#include "FreeRTOS.h"
#include "task.h"
#include "diag.h"
#include "platform_stdlib.h"
#include "wifi_constants.h"
#include "wifi_conf.h"
#include <lwip/sockets.h>
#include <lwip/netdb.h>

#include "sn_coap_protocol.h"
#include "sn_coap_ameba_port.h"

#define SERVER_HOST     "coap.me"
#define URI_PATH        "/hello" 
#define SERVER_PORT     5683
#define BUF_LEN         1280 // Suggested is to keep packet size under 1280 bytes

struct coap_s*          coapHandle;
coap_version_e          coapVersion = COAP_VERSION_1;

uint8_t coap_tx_cb(uint8_t *a, uint16_t b, sn_nsdl_addr_s *c, void *d) {
  printf("coap tx cb\n");
  return 0;
}

int8_t coap_rx_cb(sn_coap_hdr_s *a, sn_nsdl_addr_s *b, void *c) {
  printf("coap rx cb\n");
  return 0;
}

static void example_coap_thread(void *para){
  
  printf("\nCoAP Client Example\n");
  
  while(wifi_is_ready_to_transceive(RTW_STA_INTERFACE) != RTW_SUCCESS){
    printf("Wait for WIFI connection ...\n");
    vTaskDelay(1000);
  }
  
  // Initialize the CoAP protocol handle, pointing to local implementations on malloc/free/tx/rx functions
  coapHandle = coap_protocol_init(&coap_tx_cb, &coap_rx_cb);
  
  // See ns_coap_header.h
  sn_coap_hdr_s *coap_res_ptr = (sn_coap_hdr_s*)coap_calloc(1*sizeof(sn_coap_hdr_s)); 
  
  coap_res_ptr->token_len = 0;
  coap_res_ptr->coap_status = COAP_STATUS_OK;
  coap_res_ptr->msg_code = COAP_MSG_CODE_REQUEST_GET;
  coap_res_ptr->msg_type = COAP_MSG_TYPE_CONFIRMABLE;
  coap_res_ptr->content_format = COAP_CT_TEXT_PLAIN;
  coap_res_ptr->msg_id = 7;
  coap_res_ptr->uri_path_len = strlen(URI_PATH);
  coap_res_ptr->payload_len = 0;
  coap_res_ptr->token_ptr = NULL;
  coap_res_ptr->uri_path_ptr = (uint8_t*)URI_PATH;
  coap_res_ptr->payload_ptr = NULL;
  coap_res_ptr->options_list_ptr = NULL;
  
  
  int socket = coap_sock_open();
  
  //send CoAP message
  coap_send(SERVER_HOST, SERVER_PORT, socket, coap_res_ptr);
  
  coap_free(coap_res_ptr);
  
  //receive CoAP message
  struct sockaddr_in from_address;
  uint8_t* recv_buffer = (uint8_t*)coap_calloc(BUF_LEN); 
  int ret;
  
  while((ret = coap_recv(socket, &from_address, recv_buffer, BUF_LEN)) >= 0)
  {
    uint32_t ip = from_address.sin_addr.s_addr;
    uint8_t bytes[4];
    bytes[0] = ip & 0xFF;
    bytes[1] = (ip >> 8) & 0xFF;
    bytes[2] = (ip >> 16) & 0xFF;
    bytes[3] = (ip >> 24) & 0xFF;
    
    printf("\nReceived %d bytes from '%d.%d.%d.%d:%d'\n", ret, bytes[0], bytes[1], bytes[2], bytes[3], from_address.sin_port);
    
    sn_coap_hdr_s* parsed = sn_coap_parser(coapHandle, ret, recv_buffer, &coapVersion);
    
    coap_print_hdr(parsed);
  }
  
  coap_free(recv_buffer);
  
  coap_sock_close(socket);
    
  vTaskDelete(NULL);
}

void example_coap(void)
{
  if(xTaskCreate(example_coap_thread, ((const char*)"example_coap_thread"), 2048, NULL, tskIDLE_PRIORITY + 1, NULL) != pdPASS)
    printf("\n\r%s xTaskCreate(init_thread) failed", __FUNCTION__);
}