/* SPDX-License-Identifier: GPL-3.0-or-later

 * Copyright © 2016-2025 The TokTok team.

 * Copyright © 2014 Tox project.

 */

#ifndef C_TOXCORE_TOXCORE_TCP_COMMON_H

#define C_TOXCORE_TOXCORE_TCP_COMMON_H

#include "attributes.h"

#include "crypto_core.h"

#include "logger.h"

#include "mem.h"

#include "net_profile.h"

#include "network.h"

typedef struct TCP_Priority_List TCP_Priority_List;

struct TCP_Priority_List {

    TCP_Priority_List *_Nullable next;

    uint16_t size;

    uint16_t sent;

    uint8_t *_Nonnull data;

};

void wipe_priority_list(const Memory *_Nonnull mem, TCP_Priority_List *_Nullable p);

#define NUM_RESERVED_PORTS 16

#define NUM_CLIENT_CONNECTIONS (256 - NUM_RESERVED_PORTS)

typedef enum Tcp_Packet {

    TCP_PACKET_ROUTING_REQUEST          = 0,

    TCP_PACKET_ROUTING_RESPONSE         = 1,

    TCP_PACKET_CONNECTION_NOTIFICATION  = 2,

    TCP_PACKET_DISCONNECT_NOTIFICATION  = 3,

    TCP_PACKET_PING                     = 4,

    TCP_PACKET_PONG                     = 5,

    TCP_PACKET_OOB_SEND                 = 6,

    TCP_PACKET_OOB_RECV                 = 7,

    TCP_PACKET_ONION_REQUEST            = 8,

    TCP_PACKET_ONION_RESPONSE           = 9,

    TCP_PACKET_FORWARD_REQUEST          = 10,

    TCP_PACKET_FORWARDING               = 11,

} Tcp_Packet;

#define TCP_HANDSHAKE_PLAIN_SIZE (CRYPTO_PUBLIC_KEY_SIZE + CRYPTO_NONCE_SIZE)

#define TCP_SERVER_HANDSHAKE_SIZE (CRYPTO_NONCE_SIZE + TCP_HANDSHAKE_PLAIN_SIZE + CRYPTO_MAC_SIZE)

#define TCP_CLIENT_HANDSHAKE_SIZE (CRYPTO_PUBLIC_KEY_SIZE + TCP_SERVER_HANDSHAKE_SIZE)

#define TCP_MAX_OOB_DATA_LENGTH 1024

/** frequency to ping connected nodes and timeout in seconds */

#define TCP_PING_FREQUENCY 30

#define TCP_PING_TIMEOUT 10

#define MAX_PACKET_SIZE 2048

typedef struct TCP_Connection {

    const Memory *_Nonnull mem;

    const Random *_Nonnull rng;

    const Network *_Nonnull ns;

    Socket sock;

    IP_Port ip_port;  // for debugging.

    uint8_t sent_nonce[CRYPTO_NONCE_SIZE]; /* Nonce of sent packets. */

    uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];

    uint8_t last_packet[2 + MAX_PACKET_SIZE];

    uint16_t last_packet_length;

    uint16_t last_packet_sent;

    TCP_Priority_List *_Nullable priority_queue_start;

    TCP_Priority_List *_Nullable priority_queue_end;

    // This is a shared pointer to the parent's respective Net_Profile object

    // (either TCP_Server for TCP server packets or TCP_Connections for TCP client packets).

    Net_Profile *_Nullable net_profile;

} TCP_Connection;

/**

 * @retval 0 if pending data was sent completely

 * @retval -1 if it wasn't

 */

int send_pending_data_nonpriority(const Logger *_Nonnull logger, TCP_Connection *_Nonnull con);

/**

 * @retval 0 if pending data was sent completely

 * @retval -1 if it wasn't

 */

int send_pending_data(const Logger *_Nonnull logger, TCP_Connection *_Nonnull con);

/**

 * @retval 1 on success.

 * @retval 0 if could not send packet.

 * @retval -1 on failure (connection must be killed).

 */

int write_packet_tcp_secure_connection(const Logger *_Nonnull logger, TCP_Connection *_Nonnull con, const uint8_t *_Nonnull data, uint16_t length, bool priority);

/** @brief Read length bytes from socket.

 *

 * return length on success

 * return -1 on failure/no data in buffer.

 */

int read_tcp_packet(const Logger *_Nonnull logger, const Memory *_Nonnull mem, const Network *_Nonnull ns, Socket sock, uint8_t *_Nonnull data, uint16_t length,

                    const IP_Port *_Nonnull ip_port);

/**

 * @return length of received packet on success.

 * @retval 0 if could not read any packet.

 * @retval -1 on failure (connection must be killed).

 */

int read_packet_tcp_secure_connection(const Logger *_Nonnull logger, const Memory *_Nonnull mem, const Network *_Nonnull ns, Socket sock, uint16_t *_Nonnull next_packet_length,

                                      const uint8_t *_Nonnull shared_key, uint8_t *_Nonnull recv_nonce, uint8_t *_Nonnull data, uint16_t max_len, const IP_Port *_Nonnull ip_port);

#endif /* C_TOXCORE_TOXCORE_TCP_COMMON_H */