/*
 * SPDX-FileCopyrightText: 2021 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: CC0
 *
 * OpenThread Command Line Example
 *
 * This example code is in the Public Domain (or CC0 licensed, at your option.)
 *
 * Unless required by applicable law or agreed to in writing, this
 * software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
 * CONDITIONS OF ANY KIND, either express or implied.
*/

#include "esp_check.h"
#include "esp_err.h"
#include "esp_log.h"
#include "esp_ot_udp_socket.h"
#include "lwip/err.h"
#include "lwip/sockets.h"

#define TAG "ot_socket"

static void udp_socket_server_task(void *pvParameters)
{
    char addr_str[128];
    char *payload = "This message is from server\n";
    char rx_buffer[128];
    esp_err_t ret = ESP_OK;
    int err = 0;
    int len;
    int listen_sock;

    int port = CONFIG_OPENTHREAD_CLI_UDP_SERVER_PORT;
    struct timeval timeout = { 0 };
    struct sockaddr_storage source_addr; // Large enough for both IPv4 or IPv6
    struct sockaddr_in6 listen_addr;

    inet6_aton("::", &listen_addr.sin6_addr);
    listen_addr.sin6_family = AF_INET6;
    listen_addr.sin6_port = htons(port);

    listen_sock = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    ESP_GOTO_ON_FALSE((listen_sock >= 0), ESP_OK, exit, TAG, "Unable to create socket: errno %d", errno);
    ESP_LOGI(TAG, "Socket created");

    // Note that by default IPV6 binds to both protocols, it is must be disabled
    // if both protocols used at the same time (used in CI)
    int opt = 1;
    setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
    setsockopt(listen_sock, IPPROTO_IPV6, IPV6_V6ONLY, &opt, sizeof(opt));

    err = bind(listen_sock, (struct sockaddr *)&listen_addr, sizeof(listen_addr));
    ESP_GOTO_ON_FALSE((err == 0), ESP_FAIL, exit, TAG, "Socket unable to bind: errno %d", errno);
    ESP_LOGI(TAG, "Socket bound, port %d", port);

    timeout.tv_sec = 30;
    setsockopt(listen_sock, SOL_SOCKET, SO_RCVTIMEO, &timeout, sizeof(timeout));

    ESP_LOGI(TAG, "Waiting for data, timeout is 30 seconds");
    socklen_t socklen = sizeof(source_addr);
    len = recvfrom(listen_sock, rx_buffer, sizeof(rx_buffer) - 1, 0, (struct sockaddr *)&source_addr, &socklen);

    // Error occurred during receiving
    ESP_GOTO_ON_FALSE((len >= 0), ESP_FAIL, exit, TAG, "recvfrom failed: errno %d", errno);
    // Data received
    // Get the sender's ip address as string
    inet6_ntoa_r(((struct sockaddr_in6 *)&source_addr)->sin6_addr, addr_str, sizeof(addr_str) - 1);

    rx_buffer[len] = 0; // Null-terminate whatever we received and treat like a string...
    ESP_LOGI(TAG, "Received %d bytes from %s:", len, addr_str);
    ESP_LOGI(TAG, "%s", rx_buffer);

    err = sendto(listen_sock, payload, strlen(payload), 0, (struct sockaddr *)&source_addr, sizeof(source_addr));
    ESP_GOTO_ON_FALSE((err >= 0), ESP_FAIL, exit, TAG, "Error occurred during sending: errno %d", errno);
exit:
    if (ret != ESP_OK || listen_sock != -1) {
        shutdown(listen_sock, 0);
        close(listen_sock);
    }
    ESP_LOGI(TAG, "Socket server is closed.");
    vTaskDelete(NULL);
}

static void udp_socket_client_task(void *pvParameters)
{
    char rx_buffer[128];
    char *host_ip = (char *)pvParameters;
    char *payload = "This message is from client\n";
    int client_sock;
    int port = CONFIG_OPENTHREAD_CLI_UDP_SERVER_PORT;
    int err = 0;
    int len;
    esp_err_t ret = ESP_OK;
    struct sockaddr_storage source_addr; // Large enough for both IPv4 or IPv6
    struct sockaddr_in6 dest_addr = { 0 };

    inet6_aton(host_ip, &dest_addr.sin6_addr);
    dest_addr.sin6_family = AF_INET6;
    dest_addr.sin6_port = htons(port);

    client_sock = socket(AF_INET6, SOCK_DGRAM, IPPROTO_UDP);
    ESP_GOTO_ON_FALSE((client_sock >= 0), ESP_OK, exit, TAG, "Unable to create socket: errno %d", errno);
    ESP_LOGI(TAG, "Socket created, sending to %s:%d", host_ip, port);

    err = sendto(client_sock, payload, strlen(payload), 0, (struct sockaddr *)&dest_addr, sizeof(dest_addr));
    ESP_GOTO_ON_FALSE((err >= 0), ESP_FAIL, exit, TAG, "Error occurred during sending: errno %d", errno);
    ESP_LOGI(TAG, "Message sent");

    socklen_t socklen = sizeof(source_addr);
    len = recvfrom(client_sock, rx_buffer, sizeof(rx_buffer) - 1, 0, (struct sockaddr *)&source_addr, &socklen);

    // Error occurred during receiving
    ESP_GOTO_ON_FALSE((len >= 0), ESP_FAIL, exit, TAG, "recvfrom failed: errno %d", errno);
    // Data received
    rx_buffer[len] = 0; // Null-terminate whatever we received and treat like a string
    ESP_LOGI(TAG, "Received %d bytes from %s:", len, host_ip);
    ESP_LOGI(TAG, "%s", rx_buffer);
exit:
    if (ret != ESP_OK || client_sock != -1) {
        shutdown(client_sock, 0);
        close(client_sock);
    }
    ESP_LOGI(TAG, "Socket client is closed");
    vTaskDelete(NULL);
}

void esp_ot_process_udp_server(void *aContext, uint8_t aArgsLength, char *aArgs[])
{
    (void)(aContext);
    (void)(aArgsLength);
    xTaskCreate(udp_socket_server_task, "ot_udp_scoket_server", 4096, xTaskGetCurrentTaskHandle(), 4, NULL);
}

void esp_ot_process_udp_client(void *aContext, uint8_t aArgsLength, char *aArgs[])
{
    (void)(aContext);
    (void)(aArgsLength);
    if (aArgsLength == 0) {
        ESP_LOGE(TAG, "Invalid arguments.");
    } else {
        xTaskCreate(udp_socket_client_task, "ot_udp_socket_client", 4096, aArgs[0], 4, NULL);
    }
}