Email.ios.cs

using System;
using System.IO;
using System.Threading.Tasks;
using Foundation;
using MessageUI;
using UIKit;

namespace Xamarin.Essentials
{
    public static partial class Email
    {
        internal static bool IsComposeSupported =>
            MFMailComposeViewController.CanSendMail ||
            MainThread.InvokeOnMainThread(() => UIApplication.SharedApplication.CanOpenUrl(NSUrl.FromString("mailto:")));

        static Task PlatformComposeAsync(EmailMessage message)
        {
            if (MFMailComposeViewController.CanSendMail)
                return ComposeWithMailCompose(message);
            else
                return ComposeWithUrl(message);
        }

        static Task ComposeWithMailCompose(EmailMessage message)
        {
            // do this first so we can throw as early as possible
            var parentController = Platform.GetCurrentViewController();

            // create the controller
            var controller = new MFMailComposeViewController();
            if (!string.IsNullOrEmpty(message?.Body))
                controller.SetMessageBody(message.Body, message.BodyFormat == EmailBodyFormat.Html);
            if (!string.IsNullOrEmpty(message?.Subject))
                controller.SetSubject(message.Subject);
            if (message?.To?.Count > 0)
                controller.SetToRecipients(message.To.ToArray());
            if (message?.Cc?.Count > 0)
                controller.SetCcRecipients(message.Cc.ToArray());
            if (message?.Bcc?.Count > 0)
                controller.SetBccRecipients(message.Bcc.ToArray());

            if (message?.Attachments?.Count > 0)
            {
                foreach (var attachment in message.Attachments)
                {
                    var data = NSData.FromFile(attachment.FullPath);
                    if (data == null)
                        throw new FileNotFoundException($"Attachment {attachment.FileName} not found.", attachment.FullPath);

                    controller.AddAttachmentData(data, attachment.ContentType, attachment.FileName);
                }
            }

            var tcs = new TaskCompletionSource<bool>();
            controller.Finished += (sender, e) =>
            {
                controller.DismissViewController(true, null);
                tcs.TrySetResult(e.Result == MFMailComposeResult.Sent);
            };

            if (controller.PresentationController != null)
            {
                controller.PresentationController.Delegate = new Platform.UIPresentationControllerDelegate
                {
                    DismissHandler = () => tcs.TrySetResult(false)
                };
            }

            parentController.PresentViewController(controller, true, null);

            return tcs.Task;
        }

        static async Task ComposeWithUrl(EmailMessage message)
        {
            var url = GetMailToUri(message);
            var nsurl = NSUrl.FromString(url);
            await Launcher.PlatformOpenAsync(nsurl);
        }
    }
}