// TcpClient: persistent TCP connection with automatic reconnection.

#pragma once

#include <cstdint>

#include <string>

// Maximum reconnect attempts per reconnect() call.

static constexpr int kMaxRetries = 3;

// Manages a single outbound TCP connection with retry support.

class TcpClient {

public:

  TcpClient() = default;

  ~TcpClient();

  // Opens a TCP connection to host:port.

  // Parameters:

  //   host - remote hostname or IPv4 address

  //   port - remote TCP port

  // Returns: true if the TCP handshake completed.

  //   Sets isConnected() to true only after a successful handshake.

  //   On any failure, isConnected() remains false.

  bool connect(const std::string& host, uint16_t port);

  // Retries connect() using the last known host and port.

  // Parameters: none

  // Attempts exactly kMaxRetries reconnections.

  // Returns: true if any attempt succeeded within the retry budget

  bool reconnect();

  // Closes the connection and sets isConnected() to false.

  // Parameters: none

  // Returns: void; fd_ is closed and connected_ is set to false

  void disconnect();

  // Returns: true if a TCP handshake is currently established

  bool isConnected() const { return connected_; }

private:

  bool        connected_ = false;        // true only when a live TCP connection exists

  std::string host_;                     // remote hostname saved by connect()

  uint16_t    port_       = 0;           // remote port saved by connect()

  int         fd_         = -1;          // socket file descriptor; -1 when not open

  int         retriesLeft_ = kMaxRetries; // remaining reconnect attempts

};