#pragma once

#include <chrono>

#include <functional>

#include <list>

#include <string>

#include <utility>

#include <vector>

#include "envoy/http/filter.h"

#include "envoy/http/request_id_extension.h"

#include "envoy/network/filter.h"

#include "envoy/network/listen_socket.h"

#include "envoy/server/admin.h"

#include "envoy/server/instance.h"

#include "envoy/server/listener_manager.h"

#include "envoy/upstream/outlier_detection.h"

#include "envoy/upstream/resource_manager.h"

#include "source/common/common/assert.h"

#include "source/common/common/basic_resource_impl.h"

#include "source/common/common/empty_string.h"

#include "source/common/common/logger.h"

#include "source/common/common/macros.h"

#include "source/common/http/conn_manager_config.h"

#include "source/common/http/conn_manager_impl.h"

#include "source/common/http/date_provider_impl.h"

#include "source/common/http/default_server_string.h"

#include "source/common/http/http1/codec_stats.h"

#include "source/common/http/http2/codec_stats.h"

#include "source/common/http/request_id_extension_impl.h"

#include "source/common/http/utility.h"

#include "source/common/network/connection_balancer_impl.h"

#include "source/common/network/raw_buffer_socket.h"

#include "source/common/router/scoped_config_impl.h"

#include "source/common/stats/isolated_store_impl.h"

#include "source/extensions/filters/http/common/pass_through_filter.h"

#include "source/server/admin/admin_factory_context.h"

#include "source/server/admin/admin_filter.h"

#include "source/server/admin/clusters_handler.h"

#include "source/server/admin/config_dump_handler.h"

#include "source/server/admin/config_tracker_impl.h"

#include "source/server/admin/init_dump_handler.h"

#include "source/server/admin/listeners_handler.h"

#include "source/server/admin/logs_handler.h"

#include "source/server/admin/profiling_handler.h"

#include "source/server/admin/runtime_handler.h"

#include "source/server/admin/server_cmd_handler.h"

#include "source/server/admin/server_info_handler.h"

#include "source/server/admin/stats_handler.h"

#include "source/server/null_overload_manager.h"

#include "absl/strings/string_view.h"

namespace Envoy {

namespace Server {

class AdminInternalAddressConfig : public Http::InternalAddressConfig {

  bool isInternalAddress(const Network::Address::Instance&) const override { return false; }

};

/**

 * Implementation of Server::Admin.

 */

class AdminImpl : public Admin,

                  public Network::FilterChainManager,

                  public Network::FilterChainFactory,

                  public Http::FilterChainFactory,

                  public Http::ConnectionManagerConfig,

                  public std::enable_shared_from_this<AdminImpl>,

                  Logger::Loggable<Logger::Id::admin> {

public:

  AdminImpl(const std::string& profile_path, Server::Instance& server,

            bool ignore_global_conn_limit);

  Http::Code runCallback(Http::ResponseHeaderMap& response_headers, Buffer::Instance& response,

                         AdminStream& admin_stream);

  const Network::Socket& socket() override { return *socket_; }

  Network::Socket& mutableSocket() { return *socket_; }

  Configuration::FactoryContext& factoryContext() { return factory_context_; }

  // Server::Admin

  // TODO(jsedgwick) These can be managed with a generic version of ConfigTracker.

  // Wins would be no manual removeHandler() and code reuse.

  //

  // The prefix must start with "/" and contain at least one additional character.

  bool addHandler(const std::string& prefix, const std::string& help_text, HandlerCb callback,

                  bool removable, bool mutates_server_state,

                  const ParamDescriptorVec& params = {}) override;

  bool addStreamingHandler(const std::string& prefix, const std::string& help_text,

                           GenRequestFn callback, bool removable, bool mutates_server_state,

                           const ParamDescriptorVec& params = {}) override;

  bool removeHandler(const std::string& prefix) override;

  ConfigTracker& getConfigTracker() override;

  void startHttpListener(std::list<AccessLog::InstanceSharedPtr> access_logs,

                         Network::Address::InstanceConstSharedPtr address,

                         Network::Socket::OptionsSharedPtr socket_options) override;

  uint32_t concurrency() const override { return server_.options().concurrency(); }

  // Network::FilterChainManager

  const Network::FilterChain* findFilterChain(const Network::ConnectionSocket&,

                                              const StreamInfo::StreamInfo&) const override {

    return admin_filter_chain_.get();

  }

  // Network::FilterChainFactory

  bool

  createNetworkFilterChain(Network::Connection& connection,

                           const Filter::NetworkFilterFactoriesList& filter_factories) override;

  bool createListenerFilterChain(Network::ListenerFilterManager&) override { return true; }

  void createUdpListenerFilterChain(Network::UdpListenerFilterManager&,

                                    Network::UdpReadFilterCallbacks&) override {}

  bool createQuicListenerFilterChain(Network::QuicListenerFilterManager&) override { return true; }

  // Http::FilterChainFactory

  bool createFilterChain(Http::FilterChainManager& manager, bool,

                         const Http::FilterChainOptions&) const override;

  bool createUpgradeFilterChain(absl::string_view, const Http::FilterChainFactory::UpgradeMap*,

                                Http::FilterChainManager&,

                                const Http::FilterChainOptions&) const override {

    return false;

  }

  // Http::ConnectionManagerConfig

  const Http::RequestIDExtensionSharedPtr& requestIDExtension() override {

    return request_id_extension_;

  }

  const std::list<AccessLog::InstanceSharedPtr>& accessLogs() override { return access_logs_; }

  bool flushAccessLogOnNewRequest() override { return flush_access_log_on_new_request_; }

  bool flushAccessLogOnTunnelSuccessfullyEstablished() const override { return false; }

  const absl::optional<std::chrono::milliseconds>& accessLogFlushInterval() override {

    return null_access_log_flush_interval_;

  }

  Http::ServerConnectionPtr createCodec(Network::Connection& connection,

                                        const Buffer::Instance& data,

                                        Http::ServerConnectionCallbacks& callbacks,

                                        Server::OverloadManager& overload_manager) override;

  Http::DateProvider& dateProvider() override { return date_provider_; }

  std::chrono::milliseconds drainTimeout() const override { return std::chrono::milliseconds(100); }

  Http::FilterChainFactory& filterFactory() override { return *this; }

  bool generateRequestId() const override { return false; }

  bool preserveExternalRequestId() const override { return false; }

  bool alwaysSetRequestIdInResponse() const override { return false; }

  absl::optional<std::chrono::milliseconds> idleTimeout() const override { return idle_timeout_; }

  bool isRoutable() const override { return false; }

  absl::optional<std::chrono::milliseconds> maxConnectionDuration() const override {

    return max_connection_duration_;

  }

  bool http1SafeMaxConnectionDuration() const override { return false; }

  uint32_t maxRequestHeadersKb() const override { return max_request_headers_kb_; }

  uint32_t maxRequestHeadersCount() const override { return max_request_headers_count_; }

  std::chrono::milliseconds streamIdleTimeout() const override { return {}; }

  std::chrono::milliseconds requestTimeout() const override { return {}; }

  std::chrono::milliseconds requestHeadersTimeout() const override { return {}; }

  std::chrono::milliseconds delayedCloseTimeout() const override { return {}; }

  absl::optional<std::chrono::milliseconds> maxStreamDuration() const override {

    return max_stream_duration_;

  }

  Router::RouteConfigProvider* routeConfigProvider() override { return &route_config_provider_; }

  Config::ConfigProvider* scopedRouteConfigProvider() override {

    return &scoped_route_config_provider_;

  }

  OptRef<const Router::ScopeKeyBuilder> scopeKeyBuilder() override { return scope_key_builder_; }

  const std::string& serverName() const override { return Http::DefaultServerString::get(); }

  const absl::optional<std::string>& schemeToSet() const override { return scheme_; }

  bool shouldSchemeMatchUpstream() const override { return scheme_match_upstream_; }

  HttpConnectionManagerProto::ServerHeaderTransformation

  serverHeaderTransformation() const override {

    return HttpConnectionManagerProto::OVERWRITE;

  }

  Http::ConnectionManagerStats& stats() override { return stats_; }

  Http::ConnectionManagerTracingStats& tracingStats() override { return tracing_stats_; }

  bool useRemoteAddress() const override { return true; }

  const Http::InternalAddressConfig& internalAddressConfig() const override {

    return internal_address_config_;

  }

  uint32_t xffNumTrustedHops() const override { return 0; }

  bool skipXffAppend() const override { return false; }

  const std::string& via() const override { return EMPTY_STRING; }

  Http::ForwardClientCertType forwardClientCert() const override {

    return Http::ForwardClientCertType::Sanitize;

  }

  const std::vector<Http::ClientCertDetailsType>& setCurrentClientCertDetails() const override {

    return set_current_client_cert_details_;

  }

  const Network::Address::Instance& localAddress() override;

  const absl::optional<std::string>& userAgent() override { return user_agent_; }

  Tracing::TracerSharedPtr tracer() override { return nullptr; }

  const Http::TracingConnectionManagerConfig* tracingConfig() override { return nullptr; }

  Http::ConnectionManagerListenerStats& listenerStats() override { return listener_->stats_; }

  bool proxy100Continue() const override { return false; }

  bool streamErrorOnInvalidHttpMessaging() const override { return false; }

  const Http::Http1Settings& http1Settings() const override { return http1_settings_; }

  bool shouldNormalizePath() const override { return true; }

  bool shouldMergeSlashes() const override { return true; }

  bool shouldStripTrailingHostDot() const override { return false; }

  Http::StripPortType stripPortType() const override { return Http::StripPortType::None; }

  envoy::config::core::v3::HttpProtocolOptions::HeadersWithUnderscoresAction

  headersWithUnderscoresAction() const override {

    return envoy::config::core::v3::HttpProtocolOptions::ALLOW;

  }

  const LocalReply::LocalReply& localReply() const override { return *local_reply_; }

  envoy::extensions::filters::network::http_connection_manager::v3::HttpConnectionManager::

      PathWithEscapedSlashesAction

      pathWithEscapedSlashesAction() const override {

    return envoy::extensions::filters::network::http_connection_manager::v3::HttpConnectionManager::

        KEEP_UNCHANGED;

  }

  const std::vector<Http::OriginalIPDetectionSharedPtr>&

  originalIpDetectionExtensions() const override {

    return detection_extensions_;

  }

  const std::vector<Http::EarlyHeaderMutationPtr>& earlyHeaderMutationExtensions() const override {

    return early_header_mutations_;

  }

  Http::Code request(absl::string_view path_and_query, absl::string_view method,

                     Http::ResponseHeaderMap& response_headers, std::string& body) override;

  void closeSocket() override;

  void addListenerToHandler(Network::ConnectionHandler* handler) override;

  uint64_t maxRequestsPerConnection() const override { return 0; }

  const HttpConnectionManagerProto::ProxyStatusConfig* proxyStatusConfig() const override {

    return proxy_status_config_.get();

  }

  Http::ServerHeaderValidatorPtr

  makeHeaderValidator([[maybe_unused]] Http::Protocol protocol) override {

#ifdef ENVOY_ENABLE_UHV

    ENVOY_BUG(header_validator_factory_ != nullptr,

              "Admin HCM config can not have null UHV factory.");

    return header_validator_factory_ ? header_validator_factory_->createServerHeaderValidator(

                                           protocol, getHeaderValidatorStats(protocol))

                                     : nullptr;

#else

    return nullptr;

#endif

  }

  bool appendLocalOverload() const override { return false; }

  bool appendXForwardedPort() const override { return false; }

  bool addProxyProtocolConnectionState() const override { return true; }

private:

  friend class AdminTestingPeer;

#ifdef ENVOY_ENABLE_UHV

  ::Envoy::Http::HeaderValidatorStats& getHeaderValidatorStats(Http::Protocol protocol);

#endif

  RequestPtr makeRequest(AdminStream& admin_stream) const override;

  /**

   * Creates a UrlHandler structure from a non-chunked callback.

   */

  UrlHandler makeHandler(const std::string& prefix, const std::string& help_text,

                         HandlerCb callback, bool removable, bool mutates_state,

                         const ParamDescriptorVec& params = {});

  /**

   * Creates a URL prefix bound to chunked handler. Handler is expected to

   * supply a method makeRequest(AdminStream&).

   *

   * @param prefix the prefix to register

   * @param help_text a help text ot display in a table in the admin home page

   * @param handler the Handler object for the admin subsystem, supplying makeContext().

   * @param removeable indicates whether the handler can be removed after being added

   * @param mutates_state indicates whether the handler will mutate state and therefore

   *                      must be accessed via HTTP POST rather than GET.

   * @return the UrlHandler.

   */

  template <class Handler>

  UrlHandler makeStreamingHandler(const std::string& prefix, const std::string& help_text,

                                  Handler& handler, bool removable, bool mutates_state) {

    return {prefix, help_text,

            [&handler](AdminStream& admin_stream) -> Admin::RequestPtr {

              return handler.makeRequest(admin_stream);

            },

            removable, mutates_state};

  }

  /**

   * Implementation of RouteConfigProvider that returns a static null route config.

   */

  struct NullRouteConfigProvider : public Router::RouteConfigProvider {

    NullRouteConfigProvider(TimeSource& time_source);

    // Router::RouteConfigProvider

    Rds::ConfigConstSharedPtr config() const override { return config_; }

    const absl::optional<ConfigInfo>& configInfo() const override { return config_info_; }

    SystemTime lastUpdated() const override { return time_source_.systemTime(); }

    absl::Status onConfigUpdate() override { return absl::OkStatus(); }

    Router::ConfigConstSharedPtr configCast() const override { return config_; }

    void requestVirtualHostsUpdate(const std::string&, Event::Dispatcher&,

                                   std::weak_ptr<Http::RouteConfigUpdatedCallback>) override {}

    Router::ConfigConstSharedPtr config_;

    absl::optional<ConfigInfo> config_info_;

    TimeSource& time_source_;

  };

  /**

   * Implementation of ScopedRouteConfigProvider that returns a null scoped route config.

   */

  struct NullScopedRouteConfigProvider : public Config::ConfigProvider {

    NullScopedRouteConfigProvider(TimeSource& time_source)

        : config_(std::make_shared<const Router::NullScopedConfigImpl>()),

          time_source_(time_source) {}

    ~NullScopedRouteConfigProvider() override = default;

    // Config::ConfigProvider

    SystemTime lastUpdated() const override { return time_source_.systemTime(); }

    ConfigConstSharedPtr getConfig() const override { return config_; }

    ApiType apiType() const override { return ApiType::Full; }

    ConfigProtoVector getConfigProtos() const override { return {}; }

    Router::ScopedConfigConstSharedPtr config_;

    TimeSource& time_source_;

  };

  /**

   * Implementation of ScopeKeyBuilder that returns a null scope key.

   */

  struct NullScopeKeyBuilder : public Router::ScopeKeyBuilder {

    NullScopeKeyBuilder() = default;

    ~NullScopeKeyBuilder() override = default;

    Router::ScopeKeyPtr computeScopeKey(const Http::HeaderMap&) const override { return nullptr; };

  };

  std::vector<const UrlHandler*> sortedHandlers() const;

  envoy::admin::v3::ServerInfo::State serverState();

  /**

   * URL handlers.

   */

  Http::Code handlerAdminHome(Http::ResponseHeaderMap& response_headers, Buffer::Instance& response,

                              AdminStream&);

  Http::Code handlerHelp(Http::ResponseHeaderMap& response_headers, Buffer::Instance& response,

                         AdminStream&);

  void getHelp(Buffer::Instance& response) const;

  class AdminListenSocketFactory : public Network::ListenSocketFactory {

  public:

    AdminListenSocketFactory(Network::SocketSharedPtr socket) : socket_(socket) {}

    // Network::ListenSocketFactory

    Network::Socket::Type socketType() const override { return socket_->socketType(); }

    const Network::Address::InstanceConstSharedPtr& localAddress() const override {

      return socket_->connectionInfoProvider().localAddress();

    }

    Network::SocketSharedPtr getListenSocket(uint32_t) override {

      // This is only supposed to be called once.

      RELEASE_ASSERT(!socket_create_, "AdminListener's socket shouldn't be shared.");

      socket_create_ = true;

      return socket_;

    }

    Network::ListenSocketFactoryPtr clone() const override { return nullptr; }

    void closeAllSockets() override {}

    absl::Status doFinalPreWorkerInit() override { return absl::OkStatus(); }

  private:

    Network::SocketSharedPtr socket_;

    bool socket_create_{false};

  };

  class AdminListener : public Network::ListenerConfig {

  public:

    AdminListener(AdminImpl& parent, Stats::Scope& listener_scope)

        : parent_(parent), name_("admin"), scope_(listener_scope),

          stats_(Http::ConnectionManagerImpl::generateListenerStats("http.admin.", scope_)),

          init_manager_(nullptr), ignore_global_conn_limit_(parent.ignore_global_conn_limit_) {}

    // Network::ListenerConfig

    Network::FilterChainManager& filterChainManager() override { return parent_; }

    Network::FilterChainFactory& filterChainFactory() override { return parent_; }

    std::vector<Network::ListenSocketFactoryPtr>& listenSocketFactories() override {

      return parent_.socket_factories_;

    }

    bool bindToPort() const override { return true; }

    bool handOffRestoredDestinationConnections() const override { return false; }

    uint32_t perConnectionBufferLimitBytes() const override { return 0; }

    std::chrono::milliseconds listenerFiltersTimeout() const override { return {}; }

    bool continueOnListenerFiltersTimeout() const override { return false; }

    Stats::Scope& listenerScope() override { return scope_; }

    uint64_t listenerTag() const override { return 0; }

    const std::string& name() const override { return name_; }

    const Network::ListenerInfoConstSharedPtr& listenerInfo() const override {

      return parent_.listener_info_;

    }

    Network::UdpListenerConfigOptRef udpListenerConfig() override { return {}; }

    Network::InternalListenerConfigOptRef internalListenerConfig() override { return {}; }

    Network::ConnectionBalancer& connectionBalancer(const Network::Address::Instance&) override {

      return connection_balancer_;

    }

    ResourceLimit& openConnections() override { return open_connections_; }

    const std::vector<AccessLog::InstanceSharedPtr>& accessLogs() const override {

      return empty_access_logs_;

    }

    uint32_t tcpBacklogSize() const override { return ENVOY_TCP_BACKLOG_SIZE; }

    uint32_t maxConnectionsToAcceptPerSocketEvent() const override {

      return Network::DefaultMaxConnectionsToAcceptPerSocketEvent;

    }

    Init::Manager& initManager() override { return *init_manager_; }

    bool ignoreGlobalConnLimit() const override { return ignore_global_conn_limit_; }

    bool shouldBypassOverloadManager() const override { return true; }

    AdminImpl& parent_;

    const std::string name_;

    Stats::Scope& scope_;

    Http::ConnectionManagerListenerStats stats_;

    Network::NopConnectionBalancerImpl connection_balancer_;

    BasicResourceLimitImpl open_connections_;

  private:

    const std::vector<AccessLog::InstanceSharedPtr> empty_access_logs_;

    std::unique_ptr<Init::Manager> init_manager_;

    const bool ignore_global_conn_limit_;

  };

  using AdminListenerPtr = std::unique_ptr<AdminListener>;

  class AdminFilterChain : public Network::FilterChain {

  public:

    // We can't use the default constructor because transport_socket_factory_ doesn't have a

    // default constructor.

    AdminFilterChain() {} // NOLINT(modernize-use-equals-default)

    // Network::FilterChain

    const Network::DownstreamTransportSocketFactory& transportSocketFactory() const override {

      return transport_socket_factory_;

    }

    std::chrono::milliseconds transportSocketConnectTimeout() const override {

      return std::chrono::milliseconds::zero();

    }

    const Filter::NetworkFilterFactoriesList& networkFilterFactories() const override {

      return empty_network_filter_factory_;

    }

    absl::string_view name() const override { return "admin"; }

  private:

    const Network::RawBufferSocketFactory transport_socket_factory_;

    const Filter::NetworkFilterFactoriesList empty_network_filter_factory_;

  };

  Server::Instance& server_;

  const Network::ListenerInfoConstSharedPtr listener_info_;

  AdminFactoryContext factory_context_;

  Http::RequestIDExtensionSharedPtr request_id_extension_;

  std::list<AccessLog::InstanceSharedPtr> access_logs_;

  const bool flush_access_log_on_new_request_ = false;

  const absl::optional<std::chrono::milliseconds> null_access_log_flush_interval_;

  const std::string profile_path_;

  Http::ConnectionManagerStats stats_;

  NullOverloadManager null_overload_manager_;

  // Note: this is here to essentially blackhole the tracing stats since they aren't used in the

  // Admin case.

  Stats::IsolatedStoreImpl no_op_store_;

  Http::ConnectionManagerTracingStats tracing_stats_;

  NullRouteConfigProvider route_config_provider_;

  NullScopedRouteConfigProvider scoped_route_config_provider_;

  NullScopeKeyBuilder scope_key_builder_;

  Server::ClustersHandler clusters_handler_;

  Server::ConfigDumpHandler config_dump_handler_;

  Server::InitDumpHandler init_dump_handler_;

  Server::StatsHandler stats_handler_;

  Server::LogsHandler logs_handler_;

  Server::ProfilingHandler profiling_handler_;

  Server::TcmallocProfilingHandler tcmalloc_profiling_handler_;

  Server::RuntimeHandler runtime_handler_;

  Server::ListenersHandler listeners_handler_;

  Server::ServerCmdHandler server_cmd_handler_;

  Server::ServerInfoHandler server_info_handler_;

  std::list<UrlHandler> handlers_;

  const uint32_t max_request_headers_kb_{Http::DEFAULT_MAX_REQUEST_HEADERS_KB};

  const uint32_t max_request_headers_count_{Http::DEFAULT_MAX_HEADERS_COUNT};

  absl::optional<std::chrono::milliseconds> idle_timeout_;

  absl::optional<std::chrono::milliseconds> max_connection_duration_;

  absl::optional<std::chrono::milliseconds> max_stream_duration_;

  absl::optional<std::string> user_agent_;

  Http::SlowDateProviderImpl date_provider_;

  std::vector<Http::ClientCertDetailsType> set_current_client_cert_details_;

  Http::Http1Settings http1_settings_;

  Http::Http1::CodecStats::AtomicPtr http1_codec_stats_;

  Http::Http2::CodecStats::AtomicPtr http2_codec_stats_;

  ConfigTrackerImpl config_tracker_;

  const Network::FilterChainSharedPtr admin_filter_chain_;

  Network::SocketSharedPtr socket_;

  std::vector<Network::ListenSocketFactoryPtr> socket_factories_;

  AdminListenerPtr listener_;

  const AdminInternalAddressConfig internal_address_config_;

  const LocalReply::LocalReplyPtr local_reply_;

  const std::vector<Http::OriginalIPDetectionSharedPtr> detection_extensions_{};

  const std::vector<Http::EarlyHeaderMutationPtr> early_header_mutations_{};

  const absl::optional<std::string> scheme_{};

  const bool scheme_match_upstream_ = false;

  const bool ignore_global_conn_limit_;

  std::unique_ptr<HttpConnectionManagerProto::ProxyStatusConfig> proxy_status_config_;

  const Http::HeaderValidatorFactoryPtr header_validator_factory_;

};

} // namespace Server

} // namespace Envoy