#include <stdio.h>
#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_loop.h"
#include "esp_log.h"
#include "nvs_flash.h"

#define STA_SSID				"AndroidAP68BE"
#define STA_PASSWORD			"iqbm8033"
#define AP_SSID      			"Test_Transmitter"
#define AP_PASSWORD      		"1234"
#define AP_MAX_CONN 			4
#define	AP_CHANNEL				0

// Event group
static EventGroupHandle_t event_group;
const int STA_CONNECTED_BIT = BIT0;
const int STA_DISCONNECTED_BIT = BIT1;

// AP event handler
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
    switch(event->event_id) {

    case SYSTEM_EVENT_AP_START:
		printf("Access point started\n");
		break;

	case SYSTEM_EVENT_AP_STACONNECTED:
		xEventGroupSetBits(event_group, STA_CONNECTED_BIT);
		break;

	case SYSTEM_EVENT_AP_STADISCONNECTED:
		xEventGroupSetBits(event_group, STA_DISCONNECTED_BIT);
		break;

	default:
        break;
    }

	return ESP_OK;
}

// print the list of connected stations
void printStationList()
{
	printf(" Connected stations:\n");
	printf("--------------------------------------------------\n");

	wifi_sta_list_t wifi_sta_list;
	tcpip_adapter_sta_list_t adapter_sta_list;

	memset(&wifi_sta_list, 0, sizeof(wifi_sta_list));
	memset(&adapter_sta_list, 0, sizeof(adapter_sta_list));

	ESP_ERROR_CHECK(esp_wifi_ap_get_sta_list(&wifi_sta_list));
	ESP_ERROR_CHECK(tcpip_adapter_get_sta_list(&wifi_sta_list, &adapter_sta_list));

	for(int i = 0; i < adapter_sta_list.num; i++) {

		tcpip_adapter_sta_info_t station = adapter_sta_list.sta[i];
         printf("%d - mac: %.2x:%.2x:%.2x:%.2x:%.2x:%.2x - IP: %s\n", i + 1,
				station.mac[0], station.mac[1], station.mac[2],
				station.mac[3], station.mac[4], station.mac[5],
				ip4addr_ntoa(&(station.ip)));
	}

	printf("\n");
}

// Monitor task, receive Wifi AP events
void monitor_task(void *pvParameter)
{
	while(1) {

		EventBits_t staBits = xEventGroupWaitBits(event_group, STA_CONNECTED_BIT | STA_DISCONNECTED_BIT, pdTRUE, pdFALSE, portMAX_DELAY);
		if((staBits & STA_CONNECTED_BIT) != 0) printf("New station connected\n\n");
		else printf("A station disconnected\n\n");
	}
}

// Station list task, print station list every 10 seconds
void station_list_task(void *pvParameter)
{
	while(1) {

		printStationList();
		vTaskDelay(10000 / portTICK_RATE_MS);
	}
}

// Main application
void app_main()
{

	// disable the default wifi logging
	esp_log_level_set("wifi", ESP_LOG_NONE);

	// create the event group to handle wifi events
	event_group = xEventGroupCreate();

	// initialize NVS
	ESP_ERROR_CHECK(nvs_flash_init());


	// initialize the tcp stack
	tcpip_adapter_init();

	// stop DHCP server
	ESP_ERROR_CHECK(tcpip_adapter_dhcps_stop(TCPIP_ADAPTER_IF_AP));

	// assign a static IP to the network interface
	tcpip_adapter_ip_info_t info;
    memset(&info, 0, sizeof(info));
	IP4_ADDR(&info.ip, 192, 168, 10, 1);
    IP4_ADDR(&info.gw, 192, 168, 10, 1);
    IP4_ADDR(&info.netmask, 255, 255, 255, 0);
	ESP_ERROR_CHECK(tcpip_adapter_set_ip_info(TCPIP_ADAPTER_IF_AP, &info));

	// start the DHCP server
    ESP_ERROR_CHECK(tcpip_adapter_dhcps_start(TCPIP_ADAPTER_IF_AP));

	// initialize the wifi event handler
	ESP_ERROR_CHECK(esp_event_loop_init(event_handler, NULL));

	// initialize the WiFi stack in AccessPoint mode with configuration in RAM
	wifi_init_config_t wifi_init_config = WIFI_INIT_CONFIG_DEFAULT();
	ESP_ERROR_CHECK(esp_wifi_init(&wifi_init_config));
	ESP_ERROR_CHECK(esp_wifi_set_storage(WIFI_STORAGE_RAM));

	ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_APSTA));

	wifi_config_t ap_config;
	wifi_config_t sta_config;

	memset(&ap_config, 0, sizeof(wifi_config_t));
	strncpy((char *)ap_config.ap.ssid,AP_SSID,NULL);
	strncpy((char *)ap_config.ap.password, AP_PASSWORD, NULL);
	ap_config.ap.authmode = WIFI_AUTH_OPEN;
	ap_config.ap.ssid_len = 0;
	ap_config.ap.max_connection = AP_MAX_CONN;
	ap_config.ap.channel = AP_CHANNEL;

	ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_AP, &ap_config));

	memset(&sta_config, 0, sizeof(wifi_config_t));
	strncpy((char *)sta_config.sta.ssid, STA_SSID, NULL);
	strncpy((char *)sta_config.sta.password, STA_PASSWORD, NULL);

	ESP_ERROR_CHECK(esp_wifi_set_config(ESP_IF_WIFI_STA, &sta_config));
	ESP_ERROR_CHECK( esp_wifi_start() );

	printf("Starting access point, SSID=%s\n", "Test_Transmitter");

	// start the main task
    xTaskCreate(&monitor_task, "monitor_task", 2048, NULL, 5, NULL);
	xTaskCreate(&station_list_task, "station_list_task", 2048, NULL, 5, NULL);
}