#include <string.h>
#include <stdint.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 "lwip/err.h"
#include "lwip/sys.h"

#include "nvs_flash.h"
#include "nvs.h"

/* FreeRTOS event group to signal when we are connected*/
static EventGroupHandle_t s_wifi_event_group;

/* 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 const char *TAG = "wifi station";

static int s_retry_num = 0;

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 (s_retry_num < CONFIG_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);
    }
}

void nvs_dumpall() {
    printf("NVS Dump: \n");
    nvs_iterator_t it = nvs_entry_find("nvs", NULL, NVS_TYPE_ANY);
    while (it != NULL) {
        char * value = NULL;
        char namespace[17];
        memset(namespace, 0, 17);
        nvs_entry_info_t info;
        nvs_entry_info(it, &info);
        memcpy(namespace, info.namespace_name, 16);
        printf("%s/%s: type 0x%02x, value = %s\n", namespace, info.key, info.type, value ? value : "<UNKNOWN>");
        it = nvs_entry_next(it);
    };
}

void wifi_init_sta(void)
{
    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));

    wifi_config_t wifi_config = {
        .sta = {
            .ssid = CONFIG_ESP_WIFI_SSID,
            .password = CONFIG_ESP_WIFI_PASSWORD,
	        .threshold.authmode = WIFI_AUTH_WPA2_PSK,

            .pmf_cfg = {
                .capable = true,
                .required = false
            },
        },
    };
    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, "wifi_init_sta finished.");

    /* 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 ap SSID:%s password:%s",
                 CONFIG_ESP_WIFI_SSID, CONFIG_ESP_WIFI_PASSWORD);
    } else if (bits & WIFI_FAIL_BIT) {
        ESP_LOGI(TAG, "Failed to connect to SSID:%s, password:%s",
                 CONFIG_ESP_WIFI_SSID, CONFIG_ESP_WIFI_PASSWORD);
    } else {
        ESP_LOGE(TAG, "UNEXPECTED EVENT");
    }

    nvs_handle_t nvs;
    ESP_ERROR_CHECK(nvs_open("mqtt", NVS_READWRITE, &nvs));
    nvs_set_str(nvs, "url", CONFIG_MQTT_URI);
    nvs_set_str(nvs, "username", CONFIG_MQTT_USERNAME);
    nvs_set_str(nvs, "password", CONFIG_MQTT_PASSWORD);
    nvs_close(nvs);

    ESP_ERROR_CHECK(nvs_open("ota", NVS_READWRITE, &nvs));
    nvs_set_str(nvs, "update_url", CONFIG_FIRMWARE_URL_PATTERN);
    nvs_close(nvs);

    ESP_ERROR_CHECK(nvs_open("solar", NVS_READWRITE, &nvs));
    nvs_set_str(nvs, "panel_sensor", CONFIG_PANEL_SENSOR_ADDR);
    nvs_set_str(nvs, "store_h_sensor", CONFIG_STORE_HIGHER_SENSOR_ADDR);
    nvs_set_str(nvs, "store_l_sensor", CONFIG_STORE_LOWER_SENSOR_ADDR);
    nvs_set_str(nvs, "fl_ht_sensor", CONFIG_FLOOR_HEATING_SENSOR_ADDR);
    nvs_close(nvs);

    nvs_dumpall();

    /* The event will not be processed after unregister */
    ESP_ERROR_CHECK(esp_event_handler_instance_unregister(IP_EVENT, IP_EVENT_STA_GOT_IP, instance_got_ip));
    ESP_ERROR_CHECK(esp_event_handler_instance_unregister(WIFI_EVENT, ESP_EVENT_ANY_ID, instance_any_id));
    vEventGroupDelete(s_wifi_event_group);
}

void app_main(void)
{
    //Initialize NVS
    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);

    ESP_LOGI(TAG, "ESP_WIFI_MODE_STA");
    wifi_init_sta();
}