# encoding: utf-8

require 'socket'
require 'net/https'
require 'net/http'
require 'logger'
require 'zlib'
require 'stringio'

require 'one_apm/support/event_buffer/sampled_buffer'
require 'one_apm/agent/harvester'

require 'one_apm/support/hostname'
require 'one_apm/support/ip'
require 'one_apm/support/environment_report'

require 'one_apm/configuration'

require 'one_apm/collector/collector_service'
require 'one_apm/collector/containers/agent_command_router'
require 'one_apm/collector/containers/transaction_event_aggregator'
require 'one_apm/collector/containers/custom_event_aggregator'
require 'one_apm/collector/containers/utilization_data'

require 'one_apm/collector/support/forked_process_service'
require 'one_apm/collector/support/sampler_collection'

require 'one_apm/agent/database'
require 'one_apm/support/event/event_listener'
require 'one_apm/agent/cross_app/cross_app_monitor'
require 'one_apm/agent/synthetics_monitor'
require 'one_apm/support/event_buffer/synthetics_event_buffer'
require 'one_apm/agent/javascript_instrumentor'
require 'one_apm/support/vm/monotonic_gc_profiler'

require 'one_apm/agent/agent/start'
require 'one_apm/agent/agent/start_worker_thread'
require 'one_apm/agent/agent/connect'
require 'one_apm/agent/agent/helpers'
require 'one_apm/agent/agent/container_data_manager'
require 'one_apm/agent/agent/forkable_dispatcher_functions'
require 'one_apm/agent/agent/restart_monitor'
require 'one_apm/agent/agent/restart'
require 'one_apm/agent/agent/cross_app_samples_sender'
require 'one_apm/agent/agent/rule_fetcher'

module OneApm
  module Agent
    class Agent
      include OneApm::Agent::Agent::Start
      include OneApm::Agent::Agent::StartWorkerThread
      include OneApm::Agent::Agent::Connect
      include OneApm::Agent::Agent::Helpers
      include OneApm::Agent::Agent::ContainerDataManager
      include OneApm::Agent::Agent::ForkableDispatcherFunctions
      include OneApm::Agent::Agent::RuleFetcher

      attr_reader :record_sql
      attr_reader :javascript_instrumentor

      attr_reader :cross_process_id
      attr_reader :cross_app_encoding_bytes
      attr_reader :cross_app_monitor

      attr_accessor :service

      attr_reader :events

      attr_reader :transaction_rules
      attr_accessor :external_rename_rules

      attr_reader :harvester
      attr_reader :harvest_samplers
      attr_reader :harvest_lock

      attr_reader :monotonic_gc_profiler

      def self.instance
        @instance ||= self.new
      end

      def self.config
        OneApm::Manager.config
      end

      def initialize
        start_service

        @events = OneApm::Support::EventListener.new

        init_containers
        
        OneApm::Agent::SyntheticsMonitor.new @events
        OneApm::Agent::RestartMonitor.new

        @cross_app_monitor        = OneApm::Agent::CrossAppMonitor.new(@events)
        @transaction_rules        = OneApm::Support::RulesEngine.new
        @harvest_samplers         = OneApm::Collector::SamplerCollection.new(@events)
        @monotonic_gc_profiler    = OneApm::Support::VM::MonotonicGCProfiler.new
        @javascript_instrumentor  = OneApm::Agent::JavascriptInstrumentor.new(@events)
        @restart                  = OneApm::Agent::Restart.new(@events)
        @cross_app_samples_sender = OneApm::Agent::CrossAppSamplesSender.new(@events, self)

        @harvester       = OneApm::Agent::Harvester.new(@events)
        @after_fork_lock = Mutex.new

        @connect_state      = :pending
        @connect_attempts   = 0
        @environment_report = nil

        @harvest_lock = Mutex.new
      end

      def probe
        OneApm::Probe.instance
      end

      def start_service
        if OneApm::Manager.config[:monitor_mode] && !@service
          @service = OneApm::Collector::CollectorService.new
        end
      end

      def start
        return unless agent_should_start?

        log_startup
        check_config_and_start_agent
        log_version_and_pid

        events.subscribe(:finished_configuring) do
          log_ignore_url_regexes
        end
      end

      def shutdown(options = {})
        return if not started?
        OneApm::Manager.logger.info "Starting Agent shutdown"

        stop_event_loop
        untraced_graceful_disconnect
        OneApm::Manager.revert_to_default_configuration

        @started = nil
        OneApm::Probe.reset
      end

      def agent_should_start?
        return false if already_started? || disabled? || defer_for_background_jobs?
        
        unless app_name_configured? && tier_name_configured?
          OneApm::Manager.logger.error "No application name or tier name configured in #{probe.env} environment"
          false
        else
          true
        end
      end

      def connect(options={})
        opts = {
          :keep_retrying => OneApm::Manager.config[:keep_retrying],
          :force_reconnect => OneApm::Manager.config[:force_reconnect]
        }.merge(options)

        return unless should_connect?(opts[:force_reconnect])

        OneApm::Manager.logger.debug "Connecting Process to OneApm: #$0"
        query_server_for_configuration
        @connected_pid = Process.pid
        @connect_state = :connected
      rescue OneApm::ForceDisconnectException => e
        handle_force_disconnect(e)
      rescue OneApm::LicenseException => e
        handle_license_error(e)
      rescue OneApm::UnrecoverableAgentException => e
        handle_unrecoverable_agent_error(e)
      rescue StandardError, Timeout::Error, OneApm::ServerConnectionException => e
        log_error(e)
        if opts[:keep_retrying]
          note_connect_failure
          OneApm::Manager.logger.info "Will re-attempt in #{connect_retry_period} seconds"
          sleep connect_retry_period
          retry
        else
          disconnect
        end
      rescue Exception => e
        OneApm::Manager.logger.error "Exception of unexpected type during Agent#connect():", e

        raise
      end

      def graceful_disconnect
        if connected?
          begin
            @service.request_timeout = 10

            @events.notify(:before_shutdown)
            transmit_data
            transmit_event_data
            transmit_utilization_data if OneApm::Manager.config[:collect_utilization]

            if @connected_pid == $$ && !@service.kind_of?(OneApm::Collector::CollectorService)
              OneApm::Manager.logger.debug "Sending OneApm service agent run shutdown message"
              @service.shutdown(Time.now.to_f)
            else
              OneApm::Manager.logger.debug "This agent connected from parent process #{@connected_pid}--not sending shutdown"
            end
            OneApm::Manager.logger.debug "Graceful disconnect complete"
          rescue Timeout::Error, StandardError => e
            OneApm::Manager.logger.debug "Error when disconnecting #{e.class.name}: #{e.message}"
          end
        else
          OneApm::Manager.logger.debug "Bypassing graceful disconnect - agent not connected"
        end
      end

      def untraced_graceful_disconnect
        OneApm::Manager.disable_all_tracing do
          graceful_disconnect
        end
      rescue => e
        OneApm::Manager.logger.error e
      end
    end

    class ShimAgent < OneApm::Agent::Agent
      def self.instance
        @instance ||= self.new
      end

      def initialize
        super
        @stats_engine.extend OneApm::Collector::StatsEngine::Shim
        @transaction_sampler.extend OneApm::Collector::TransactionSampler::Shim
        @sql_sampler.extend OneApm::Collector::SqlSampler::Shim
        @error_collector.extend OneApm::Collector::ErrorCollector::Shim
      end

      def after_fork *args; end
      def start *args; end
      def shutdown *args; end
      def merge_data_for_endpoint *args; end
      def push_trace_execution_flag *args; end
      def pop_trace_execution_flag *args; end
      def browser_timing_header; "" end
    end
  end
end