#ifndef THIRD_PARTY_GBMCWEB_INCLUDE_OBMC_CONSOLE_H_
#define THIRD_PARTY_GBMCWEB_INCLUDE_OBMC_CONSOLE_H_

#include <sys/socket.h>

#include <array>
#include <cstddef>
#include <memory>
#include <string>
#include <string_view>

#include "boost/asio/local/stream_protocol.hpp"  // NOLINT
#include "boost/container/flat_set.hpp"  // NOLINT
#include "app.hpp"
#include "logging.hpp"
#include "websocket.hpp"

namespace crow {
namespace obmc_console {

// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static std::unique_ptr<boost::asio::local::stream_protocol::socket> hostSocket;

// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static std::array<char, 4096> outputBuffer;
// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static std::string inputBuffer;  // NOLINT

// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static boost::container::flat_set<crow::websocket::Connection*> sessions;

// NOLINTNEXTLINE(cppcoreguidelines-avoid-non-const-global-variables)
static bool doingWrite = false;

inline void doWrite() {
  if (doingWrite) {
    BMCWEB_LOG_DEBUG << "Already writing.  Bailing out";
    return;
  }

  if (inputBuffer.empty()) {
    BMCWEB_LOG_DEBUG << "Outbuffer empty.  Bailing out";
    return;
  }

  if (!hostSocket) {
    BMCWEB_LOG_ERROR << "doWrite(): Socket closed.";
    return;
  }

  doingWrite = true;
  hostSocket->async_write_some(
      boost::asio::buffer(inputBuffer.data(), inputBuffer.size()),
      [](boost::beast::error_code ec, std::size_t bytesWritten) {
        doingWrite = false;
        inputBuffer.erase(0, bytesWritten);

        if (ec == boost::asio::error::eof) {
          for (crow::websocket::Connection* session : sessions) {
            session->close("Error in reading to host port");
          }
          return;
        }
        if (ec) {
          BMCWEB_LOG_ERROR << "Error in host serial write " << ec;
          return;
        }
        doWrite();
      });
}

inline void doRead() {
  if (!hostSocket) {
    BMCWEB_LOG_ERROR << "doRead(): Socket closed.";
    return;
  }

  BMCWEB_LOG_DEBUG << "Reading from socket";
  hostSocket->async_read_some(
      boost::asio::buffer(outputBuffer.data(), outputBuffer.size()),
      [](const boost::system::error_code& ec, std::size_t bytesRead) {
        BMCWEB_LOG_DEBUG << "read done.  Read " << bytesRead << " bytes";
        if (ec) {
          BMCWEB_LOG_ERROR << "Couldn't read from host serial port: " << ec;
          for (crow::websocket::Connection* session : sessions) {
            session->close("Error in connecting to host port");
          }
          return;
        }
        std::string_view payload(outputBuffer.data(), bytesRead);
        for (crow::websocket::Connection* session : sessions) {
          session->sendBinary(payload);
        }
        doRead();
      });
}

inline void connectHandler(const boost::system::error_code& ec) {
  if (ec) {
    BMCWEB_LOG_ERROR << "Couldn't connect to host serial port: " << ec;
    for (crow::websocket::Connection* session : sessions) {
      session->close("Error in connecting to host port");
    }
    return;
  }

  doWrite();
  doRead();
}

inline void requestRoutes(App& app) {
  BMCWEB_ROUTE(app, "/console0")
      .privileges({{"ConfigureComponents", "ConfigureManager"}})
      .websocket()
      .onopen([](crow::websocket::Connection& conn) {
        BMCWEB_LOG_DEBUG << "Connection " << &conn << " opened";

        sessions.insert(&conn);
        if (hostSocket == nullptr) {
          const std::string consoleName("\0obmc-console", 13);
          boost::asio::local::stream_protocol::endpoint ep(consoleName);

          hostSocket =
              std::make_unique<boost::asio::local::stream_protocol::socket>(
                  conn.getIoContext());
          hostSocket->async_connect(ep, connectHandler);
        }
      })
      .onclose([](crow::websocket::Connection& conn,
                  [[maybe_unused]] const std::string& reason) {
        BMCWEB_LOG_INFO << "Closing websocket. Reason: " << reason;

        sessions.erase(&conn);
        if (sessions.empty()) {
          hostSocket = nullptr;
          inputBuffer.clear();
          inputBuffer.shrink_to_fit();
        }
      })
      .onmessage([]([[maybe_unused]] crow::websocket::Connection& conn,
                    const std::string& data, [[maybe_unused]] bool isBinary) {
        inputBuffer += data;
        doWrite();
      });
}
}  // namespace obmc_console
}  // namespace crow

#endif  // THIRD_PARTY_GBMCWEB_INCLUDE_OBMC_CONSOLE_H_