/* ESP drivers */
#include "esp_event.h"
#include "esp_log.h"
#include "esp_system.h"
#include "esp_wifi.h"

/* FreeRTOS */
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "freertos/task.h"

/* App specific */
#include "app_wifi.h"

#define APP_LOG_TAG "APP_WIFI"

EventGroupHandle_t g_app_wifi_event_group;

static uint8_t s_retries = 0U;

static void app_wifi_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data);

esp_err_t app_wifi_init(void) {
    g_app_wifi_event_group = xEventGroupCreate();
    if (g_app_wifi_event_group == NULL) {
        return ESP_FAIL;
    }

    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());
    esp_netif_create_default_wifi_sta();

    wifi_init_config_t wifi_init_cfg = WIFI_INIT_CONFIG_DEFAULT();
    ESP_ERROR_CHECK(esp_wifi_init(&wifi_init_cfg));

    esp_event_handler_instance_t inst_any_id;
    esp_event_handler_instance_t inst_got_ip;

    ESP_ERROR_CHECK(
        esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, app_wifi_event_handler, NULL, &inst_any_id));

    ESP_ERROR_CHECK(
        esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, app_wifi_event_handler, NULL, &inst_got_ip));

    wifi_config_t wifi_config = {
        .sta =
            {
                .ssid               = CONFIG_APP_WIFI_SSID,
                .password           = CONFIG_APP_WIFI_PASSWORD,
                .threshold.authmode = WIFI_AUTH_WPA2_PSK,
            },
    };

    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
    ESP_ERROR_CHECK(esp_wifi_start());

    ESP_LOGI(APP_LOG_TAG, "WiFi initialized, heap free: %d.", esp_get_free_heap_size());

    return ESP_OK;
}

static void app_wifi_event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data) {
    /* Event handler */

    if (event_base == WIFI_EVENT) {
        if (event_id == WIFI_EVENT_STA_START) {
            esp_wifi_connect();
        }

        if (event_id == WIFI_EVENT_STA_DISCONNECTED) {
            if (s_retries < CONFIG_APP_MAXIMUM_RETRY) {
                esp_wifi_connect();
                s_retries++;

                ESP_LOGI(APP_LOG_TAG, "Connection lost, retrying #%d/%d...", s_retries, CONFIG_APP_MAXIMUM_RETRY);
            } else {
                xEventGroupSetBits(g_app_wifi_event_group, APP_WIFI_EVENT_GROUP_EVENT_FAILED);

                ESP_LOGW(APP_LOG_TAG, "Connection lost, maximum retries reached.");
            }
        }
    } else if(event_base == IP_EVENT) {
        if(event_id == IP_EVENT_STA_GOT_IP) {
            xEventGroupSetBits(g_app_wifi_event_group, APP_WIFI_EVENT_GROUP_EVENT_CONNECTED);
            s_retries = 0U;

            ip_event_got_ip_t *event = event_data;

            ESP_LOGI(APP_LOG_TAG, "Connected, IP address: "IPSTR, IP2STR(&event->ip_info.ip));
        }
    }
}