#include "wifi.h"

#include <string.h>

#include "esp_event.h"
#include "esp_log.h"
#include "esp_netif.h"
#include "esp_wifi.h"
#include "freertos/FreeRTOS.h"
#include "freertos/event_groups.h"
#include "nvs_flash.h"

static const char *TAG = "wifi";

#define WIFI_CONNECTED_BIT BIT0
#define WIFI_FAIL_BIT BIT1
#define WIFI_MAXIMUM_RETRY 8

static EventGroupHandle_t s_wifi_event_group;
static int s_retry_num;

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

    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
        if (strlen(CONFIG_SCARA_WIFI_SSID) > 0) {
            esp_wifi_connect();
        }
    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
        if (s_retry_num < WIFI_MAXIMUM_RETRY) {
            esp_wifi_connect();
            ++s_retry_num;
            ESP_LOGI(TAG, "retrying Wi-Fi connection (%d/%d)", s_retry_num, WIFI_MAXIMUM_RETRY);
        } else {
            xEventGroupSetBits(s_wifi_event_group, WIFI_FAIL_BIT);
        }
    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        const ip_event_got_ip_t *event = (const ip_event_got_ip_t *)event_data;
        ESP_LOGI(TAG, "STA IP: " IPSTR, IP2STR(&event->ip_info.ip));
        s_retry_num = 0;
        xEventGroupSetBits(s_wifi_event_group, WIFI_CONNECTED_BIT);
    }
}

static esp_err_t init_nvs(void)
{
    esp_err_t err = nvs_flash_init();
    if (err == ESP_ERR_NVS_NO_FREE_PAGES || err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        ESP_ERROR_CHECK(nvs_flash_erase());
        err = nvs_flash_init();
    }
    return err;
}

esp_err_t wifi_init_sta(void)
{
    ESP_ERROR_CHECK(init_nvs());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    s_wifi_event_group = xEventGroupCreate();
    if (s_wifi_event_group == NULL) {
        return ESP_ERR_NO_MEM;
    }

    esp_netif_create_default_wifi_sta();
    esp_netif_create_default_wifi_ap();

    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
    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));

    wifi_config_t sta_config = {0};
    strncpy((char *)sta_config.sta.ssid, CONFIG_SCARA_WIFI_SSID, sizeof(sta_config.sta.ssid));
    strncpy((char *)sta_config.sta.password, CONFIG_SCARA_WIFI_PASSWORD, sizeof(sta_config.sta.password));
    sta_config.sta.threshold.authmode = strlen(CONFIG_SCARA_WIFI_PASSWORD) > 0 ? WIFI_AUTH_WPA2_PSK : WIFI_AUTH_OPEN;

    wifi_config_t ap_config = {0};
    strncpy((char *)ap_config.ap.ssid, CONFIG_SCARA_SOFTAP_SSID, sizeof(ap_config.ap.ssid));
    strncpy((char *)ap_config.ap.password, CONFIG_SCARA_SOFTAP_PASSWORD, sizeof(ap_config.ap.password));
    ap_config.ap.ssid_len = strlen(CONFIG_SCARA_SOFTAP_SSID);
    ap_config.ap.channel = 1;
    ap_config.ap.max_connection = 2;
    ap_config.ap.authmode =
        strlen(CONFIG_SCARA_SOFTAP_PASSWORD) >= 8 ? WIFI_AUTH_WPA_WPA2_PSK : WIFI_AUTH_OPEN;

    wifi_mode_t mode = strlen(CONFIG_SCARA_WIFI_SSID) > 0 ? WIFI_MODE_APSTA : WIFI_MODE_AP;
    ESP_ERROR_CHECK(esp_wifi_set_mode(mode));
    if (mode == WIFI_MODE_APSTA) {
        ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &sta_config));
    }
    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_AP, &ap_config));
    ESP_ERROR_CHECK(esp_wifi_start());

    ESP_LOGI(TAG, "SoftAP active: ssid=%s url=http://192.168.4.1/", CONFIG_SCARA_SOFTAP_SSID);

    if (mode == WIFI_MODE_APSTA) {
        EventBits_t bits = xEventGroupWaitBits(
            s_wifi_event_group, WIFI_CONNECTED_BIT | WIFI_FAIL_BIT, pdFALSE, pdFALSE, pdMS_TO_TICKS(15000));
        if (bits & WIFI_CONNECTED_BIT) {
            ESP_LOGI(TAG, "connected to STA ssid=%s", CONFIG_SCARA_WIFI_SSID);
        } else {
            ESP_LOGW(TAG, "STA connection failed; keep using SoftAP url=http://192.168.4.1/");
        }
    }

    return ESP_OK;
}