#include <stdio.h>
#include <string.h>
#include "esp_wifi.h"
#include "esp_event.h"
#include "esp_log.h"
#include "nvs_flash.h"
#include "esp_http_client.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"

#define WIFI_SSID "UCLA_WEB"  // Your Wi-Fi network
#define WIFI_PASSWORD ""      // No password for UCLA_WEB (if required, add it here)

#define DEVICE_CONNECTION_STRING "HostName=ESP32-IoTHub.azure-devices.net;DeviceId=Simulated-ESP32;SharedAccessKey=hGbt7EnzeJDtfCirbRuNVLr/6AMSXyLgVqTo4DNlTuI="
#define UPDATE_INTERVAL 60000  // Update every 60 seconds

static const char *TAG = "ESP32_IoT_Hub";

void send_data_to_azure(void *pvParameter) {
    char post_data[256];
    char url[] = "https://ESP32-IoTHub.azure-devices.net/devices/Simulated-ESP32/messages/events?api-version=2020-09-30";
    
    esp_http_client_config_t config = {
        .url = url,
        .method = HTTP_METHOD_POST,
        .transport_type = HTTP_TRANSPORT_OVER_SSL,  // Ensures the data is sent securely over HTTPS
    };

    while (1) {
        // Random simulated data 
        float temperature = 25.0 + (rand() % 10);  // Simulated temperature
        float humidity = 50.0 + (rand() % 20);  // Simulated humidity
        
        // Format the data as JSON string
        snprintf(post_data, sizeof(post_data), "{\"temperature\": %.2f, \"humidity\": %.2f}", temperature, humidity);

        esp_http_client_handle_t client = esp_http_client_init(&config);
        esp_http_client_set_header(client, "Content-Type", "application/json");
        esp_http_client_set_header(client, "Authorization", "SharedAccessSignature sr=ESP32-IoTHub.azure-devices.net%2Fdevices%2FSimulated-ESP32&sig=DoH%2FR8ZjZeRnZF68b91IYP6xXTX9u89C9u1r8GA0keY%3D&se=1742276297");


        // Send the POST request with the data to IoT Hub
        esp_http_client_set_post_field(client, post_data, strlen(post_data));
        
        esp_err_t err = esp_http_client_perform(client);
        
        if (err == ESP_OK) {
            ESP_LOGI(TAG, "Message sent successfully: %s", post_data);
        } else {
            ESP_LOGE(TAG, "HTTP request failed: %s", esp_err_to_name(err));
        }

        esp_http_client_cleanup(client);
        
        // Wait for the specified interval before sending next data
        vTaskDelay(UPDATE_INTERVAL / portTICK_PERIOD_MS);
    }
}

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 == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
        ESP_LOGI(TAG, "Connected to Wi-Fi!");
        xTaskCreate(&send_data_to_azure, "send_data_to_azure", 4096, NULL, 5, NULL);
    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
        ESP_LOGI(TAG, "Disconnected! Reconnecting...");
        esp_wifi_connect();
    }
}

void wifi_init() {
    esp_netif_init();
    esp_event_loop_create_default();
    esp_netif_create_default_wifi_sta();

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

    esp_event_handler_instance_t instance_any_id;
    esp_event_handler_instance_t instance_got_ip;
    esp_event_handler_instance_register(WIFI_EVENT, ESP_EVENT_ANY_ID, &wifi_event_handler, NULL, &instance_any_id);
    esp_event_handler_instance_register(IP_EVENT, IP_EVENT_STA_GOT_IP, &wifi_event_handler, NULL, &instance_got_ip);

    wifi_config_t wifi_config = {
        .sta = {
            .ssid = WIFI_SSID,
            .password = WIFI_PASSWORD,  // Use your Wi-Fi password if required
        },
    };

    esp_wifi_set_mode(WIFI_MODE_STA);
    esp_wifi_set_config(WIFI_IF_STA, &wifi_config);
    esp_wifi_start();
}

void app_main() {
    ESP_ERROR_CHECK(nvs_flash_init());
    wifi_init();
}