/********************************************************************************
 *      Copyright:  (C) 2020 LingYun IoT System Studio
 *                  All rights reserved.
 *
 *       Filename:  socket.h
 *    Description:  This head file is for socket API
 *
 *        Version:  1.0.0(2020年04月16日)
 *         Author:  Guo Wenxue <guowenxue@gmail.com>
 *      ChangeLog:  1, Release initial version on "2020年04月16日 13时45分33秒"
 *                 
 ********************************************************************************/
#ifndef  _SOCKET_H_
#define  _SOCKET_H_

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <netdb.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/un.h>
#include <poll.h>
#include <errno.h> 

#include <sys/types.h>
#include <sys/socket.h>
#include <linux/sockios.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>

#include <sys/epoll.h>
#include <sys/resource.h>

#include "list.h"

#define HOSTNAME_LEN         128

enum
{
    SOCK_TYPE_LISTEN,  /* listen  socket */
    SOCK_TYPE_ACCEPT,  /* accept  socket */
    SOCK_TYPE_CONNECT, /* connect socket */
};

enum
{
    SOCK_STAT_UNINIT     = 0,  /* socket not initial */
    SOCK_STAT_INIT       = 1,  /* socket initialed */

    SOCK_STAT_CONNECTING = 2,  /* socket connecting in non-block mode */

    SOCK_STAT_CONNECTED  = 3,  /* socket connected in client mdoe */
    SOCK_STAT_LISTENED   = 3,  /* socket listened  in server mode */
    SOCK_STAT_ACCEPTED   = 3,  /* socket already accepted */
};

typedef struct socket_s
{
    int            fd;          /* socket fd  */ 
    uint8_t        type;        /* socket type: listen, accept or accept */
    uint8_t        status;      /* socket status: SOCK_STAT_INIT,SOCK_STAT_CONNECTED... */
    
    /* socket server/client IP address and port */
    char           raddr[HOSTNAME_LEN];  /* remote IP address or domain name */ 
    char           laddr[HOSTNAME_LEN];  /* local IP address */ 
    uint16_t       lport;                /* local listen port */ 
    uint16_t       rport;                /* remote connected port */ 

    /* socket heartbeat settings  */
    int            keepintvl;   /* keepalive detect interval */ 
    int            keepcnt;     /* keepalive count */ 

    struct sockaddr  saddr;     /* sockaddr for connect */ 

    struct list_head list;      /* socket server manage client link list */
} socket_t;


/*+-------------------------------------------------------------------+
 *|           client/server  socket API functions                     |
 *+-------------------------------------------------------------------+*/

/*  description: initialise socket context and create socket fd if sepecified
 *   input args: $sock: socket context 
 *               $type: SOCK_TYPE_LISTEN, SOCK_TYPE_ACCEPT or SOCK_TYPE_CONNEC
 *               $create: call socket() create or not
 * return value: <0: failure  0: successfully
 */                           
enum 
{
    SOCK_NOT_CREATE,
    SOCK_CREATE,
};
int socket_init(socket_t *sock, uint8_t type, int create);


/*  description: close socket and set socket status as SOCK_STAT_INIT 
 *   input args: $sock: socket context
 * return value: <0: failure  0: successfully
 */
int socket_close(socket_t *sock);


/*  description: close socket
 *   input args: $sock: socket context
 *               $lport: specify use local port $lport to connect remote server
 *               $host: IP address and port, format as "host:port", such as "127.0.0.1:8000"
 *              $block: block mode(1) or none-block(0)
 *return value:  <0: error   0: connecing in non-block mode   1:connected
 */
enum 
{
    MODE_NONBLOCK,
    MODE_BLOCK,
};
int socket_connect(socket_t *sock, int lport, char *host, int block);


/*  description: create socket and listen on port $port
 *   input args: $sock: socket context
 *                 $ip: listen IP address, NULL for any address
 *               $port: listen port
 * return value: <0: failure  0: successfully
 */
int socket_listen(socket_t *sock, char *ipaddr, int port);


/*  description: accept a new client socket
 *   input args: $sock: socket context
 *               $listenfd: listen socket fd
 * return value: <0: failure  0: successfully
 */
int socket_accept(socket_t *sock, int listenfd);

/*  description: send data to the socket, make sure all data send over. 
 *   input args: $sock: socket context
 *               $data: send data
 *               $bytes: data size
 * return value: <0: failure  0: successfully
 */
int socket_send(socket_t *sock, char *data, int bytes);


/*  description: receive data from the socket in some time
 *   input args: $sock: socket context
 *               $data: send data
 *               $bytes: data size
 *               $timeout: receive data time, <=0 will don't timeout
 * return value: <0: error  >=0: receive data bytes;
 */
int socket_recv(socket_t *sock, char *buf, int size, int timeout);


/*  description: create epoll for socket server and add listenfd into it
 *   input args: $max_evts:  max events for epoll_create()
 *               $listenfd:  listen socket fd
 * return value: <0: failure  >=0: epollfd
 */ 
int epoll_init(int max_evts, int listenfd);

/*  description: add new fd into epoll to monitor
 *   input args: $epollfd:  epoll fd
 *               $fd:       socket fd need added into epoll
 * return value: <0: failure  0: successfully
 */ 
inline int epoll_add(int epollfd, int fd);

static inline int epoll_del(int epollfd, int fd)
{
    return epoll_ctl(epollfd, EPOLL_CTL_DEL, fd, NULL);
}

/*+-------------------------------------------------------------------+
 *|                socket utils function                              |
 *+-------------------------------------------------------------------+*/

/*  description: parser hostname and port from $host and set it into $sock 
 *   input args: $sock: socket context
 *               $host: connect hostname, format as "hostname:port"
 */
int parser_host_port(socket_t *sock, char *host);


/* description: set socket listen port as reusable, fix port already used bug  */
int socket_set_reuseaddr(int sockfd);

/* set socket as non-block mode, common socket default work as block mode */
int socket_set_nonblock(int sockfd);

/* set socket receive and send buffer size in linux kernel space */
int socket_set_buffer(int sockfd, int rsize, int ssize);

/* set heartbeat keepalive  */
int socket_set_keepalive(int sockfd, int keepintvl, int keepcnt);

/*  Set open file description count to max */
void set_socket_rlimit(void);

#endif   /* ----- #ifndef _SOCKET_H_  ----- */