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

 * Copyright © 2016-2025 The TokTok team.

 * Copyright © 2013 Tox project.

 */

/**

 * An implementation of a simple text chat only messenger on the tox network

 * core.

 */

#ifndef C_TOXCORE_TOXCORE_MESSENGER_H

#define C_TOXCORE_TOXCORE_MESSENGER_H

#include "DHT.h"

#include "TCP_client.h"

#include "TCP_server.h"

#include "announce.h"

#include "attributes.h"

#include "crypto_core.h"

#include "forwarding.h"

#include "friend_connection.h"

#include "friend_requests.h"

#include "group_announce.h"

#include "group_common.h"

#include "logger.h"

#include "mem.h"

#include "mono_time.h"

#include "net_crypto.h"

#include "net_profile.h"

#include "network.h"

#include "onion.h"

#include "onion_announce.h"

#include "onion_client.h"

#include "state.h"

#define MAX_NAME_LENGTH 128

/* TODO(irungentoo): this must depend on other variable. */

#define MAX_STATUSMESSAGE_LENGTH 1007

/* Used for TCP relays in Messenger struct (may need to be `% 2 == 0`)*/

#define NUM_SAVED_TCP_RELAYS 8

/* This cannot be bigger than 256 */

#define MAX_CONCURRENT_FILE_PIPES 256

#define FRIEND_ADDRESS_SIZE (CRYPTO_PUBLIC_KEY_SIZE + sizeof(uint32_t) + sizeof(uint16_t))

typedef enum Message_Type {

    MESSAGE_NORMAL,

    MESSAGE_ACTION,

} Message_Type;

// TODO(Jfreegman, Iphy): Remove this before merge

#ifndef MESSENGER_DEFINED

#define MESSENGER_DEFINED

typedef struct Messenger Messenger;

#endif /* MESSENGER_DEFINED */

// Returns the size of the data

typedef uint32_t m_state_size_cb(const Messenger *_Nonnull m);

// Returns the new pointer to data

typedef uint8_t *m_state_save_cb(const Messenger *_Nonnull m, uint8_t *_Nonnull data);

// Returns if there were any erros during loading

typedef State_Load_Status m_state_load_cb(Messenger *_Nonnull m, const uint8_t *_Nonnull data, uint32_t length);

typedef struct Messenger_State_Plugin {

    State_Type type;

    m_state_size_cb *_Nullable size;

    m_state_save_cb *_Nullable save;

    m_state_load_cb *_Nullable load;

} Messenger_State_Plugin;

typedef struct Messenger_Options {

    bool ipv6enabled;

    bool udp_disabled;

    TCP_Proxy_Info proxy_info;

    uint16_t port_range[2];

    uint16_t tcp_server_port;

    bool hole_punching_enabled;

    bool local_discovery_enabled;

    bool dht_announcements_enabled;

    bool groups_persistence_enabled;

    logger_cb *_Nullable log_callback;

    void *_Nullable log_context;

    void *_Nullable log_user_data;

    Messenger_State_Plugin *_Nullable state_plugins;

    uint8_t state_plugins_length;

    bool dns_enabled;

} Messenger_Options;

struct Receipts {

    uint32_t packet_num;

    uint32_t msg_id;

    struct Receipts *_Nullable next;

};

/** Status definitions. */

typedef enum Friend_Status {

    NOFRIEND,

    FRIEND_ADDED,

    FRIEND_REQUESTED,

    FRIEND_CONFIRMED,

    FRIEND_ONLINE,

} Friend_Status;

/** @brief Errors for m_addfriend

 *

 * FAERR - Friend Add Error

 */

typedef enum Friend_Add_Error {

    FAERR_TOOLONG = -1,

    FAERR_NOMESSAGE = -2,

    FAERR_OWNKEY = -3,

    FAERR_ALREADYSENT = -4,

    FAERR_BADCHECKSUM = -6,

    FAERR_SETNEWNOSPAM = -7,

    FAERR_NOMEM = -8,

} Friend_Add_Error;

/** Default start timeout in seconds between friend requests. */

#define FRIENDREQUEST_TIMEOUT 5

typedef enum Connection_Status {

    CONNECTION_NONE,

    CONNECTION_TCP,

    CONNECTION_UDP,

} Connection_Status;

/**

 * Represents userstatuses someone can have.

 */

typedef enum Userstatus {

    USERSTATUS_NONE,

    USERSTATUS_AWAY,

    USERSTATUS_BUSY,

    USERSTATUS_INVALID,

} Userstatus;

#define FILE_ID_LENGTH 32

struct File_Transfers {

    uint64_t size;

    uint64_t transferred;

    uint8_t status; /* 0 == no transfer, 1 = not accepted, 3 = transferring, 4 = broken, 5 = finished */

    uint8_t paused; /* 0: not paused, 1 = paused by us, 2 = paused by other, 3 = paused by both. */

    uint32_t last_packet_number; /* number of the last packet sent. */

    uint64_t requested; /* total data requested by the request chunk callback */

    uint8_t id[FILE_ID_LENGTH];

};

typedef enum Filestatus {

    FILESTATUS_NONE,

    FILESTATUS_NOT_ACCEPTED,

    FILESTATUS_TRANSFERRING,

    // FILESTATUS_BROKEN,

    FILESTATUS_FINISHED,

} Filestatus;

typedef enum File_Pause {

    FILE_PAUSE_NOT,

    FILE_PAUSE_US,

    FILE_PAUSE_OTHER,

    FILE_PAUSE_BOTH,

} File_Pause;

typedef enum Filecontrol {

    FILECONTROL_ACCEPT,

    FILECONTROL_PAUSE,

    FILECONTROL_KILL,

    FILECONTROL_SEEK,

} Filecontrol;

typedef enum Filekind {

    FILEKIND_DATA,

    FILEKIND_AVATAR,

} Filekind;

typedef void m_self_connection_status_cb(Messenger *_Nonnull m, Onion_Connection_Status connection_status, void *_Nullable user_data);

typedef void m_friend_status_cb(Messenger *_Nonnull m, uint32_t friend_number, unsigned int status, void *_Nullable user_data);

typedef void m_friend_connection_status_cb(Messenger *_Nonnull m, uint32_t friend_number, unsigned int connection_status,

        void *_Nullable user_data);

typedef void m_friend_message_cb(Messenger *_Nonnull m, uint32_t friend_number, unsigned int message_type,

                                 const uint8_t *_Nonnull message, size_t length, void *_Nullable user_data);

typedef void m_file_recv_control_cb(Messenger *_Nonnull m, uint32_t friend_number, uint32_t file_number, unsigned int control,

                                    void *_Nullable user_data);

typedef void m_friend_request_cb(Messenger *_Nonnull m, const uint8_t *_Nonnull public_key, const uint8_t *_Nonnull message, size_t length,

                                 void *_Nullable user_data);

typedef void m_friend_name_cb(Messenger *_Nonnull m, uint32_t friend_number, const uint8_t *_Nonnull name, size_t length,

                              void *_Nullable user_data);

typedef void m_friend_status_message_cb(Messenger *_Nonnull m, uint32_t friend_number, const uint8_t *_Nonnull message, size_t length,

                                        void *_Nullable user_data);

typedef void m_friend_typing_cb(Messenger *_Nonnull m, uint32_t friend_number, bool is_typing, void *_Nullable user_data);

typedef void m_friend_read_receipt_cb(Messenger *_Nonnull m, uint32_t friend_number, uint32_t message_id, void *_Nullable user_data);

typedef void m_file_recv_cb(Messenger *_Nonnull m, uint32_t friend_number, uint32_t file_number, uint32_t kind,

                            uint64_t file_size, const uint8_t *_Nonnull filename, size_t filename_length, void *_Nullable user_data);

typedef void m_file_chunk_request_cb(Messenger *_Nonnull m, uint32_t friend_number, uint32_t file_number, uint64_t position,

                                     size_t length, void *_Nullable user_data);

typedef void m_file_recv_chunk_cb(Messenger *_Nonnull m, uint32_t friend_number, uint32_t file_number, uint64_t position,

                                  const uint8_t *_Nullable data, size_t length, void *_Nullable user_data);

typedef void m_friend_lossy_packet_cb(Messenger *_Nonnull m, uint32_t friend_number, uint8_t packet_id, const uint8_t *_Nonnull data,

                                      size_t length, void *_Nullable user_data);

typedef void m_friend_lossless_packet_cb(Messenger *_Nonnull m, uint32_t friend_number, uint8_t packet_id, const uint8_t *_Nonnull data,

        size_t length, void *_Nullable user_data);

typedef void m_conference_invite_cb(Messenger *_Nonnull m, uint32_t friend_number, const uint8_t *_Nonnull cookie, uint16_t length,

                                    void *_Nullable user_data);

typedef void m_group_invite_cb(const Messenger *_Nonnull m, uint32_t friend_number, const uint8_t *_Nonnull invite_data, size_t length,

                               const uint8_t *_Nullable group_name, size_t group_name_length, void *_Nullable user_data);

typedef struct Friend {

    uint8_t real_pk[CRYPTO_PUBLIC_KEY_SIZE];

    int friendcon_id;

    uint64_t friendrequest_lastsent; // Time at which the last friend request was sent.

    uint32_t friendrequest_timeout; // The timeout between successful friendrequest sending attempts.

    uint8_t status; // 0 if no friend, 1 if added, 2 if friend request sent, 3 if confirmed friend, 4 if online.

    uint8_t info[MAX_FRIEND_REQUEST_DATA_SIZE]; // the data that is sent during the friend requests we do.

    uint8_t name[MAX_NAME_LENGTH];

    uint16_t name_length;

    bool name_sent; // false if we didn't send our name to this friend, true if we have.

    uint8_t statusmessage[MAX_STATUSMESSAGE_LENGTH];

    uint16_t statusmessage_length;

    bool statusmessage_sent;

    Userstatus userstatus;

    bool userstatus_sent;

    bool user_istyping;

    bool user_istyping_sent;

    bool is_typing;

    uint16_t info_size; // Length of the info.

    uint32_t message_id; // a semi-unique id used in read receipts.

    uint32_t friendrequest_nospam; // The nospam number used in the friend request.

    uint64_t last_seen_time;

    Connection_Status last_connection_udp_tcp;

    struct File_Transfers file_sending[MAX_CONCURRENT_FILE_PIPES];

    uint32_t num_sending_files;

    struct File_Transfers file_receiving[MAX_CONCURRENT_FILE_PIPES];

    struct Receipts *_Nullable receipts_start;

    struct Receipts *_Nullable receipts_end;

} Friend;

struct Messenger {

    Logger *_Nullable log;

    Mono_Time *_Nullable mono_time;

    const Memory *_Nullable mem;

    const Random *_Nullable rng;

    const Network *_Nullable ns;

    Networking_Core *_Nonnull net;

    Net_Crypto *_Nonnull net_crypto;

    Net_Profile *_Nullable tcp_np;

    DHT *_Nonnull dht;

    Forwarding *_Nullable forwarding;

    Announcements *_Nullable announce;

    Onion *_Nullable onion;

    Onion_Announce *_Nullable onion_a;

    Onion_Client *_Nullable onion_c;

    Friend_Connections *_Nullable fr_c;

    TCP_Server *_Nullable tcp_server;

    Friend_Requests *_Nullable fr;

    uint8_t name[MAX_NAME_LENGTH];

    uint16_t name_length;

    uint8_t statusmessage[MAX_STATUSMESSAGE_LENGTH];

    uint16_t statusmessage_length;

    Userstatus userstatus;

    Friend *_Nullable friendlist;

    uint32_t numfriends;

    uint64_t lastdump;

    uint8_t is_receiving_file;

    GC_Session *_Nonnull group_handler;

    GC_Announces_List *_Nonnull group_announce;

    bool has_added_relays; // If the first connection has occurred in do_messenger

    uint16_t num_loaded_relays;

    Node_format loaded_relays[NUM_SAVED_TCP_RELAYS]; // Relays loaded from config

    m_friend_request_cb *_Nullable friend_request;

    m_friend_message_cb *_Nullable friend_message;

    m_friend_name_cb *_Nullable friend_namechange;

    m_friend_status_message_cb *_Nullable friend_statusmessagechange;

    m_friend_status_cb *_Nullable friend_userstatuschange;

    m_friend_typing_cb *_Nullable friend_typingchange;

    m_friend_read_receipt_cb *_Nullable read_receipt;

    m_friend_connection_status_cb *_Nullable friend_connectionstatuschange;

    struct Group_Chats *_Nullable conferences_object;

    m_conference_invite_cb *_Nullable conference_invite;

    m_group_invite_cb *_Nullable group_invite;

    m_file_recv_cb *_Nullable file_sendrequest;

    m_file_recv_control_cb *_Nullable file_filecontrol;

    m_file_recv_chunk_cb *_Nullable file_filedata;

    m_file_chunk_request_cb *_Nullable file_reqchunk;

    m_friend_lossy_packet_cb *_Nullable lossy_packethandler;

    m_friend_lossless_packet_cb *_Nullable lossless_packethandler;

    m_self_connection_status_cb *_Nullable core_connection_change;

    Onion_Connection_Status last_connection_status;

    Messenger_Options options;

};

/**

 * Determines if the friendnumber passed is valid in the Messenger object.

 *

 * @param friendnumber The index in the friend list.

 */

bool friend_is_valid(const Messenger *_Nonnull m, int32_t friendnumber);

/**

 * Format: `[real_pk (32 bytes)][nospam number (4 bytes)][checksum (2 bytes)]`

 *

 * @param[out] address FRIEND_ADDRESS_SIZE byte address to give to others.

 */

void getaddress(const Messenger *_Nonnull m, uint8_t *_Nonnull address);

/**

 * Add a friend.

 *

 * Set the data that will be sent along with friend request.

 *

 * @param address is the address of the friend (returned by getaddress of the friend

 *   you wish to add) it must be FRIEND_ADDRESS_SIZE bytes.

 *   TODO(irungentoo): add checksum.

 * @param data is the data.

 * @param length is the length.

 *

 * @return the friend number if success.

 * @retval FA_TOOLONG if message length is too long.

 * @retval FAERR_NOMESSAGE if no message (message length must be >= 1 byte).

 * @retval FAERR_OWNKEY if user's own key.

 * @retval FAERR_ALREADYSENT if friend request already sent or already a friend.

 * @retval FAERR_BADCHECKSUM if bad checksum in address.

 * @retval FAERR_SETNEWNOSPAM if the friend was already there but the nospam was different.

 *   (the nospam for that friend was set to the new one).

 * @retval FAERR_NOMEM if increasing the friend list size fails.

 */

int32_t m_addfriend(Messenger *_Nonnull m, const uint8_t *_Nonnull address, const uint8_t *_Nonnull data, uint16_t length);

/** @brief Add a friend without sending a friendrequest.

 * @return the friend number if success.

 * @retval -3 if user's own key.

 * @retval -4 if friend request already sent or already a friend.

 * @retval -6 if bad checksum in address.

 * @retval -8 if increasing the friend list size fails.

 */

int32_t m_addfriend_norequest(Messenger *_Nonnull m, const uint8_t *_Nonnull real_pk);

/** @brief Initializes the friend connection and onion connection for a groupchat.

 *

 * @retval true on success.

 */

bool m_create_group_connection(Messenger *_Nonnull m, GC_Chat *_Nonnull chat);

/*

 * Kills the friend connection for a groupchat.

 */

void m_kill_group_connection(Messenger *_Nonnull m, const GC_Chat *_Nonnull chat);

/** @return the friend number associated to that public key.

 * @retval -1 if no such friend.

 */

int32_t getfriend_id(const Messenger *_Nonnull m, const uint8_t *_Nonnull real_pk);

/** @brief Copies the public key associated to that friend id into real_pk buffer.

 *

 * Make sure that real_pk is of size CRYPTO_PUBLIC_KEY_SIZE.

 *

 * @retval 0 if success.

 * @retval -1 if failure.

 */

int get_real_pk(const Messenger *_Nonnull m, int32_t friendnumber, uint8_t *_Nonnull real_pk);

/** @return friend connection id on success.

 * @retval -1 if failure.

 */

int getfriendcon_id(const Messenger *_Nonnull m, int32_t friendnumber);

/** @brief Remove a friend.

 *

 * @retval 0 if success.

 * @retval -1 if failure.

 */

int m_delfriend(Messenger *_Nonnull m, int32_t friendnumber);

/** @brief Checks friend's connection status.

 *

 * @retval CONNECTION_UDP (2) if friend is directly connected to us (Online UDP).

 * @retval CONNECTION_TCP (1) if friend is connected to us (Online TCP).

 * @retval CONNECTION_NONE (0) if friend is not connected to us (Offline).

 * @retval -1 on failure.

 */

int m_get_friend_connectionstatus(const Messenger *_Nonnull m, int32_t friendnumber);

/**

 * Checks if there exists a friend with given friendnumber.

 *

 * @param friendnumber The index in the friend list.

 *

 * @retval true if friend exists.

 * @retval false if friend doesn't exist.

 */

bool m_friend_exists(const Messenger *_Nonnull m, int32_t friendnumber);

/** @brief Send a message of type to an online friend.

 *

 * @retval -1 if friend not valid.

 * @retval -2 if too large.

 * @retval -3 if friend not online.

 * @retval -4 if send failed (because queue is full).

 * @retval -5 if bad type.

 * @retval 0 if success.

 *

 * The value in message_id will be passed to your read_receipt callback when the other receives the message.

 */

int m_send_message_generic(Messenger *_Nonnull m, int32_t friendnumber, uint8_t type, const uint8_t *_Nonnull message, uint32_t length,

                           uint32_t *_Nullable message_id);

/** @brief Set the name and name_length of a friend.

 *

 * name must be a string of maximum MAX_NAME_LENGTH length.

 * length must be at least 1 byte.

 * length is the length of name with the NULL terminator.

 *

 * @retval 0 if success.

 * @retval -1 if failure.

 */

int setfriendname(Messenger *_Nonnull m, int32_t friendnumber, const uint8_t *_Nonnull name, uint16_t length);

/** @brief Set our nickname.

 *

 * name must be a string of maximum MAX_NAME_LENGTH length.

 * length must be at least 1 byte.

 * length is the length of name with the NULL terminator.

 *

 * @retval 0 if success.

 * @retval -1 if failure.

 */

int setname(Messenger *_Nonnull m, const uint8_t *_Nonnull name, uint16_t length);

/**

 * @brief Get your nickname.

 *

 * m - The messenger context to use.

 * name needs to be a valid memory location with a size of at least MAX_NAME_LENGTH bytes.

 *

 * @return length of the name.

 * @retval 0 on error.

 */

uint16_t getself_name(const Messenger *_Nonnull m, uint8_t *_Nonnull name);

/** @brief Get name of friendnumber and put it in name.

 *

 * name needs to be a valid memory location with a size of at least MAX_NAME_LENGTH (128) bytes.

 *

 * @return length of name if success.

 * @retval -1 if failure.

 */

int getname(const Messenger *_Nonnull m, int32_t friendnumber, uint8_t *_Nonnull name);

/** @return the length of name, including null on success.

 * @retval -1 on failure.

 */

int m_get_name_size(const Messenger *_Nonnull m, int32_t friendnumber);

int m_get_self_name_size(const Messenger *_Nonnull m);

/** @brief Set our user status.

 * You are responsible for freeing status after.

 *

 * @retval 0 if success.

 * @retval -1 if failure.

 */

int m_set_statusmessage(Messenger *_Nonnull m, const uint8_t *_Nonnull status, uint16_t length);

int m_set_userstatus(Messenger *_Nonnull m, uint8_t status);

/**

 * Guaranteed to be at most MAX_STATUSMESSAGE_LENGTH.

 *

 * @return the length of friendnumber's status message, including null on success.

 * @retval -1 on failure.

 */

int m_get_statusmessage_size(const Messenger *_Nonnull m, int32_t friendnumber);

int m_get_self_statusmessage_size(const Messenger *_Nonnull m);

/** @brief Copy friendnumber's status message into buf, truncating if size is over maxlen.

 *

 * Get the size you need to allocate from m_get_statusmessage_size.

 * The self variant will copy our own status message.

 *

 * @return the length of the copied data on success

 * @retval -1 on failure.

 */

int m_copy_statusmessage(const Messenger *_Nonnull m, int32_t friendnumber, uint8_t *_Nonnull buf, uint32_t maxlen);

int m_copy_self_statusmessage(const Messenger *_Nonnull m, uint8_t *_Nonnull buf);

/** @brief return one of Userstatus values.

 *

 * Values unknown to your application should be represented as USERSTATUS_NONE.

 * As above, the self variant will return our own Userstatus.

 * If friendnumber is invalid, this shall return USERSTATUS_INVALID.

 */

uint8_t m_get_userstatus(const Messenger *_Nonnull m, int32_t friendnumber);

uint8_t m_get_self_userstatus(const Messenger *_Nonnull m);

/** @brief returns timestamp of last time friendnumber was seen online or 0 if never seen.

 * if friendnumber is invalid this function will return UINT64_MAX.

 */

uint64_t m_get_last_online(const Messenger *_Nonnull m, int32_t friendnumber);

/** @brief Set our typing status for a friend.

 * You are responsible for turning it on or off.

 *

 * @retval 0 on success.

 * @retval -1 on failure.

 */

int m_set_usertyping(Messenger *_Nonnull m, int32_t friendnumber, bool is_typing);

/** @brief Get the typing status of a friend.

 *

 * @retval -1 if friend number is invalid.

 * @retval 0 if friend is not typing.

 * @retval 1 if friend is typing.

 */

int m_get_istyping(const Messenger *_Nonnull m, int32_t friendnumber);

/** Set the function that will be executed when a friend request is received. */

void m_callback_friendrequest(Messenger *_Nonnull m, m_friend_request_cb *_Nullable function);

/** Set the function that will be executed when a message from a friend is received. */

void m_callback_friendmessage(Messenger *_Nonnull m, m_friend_message_cb *_Nonnull function);

/** @brief Set the callback for name changes.

 * You are not responsible for freeing newname.

 */

void m_callback_namechange(Messenger *_Nonnull m, m_friend_name_cb *_Nonnull function);

/** @brief Set the callback for status message changes.

 *

 * You are not responsible for freeing newstatus

 */

void m_callback_statusmessage(Messenger *_Nonnull m, m_friend_status_message_cb *_Nonnull function);

/** @brief Set the callback for status type changes. */

void m_callback_userstatus(Messenger *_Nonnull m, m_friend_status_cb *_Nonnull function);

/** @brief Set the callback for typing changes. */

void m_callback_typingchange(Messenger *_Nonnull m, m_friend_typing_cb *_Nonnull function);

/** @brief Set the callback for read receipts.

 *

 * If you are keeping a record of returns from m_sendmessage,

 * receipt might be one of those values, meaning the message

 * has been received on the other side.

 * Since core doesn't track ids for you, receipt may not correspond to any message.

 * In that case, you should discard it.

 */

void m_callback_read_receipt(Messenger *_Nonnull m, m_friend_read_receipt_cb *_Nonnull function);

/** @brief Set the callback for connection status changes.

 *

 * Status:

 * - 0: friend went offline after being previously online.

 * - 1: friend went online.

 *

 * Note that this callback is not called when adding friends, thus the

 * "after being previously online" part.

 * It's assumed that when adding friends, their connection status is offline.

 */

void m_callback_connectionstatus(Messenger *_Nonnull m, m_friend_connection_status_cb *_Nonnull function);

/** @brief Set the callback for typing changes. */

void m_callback_core_connection(Messenger *_Nonnull m, m_self_connection_status_cb *_Nonnull function);

/*** CONFERENCES */

/** @brief Set the callback for conference invites. */

void m_callback_conference_invite(Messenger *_Nonnull m, m_conference_invite_cb *_Nullable function);

/* Set the callback for group invites.

 */

void m_callback_group_invite(Messenger *_Nonnull m, m_group_invite_cb *_Nullable function);

/** @brief Send a conference invite packet.

 *

 * return true on success

 * return false on failure

 */

bool send_conference_invite_packet(const Messenger *_Nonnull m, int32_t friendnumber, const uint8_t *_Nonnull data, uint16_t length);

/* Send a group invite packet.

 *

 *  WARNING: Return-value semantics are different than for

 *  send_conference_invite_packet().

 *

 *  return true on success

 */

bool send_group_invite_packet(const Messenger *_Nonnull m, uint32_t friendnumber, const uint8_t *_Nonnull packet, uint16_t length);

/*** FILE SENDING */

/** @brief Set the callback for file send requests. */

void callback_file_sendrequest(Messenger *_Nonnull m, m_file_recv_cb *_Nonnull function);

/** @brief Set the callback for file control requests. */

void callback_file_control(Messenger *_Nonnull m, m_file_recv_control_cb *_Nonnull function);

/** @brief Set the callback for file data. */

void callback_file_data(Messenger *_Nonnull m, m_file_recv_chunk_cb *_Nonnull function);

/** @brief Set the callback for file request chunk. */

void callback_file_reqchunk(Messenger *_Nonnull m, m_file_chunk_request_cb *_Nonnull function);

/** @brief Copy the file transfer file id to file_id

 *

 * @retval 0 on success.

 * @retval -1 if friend not valid.

 * @retval -2 if filenumber not valid

 */

int file_get_id(const Messenger *_Nonnull m, int32_t friendnumber, uint32_t filenumber, uint8_t *_Nonnull file_id);

/** @brief Send a file send request.

 *

 * Maximum filename length is 255 bytes.

 *

 * @return file number on success

 * @retval -1 if friend not found.

 * @retval -2 if filename length invalid.

 * @retval -3 if no more file sending slots left.

 * @retval -4 if could not send packet (friend offline).

 */

long int new_filesender(const Messenger *_Nonnull m, int32_t friendnumber, uint32_t file_type, uint64_t filesize, const uint8_t *_Nonnull file_id, const uint8_t *_Nonnull filename,

                        uint16_t filename_length);

/** @brief Send a file control request.

 *

 * @retval 0 on success

 * @retval -1 if friend not valid.

 * @retval -2 if friend not online.

 * @retval -3 if file number invalid.

 * @retval -4 if file control is bad.

 * @retval -5 if file already paused.

 * @retval -6 if resume file failed because it was only paused by the other.

 * @retval -7 if resume file failed because it wasn't paused.

 * @retval -8 if packet failed to send.

 */

int file_control(const Messenger *_Nonnull m, int32_t friendnumber, uint32_t filenumber, unsigned int control);

/** @brief Send a seek file control request.

 *

 * @retval 0 on success

 * @retval -1 if friend not valid.

 * @retval -2 if friend not online.

 * @retval -3 if file number invalid.

 * @retval -4 if not receiving file.

 * @retval -5 if file status wrong.

 * @retval -6 if position bad.

 * @retval -8 if packet failed to send.

 */

int file_seek(const Messenger *_Nonnull m, int32_t friendnumber, uint32_t filenumber, uint64_t position);

/** @brief Send file data.

 *

 * @retval 0 on success

 * @retval -1 if friend not valid.

 * @retval -2 if friend not online.

 * @retval -3 if filenumber invalid.

 * @retval -4 if file transfer not transferring.

 * @retval -5 if bad data size.

 * @retval -6 if packet queue full.

 * @retval -7 if wrong position.

 */

int send_file_data(const Messenger *_Nonnull m, int32_t friendnumber, uint32_t filenumber, uint64_t position,

                   const uint8_t *_Nullable data, uint16_t length);

/*** CUSTOM PACKETS */

/** @brief Set handlers for custom lossy packets. */

void custom_lossy_packet_registerhandler(Messenger *_Nonnull m, m_friend_lossy_packet_cb *_Nonnull lossy_packethandler);

/** @brief High level function to send custom lossy packets.

 *

 * @retval -1 if friend invalid.

 * @retval -2 if length wrong.

 * @retval -3 if first byte invalid.

 * @retval -4 if friend offline.

 * @retval -5 if packet failed to send because of other error.

 * @retval 0 on success.

 */

int m_send_custom_lossy_packet(const Messenger *_Nonnull m, int32_t friendnumber, const uint8_t *_Nonnull data, uint32_t length);

/** @brief Set handlers for custom lossless packets. */

void custom_lossless_packet_registerhandler(Messenger *_Nonnull m, m_friend_lossless_packet_cb *_Nonnull lossless_packethandler);

/** @brief High level function to send custom lossless packets.

 *

 * @retval -1 if friend invalid.

 * @retval -2 if length wrong.

 * @retval -3 if first byte invalid.

 * @retval -4 if friend offline.

 * @retval -5 if packet failed to send because of other error.

 * @retval 0 on success.

 */

int send_custom_lossless_packet(const Messenger *_Nonnull m, int32_t friendnumber, const uint8_t *_Nonnull data, uint32_t length);

/*** Messenger constructor/destructor/operations. */

typedef enum Messenger_Error {

    MESSENGER_ERROR_NONE,

    MESSENGER_ERROR_PORT,

    MESSENGER_ERROR_TCP_SERVER,

    MESSENGER_ERROR_OTHER,

} Messenger_Error;

/** @brief Run this at startup.

 *

 * @return allocated instance of Messenger on success.

 * @retval 0 if there are problems.

 *

 * if error is not NULL it will be set to one of the values in the enum above.

 */

Messenger *_Nullable new_messenger(Mono_Time *_Nonnull mono_time, const Memory *_Nonnull mem, const Random *_Nonnull rng, const Network *_Nonnull ns, Messenger_Options *_Nonnull options,

                                   Messenger_Error *_Nonnull error);

/** @brief Run this before closing shop.

 *

 * Free all datastructures.

 */

void kill_messenger(Messenger *_Nullable m);

/** @brief The main loop that needs to be run at least 20 times per second. */

void do_messenger(Messenger *_Nonnull m, void *_Nullable userdata);

/**

 * @brief Return the time in milliseconds before `do_messenger()` should be called again

 *   for optimal performance.

 *

 * @return time (in ms) before the next `do_messenger()` needs to be run on success.

 */

uint32_t messenger_run_interval(const Messenger *_Nonnull m);

/* SAVING AND LOADING FUNCTIONS: */

/** @brief Registers a state plugin for saving, loading, and getting the size of a section of the save.

 *

 * @retval true on success

 * @retval false on error

 */

bool m_register_state_plugin(Messenger *_Nonnull m, State_Type type, m_state_size_cb *_Nonnull size_callback, m_state_load_cb *_Nonnull load_callback, m_state_save_cb *_Nonnull save_callback);

/** return size of the messenger data (for saving). */

uint32_t messenger_size(const Messenger *_Nonnull m);

/** Save the messenger in data (must be allocated memory of size at least `Messenger_size()`) */

uint8_t *_Nonnull messenger_save(const Messenger *_Nonnull m, uint8_t *_Nonnull data);

/** @brief Load a state section.

 *

 * @param data Data to load.

 * @param length Length of data.

 * @param type Type of section (`STATE_TYPE_*`).

 * @param status Result of loading section is stored here if the section is handled.

 * @return true iff section handled.

 */

bool messenger_load_state_section(Messenger *_Nonnull m, const uint8_t *_Nonnull data, uint32_t length, uint16_t type, State_Load_Status *_Nonnull status);

/** @brief Return the number of friends in the instance m.

 *

 * You should use this to determine how much memory to allocate

 * for copy_friendlist.

 */

uint32_t count_friendlist(const Messenger *_Nonnull m);

/** @brief Copy a list of valid friend IDs into the array out_list.

 * If out_list is NULL, returns 0.

 * Otherwise, returns the number of elements copied.

 * If the array was too small, the contents

 * of out_list will be truncated to list_size.

 */

uint32_t copy_friendlist(const Messenger *_Nonnull m, uint32_t *_Nonnull out_list, uint32_t list_size);

bool m_is_receiving_file(Messenger *_Nonnull m);

#endif /* C_TOXCORE_TOXCORE_MESSENGER_H */