using System;
using System.IO;
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 Newtonsoft.Json;
using System.Net.Http;
using Microsoft.IdentityModel.Clients.ActiveDirectory;

namespace SampleFunctionApp
{
    public static class D365
    {
        [FunctionName("ConnecttoD365")]
        public static async Task<IActionResult> Run(
            [HttpTrigger(AuthorizationLevel.Function, "get", "post", Route = null)] HttpRequest req,
            ILogger log)
        {
            log.LogInformation("C# HTTP trigger function processed a request.");

            string name = req.Query["name"];

            string requestBody = await new StreamReader(req.Body).ReadToEndAsync();
            dynamic data = JsonConvert.DeserializeObject(requestBody);
            name = name ?? data?.name;
            #region Auth Code
            //
            string cloud = "https://login.microsoftonline.com";

            //This is the Domain!

            string tenantId = "**********";

            string authority = $"{cloud}/{tenantId}";

            // ApplicationID in the new UI

            string clientId = "*********";

            //Azure App secret Key

            string clientsecret = "******";

            ClientCredential clientcred = new ClientCredential(clientId, clientsecret);

            // Application ID of the Resource (could also be the Resource URI)

            string resource = "https://******.crm.dynamics.com/";

            AuthenticationContext ac = new AuthenticationContext(authority);
            AuthenticationResult result = null;
            var bearerToken = string.Empty;
            string ErrorMessege = string.Empty;
            try

            {
                //already having token
                result = await ac.AcquireTokenSilentAsync(resource, clientId);
                if (result != null)
                {
                    bearerToken = result.AccessToken;
                    log.LogInformation("Token Acquired:"+ bearerToken);
                }
            }

            catch (AdalException adalException)

            {//Acquire token
                if (adalException.ErrorCode == AdalError.FailedToAcquireTokenSilently

                || adalException.ErrorCode == AdalError.InteractionRequired)

                {

                    result = await ac.AcquireTokenAsync(resource, clientcred);
                    if (result != null)
                    {
                        bearerToken = result.AccessToken;
                        log.LogInformation("Token Acquired="+ bearerToken);

                    }
                }
                else
                {
                    log.LogWarning("Failed to acquire Bearer Token :-" + adalException.Message);
                    var AdalException = new { adalexception = "Failed to acquire Bearer Token :-" + adalException.Message };
                    return new BadRequestObjectResult(JsonConvert.SerializeObject(AdalException));
                    throw adalException;

                }

            }

            #endregion

            string responseMessage = string.IsNullOrEmpty(name)
                ? "This HTTP triggered function executed successfully. Pass a name in the query string or in the request body for a better response."
                : $"Hello, {name}. This HTTP triggered function executed successfully.";

            return new OkObjectResult(responseMessage);
        }
    }
}