#include <stdio.h>
#include "freertos/FreeRTOS.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 "mqtt_client.h"
#include "driver/uart.h"

#define URL "mqtt://mqtt.eclipseprojects.io"
#define WIFI_SSID "Wokwi-GUEST"
#define WIFI_PASS ""
esp_mqtt_client_handle_t client;
#define UART_PORT UART_NUM_0
#define BUF_SIZE 128

void uart_init() {
    uart_config_t uart_config = {
        .baud_rate = 115200,
        .data_bits = UART_DATA_8_BITS,
        .parity = UART_PARITY_DISABLE,
        .stop_bits = UART_STOP_BITS_1,
        .flow_ctrl = UART_HW_FLOWCTRL_DISABLE
    };
    uart_param_config(UART_PORT, &uart_config);
    uart_set_pin(UART_PORT, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE);
    uart_driver_install(UART_PORT, BUF_SIZE * 2, 0, 0, NULL, 0);
}

static EventGroupHandle_t wifi_event_group;
const int WIFI_CONNECTED_BIT = BIT0;
static const char *TAG = "wifi station";

static void wifi_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) {
        esp_wifi_connect();
        xEventGroupClearBits(wifi_event_group, WIFI_CONNECTED_BIT);
    } else if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        xEventGroupSetBits(wifi_event_group, WIFI_CONNECTED_BIT);
    }
}

void wifi_init_sta(void)
{
    wifi_event_group = xEventGroupCreate();

    tcpip_adapter_init();

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

    esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
                                                &wifi_event_handler, NULL);
    esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP,
                                                &wifi_event_handler, NULL);

    wifi_config_t wifi_config = {
        .sta = {
            .ssid = WIFI_SSID,
            .password = WIFI_PASS,
        },
    };
    esp_wifi_set_mode(WIFI_MODE_STA);
    esp_wifi_set_config(ESP_IF_WIFI_STA, &wifi_config);
    esp_wifi_start();

    ets_printf( "wifi_init_sta finished.\n");
    wifi_config_t current_config;

    EventBits_t bits = xEventGroupWaitBits(wifi_event_group, WIFI_CONNECTED_BIT, pdFALSE, pdTRUE, portMAX_DELAY);
    if (bits & WIFI_CONNECTED_BIT) {
       
        esp_wifi_get_config(ESP_IF_WIFI_STA, &current_config);
         ets_printf( "Wi-Fi connected\n");
        ets_printf("Connected to SSID: %s, Password: %s", current_config.sta.ssid, current_config.sta.password);
    } else {
        ets_printf("Failed to connect to Wi-Fi");
    }
}

//////////////////////////////////////////////////////////////////////////////////
static void mqtt_event_handler(void *handler_args,esp_event_base_t base, int32_t event_id, void *event_data)
{
  esp_mqtt_event_handle_t event = event_data;
  client = event->client;
  int msg_id;
    switch ((esp_mqtt_event_id_t)event_id) {
    case MQTT_EVENT_CONNECTED:
         printf ("MQTT_EVENT_CONNECTED");
        msg_id = esp_mqtt_client_publish(client, "/topicc/qos2", "Wokwi Data", 0, 2, 0);
        printf ("sent publish successful, msg_id=%d", msg_id);

        msg_id = esp_mqtt_client_subscribe(client, "/srktopic/", 2);
        printf("sent subscribe successful, msg_id=%d", msg_id);

        msg_id = esp_mqtt_client_subscribe(client, "/srktopic/", 2);
        printf("sent subscribe successful, msg_id=%d", msg_id);

        break;
    case MQTT_EVENT_DISCONNECTED:
        printf("MQTT_EVENT_DISCONNECTED");
        break;

    case MQTT_EVENT_SUBSCRIBED:
        printf("MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
        msg_id = esp_mqtt_client_publish(client, "/topicc/qos2", "Wokwi Data", 0, 2, 0);
        printf("sent publish successful, msg_id=%d", msg_id);
        break;
    case MQTT_EVENT_UNSUBSCRIBED:
        printf("MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_PUBLISHED:
        printf("MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_DATA:
        printf("MQTT_EVENT_DATA");
        printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
        printf("DATA=%.*s\r\n", event->data_len, event->data);
        break;
     default:
        printf("Other event id:%d", event->event_id);
        break;    
    }

}
static void mqtt_app_start(void)
{
    esp_mqtt_client_config_t mqtt_cfg = {
       .uri = URL,
    };
    esp_mqtt_client_handle_t client = esp_mqtt_client_init(&mqtt_cfg);
    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);
   /*int msg_id;
    msg_id = esp_mqtt_client_enqueue(client, "/topic/qos1", "data_3", 0, 1, 0, true);
    ESP_LOGI(TAG, "Enqueued msg_id=%d", msg_id);
    msg_id = esp_mqtt_client_enqueue(client, "/topic/qos2", "QoS2 message", 0, 2, 0, true);
    ESP_LOGI(TAG, "Enqueued msg_id=%d", msg_id);*/
    esp_mqtt_client_start(client);

}
//////////////////////////////////////////////
void uart_task(void *pvParameters) {
    char data[BUF_SIZE]; // Changed from uint8_t to char
    char buffer[BUF_SIZE];
    int index = 0;
    int bufferIndex = 0;
    
    while (1) {
        int len = uart_read_bytes(UART_PORT, data + index, 1, 20 / portTICK_PERIOD_MS);
        if (len > 0){
          for (int i = 0; i < len; i++) {
        buffer[bufferIndex++] = data[i];
        // Check for newline character
        if (data[i] == '\n') {
            // Null-terminate the string and print
            buffer[bufferIndex] = '\0';
            printf("received %s\n", buffer);
             int msg_id = esp_mqtt_client_publish(client, "/topicc/qos2", buffer, 0, 2, 0);
            // Reset buffer index for next message
            bufferIndex = 0;
        }
        }
        }
  }
}



void app_main()
{
    uart_init();
    // 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();
    }
    ret;

    ets_printf("ESP_WIFI_MODE_STA\n");

    wifi_init_sta();
    vTaskDelay(3000 / portTICK_PERIOD_MS);
    mqtt_app_start();
    xTaskCreate(uart_task, "uart_task", 2048, NULL, 10, NULL);
}