SimpleGraphClient.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Threading.Tasks;
using Microsoft.Graph;

namespace Microsoft.BotBuilderSamples
{
    // This class is a wrapper for the Microsoft Graph API
    // See: https://developer.microsoft.com/en-us/graph
    public class SimpleGraphClient
    {
        private readonly string _token;

        public SimpleGraphClient(string token)
        {
            if (string.IsNullOrWhiteSpace(token))
            {
                throw new ArgumentNullException(nameof(token));
            }

            _token = token;
        }

        // Sends an email on the users behalf using the Microsoft Graph API
        public async Task SendMailAsync(string toAddress, string subject, string content)
        {
            if (string.IsNullOrWhiteSpace(toAddress))
            {
                throw new ArgumentNullException(nameof(toAddress));
            }

            if (string.IsNullOrWhiteSpace(subject))
            {
                throw new ArgumentNullException(nameof(subject));
            }

            if (string.IsNullOrWhiteSpace(content))
            {
                throw new ArgumentNullException(nameof(content));
            }

            var graphClient = GetAuthenticatedClient();
            var recipients = new List<Recipient>
            {
                new Recipient
                {
                    EmailAddress = new EmailAddress
                    {
                        Address = toAddress,
                    },
                },
            };

            // Create the message.
            var email = new Message
            {
                Body = new ItemBody
                {
                    Content = content,
                    ContentType = BodyType.Text,
                },
                Subject = subject,
                ToRecipients = recipients,
            };

            // Send the message.
            await graphClient.Me.SendMail(email, true).Request().PostAsync();
        }

        // Gets mail for the user using the Microsoft Graph API
        public async Task<Message[]> GetRecentMailAsync()
        {
            var graphClient = GetAuthenticatedClient();
            var messages = await graphClient.Me.MailFolders.Inbox.Messages.Request().GetAsync();
            return messages.Take(5).ToArray();
        }

        // Get information about the user.
        public async Task<User> GetMeAsync()
        {
            var graphClient = GetAuthenticatedClient();
            var me = await graphClient.Me.Request().GetAsync();
            return me;
        }

        // gets information about the user's manager.
        public async Task<User> GetManagerAsync()
        {
            var graphClient = GetAuthenticatedClient();
            var manager = await graphClient.Me.Manager.Request().GetAsync() as User;
            return manager;
        }

        // Gets the user's photo
        public async Task<PhotoResponse> GetPhotoAsync()
        {
            HttpClient client = new HttpClient();
            client.DefaultRequestHeaders.Add("Authorization", "Bearer " + _token);
            client.DefaultRequestHeaders.Add("Accept", "application/json");

            using (var response = await client.GetAsync("https://graph.microsoft.com/v1.0/me/photo/$value"))
            {
                if (!response.IsSuccessStatusCode)
                {
                    throw new HttpRequestException($"Graph returned an invalid success code: {response.StatusCode}");
                }

                var stream = await response.Content.ReadAsStreamAsync();
                var bytes = new byte[stream.Length];
                stream.Read(bytes, 0, (int)stream.Length);

                var photoResponse = new PhotoResponse
                {
                    Bytes = bytes,
                    ContentType = response.Content.Headers.ContentType?.ToString(),
                };

                if (photoResponse != null)
                {
                    photoResponse.Base64String = $"data:{photoResponse.ContentType};base64," +
                                                 Convert.ToBase64String(photoResponse.Bytes);
                }

                return photoResponse;
            }
        }

        // Get an Authenticated Microsoft Graph client using the token issued to the user.
        private GraphServiceClient GetAuthenticatedClient()
        {
            var graphClient = new GraphServiceClient(
                new DelegateAuthenticationProvider(
                    requestMessage =>
                    {
                        // Append the access token to the request.
                        requestMessage.Headers.Authorization = new AuthenticationHeaderValue("bearer", _token);

                        // Get event times in the current time zone.
                        requestMessage.Headers.Add("Prefer", "outlook.timezone=\"" + TimeZoneInfo.Local.Id + "\"");

                        return Task.CompletedTask;
                    }));
            return graphClient;
        }
    }
}