DoorActionFunction.cs

using System;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.AspNetCore.Http;
using Microsoft.Extensions.Logging;
using System.Net.Http;
using System.Text;
using Azure.Identity;

namespace IoTCentralTriggerFunctions
{
    public static class DoorActionFunction
    {
        [FunctionName("DoorActionFunction")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            //Check if GET is used
            if (req.Method != HttpMethod.Get.ToString())
            {
                //Send an Error if wrong HTTP method is used
                return new BadRequestObjectResult("Bad Request");
            }

            //Define the variable which will be used to store the query parameter of the door being addressed
            string door;
            // parse query parameter
            try
            {
                door = req.GetQueryParameterDictionary()["door"];
            }
            catch (Exception)
            {
                return new BadRequestObjectResult("Bad Request");
            }

            log.LogInformation("Received request to control door " + door);

            //Get a AzureAD Token from Azure Default Credentials to be used for IoT Central API Call
            var credential = new DefaultAzureCredential();
            var token = credential.GetToken(new Azure.Core.TokenRequestContext(new[] { "https://apps.azureiotcentral.com/.default" }));


            //Check for notification settings 
            string announcementTriggerUrl = Environment.GetEnvironmentVariable("Announcement_TriggerUrl");
            string announcementToken = Environment.GetEnvironmentVariable("Announcement_Token");
            string announcementFlowId = Environment.GetEnvironmentVariable("Announcement_FlowId");


            if (!string.IsNullOrEmpty(announcementTriggerUrl) 
                && !string.IsNullOrEmpty(announcementToken)
                && !string.IsNullOrEmpty(announcementFlowId))
            {
                log.LogInformation("Announcement API settings found. Triggering announcement");

                //Trigger announcement of Door Action via Voice Monkey
                using (var httpClient = new HttpClient())
                {
                    var response = await httpClient.GetAsync($"{announcementTriggerUrl}?token={announcementToken}&flow={announcementFlowId}");
                    if (response.IsSuccessStatusCode)
                    {
                        var responseBody = await response.Content.ReadAsStringAsync();
                        log.LogInformation("Announcement request successful. Response: " + responseBody);
                    }
                    else
                    {
                        log.LogWarning("Annoucement request failed. Status code: " + response.StatusCode);
                    }
                }
            }

            //Send IoT Central API Call to open/close door
            using (var client = new HttpClient())
            {
                string IoTAppName = Environment.GetEnvironmentVariable("IoTAppName");
                string IoTDeviceName = Environment.GetEnvironmentVariable("IoTDeviceName");
                string IoTComponentName = Environment.GetEnvironmentVariable("IoTComponentName");
                string CommandName = Environment.GetEnvironmentVariable("CommandName");

                //Build the API Call Url
                var request = new HttpRequestMessage()
                {
                    RequestUri = new Uri($"https://{IoTAppName}.azureiotcentral.com/api/devices/{IoTDeviceName}/commands/{CommandName}?api-version=2022-07-31"),
                    Method = HttpMethod.Post,
                };
                request.Headers.Authorization = new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", token.Token);
                request.Content = new StringContent("{\"request\": " + door + "}", Encoding.UTF8, "application/json");
                //Send the request
                var response = await client.SendAsync(request);
            }
            string responseMessage = "I sent the command to door: " + door;
            return new OkObjectResult(responseMessage);
        }
    }
}