/*
 * ZeroTier SDK - Network Virtualization Everywhere
 * Copyright (C) 2011-2017  ZeroTier, Inc.  https://www.zerotier.com/
 *
 * This program 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.
 *
 * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 * --
 *
 * You can be released from the requirements of the license by purchasing
 * a commercial license. Buying such a license is mandatory as soon as you
 * develop commercial closed-source software that incorporates or links
 * directly against ZeroTier software without disclosing the source code
 * of your own application.
 */

/**
 * @file
 *
 * Application-facing, partially-POSIX-compliant socket API
 */

#ifndef LIBZT_H
#define LIBZT_H

#include <poll.h>
#include <stdlib.h>
#include <stdint.h>
#include <vector>

#include "Debug.hpp"
#include "Defs.h"

/****************************************************************************/
/* Socket API Signatures                                                    */
/****************************************************************************/

#define ZT_SETSOCKOPT_SIG int fd, int level, int optname, const void *optval, socklen_t optlen
#define ZT_GETSOCKOPT_SIG int fd, int level, int optname, void *optval, socklen_t *optlen
#define ZT_SENDMSG_SIG int fd, const struct msghdr *msg, int flags
#define ZT_SENDTO_SIG int fd, const void *buf, size_t len, int flags, const struct sockaddr *addr, socklen_t addrlen
#define ZT_RECV_SIG int fd, void *buf, size_t len, int flags
#define ZT_RECVFROM_SIG int fd, void *buf, size_t len, int flags, struct sockaddr *addr, socklen_t *addrlen
#define ZT_RECVMSG_SIG int fd, struct msghdr *msg,int flags
#define ZT_SEND_SIG int fd, const void *buf, size_t len, int flags
#define ZT_READ_SIG int fd, void *buf, size_t len
#define ZT_WRITE_SIG int fd, const void *buf, size_t len
#define ZT_SHUTDOWN_SIG int fd, int how
#define ZT_SOCKET_SIG int socket_family, int socket_type, int protocol
#define ZT_CONNECT_SIG int fd, const struct sockaddr *addr, socklen_t addrlen
#define ZT_BIND_SIG int fd, const struct sockaddr *addr, socklen_t addrlen
#define ZT_LISTEN_SIG int fd, int backlog
#define ZT_ACCEPT4_SIG int fd, struct sockaddr *addr, socklen_t *addrlen, int flags
#define ZT_ACCEPT_SIG int fd, struct sockaddr *addr, socklen_t *addrlen
#define ZT_CLOSE_SIG int fd
#define ZT_POLL_SIG struct pollfd *fds, nfds_t nfds, int timeout
#define ZT_SELECT_SIG int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout
#define ZT_GETSOCKNAME_SIG int fd, struct sockaddr *addr, socklen_t *addrlen
#define ZT_GETPEERNAME_SIG int fd, struct sockaddr *addr, socklen_t *addrlen
#define ZT_GETHOSTNAME_SIG char *name, size_t len
#define ZT_SETHOSTNAME_SIG const char *name, size_t len
#define ZT_FCNTL_SIG int fd, int cmd, int flags
#define ZT_IOCTL_SIG int fd, unsigned long request, void *argp
#define ZT_SYSCALL_SIG long number, ...


/****************************************************************************/
/* SDK Socket API (ZeroTier Service Controls)                               */
/****************************************************************************/

#ifdef __cplusplus
extern "C" {
#endif

// forward declarations from ZT1Service.h
void zts_simple_start(const char *path, const char *nwid);
int zts_get_device_id(char *devID); 

void init_network_stack();

/** \brief Start core ZeroTier service (generates cryptographic identity).
 *         
 *
 * ...
 * Errno values:
 * ~~~
 * Value  | Meaning
 * ------ | ----------------
 * EINVAL | Invalid argument
 * ~~~
 */
void zts_start(const char *path);

/**
 *  @brief      Should be called at the beginning of your application  
 *
 *  @usage      Blocks until all of the following conditions are met:
 *                - ZeroTier core service has been initialized
 *                - Cryptographic identity has been generated or loaded from directory specified by `path`
 *                - Virtual network is successfully joined
 *                - IP address is assigned by network controller service 
 * 
 *  @param      path directory where cryptographic identities and network configuration files are stored and retrieved 
 *              (`identity.public`, `identity.secret`)
 *  @param      nwid the 16-digit hexidecimal network identifier (e.g. Earth: `8056c2e21c000001`)
 *
 *  @return     0 if successful; or 1 if failed
 */
void zts_simple_start(const char *path, const char *nwid);

/**
 * @brief Stops the ZeroTier core service and disconnects from all virtual networks  
 * 
 * @usage Called at the end of your application. This call will block until everything is shut down
 * @return 
 */
void zts_stop();

/**
 * @brief Joins a virtual network 
 * 
 * @usage Called after zts_start() or zts_simple_start()
 * @param nwid the 16-digit hexidecimal network identifier
 * @return 
 */
void zts_join(const char * nwid);

/**
 * @brief Joins a network (eventually), this will create the dir and conf file required, don't instruct the core 
 * to do anything
 * 
 * @usage Candidate for deletion
 * @param filepath path to the `*.conf` file named after the network
 * @param nwid
 * @return 
 */
void zts_join_soft(const char * filepath, const char * nwid);

/**
 * @brief Leaves a virtual network.
 * 
 * @usage 
 * @param nwid
 * @return 
 */
void zts_leave(const char * nwid);

/**
 * @brief Leave a network - Only delete the .conf file, this will prevent the service from joining upon next startup
 * 
 * @usage 
 * @param filepath
 * @param nwid
 * @return 
 */
void zts_leave_soft(const char * filepath, const char * nwid);

/**
 * @brief Return the home path for this instance of ZeroTier
 * 
 * @usage 
 * @param homePath
 * @param len
 * @return 
 */
void zts_get_homepath(char *homePath, const int len);

/**
 * @brief 
 * 
 * @usage Copies ZeroTier core version string into `ver`
 * @param ver
 * @return 
 */
void zts_core_version(char *ver);

/**
 * @brief Copies libzt version string into `ver`
 * 
 * @usage 
 * @param ver
 * @return 
 */
void zts_lib_version(char *ver);

/**
 * @brief Get device ID (10-digit hex + NULL byte)
 * 
 * @usage 
 * @param devID
 * @return 
 */
int zts_get_device_id(char *devID);

/**
 * @brief Check whether the service is running
 * 
 * @usage 
 * @return 
 */
int zts_running();

/**
 * @brief Returns whether any IPv6 address has been assigned to the SockTap for this network
 * 
 * @usage This is used as an indicator of readiness for service for the ZeroTier core and stack
 * @param nwid
 * @return 
 */
int zts_has_ipv4_address(const char *nwid);

/**
 * @brief Returns whether any IPv4 address has been assigned to the SockTap for this network
 * 
 * @usage This is used as an indicator of readiness for service for the ZeroTier core and stack
 * @param nwid
 * @return 
 */
int zts_has_ipv6_address(const char *nwid);

/**
 * @brief Returns whether any address has been assigned to the SockTap for this network
 * 
 * @usage This is used as an indicator of readiness for service for the ZeroTier core and stack
 * @param nwid
 * @return 
 */
int zts_has_address(const char *nwid);

/**
 * @brief Get IPV4 Address for this device on a given network
 * 
 * @usage FIXME: Only returns first address found for given protocol and network (should be enough for now)
 * @param nwid
 * @param addrstr
 * @param addrlen
 * @return 
 */
void zts_get_ipv4_address(const char *nwid, char *addrstr, const int addrlen);

/**
 * @brief Get IPV6 Address for this device on a given network
 * 
 * @usage FIXME: Only returns first address found for given protocol and network (should be enough for now)
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
void zts_get_ipv6_address(const char *nwid, char *addrstr, const int addrlen);

/**
 * @brief Returns a 6PLANE IPv6 address given a network ID and zerotier ID
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
void zts_get_6plane_addr(char *addr, const char *nwid, const char *devID);

/**
 * @brief Returns an RFC 4193 IPv6 address given a network ID and zerotier ID
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
void zts_get_rfc4193_addr(char *addr, const char *nwid, const char *devID);

/**
 * @brief Return the number of peers on this network
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
unsigned long zts_get_peer_count();

/**
 * @brief Get the IP address of a peer if a direct path is available
 * 
 * @usage 
 * @param peer
 * @param devID
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_get_peer_address(char *peer, const char *devID);

/**
 * @brief Enable HTTP control plane (traditionally used by zerotier-cli)
 *              - Allows one to control the ZeroTier core via HTTP requests
 *              FIXME: Implement
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
void zts_enable_http_control_plane();

/**
 * @brief Disable HTTP control plane (traditionally used by zerotier-cli)
 *              - Allows one to control the ZeroTier core via HTTP requests
 *              FIXME: Implement
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
void zts_disable_http_control_plane();

/****************************************************************************/
/* SDK Socket API (Socket User Controls)                                    */
/* - These functions are designed to work just like ordinary socket calls   */
/*   but are provisioned and handled by ZeroTier                            */
/****************************************************************************/

/**
 * @brief Create a socket
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_socket(int socket_family, int socket_type, int protocol);

/**
 * @brief Connect a socket to a remote host
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_connect(int fd, const struct sockaddr *addr, socklen_t addrlen);

/**
 * @brief 
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_bind(int fd, const struct sockaddr *addr, socklen_t addrlen);

/**
 * @brief Listen for incoming VirtualSockets
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_listen(int fd, int backlog);

/**
 * @brief Accept a VirtualSocket
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_accept(int fd, struct sockaddr *addr, socklen_t *addrlen);

/**
 * @brief Accept a VirtualSocket
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
#if defined(__linux__)
	int zts_accept4(int fd, struct sockaddr *addr, socklen_t *addrlen, int flags);
#endif

/**
 * @brief Set socket options
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_setsockopt(int fd, int level, int optname, const void *optval, socklen_t optlen);

/**
 * @brief Get socket options
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_getsockopt(int fd, int level, int optname, void *optval, socklen_t *optlen);

/**
 * @brief Get socket name
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_getsockname(int fd, struct sockaddr *addr, socklen_t *addrlen);

/**
 * @brief Get a peer name
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_getpeername(int fd, struct sockaddr *addr, socklen_t *addrlen);

/**
 * @brief Gets current hostname
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_gethostname(char *name, size_t len);

/**
 * @brief Sets current hostname
 * 
 * @usage 
 * @param 
 * @param 
 * @param 
 * @param 
 * @param 
 * @return 
 */
int zts_sethostname(const char *name, size_t len);

/**
 * @brief close a socket
 * 
 * @usage 
 * @param fd
 * @return 
 */
int zts_close(int fd);

/**
 * @brief waits for one of a set of file descriptors to become ready to perform I/O.
 * 
 * @usage 
 * @param fds
 * @param nfds
 * @param timeout
 * @return 
 */
int zts_poll(struct pollfd *fds, nfds_t nfds, int timeout);

/**
 * @brief monitor multiple file descriptors, waiting until one or more of the file descriptors become "ready"
 * 
 * @usage 
 * @param nfds
 * @param readfds
 * @param writefds
 * @param exceptfds
 * @param timeout
 * @return 
 */
int zts_select(int nfds, fd_set *readfds, fd_set *writefds, fd_set *exceptfds, struct timeval *timeout);

/**
 * @brief Issue file control commands on a socket
 * 
 * @usage 
 * @param fd
 * @param cmd
 * @param flags
 * @return 
 */
int zts_fcntl(int fd, int cmd, int flags);

/**
 * @brief Control a device
 * 
 * @usage 
 * @param fd
 * @param request
 * @param argp
 * @return 
 */
int zts_ioctl(int fd, unsigned long request, void *argp);

/**
 * @brief Send data to remote host
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param flags
 * @return 
 */
ssize_t zts_send(int fd, const void *buf, size_t len, int flags);

/**
 * @brief Send data to remote host
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param flags
 * @param addr
 * @param addrlen
 * @return 
 */
ssize_t zts_sendto(int fd, const void *buf, size_t len, int flags, const struct sockaddr *addr, socklen_t addrlen);

/**
 * @brief Send message to remote host
 * 
 * @usage 
 * @param fd
 * @param msg
 * @param flags
 * @return 
 */
ssize_t zts_sendmsg(int fd, const struct msghdr *msg, int flags);

/**
 * @brief Receive data from remote host
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param flags
 * @param 
 * @return 
 */
ssize_t zts_recv(int fd, void *buf, size_t len, int flags);

/**
 * @brief Receive data from remote host
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param flags
 * @param addr
 * @param addrlen
 * @return 
 */
ssize_t zts_recvfrom(int fd, void *buf, size_t len, int flags, struct sockaddr *addr, socklen_t *addrlen);

/**
 * @brief Receive a message from remote host
 * 
 * @usage 
 * @param fd
 * @param msg
 * @param flags
 * @return 
 */
ssize_t zts_recvmsg(int fd, struct msghdr *msg,int flags);

/**
 * @brief Read bytes from socket onto buffer
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param 
 * @param 
 * @return 
 */
int zts_read(int fd, void *buf, size_t len);

/**
 * @brief Write bytes from buffer to socket
 * 
 * @usage 
 * @param fd
 * @param buf
 * @param len
 * @param 
 * @param 
 * @return 
 */
int zts_write(int fd, const void *buf, size_t len);

/**
 * @brief 
 * 
 * @usage 
 * @param fd
 * @param how
 * @return 
 */
int zts_shutdown(int fd, int how);

/**
 * @brief Adds a DNS nameserver for the network stack to use
 * 
 * @usage 
 * @param addr
 * @return 
 */
int zts_add_dns_nameserver(struct sockaddr *addr);

/**
 * @brief Removes a DNS nameserver
 * 
 * @usage 
 * @param addr
 * @return 
 */
int zts_del_dns_nameserver(struct sockaddr *addr);

#ifdef __cplusplus
} // extern "C"
#endif

#endif // ZT_ZEROTIERSDK_H