/* network.h
 *
 * Datatypes, functions and includes for the core networking.
 *
 *  Copyright (C) 2013 Tox project All Rights Reserved.
 *
 *  This file is part of Tox.
 *
 *  Tox is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  Tox is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with Tox.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef NETWORK_H
#define NETWORK_H

#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <time.h>

#ifdef WIN32 /* Put win32 includes here */
#ifndef WINVER
//Windows XP
#define WINVER 0x0501
#endif
#include <winsock2.h>
#include <windows.h>
#include <ws2tcpip.h>

#undef VANILLA_NACL /* Make sure on Windows we use libsodium. */

#else // Linux includes

#include <fcntl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <errno.h>
#include <sys/time.h>
#include <sys/types.h>
#include <netdb.h>
#include <unistd.h>

#endif

#ifndef VANILLA_NACL
/* We use libsodium by default. */
#include <sodium.h>
#else
#include <crypto_box.h>
#define crypto_box_MACBYTES (crypto_box_ZEROBYTES - crypto_box_BOXZEROBYTES)
#endif


#define MAX_UDP_PACKET_SIZE 65507

#define NET_PACKET_PING_REQUEST    0   /* Ping request packet ID. */
#define NET_PACKET_PING_RESPONSE   1   /* Ping response packet ID. */
#define NET_PACKET_GET_NODES       2   /* Get nodes request packet ID. */
#define NET_PACKET_SEND_NODES      3   /* Send nodes response packet ID. */
#define NET_PACKET_HANDSHAKE       16  /* Handshake packet ID. */
#define NET_PACKET_SYNC            17  /* SYNC packet ID. */
#define NET_PACKET_DATA            18  /* Data packet ID. */
#define NET_PACKET_CRYPTO          32  /* Encrypted data packet ID. */
#define NET_PACKET_LAN_DISCOVERY   33  /* LAN discovery packet ID. */


/* Current time, unix format */
#define unix_time() ((uint64_t)time(NULL))


typedef union {
    uint8_t uint8[4];
    uint16_t uint16[2];
    uint32_t uint32;
} IP;

typedef union {
    struct {
        IP ip;
        uint16_t port;
        /* Not used for anything right now. */
        uint16_t padding;
    };
    uint8_t uint8[8];
} IP_Port;

typedef struct {
    int16_t family;
    uint16_t port;
    IP ip;
    uint8_t zeroes[8];
#ifdef ENABLE_IPV6
    uint8_t zeroes2[12];
#endif
} ADDR;

/* Function to receive data, ip and port of sender is put into ip_port.
 * Packet data is put into data.
 * Packet length is put into length.
 */
typedef int (*packet_handler_callback)(void *object, IP_Port ip_port, uint8_t *data, uint32_t len);

typedef struct {
    packet_handler_callback function;
    void *object;
} Packet_Handles;

typedef struct {
    Packet_Handles packethandlers[256];
    /* Our UDP socket. */
    int sock;
} Networking_Core;

/* return current time in milleseconds since the epoch. */
uint64_t current_time(void);

/* return a random number.
 * NOTE: this function should probably not be used where cryptographic randomness is absolutely necessary.
 */
uint32_t random_int(void);

/* Basic network functions: */

/* Function to send packet(data) of length length to ip_port. */
int sendpacket(int sock, IP_Port ip_port, uint8_t *data, uint32_t length);

/* Function to call when packet beginning with byte is received. */
void networking_registerhandler(Networking_Core *net, uint8_t byte, packet_handler_callback cb, void *object);

/* Call this several times a second. */
void networking_poll(Networking_Core *net);

/* Initialize networking.
 *  bind to ip and port.
 *  ip must be in network order EX: 127.0.0.1 = (7F000001).
 *  port is in host byte order (this means don't worry about it).
 *
 *  returns 0 if no problems.
 *  returns -1 if there were problems.
 */
Networking_Core *new_networking(IP ip, uint16_t port);

/* Function to cleanup networking stuff (doesn't do much right now). */
void kill_networking(Networking_Core *net);


#endif