/** @file

  Http2ServerSession.

  @section license License

  Licensed to the Apache Software Foundation (ASF) under one
  or more contributor license agreements.  See the NOTICE file
  distributed with this work for additional information
  regarding copyright ownership.  The ASF licenses this file
  to you 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.
 */

#pragma once

#include "proxy/Plugin.h"
#include "proxy/http2/Http2CommonSession.h"
#include <string_view>
#include "tscore/ink_inet.h"
#include "tscore/History.h"
#include "proxy/Milestones.h"
#include "proxy/PoolableSession.h"

class Http2ServerSession : public PoolableSession, public Http2CommonSession
{
public:
  using super          = PoolableSession; ///< Parent type.
  using SessionHandler = int (Http2ServerSession::*)(int, void *);

  Http2ServerSession();

  /////////////////////
  // Methods

  // Implement VConnection interface
  void do_io_close(int lerrno = -1) override;

  // Implement ProxySession interface
  void              new_connection(NetVConnection *new_vc, MIOBuffer *iobuf, IOBufferReader *reader) override;
  void              start() override;
  void              destroy() override;
  void              release(ProxyTransaction *trans) override;
  void              free() override;
  ProxyTransaction *new_transaction() override;
  bool              is_protocol_framed() const override;
  uint64_t          get_received_frame_count(uint64_t type) const override;

  void add_session() override;
  void remove_session();

  /** Eagerly drop a half-closed session out of the server-session pool.
   *
   *  Sets the half-close-local flag (delegating to the base class) and, when
   *  the flag transitions to @c true, immediately removes this session from
   *  the per-thread server-session pool. Once @c half_close_local is set,
   *  every subsequent @c create_initiating_stream on this session
   *  short-circuits with @c REFUSED_STREAM, so leaving it discoverable in
   *  the pool produces a stream of REFUSED_STREAM aborts on otherwise
   *  unrelated requests until the session is finally torn down. The pool
   *  must be made aware as soon as the half-close decision is made, not at
   *  session destruction time.
   */
  void set_half_close_local_flag(bool flag) override;

  ////////////////////
  // Accessors
  sockaddr const *get_remote_addr() const override;
  sockaddr const *get_local_addr() override;
  int             get_transact_count() const override;
  const char     *get_protocol_string() const override;
  int             populate_protocol(std::string_view *result, int size) const override;
  const char     *protocol_contains(std::string_view prefix) const override;
  HTTPVersion     get_version(HTTPHdr &hdr) const override;
  IOBufferReader *get_remote_reader() override;

  ProxySession *get_proxy_session() override;

  void
  increment_current_active_connections_stat() override
  {
    Metrics::Gauge::increment(http2_rsb.current_active_server_connection_count);
  }

  void
  decrement_current_active_connections_stat() override
  {
    Metrics::Gauge::decrement(http2_rsb.current_active_server_connection_count);
  }

  // noncopyable
  Http2ServerSession(Http2ServerSession &)                  = delete;
  Http2ServerSession &operator=(const Http2ServerSession &) = delete;

  bool is_multiplexing() const override;
  bool is_outbound() const override;

  void set_netvc(NetVConnection *netvc) override;

  void set_no_activity_timeout() override;

private:
  int main_event_handler(int, void *);

  IpEndpoint cached_client_addr;
  IpEndpoint cached_local_addr;

  bool in_session_table = false;
};

extern ClassAllocator<Http2ServerSession, false> http2ServerSessionAllocator;