#include <string.h>
#include <sys/param.h>
#include "sdkconfig.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_netif.h"

#include "lwip/err.h"
#include "lwip/sockets.h"
#include "lwip/sys.h"
#include <lwip/netdb.h>

#include "udp_client.h"
#include "wifi.h"
#include "nexaTransmit.h"

/**********************************************************************************
 * For sending and receiving UDP-Data from the Debian-server use these commands:
 * echo "<NT4C90AD91>" | nc -uv 192.168.1.164 53000
 * nc -lu -p 53000
 **********************************************************************************/

#ifdef WIFI_ENABLED

#define HOST_IP_ADDR CONFIG_BACK_END_SERVER_IP_ADDRESS
#define PORT CONFIG_UDP_PORT_NO

static QueueHandle_t udpTxQueue = NULL; // Queue for transmitting UDP-Data to back-end server

static void setupConnection(int *socket_fd, struct sockaddr_in *backEndAddress) {

    struct sockaddr_in recvFromAddress;

    closesocket(*socket_fd);

    backEndAddress->sin_addr.s_addr = inet_addr(HOST_IP_ADDR);
    backEndAddress->sin_family = AF_INET;
    backEndAddress->sin_port = htons(PORT);

    // Wait for WiFi to be connected first
    while( commIsUpAndRunning == 0 ) vTaskDelay(500 / portTICK_PERIOD_MS);

    *socket_fd = socket(AF_INET, SOCK_DGRAM, 0);
    if (*socket_fd < 0) ESP_LOGE("UDP","Socket error");

    // Bind our server socket to a port.
    recvFromAddress.sin_family = AF_INET;
    recvFromAddress.sin_addr.s_addr = htonl(INADDR_ANY);
    recvFromAddress.sin_port = htons(PORT);
    if( (bind(*socket_fd, (const struct sockaddr *)&recvFromAddress, sizeof(struct sockaddr_in))) == -1 )
        ESP_LOGE("UDP","Bind error");
    else
        ESP_LOGI("UDP","UDP Rx Bind.");
}


void udp_client_task(void *pvParameter)
{
    struct sockaddr_in backEndAddress;
    int recv_len;
    char dataBuff[UDP_QUEUE_OBJ_LENGTH];
    int socket_fd;

    setupConnection(&socket_fd, &backEndAddress);

    while(1)
    {
        memset(dataBuff,0,UDP_QUEUE_OBJ_LENGTH);

        // Receive
        if( (recv_len = recvfrom(socket_fd, dataBuff, UDP_QUEUE_OBJ_LENGTH,MSG_DONTWAIT, NULL, NULL)) > 0 ) {

            if( dataBuff[recv_len-1] == '\n' ) dataBuff[recv_len-1] = '\0';
            sendNexaCodeStr(dataBuff);
            ESP_LOGI("UDP","UDP Task: Data: %s -- %d" , dataBuff, recv_len);
        }
        else if( recv_len == -1 && errno != 11 ) {
            ESP_LOGE("UDP", "Error occurred during recvfrom: errno %d", errno);
        }

        // Transmit
        while( xQueueReceive( udpTxQueue, &dataBuff, 0 ) == pdTRUE ) {

            //ESP_LOGI("UDP","Send data:%s",dataBuff);
            sendto(socket_fd, dataBuff, strlen(dataBuff), 0, (struct sockaddr *)&backEndAddress, sizeof(backEndAddress));
        }

        vTaskDelay(50 / portTICK_RATE_MS);
    }

    vTaskDelete(NULL);
}

// Public interface for sending a UDP Message to the back-end server.
// Argument #1 must be UDP_QUEUE_OBJ_LENGTH chars in length.
void sendUDPMessage(char *p) {

  if( udpTxQueue != NULL ) xQueueSend( udpTxQueue, p, 0 );
}

void udpClientInit()
{
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    udpTxQueue = xQueueCreate( 5, UDP_QUEUE_OBJ_LENGTH );

    xTaskCreate(udp_client_task, "udp_client", 4096, NULL, 5, NULL);
}

#endif