/*
 * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <string.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 "sdkconfig.h"

#include "lwip/err.h"
#include "lwip/sys.h"

#if (ESP_IDF_VERSION_MAJOR >= 5)
#include "esp_mac.h"
#include "lwip/ip_addr.h"
#endif

/* The examples use WiFi configuration that you can set via 'make menuconfig'.

   If you'd rather not, just change the below entries to strings with
   the config you want - ie #define EXAMPLE_WIFI_SSID "mywifissid"
*/
#define EXAMPLE_ESP_WIFI_SSID      CONFIG_ESP_WIFI_SSID
#define EXAMPLE_ESP_WIFI_PASS      CONFIG_ESP_WIFI_PASSWORD
#define EXAMPLE_ESP_MAXIMUM_RETRY  CONFIG_ESP_MAXIMUM_RETRY
#define EXAMPLE_ESP_WIFI_AP_SSID   CONFIG_ESP_WIFI_AP_SSID
#define EXAMPLE_ESP_WIFI_AP_PASS   CONFIG_ESP_WIFI_AP_PASSWORD
#define EXAMPLE_MAX_STA_CONN       CONFIG_MAX_STA_CONN
#define EXAMPLE_IP_ADDR            CONFIG_SERVER_IP
#define EXAMPLE_ESP_WIFI_AP_CHANNEL CONFIG_ESP_WIFI_AP_CHANNEL

static const char *TAG = "camera wifi";

static int s_retry_num = 0;
/* FreeRTOS event group to signal when we are connected*/
static EventGroupHandle_t s_wifi_event_group = NULL;

/* The event group allows multiple bits for each event, but we only care about two events:
 * - we are connected to the AP with an IP
 * - we failed to connect after the maximum amount of retries */
#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT      BIT1

static void wifi_event_handler(void* arg, esp_event_base_t event_base,
                               int32_t event_id, void* event_data)
{
    /* AP mode */
    if (event_id == WIFI_EVENT_AP_STACONNECTED) {
        wifi_event_ap_staconnected_t* event = (wifi_event_ap_staconnected_t*) event_data;
        ESP_LOGI(TAG, "station "MACSTR" join, AID=%d",
                 MAC2STR(event->mac), event->aid);
    } else if (event_id == WIFI_EVENT_AP_STADISCONNECTED) {
        wifi_event_ap_stadisconnected_t* event = (wifi_event_ap_stadisconnected_t*) event_data;
        ESP_LOGI(TAG, "station "MACSTR" leave, AID=%d",
                 MAC2STR(event->mac), event->aid);
    }
    /* Sta mode */
    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
        esp_wifi_connect();
    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
        if (s_retry_num < EXAMPLE_ESP_MAXIMUM_RETRY) {
            esp_wifi_connect();
            s_retry_num++;
            ESP_LOGI(TAG, "retry to connect to the AP");
        } else {
            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
        }
        ESP_LOGI(TAG, "connect to the AP fail");
    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        ip_event_got_ip_t* event = (ip_event_got_ip_t*) event_data;
        ESP_LOGI(TAG, "got ip:" IPSTR, IP2STR(&event->ip_info.ip));
        s_retry_num = 0;
        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
    }

    return;
}

static void wifi_init_softap(esp_netif_t * netif)
{
    if (strcmp(EXAMPLE_IP_ADDR, "192.168.4.1")) {
        int a, b, c, d;
        sscanf(EXAMPLE_IP_ADDR, "%d.%d.%d.%d", &a, &b, &c, &d);
        esp_netif_ip_info_t ip_info;
        IP4_ADDR(&ip_info.ip, a, b, c, d);
        IP4_ADDR(&ip_info.gw, a, b, c, d);
        IP4_ADDR(&ip_info.netmask, 255, 255, 255, 0);
        ESP_ERROR_CHECK(esp_netif_dhcps_stop(netif));
        ESP_ERROR_CHECK(esp_netif_set_ip_info(netif, &ip_info));
        ESP_ERROR_CHECK(esp_netif_dhcps_start(netif));
    }
    wifi_config_t wifi_config;
    memset(&wifi_config, 0, sizeof(wifi_config_t));
    snprintf((char *)wifi_config.ap.ssid, 32, "%s", EXAMPLE_ESP_WIFI_AP_SSID);
    wifi_config.ap.ssid_len = strlen((char *)wifi_config.ap.ssid);
    snprintf((char *)wifi_config.ap.password, 64, "%s", EXAMPLE_ESP_WIFI_AP_PASS);
    wifi_config.ap.max_connection = EXAMPLE_MAX_STA_CONN;
    wifi_config.ap.authmode = WIFI_AUTH_WPA_WPA2_PSK;
    if (strlen(EXAMPLE_ESP_WIFI_AP_PASS) == 0) {
        wifi_config.ap.authmode = WIFI_AUTH_OPEN;
    }
    if (strlen(EXAMPLE_ESP_WIFI_AP_CHANNEL)) {
        int channel;
        sscanf(EXAMPLE_ESP_WIFI_AP_CHANNEL, "%d", &channel);
        wifi_config.ap.channel = channel;
    }

    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &wifi_config));

    ESP_LOGI(TAG, "wifi_init_softap finished.SSID:%s password:%s",
             EXAMPLE_ESP_WIFI_AP_SSID, EXAMPLE_ESP_WIFI_AP_PASS);
}

static void wifi_init_sta()
{
    wifi_config_t wifi_config;
    memset(&wifi_config, 0, sizeof(wifi_config_t));
    snprintf((char *)wifi_config.sta.ssid, 32, "%s", EXAMPLE_ESP_WIFI_SSID);
    snprintf((char *)wifi_config.sta.password, 64, "%s", EXAMPLE_ESP_WIFI_PASS);

    ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config));

    ESP_LOGI(TAG, "wifi_init_sta finished.");
    ESP_LOGI(TAG, "connect to ap SSID:%s password:%s",
             EXAMPLE_ESP_WIFI_SSID, EXAMPLE_ESP_WIFI_PASS);
}

void app_wifi_main()
{
    esp_err_t ret = nvs_flash_init();
    if (ret == ESP_ERR_NVS_NO_FREE_PAGES || ret == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        ret = nvs_flash_init();
    }
    ESP_ERROR_CHECK(ret);

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    wifi_mode_t mode = WIFI_MODE_NULL;

    if (strlen(EXAMPLE_ESP_WIFI_AP_SSID) && strlen(EXAMPLE_ESP_WIFI_SSID)) {
        mode = WIFI_MODE_APSTA;
    } else if (strlen(EXAMPLE_ESP_WIFI_AP_SSID)) {
        mode = WIFI_MODE_AP;
    } else if (strlen(EXAMPLE_ESP_WIFI_SSID)) {
        mode = WIFI_MODE_STA;
    }

    if (mode == WIFI_MODE_NULL) {
        ESP_LOGW(TAG, "Neither AP or STA have been configured. WiFi will be off.");
        return;
    }

    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
    s_wifi_event_group = xEventGroupCreate();

    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT,
                                                        ESP_EVENT_ANY_ID,
                                                        &wifi_event_handler,
                                                        NULL,
                                                        NULL));
    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT,
                                                        IP_EVENT_STA_GOT_IP,
                                                        &wifi_event_handler,
                                                        NULL,
                                                        NULL));

    ESP_ERROR_CHECK(esp_wifi_set_mode(mode));

    if (mode & WIFI_MODE_AP) {
        esp_netif_t * ap_netif = esp_netif_create_default_wifi_ap();
        wifi_init_softap(ap_netif);
    }

    if (mode & WIFI_MODE_STA) {
        esp_netif_create_default_wifi_sta();
        wifi_init_sta();
    }
    ESP_ERROR_CHECK(esp_wifi_start());
    ESP_ERROR_CHECK(esp_wifi_set_ps(WIFI_PS_NONE));
    ESP_LOGI(TAG, "wifi init finished.");

    if (mode & WIFI_MODE_STA) {
        xEventGroupWaitBits(s_wifi_event_group,
                            WIFI_CONNECTED_BIT | WIFI_FAIL_BIT,
                            pdFALSE,
                            pdFALSE,
                            portMAX_DELAY);
    }
    vEventGroupDelete(s_wifi_event_group);
    s_wifi_event_group = NULL;
}