default_service_version}
        #
        # @example
        #   require "google/cloud/error_reporting"
        #
        #   error_reporting = Google::Cloud::ErrorReporting.new
        #
        #   begin
        #     fail StandardError, "A serious problem"
        #   rescue => exception
        #     error_reporting.report_exception exception,
        #                                      service_name: "my_app_name",
        #                                      service_version: "v8"
        #   end
        #
        def report_exception exception, service_name: nil, service_version: nil
          error_event = ErrorEvent.from_exception exception

          error_event.service_name =
            service_name || self.class.default_service_name
          error_event.service_version =
            service_version || self.class.default_service_version

          yield error_event if block_given?

          report error_event
        end

        ##
        # Create a new {Google::Cloud::ErrorReporting::ErrorEvent} instance
        # with given parameters.
        #
        # @param [String] message The error message along with backtrace
        # @param [String] service_name The service's name.
        #   Default to {default_service_name}
        # @param [String] service_version The service's version.
        #   Default to {default_service_version}
        # @param [Time] event_time Time when the event occurred. If not
        #   provided, the time when the event was received by the Error
        #   Reporting system will be used.
        # @param [String] user The user who caused or was affected by the crash.
        #   This can be a user ID, an email address, or an arbitrary token that
        #   uniquely identifies the user. When sending an error report, leave
        #   this field empty if the user was not logged in. In this case the
        #   Error Reporting system will use other data, such as remote IP
        #   address, to distinguish affected users.
        # @param [String] file_path The source code filename, which can include
        #   a truncated relative path, or a full path from a production machine.
        # @param [Number] line_number 1-based. 0 indicates that the line number
        #   is unknown.
        # @param [String] function_name Human-readable name of a function or
        #   method. The value can include optional context like the class or
        #   package name. For example, my.package.MyClass.method in case of
        #   Java.
        #
        # @return [ErrorEvent] A new ErrorEvent instance
        #
        # @example
        #   require "google/cloud/error_reporting"
        #
        #   error_reporting = Google::Cloud::ErrorReporting.new
        #
        #   error_event =
        #     error_reporting.error_event "Error Message with Backtrace",
        #                                 event_time: Time.now,
        #                                 service_name: "my_app_name",
        #                                 service_version: "v8",
        #                                 user: "johndoh",
        #                                 file_path: "MyController.rb",
        #                                 line_number: 123,
        #                                 function_name: "index"
        #   error_reporting.report error_event
        #
        def error_event message = nil, service_name: nil, service_version: nil,
                        event_time: nil, user: nil, file_path: nil,
                        line_number: nil, function_name: nil
          ErrorEvent.new.tap do |e|
            e.message = message
            e.event_time = event_time
            e.service_name = service_name || self.class.default_service_name
            e.service_version = service_version ||
                                self.class.default_service_version
            e.user = user
            e.file_path = file_path
            e.line_number = line_number
            e.function_name = function_name
          end
        end
      end
    end
  end
end