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

#include "wifi_connection.h"

static const char *TAG = "wifi_connection";

#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT      BIT1

static EventGroupHandle_t s_wifi_event_group;

static uint8_t gRetryCounter = 0;
static uint8_t gRetryMax = 3;

static void event_handler(void* arg, esp_event_base_t event_base, int32_t event_id, void* event_data) {
    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 (gRetryCounter < 3) {
            esp_wifi_connect();
            gRetryCounter++;
            ESP_LOGI(TAG, "retry to connect to the AP");
        } else {
            ESP_LOGI(TAG,"connect to the AP fail");
            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
        }
    } 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));
        gRetryCounter = 0;
        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
    }
}

void wifi_init() {
    s_wifi_event_group = xEventGroupCreate();

    ESP_ERROR_CHECK(esp_netif_init());

    ESP_ERROR_CHECK(esp_event_loop_create_default());
    esp_netif_create_default_wifi_sta();

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

    esp_event_handler_instance_t instance_any_id;
    esp_event_handler_instance_t instance_got_ip;
    ESP_ERROR_CHECK(esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &event_handler, NULL, &instance_any_id));
    ESP_ERROR_CHECK(esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &event_handler, NULL, &instance_got_ip));
    
    ESP_ERROR_CHECK(esp_wifi_stop());
}

bool wifi_connect(const char* aSsid, const char* aPassword, wifi_auth_mode_t aAuthmode, uint8_t aRetryMax) {
    gRetryCounter = 0;
    gRetryMax = aRetryMax;
    wifi_config_t wifi_config = {0};
    strcpy((char*) wifi_config.sta.ssid, aSsid);
    strcpy((char*) wifi_config.sta.password, aPassword);
    wifi_config.sta.threshold.authmode = aAuthmode;

    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(TAG, "Connecting to WiFi...");

    /* Waiting until either the connection is established (WIFI_CONNECTED_BIT) or connection failed for the maximum
     * number of re-tries (WIFI_FAIL_BIT). The bits are set by event_handler() (see above) */
    EventBits_t bits = xEventGroupWaitBits(s_wifi_event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT, pdFALSE, pdFALSE, portMAX_DELAY);
    /* xEventGroupWaitBits() returns the bits before the call returned, hence we can test which event actually happened. */
    if (bits & WIFI_CONNECTED_BIT) {
        ESP_LOGI(TAG, "Connected to WiFi");
        return true;
    } else if (bits & WIFI_FAIL_BIT) {
        ESP_LOGE(TAG, "Failed to connect");
        ESP_ERROR_CHECK(esp_wifi_stop());
    } else {
        ESP_LOGE(TAG, "Unknown event received while waiting on connection");
        ESP_ERROR_CHECK(esp_wifi_stop());
    }
    return false;
}