/*
Sample code below is based on ESP8266 SDK without OS.
1. Start from user_init
2. Connect to router
3. Connect to cn.bing.com as example
4. Send some HTTP packet..
Note: for ESP8266_RTOS_SDK, please call espconn_init() in the user_init to initialize espconn first.
*/

#include "espconn.h"
#include "mem.h"
  
#define NET_DOMAIN "cn.bing.com"
#define pheadbuffer "GET / HTTP/1.1\r\nUser-Agent: curl/7.37.0\r\nHost: %s\r\nAccept: */*\r\n\r\n"
  
#define packet_size   (2 * 1024)
  
LOCAL os_timer_t test_timer;
LOCAL struct espconn user_tcp_conn;
LOCAL struct _esp_tcp user_tcp;
ip_addr_t tcp_server_ip;
  
  
/******************************************************************************
 * FunctionName : user_tcp_recv_cb
 * Description  : receive callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recv_cb(void *arg, char *pusrdata, unsigned short length)
{
   //received some data from tcp connection
     
    os_printf("Received data string: %s \r\n", pusrdata);
     
}
/******************************************************************************
 * FunctionName : user_tcp_sent_cb
 * Description  : data sent callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_sent_cb(void *arg)
{
   //data sent successfully
  
    os_printf("Sent callback: data sent successfully.\r\n");
}
/******************************************************************************
 * FunctionName : user_tcp_discon_cb
 * Description  : disconnect callback.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_discon_cb(void *arg)
{
   //tcp disconnect successfully
     
    os_printf("Disconnected from server.\r\n");
}
/******************************************************************************
 * FunctionName : user_esp_platform_sent
 * Description  : Processing the application data and sending it to the host
 * Parameters   : pespconn -- the espconn used to connetion with the host
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_send_data(struct espconn *pespconn)
{
    char *pbuf = (char *)os_zalloc(packet_size);
  
    os_sprintf(pbuf, pheadbuffer, NET_DOMAIN);
  
   espconn_send(pespconn, pbuf, os_strlen(pbuf));
     
   os_free(pbuf);
  
}
  
/******************************************************************************
 * FunctionName : user_tcp_connect_cb
 * Description  : A new incoming tcp connection has been connected.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_connect_cb(void *arg)
{
    struct espconn *pespconn = arg;
  
    os_printf("Connected to server...\r\n");
  
    espconn_regist_recvcb(pespconn, user_tcp_recv_cb);
    espconn_regist_sentcb(pespconn, user_tcp_sent_cb);
    espconn_regist_disconcb(pespconn, user_tcp_discon_cb);
     
    user_send_data(pespconn);
}
  
/******************************************************************************
 * FunctionName : user_tcp_recon_cb
 * Description  : reconnect callback, error occured in TCP connection.
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_tcp_recon_cb(void *arg, sint8 err)
{
   //error occured , tcp connection broke. user can try to reconnect here. 
     
    os_printf("Reconnect callback called, error code: %d !!! \r\n",err);
}
  
#ifdef DNS_ENABLE
/******************************************************************************
 * FunctionName : user_dns_found
 * Description  : dns found callback
 * Parameters   : name -- pointer to the name that was looked up.
 *                ipaddr -- pointer to an ip_addr_t containing the IP address of
 *                the hostname, or NULL if the name could not be found (or on any
 *                other error).
 *                callback_arg -- a user-specified callback argument passed to
 *                dns_gethostbyname
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_found(const char *name, ip_addr_t *ipaddr, void *arg)
{
    struct espconn *pespconn = (struct espconn *)arg;
  
    if (ipaddr == NULL) 
   {
        os_printf("user_dns_found NULL \r\n");
        return;
    }
  
   //dns got ip
    os_printf("user_dns_found %d.%d.%d.%d \r\n",
            *((uint8 *)&ipaddr->addr), *((uint8 *)&ipaddr->addr + 1),
            *((uint8 *)&ipaddr->addr + 2), *((uint8 *)&ipaddr->addr + 3));
  
    if (tcp_server_ip.addr == 0 && ipaddr->addr != 0) 
   {
      // dns succeed, create tcp connection
        os_timer_disarm(&test_timer);
        tcp_server_ip.addr = ipaddr->addr;
        os_memcpy(pespconn->proto.tcp->remote_ip, &ipaddr->addr, 4); // remote ip of tcp server which get by dns
  
        pespconn->proto.tcp->remote_port = 80; // remote port of tcp server
        
        pespconn->proto.tcp->local_port = espconn_port(); //local port of ESP8266
  
        espconn_regist_connectcb(pespconn, user_tcp_connect_cb); // register connect callback
        espconn_regist_reconcb(pespconn, user_tcp_recon_cb); // register reconnect callback as error handler
  
        espconn_connect(pespconn); // tcp connect
    }
}
  
/******************************************************************************
 * FunctionName : user_esp_platform_dns_check_cb
 * Description  : 1s time callback to check dns found
 * Parameters   : arg -- Additional argument to pass to the callback function
 * Returns      : none
*******************************************************************************/
LOCAL void ICACHE_FLASH_ATTR
user_dns_check_cb(void *arg)
{
    struct espconn *pespconn = arg;
  
    espconn_gethostbyname(pespconn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // recall DNS function
  
    os_timer_arm(&test_timer, 1000, 0);
}
#endif
/******************************************************************************
 * FunctionName : user_check_ip
 * Description  : check whether get ip addr or not
 * Parameters   : none
 * Returns      : none
*******************************************************************************/
void ICACHE_FLASH_ATTR
user_check_ip(void)
{
    struct ip_info ipconfig;
  
   //disarm timer first
    os_timer_disarm(&test_timer);
  
   //get ip info of ESP8266 station
    wifi_get_ip_info(STATION_IF, &ipconfig);
  
    if (wifi_station_get_connect_status() == STATION_GOT_IP && ipconfig.ip.addr != 0) 
   {
      os_printf("Connected to router and assigned IP!\r\n");
  
      // Connect to tcp server as NET_DOMAIN
      user_tcp_conn.proto.tcp = &user_tcp;
      user_tcp_conn.type = ESPCONN_TCP;
      user_tcp_conn.state = ESPCONN_NONE;
        
#ifdef DNS_ENABLE
       tcp_server_ip.addr = 0;
       espconn_gethostbyname(&user_tcp_conn, NET_DOMAIN, &tcp_server_ip, user_dns_found); // DNS function
  
       os_timer_setfn(&test_timer, (os_timer_func_t *)user_dns_check_cb, &user_tcp_conn);
       os_timer_arm(&test_timer, 1000, 0);
#else
  
       const char esp_tcp_server_ip[4] = {X, X, X, X}; // remote IP of TCP server
  
       os_memcpy(user_tcp_conn.proto.tcp->remote_ip, esp_tcp_server_ip, 4);
  
       user_tcp_conn.proto.tcp->remote_port = XXXX;  // remote port
        
       user_tcp_conn.proto.tcp->local_port = espconn_port(); //local port of ESP8266
  
       espconn_regist_connectcb(&user_tcp_conn, user_tcp_connect_cb); // register connect callback
       espconn_regist_reconcb(&user_tcp_conn, user_tcp_recon_cb); // register reconnect callback as error handler
       espconn_connect(&user_tcp_conn); 
  
#endif
    } 
   else
   {
         
        if ((wifi_station_get_connect_status() == STATION_WRONG_PASSWORD ||
                wifi_station_get_connect_status() == STATION_NO_AP_FOUND ||
                wifi_station_get_connect_status() == STATION_CONNECT_FAIL)) 
        {
         os_printf("Connection to router failed!\r\n");
        } 
      else
      {
           //re-arm timer to check ip
            os_timer_setfn(&test_timer, (os_timer_func_t *)user_check_ip, NULL);
            os_timer_arm(&test_timer, 100, 0);
        }
    }
}
  
  
/******************************************************************************
 * FunctionName : user_set_station_config
 * Description  : set the router info which ESP8266 station will connect to 
 * Parameters   : none
 * Returns      : none
*******************************************************************************/
void ICACHE_FLASH_ATTR
user_set_station_config(void)
{
   // Wifi configuration 
   char ssid[32] = SSID; 
   char password[64] = PASSWORD; 
   struct station_config stationConf; 
     
   os_memset(stationConf.ssid, 0, 32);
   os_memset(stationConf.password, 0, 64);
     
   // No MAC-specific scanning
   stationConf.bssid_set = 0; 
     
   //Set ap settings 
   os_memcpy(&stationConf.ssid, ssid, 32); 
   os_memcpy(&stationConf.password, password, 64); 
   wifi_station_set_config(&stationConf); 
  
   // Set timer to check whether router allotted an IP 
   os_timer_disarm(&test_timer);
   os_timer_setfn(&test_timer, (os_timer_func_t *)user_check_ip, NULL);
   os_timer_arm(&test_timer, 100, 0);
  
}
  
  
/******************************************************************************
 * FunctionName : user_init
 * Description  : entry of user application, init user function here
 * Parameters   : none
 * Returns      : none
*******************************************************************************/
void user_init(void)
{
   os_printf("SDK version:%s\n", system_get_sdk_version());
     
   //Set softAP + station mode 
   wifi_set_opmode(STATIONAP_MODE); 
  
   //ESP8266 connect to router
   user_set_station_config();
  
}