// =================================================================================================
// eModbus: Copyright 2020 by Michael Harwerth, Bert Melis and the contributors to eModbus
//               MIT license - see license.md for details
// =================================================================================================
#ifndef _MODBUS_SERVER_TCP_ASYNC_H
#define _MODBUS_SERVER_TCP_ASYNC_H

#include "options.h"

#include <list>
#include <queue>
#if USE_MUTEX
#include <mutex> // NOLINT
#endif
#include <vector>

#include <Arduino.h> // for millis()

#if defined(ESP32)
#include <AsyncTCP.h>
#elif defined(ESP8266)
#include <ESPAsyncTCP.h>
#endif

#include "ModbusServer.h"

#if USE_MUTEX
using std::lock_guard;
#endif

class ModbusServerTCPasync : public ModbusServer {
  private:
    class mb_client {
        friend class ModbusServerTCPasync;

      public:
        mb_client(ModbusServerTCPasync * s, AsyncClient * c);
        ~mb_client();

      private:
        void                        onData(uint8_t * data, size_t len);
        void                        onPoll();
        void                        onDisconnect();
        void                        addResponseToOutbox(ModbusMessage * response);
        void                        handleOutbox();
        ModbusServerTCPasync *      server;
        AsyncClient *               client;
        uint32_t                    lastActiveTime;
        ModbusMessage *             message;
        Modbus::Error               error;
        std::queue<ModbusMessage *> outbox;
#if USE_MUTEX
        std::mutex obLock; // outbox protection
#endif
    };


  public:
    // Constructor
    ModbusServerTCPasync();

    // Destructor: closes the connections
    ~ModbusServerTCPasync();

    // activeClients: return number of clients currently employed
    uint16_t activeClients();

    // start: create task with TCP server to accept requests
    bool start(uint16_t port, uint8_t max_clients, uint32_t timeout, int coreID = -1);

    // stop: drop all connections and kill server task
    bool stop();

    // isRunning: return true is server is running
    bool isRunning();

  protected:
    inline void isInstance() {
    }
    void onClientConnect(AsyncClient * client);
    void onClientDisconnect(mb_client * client);

    AsyncServer *          server;
    std::list<mb_client *> clients;
    uint8_t                maxNoClients;
    uint32_t               idle_timeout;
#if USE_MUTEX
    std::mutex cListLock; // client list protection
#endif
};

#endif