# frozen_string_literal: true

require 'uri'

require_relative '../../core/environment/container'
require_relative '../../core/environment/ext'
require_relative '../../core/transport/ext'
require_relative '../../core/transport/http/adapters/net'
require_relative '../../core/transport/http/adapters/test'
require_relative '../../core/transport/http/adapters/unix_socket'
require_relative 'http/api'
require_relative 'http/builder'
require_relative '../../../datadog/version'

module Datadog
  module Tracing
    module Transport
      # Namespace for HTTP transport components
      module HTTP
        # NOTE: Due to... legacy reasons... This class likes having a default `AgentSettings` instance to fall back to.
        # Because we generate this instance with an empty instance of `Settings`, the resulting `AgentSettings` below
        # represents only settings specified via environment variables + the usual defaults.
        #
        # DO NOT USE THIS IN NEW CODE, as it ignores any settings specified by users via `Datadog.configure`.
        DO_NOT_USE_ENVIRONMENT_AGENT_SETTINGS = Datadog::Core::Configuration::AgentSettingsResolver.call(
          Datadog::Core::Configuration::Settings.new,
          logger: nil,
        )

        module_function

        # Builds a new Transport::HTTP::Client
        def new(&block)
          Builder.new(&block).to_transport
        end

        # Builds a new Transport::HTTP::Client with default settings
        # Pass a block to override any settings.
        def default(
          agent_settings: DO_NOT_USE_ENVIRONMENT_AGENT_SETTINGS,
          **options
        )
          new do |transport|
            transport.adapter(agent_settings)
            transport.headers default_headers

            apis = API.defaults

            transport.api API::V4, apis[API::V4], fallback: API::V3, default: true
            transport.api API::V3, apis[API::V3]

            # Apply any settings given by options
            unless options.empty?
              transport.default_api = options[:api_version] if options.key?(:api_version)
              transport.headers options[:headers] if options.key?(:headers)
            end

            # Call block to apply any customization, if provided
            yield(transport) if block_given?
          end
        end

        def default_headers
          {
            Datadog::Core::Transport::Ext::HTTP::HEADER_CLIENT_COMPUTED_TOP_LEVEL => '1',
            Datadog::Core::Transport::Ext::HTTP::HEADER_META_LANG => Datadog::Core::Environment::Ext::LANG,
            Datadog::Core::Transport::Ext::HTTP::HEADER_META_LANG_VERSION => Datadog::Core::Environment::Ext::LANG_VERSION,
            Datadog::Core::Transport::Ext::HTTP::HEADER_META_LANG_INTERPRETER =>
              Datadog::Core::Environment::Ext::LANG_INTERPRETER,
            Datadog::Core::Transport::Ext::HTTP::HEADER_META_LANG_INTERPRETER_VENDOR => Core::Environment::Ext::LANG_ENGINE,
            Datadog::Core::Transport::Ext::HTTP::HEADER_META_TRACER_VERSION =>
              Datadog::Core::Environment::Ext::GEM_DATADOG_VERSION
          }.tap do |headers|
            # Add container ID, if present.
            container_id = Datadog::Core::Environment::Container.container_id
            headers[Datadog::Core::Transport::Ext::HTTP::HEADER_CONTAINER_ID] = container_id unless container_id.nil?
          end
        end

        def default_adapter
          Datadog::Core::Configuration::Ext::Agent::HTTP::ADAPTER
        end

        # Add adapters to registry
        Builder::REGISTRY.set(
          Datadog::Core::Transport::HTTP::Adapters::Net,
          Datadog::Core::Configuration::Ext::Agent::HTTP::ADAPTER
        )
        Builder::REGISTRY.set(Datadog::Core::Transport::HTTP::Adapters::Test, Datadog::Core::Transport::Ext::Test::ADAPTER)
        Builder::REGISTRY.set(
          Datadog::Core::Transport::HTTP::Adapters::UnixSocket,
          Datadog::Core::Transport::Ext::UnixSocket::ADAPTER
        )
      end
    end
  end
end