Chat/ChatController/HauptKlassen/Chat.cs

using ChatController.ChatKlassen;
using Newtonsoft.Json;
using System;
using System.Collections;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Net.Security;
using System.Runtime.CompilerServices;
using System.Security.Cryptography.X509Certificates;
using System.Threading;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Forms;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using ChatController.Annotations;
using ChatController.Core;
using ChatController.Extensions;
using ChatController.LoginKlassen;
using ChatController.Utilities;
using ChatController.Utilities.Extensions;
using RestSharp;
using RestSharp.Extensions;
using Clipboard = System.Windows.Forms.Clipboard;
using ContextMenu = System.Windows.Controls.ContextMenu;
using DataFormats = System.Windows.Forms.DataFormats;
using Image = System.Drawing.Image;
using MessageBox = System.Windows.MessageBox;

namespace ChatController.HauptKlassen
{
    // Ist quasi das ViewModel
    public class Chat : INotifyPropertyChanged
    {
        private static DateTime _DefaultTime = new DateTime(1970, 1, 1);

        public Action<Exception> ExceptionCallback { get; set; }
        public Action<Exception> ThreadExceptionCallback { get; set; }

        private readonly List<Contact> _Contacts = new List<Contact>();

        public static ChatDatenUebergabe ChatDaten { get; set; }

        private UserMessages _UserMessages;
        private UserMessages _AdditionalUserMessages;

        private string _NextPage;
        private bool _HasNextPage;

        public long LastTimeStamp { get; set; }

        public Chat(ChatDatenUebergabe chatDaten, Action<Exception> exceptionCallback, Action<Exception> threadExceptionCallback)
        {
            ChatDaten = chatDaten;
            ExceptionCallback = exceptionCallback;
            ThreadExceptionCallback = threadExceptionCallback;

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            PinCertificate();
        }

        private static void PinCertificate()
        {
            ServicePointManager.ServerCertificateValidationCallback = PinPublicKey;
        }

        private const String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

        private const String PUB_KEY_R3 = "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";

        private const String PUB_KEY_E1 = "245c2da22afd1c4ba65d97732731acb2a06962ef65e8a6b0f0ac4b9fff1c0b700fd3982f4dfc0f009b37f074055732972e05ef2a4325a3fb6e342713f64f7e69d302995eeb244792c1249be6b1218fc12481fc68cc1f69ba58f51922f774c616";

        private const String PUB_KEY_E5 = "0d0b3a8a6b618eb6efdc5f58e7c6424554ab63f66661480a2e5975b481023750b73f1679dc98eca1289772201c2ccfd57c52204e54785b84146bc090ae85ecc051413c5a877f064dd4fe60d1fa6c2de17d951088a208540f991a4ce6ea0aacd8";

        private const String PUB_KEY_E6 = "d9f19e4687f8217160a826eba3fab9eada1db912a7d426d95114b1617c7596bf220b391fd5bed10a46aa2d3c4a09842ebe409555e91940376675ed324e770449f8707bc318e7cef77110feac74d800d4ed6d1c731633109c3ab2ea6c62f4bdb8";

        private const String PUB_KEY_R10 = "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";

        private const String PUB_KEY_R11 = "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";


        private static bool PinPublicKey(object sender, X509Certificate certificate, X509Chain chain, SslPolicyErrors sslpolicyerrors)
        {
            try
            {
                if (certificate == null || chain == null)
                    return false;

                bool chainContainsPk = false;

                foreach (var element in chain.ChainElements)
                {
                    String pk = element.Certificate.GetPublicKeyString().ToLower();

                    if (pk.Contains(PUB_KEY_X3.ToLower()) ||
                        pk.Contains(PUB_KEY_R3.ToLower()) ||
                        pk.Contains(PUB_KEY_E1.ToLower()) ||
                        pk.Contains(PUB_KEY_E5.ToLower()) ||
                        pk.Contains(PUB_KEY_E6.ToLower()) ||
                        pk.Contains(PUB_KEY_R10.ToLower()) ||
                        pk.Contains(PUB_KEY_R11.ToLower()))
                    {
                         chainContainsPk = true;
                    }
                }

                bool subjectAccepted = certificate.Subject.Trim().ToLower().EndsWith(".bewoplaner.de") ||
                                       certificate.Subject.Trim().ToLower().EndsWith(".ownchat.de");
                return chainContainsPk && subjectAccepted;
            }
            catch (Exception e)
            {
                return false;
            }

        }


        //!!!!Wenn hier neue Keys hinzugefügt werden, muss das auch in der Klasse BeWo.LoginControl und im DatabaseTerminator gemacht werden!!
        
        public List<Contact> AddContacts()
        {
            var groupInputs = ChatDaten?.AlleGruppen?.Response?.Groups?.ToArray() ?? new GroupInput[0];
            _Contacts.AddRange(GenerateContactsFromServerResponse(groupInputs, true));

            return _Contacts;
        }

        // Klick auf Kontakt. Die Collection muss davor geleert werden.
        // Führt zu doppelter neuester Nachricht, wenn man vorher eine verschickt hat!
        public void LoadChatMessagesForContactAsync(Contact contact, ChatMessage previousMessage, Action<List<ChatMessage>> callback)
        {
            if(!(contact is null))
            {
                LoadMessagesFromServerAsync(contact.GroupId, delegate
                {
                    callback?.Invoke(AddMessagesFromServerResponse(_UserMessages?.Response?.Messages ?? new OwnChatMessage[0], previousMessage));
                });

                return;
            }

            callback?.Invoke(new List<ChatMessage>());
        }

        private void LoadMessagesFromServerAsync(long groupId, Action callback)
        {
            var url = $"{ChatDaten.ServerUrl}{Constants.LoadMessagesForGroupUrl}{groupId}";

            var client = new RestClient(url);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                _UserMessages = JsonConvert.DeserializeObject<UserMessages>(response.Content);

                if(_UserMessages?.Response?.HasMorePages ?? false)
                {
                    _NextPage = _UserMessages.Response.NextPage;
                    _HasNextPage = true;
                }
                else
                {
                    _HasNextPage = false;
                }

                callback?.Invoke();
            });
        }

        public void LoadMoreMessagesAsync(Contact contact, ChatMessage previousMessage, Action<List<ChatMessage>> callback)
        {
            LoadMoreMessagesFromServerAsync(contact.GroupId, _NextPage, () =>
            {
                callback?.Invoke(AddMessagesFromServerResponse(_AdditionalUserMessages?.Response?.Messages ?? new OwnChatMessage[0], previousMessage));
            });
        }

        private void LoadMoreMessagesFromServerAsync(long groupId, string page, Action callback)
        {
            if(page is null || !page.Contains("="))
            {
                callback?.Invoke();
                return;
            }

            var pageParam = page.Split('=')[1];

            var url = $"{ChatDaten.ServerUrl}/api/chat/messages?groupid={groupId}&page={pageParam}";

            var client = new RestClient(url);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                _AdditionalUserMessages = null;
                _AdditionalUserMessages = JsonConvert.DeserializeObject<UserMessages>(response.Content);

                if(_AdditionalUserMessages?.Response?.HasMorePages ?? false)
                {
                    _NextPage = _AdditionalUserMessages.Response.NextPage;
                }

                _HasNextPage = _AdditionalUserMessages?.Response?.HasMorePages ?? false;

                callback?.Invoke();
            });
        }

        private double _FormerMessagesCount;

        public void CheckIfNewMessagesExistAsync(long groupId, Action<bool> callback)
        {
            #if DEBUG
            if(_UserMessages.Response is null)
            {
                throw new Exception("Too many requests.");
            }
            #endif

            var span = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
            var timespan = Convert.ToInt64(span.TotalSeconds);

            if(!(_UserMessages is null) && _UserMessages.Response.Messages.Length > 0)
            {
                timespan = _UserMessages.Response.Messages.First().CreatedAt;
            }

            GetNumberOfNewMessagesAsync(groupId, timespan, numberOfNewMessages =>
            {
                var hasNewMessages = numberOfNewMessages != _FormerMessagesCount;

                _FormerMessagesCount = numberOfNewMessages;

                callback?.Invoke(hasNewMessages);
            });
        }

        private void GetNumberOfNewMessagesAsync(long groupId, long lastTimeStamp, Action<double> callback)
        {
            try
            {
                var url = $"{ChatDaten.ServerUrl}{Constants.LoadOwnChatNewsUrl}{groupId}/{lastTimeStamp}";

                var client = new RestClient(url);
                var request = new RestRequest();

                request.AddHeader(Constants.Token, ChatDaten.AuthToken);
                request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

                client.ExecuteAsync(request, response =>
                {
                    var messageCounter = JsonConvert.DeserializeObject<MessageCounter>(response.Content);

                    callback?.Invoke(messageCounter?.MessageCount ?? 0);
                });
            }
            catch(Exception exception)
            {
                callback?.Invoke(0d);
                throw exception;
            }
        }

        public void GetNumberOfAllNewMessagesAsync(Action<double> callback)
        {
            LoadNumberOfNewMessagesFromServerAsync(0, numberOfNewMessages =>
            {
                if(numberOfNewMessages > 0)
                {
                    LastTimeStamp = DateTime.UtcNow.GetUnixTimeStamp();
                }

                callback?.Invoke(numberOfNewMessages);
            });
        }

        private void LoadNumberOfNewMessagesFromServerAsync(long groupId, Action<double> callback)
        {
            var url = $"{ChatDaten.ServerUrl}{Constants.LoadOwnChatNewsUrl}{groupId}/{LastTimeStamp}";

            var client = new RestClient(url);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                var messageCounter = JsonConvert.DeserializeObject<MessageCounter>(response.Content);

                callback?.Invoke(messageCounter?.MessageCount ?? 0);
            });
        }

        private void LoadGroupsAsync(Action<ChatGruppenDaten> callback)
        {
            var url = $"{ChatDaten.ServerUrl}{Constants.GetChatGroupsUrl}";

            var client = new RestClient(url);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                var contacts = JsonConvert.DeserializeObject<ChatGruppenDaten>(response.Content);

                callback?.Invoke(contacts);
            });
        }

        public void UpdateContactList(Action<IOrderedEnumerable<Contact>> callback)
        {
            LoadGroupsAsync(rawData =>
            {
                if(rawData.Response is null)
                {
                    return;
                }

                var contacts = GenerateContactsFromServerResponse(rawData.Response.Groups.ToArray(), true);

                callback?.Invoke(contacts.OrderByDescending(c => c.TimeStamp));
            });
        }

        public List<ChatMessage> AddNewMessage(string pMessage, long pGroupId, ChatMessage previousMessage)
        {
            var time = DateTime.Now;

            var chatMessage = new ChatMessage(pGroupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, pMessage, time, true, 0, null, null, null, null, null, ChatMessageType.Message, ChatDaten.LoggedInUser.Response.User.Oid);

            var messages = new List<ChatMessage>();

            if(!(previousMessage is null))
            {
                messages.Add(previousMessage);
            }

            messages.Add(chatMessage);

            var result = AddSeparators(messages);

            result.Remove(previousMessage);
         
            return result;
        }

        public async Task SendMessage(string message, long groupId)
        {
            var endurl = ChatDaten.ServerUrl + Constants.SendMessageUrl;

            using(var multiPartContent = new MultipartFormDataContent())
            {
                multiPartContent.Add(new StringContent(groupId.ToString()), "groupid");
                multiPartContent.Add(new StringContent(message), "text");
                
                var requestUri = new Uri(endurl);

                var httpRequest = new HttpRequestMessage {Method = HttpMethod.Post, RequestUri = requestUri, Content = multiPartContent};

                httpRequest.Headers.Add("Token", ChatDaten.AuthToken);
                httpRequest.Headers.Add("CustomerID", ChatDaten.Kundennummer);

                var httpClient = new HttpClient();
                await httpClient.SendAsync(httpRequest, CancellationToken.None);
            }
        }

        public string OpenFile()
        {
            var openFileDialog = new OpenFileDialog
            {
                Filter = Resource.OpenFileDialogFilter_Test
            };

            var result = openFileDialog.ShowDialog();
            
            return result == DialogResult.OK ? openFileDialog.FileName : null;
        }

        public List<ChatMessage> AddNewFile(string pathToScaledFile, string originalFilePath, long groupId, ChatMessage previousMessage, string chatBoxText)
        {
            var result = new List<ChatMessage>();

            if(string.IsNullOrEmpty(pathToScaledFile) || string.IsNullOrEmpty(originalFilePath))
            {
                return result;
            }

            var messageId       = 0;
            var userName        = ChatDaten.LoggedInUser.Response.User.UserName;
            var sendTime        = DateTime.Now;
            var fileName        = Path.GetFileName(pathToScaledFile);
            var imageFile       = GetImageFile(pathToScaledFile, out var fileSize);
            var isImage         = Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant());
            var messageText     = string.IsNullOrWhiteSpace(chatBoxText) ? fileName : chatBoxText;
            var filePath        = isImage ? null : pathToScaledFile;
            var originalImage   = isImage ? pathToScaledFile : null;
            var imageName       = isImage ? fileName : null;
            var linkToThumbnail = isImage ? null : $"{ChatDaten.ServerUrl}/document.png";
            var logo            = isImage ? imageFile : null;
            var chatMessageType = isImage ? ChatMessageType.Image : ChatMessageType.Document;
            var senderId        = ChatDaten.LoggedInUser.Response.User.Oid;

            var chatMessage = new ChatMessage(groupId, messageId, userName, messageText, sendTime, true, fileSize, filePath, originalImage, imageName, linkToThumbnail, logo, chatMessageType, senderId);

            result = AddSeparators(new List<ChatMessage> { previousMessage, chatMessage });

            result.Remove(previousMessage);

            return result;
        }

        private static BitmapImage GetImageFile(string pathToScaledFile, out long fileSize)
        {
            if(!File.Exists(pathToScaledFile) || !Constants.ImageFileExtensions.Contains(Path.GetExtension(pathToScaledFile).ToUpperInvariant()))
            {
                fileSize = 0L;
                return null;
            }

            byte[] file;
            using(Stream reader = File.Open(pathToScaledFile, FileMode.Open, FileAccess.Read, FileShare.ReadWrite))
            {
                file = Utils.ReadFully(reader);
            }

            using(var memoryStream = new MemoryStream(file))
            {
                var image = Image.FromStream(memoryStream);

                using(var bitmap = new Bitmap(image))
                {
                    using(var stream = new MemoryStream())
                    {
                        short orient = 0;
                        const int orientationId = 0x0112;

                        if (image.PropertyIdList.Contains(orientationId))
                        {
                            var item = image.GetPropertyItem(orientationId);

                            orient = BitConverter.ToInt16(item.Value, 0);

                            bitmap.SetPropertyItem(item);
                        }

                        var flipType = Utils.OrientationToFlipType(orient.ToString());

                        bitmap.RotateFlip(flipType);

                        bitmap.Save(stream, ImageFormat.Jpeg);

                        var bitmapImage = new BitmapImage();

                        bitmapImage.BeginInit();
                        bitmapImage.StreamSource = new MemoryStream(stream.ToArray());
                        bitmapImage.EndInit();
                        bitmapImage.Freeze();

                        fileSize = memoryStream.Length;
                        return bitmapImage;
                    }
                }
            }
        }

        public List<ChatMessage> AddFileToMessage(byte[] file, string fileName, long groupId, ChatMessage previousMessage)
        {
            var result = new List<ChatMessage>();

            if (string.IsNullOrEmpty(fileName))
            {
                return result;
            }

            if(!(previousMessage is null))
            {
                result.Add(previousMessage);
            }

            var message = _UserMessages.Response.Messages.Last();

            var sendtime = DateTime.Now;

            if(Constants.ImageFileExtensions.Contains(Path.GetExtension(fileName).ToUpperInvariant()))
            {
                var bitmapImage = new BitmapImage();
                var memoryStream = new MemoryStream(file);
                
                bitmapImage.BeginInit();
                bitmapImage.StreamSource = memoryStream;
                bitmapImage.EndInit();
                bitmapImage.Freeze();

                memoryStream.Close();
                ImageSource logo = bitmapImage;

                // Mit Logo
                var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(fileName), sendtime, true, memoryStream.Length, null, fileName, Path.GetFileName(fileName), null, logo, ChatMessageType.Image, ChatDaten.LoggedInUser.Response.User.Oid);

                result.Add(chatMessage);
            }
            else 
            {
                // Dokument
                var chatMessage = new ChatMessage(groupId, 0, ChatDaten.LoggedInUser.Response.User.UserName, Path.GetFileName(fileName), sendtime, true, 0, fileName, null, null, message.SmallerImage, null, ChatMessageType.Document, ChatDaten.LoggedInUser.Response.User.Oid);
                result.Add(chatMessage);
            }

            return AddSeparators(result);
        }

        public async Task SendFileToContact(Contact currentContact, string scaledImagePath, string originalFilePath, string message)
        {
            await SendFile(scaledImagePath, currentContact, originalFilePath, message);
        }

        private async Task SendFile(string pFile, Contact currentContact, string pOriginalFilePath, string message)
        {
            if(string.IsNullOrEmpty(pOriginalFilePath))
            {
                return;
            }

            byte[] mediaFile;
            using(Stream reader = File.OpenRead(pFile))
            {
                mediaFile = Utils.ReadFully(reader);
            }

            var fileName = Path.GetFileName(pOriginalFilePath).ToLower();

            if(Constants.ImageFileExtensions.Contains(Path.GetExtension(fileName).ToUpperInvariant()))
            { 
                fileName = fileName.Replace(".bmp", ".jpg");
            }
                
            await SendMediaMessage(fileName, currentContact.GroupId, mediaFile, message);
        }
        
        private HttpRequestMessage _HttpRequest;

        private async Task SendMediaMessage(string fileName, long groupId, byte[] mediaFile, string message)
        {
            try
            {
                using (var multiPartContent = new MultipartFormDataContent())
                {
                    var requestUri = new Uri(ChatDaten.ServerUrl + Constants.SendMessageUrl);

                    multiPartContent.Add(new ByteArrayContent(mediaFile, 0, mediaFile.Length), "file", fileName);
                    multiPartContent.Add(new StringContent(groupId.ToString()), "groupid");

                    if(!string.IsNullOrWhiteSpace(message))
                    {
                        multiPartContent.Add(new StringContent(message), "text");
                    }

                    _HttpRequest = new HttpRequestMessage
                    {
                        Method = HttpMethod.Post,
                        RequestUri = requestUri,
                        Content = multiPartContent
                    };

                    _HttpRequest.Headers.Add(Constants.Token, ChatDaten.AuthToken);
                    _HttpRequest.Headers.Add(Constants.CustomerId, ChatDaten.Kundennummer);

                    var httpClient = new HttpClient();
                    await httpClient.SendAsync(_HttpRequest, HttpCompletionOption.ResponseContentRead);
                }
            }
            catch(Exception)
            {
            }
        }

        public ContextMenu ErstelleKontextMenue()
        {
            var contextMenu = new ContextMenu();
            
            var item1 = new System.Windows.Controls.MenuItem();
            var item2 = new System.Windows.Controls.MenuItem();
            var item3 = new System.Windows.Controls.MenuItem();

            contextMenu.Items.Add(item1);
            contextMenu.Items.Add(item2);
            contextMenu.Items.Add(item3);

            item1.Header = "Speichern unter";
            item1.Visibility = Visibility.Visible;
            
            item2.Header = "Einfügen";
            item2.Visibility = Visibility.Visible;

            item3.Header = "Kopieren";
            item3.Visibility = Visibility.Visible;

            return contextMenu;
        }

        public void SaveFileAs(ChatMessage pChatMessage)
        {
            var originalImage = pChatMessage.OriginalImage;

            var fileUri = originalImage;

            if(originalImage is null)
            {
                fileUri = pChatMessage.FilePath;
            }

            if(fileUri is null)
            {
                return;
            }

            SaveAs(Path.GetFileName(fileUri), DownloadMediaFile(fileUri));
        }

        private static byte[] DownloadMediaFile(string uriToFile)
        {
            byte[] mediaFile;
            
            using(var webClient = new WebClient())
            {
                webClient.Credentials = CredentialCache.DefaultCredentials;
                webClient.Headers[Constants.Token] = ChatDaten.AuthToken;
                webClient.Headers[Constants.CustomerId] = ChatDaten.Kundennummer;
                mediaFile = webClient.DownloadData(uriToFile);
            }

            return mediaFile;
        }

        private static void SaveAs(string pFileName, byte[] pMediaFile)
        {
            var saveFileDialog = new SaveFileDialog {FileName = pFileName};

            saveFileDialog.Title = "ownChat";

            saveFileDialog.Filter = "All files (*.*)|*.*";
            saveFileDialog.DefaultExt = Path.GetExtension(pFileName);

            if(saveFileDialog.DefaultExt.Length > 0)
            {
                saveFileDialog.AddExtension = true;
                saveFileDialog.Filter = $"{saveFileDialog.DefaultExt} files (*.{saveFileDialog.DefaultExt})|*.{saveFileDialog.DefaultExt}|{saveFileDialog.Filter}";
                saveFileDialog.FilterIndex = 0;
            }

            saveFileDialog.ShowDialog();

            if (string.IsNullOrEmpty(saveFileDialog.FileName))
            {
                return;
            }

            using (var fileStream = (FileStream)saveFileDialog.OpenFile())
            {
                fileStream.Write(pMediaFile, 0, pMediaFile.Length);
            }
        }

        public async Task Paste(long pGroupOid, ChatMainControl pChatMainControl)
        {         
            var dataObject = Clipboard.GetDataObject();

            if(dataObject is null)
            {
                return;
            }
            
            if(dataObject.GetDataPresent(DataFormats.FileDrop))
            {
                if(dataObject.GetData(DataFormats.FileDrop) is string[] fileList)
                {
                    var pathToFile = fileList[0];

                    if(File.Exists(pathToFile))
                    {
                        var fileName = Path.GetFileName(pathToFile);
                        
                        var mediaFile = File.ReadAllBytes(pathToFile);

                        pChatMainControl.AddMessages(AddFileToMessage(mediaFile, fileName, pGroupOid, pChatMainControl.GetFirstMessage()));
                        
                        CollectionViewSource.GetDefaultView(pChatMainControl.ChatListBox.ItemsSource).Refresh();

                        pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                        pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);

                        await SendMediaMessage(fileName, pGroupOid, mediaFile, null);
                    }
                }
            }
            else
            {
                if(dataObject.GetDataPresent(DataFormats.Text))
                {
                    var text = (string) dataObject.GetData(DataFormats.StringFormat);

                    pChatMainControl.AddMessages(AddNewMessage(text, pGroupOid, pChatMainControl.GetFirstMessage()));
                
                    CollectionViewSource.GetDefaultView(pChatMainControl.ChatListBox.ItemsSource).Refresh();

                    pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                    pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);

                    await SendMessage(text, pGroupOid);
                }
                else if(dataObject.GetDataPresent(DataFormats.Bitmap))
                {
                    var bitmap = (Bitmap) dataObject.GetData(DataFormats.Bitmap);

                    var imageName = Utils.GenerateTempName() + ".jpg";

                    Image image = bitmap;

                    pChatMainControl.AddMessages(AddFileToMessage(Utils.ImageToByteArray(image), imageName, pGroupOid, pChatMainControl.GetFirstMessage()));
                        
                    CollectionViewSource.GetDefaultView(pChatMainControl.ChatListBox.ItemsSource).Refresh();

                    pChatMainControl.ChatListBox.Items.MoveCurrentToLast();
                    pChatMainControl.ChatListBox.ScrollIntoView(pChatMainControl.ChatListBox.Items.CurrentItem);

                    await SendMediaMessage(imageName, pGroupOid, Utils.ImageToByteArray(image), null);
                }
                else
                {
                    MessageBox.Show("Der Zwischen-Speicher kann nicht verarbeitet werden.", "Fehler", MessageBoxButton.OK);
                }
            }
        }

        public void Copy(object pData, int pDataType)
        { 
            switch(pDataType)
            {
                case 1:
                    Clipboard.SetData(DataFormats.Text, pData);
                    break;
                case 2:
                    Clipboard.SetData(DataFormats.Bitmap, pData);
                    break;
                case 3:
                    Clipboard.SetData(DataFormats.FileDrop, pData);
                    break;
            }
        }
        
        public void ShowProfilePicture(Contact currentContact)
        {
            ShowPictureWindow(currentContact.Image, currentContact.Name);
        }

        public void ShowPictureWindow(ImageSource imageSource, string title)
        {
            var imageWidth = Convert.ToInt32(imageSource.Width);
            var imageHeight = Convert.ToInt32(imageSource.Height);

            var imageAspectRatio = imageWidth / (double)imageHeight;

            var primaryScreenWidth2 = SystemParameters.PrimaryScreenWidth;
            var primaryScreenHeight2 = SystemParameters.PrimaryScreenHeight;

            var windowMaxWidth = imageWidth;
            var windowMaxHeight = imageHeight;

            if(windowMaxWidth > .8 * primaryScreenWidth2 || windowMaxHeight > .8 * primaryScreenHeight2)
            {
                if(primaryScreenWidth2 > primaryScreenHeight2)
                {
                    windowMaxHeight = (int)(.8 * primaryScreenHeight2);
                    windowMaxWidth = (int)(windowMaxHeight * imageAspectRatio);
                }
                else
                {
                    windowMaxWidth = (int)(.8 * primaryScreenWidth2);
                    windowMaxHeight = (int)(windowMaxWidth * imageAspectRatio);
                }
            }

            var maximumWindowSize = new System.Windows.Size(windowMaxWidth, windowMaxHeight);

            var minHeight = 232 / imageAspectRatio;
            var minWidth = 232d;

            var window = new Window
            {
                Title = title,
                MinHeight = minHeight,
                MinWidth = minWidth
            };

            var grid = new Grid
            {
                Width = maximumWindowSize.Width,
                Height = maximumWindowSize.Height,
                MinHeight = minHeight,
                MinWidth = minWidth
            };

            var image = new System.Windows.Controls.Image
            {
                Source = imageSource,
                Margin = new Thickness(0)
            };

            grid.Children.Clear();
            grid.Children.Add(image);

            window.SizeToContent = SizeToContent.WidthAndHeight;
            window.Content = grid;
            window.Margin = new Thickness(0);
            window.WindowStartupLocation = WindowStartupLocation.CenterScreen;

            window.ShowDialog();
        }

        public void ShowPicture(string originalImage, long groupId, Action<ImageSource, string> downloadCompletedCallback)
        {
            if(originalImage is null)
            {
                return;
            }

            Utils.DownloadImageAsync(originalImage, $"group-{groupId}", CacheCategory.MessageAttachment, imageSource =>
            {
                var splitName = originalImage.Split('/');
                var last = splitName.LastOrDefault();

                downloadCompletedCallback?.Invoke(imageSource, last ?? "Bild");
            });
        }

        public void ReloadGroupsAsync(Action<ChatGruppenDaten> callback)
        {
            var url = ChatDaten.ServerUrl + Constants.GetChatGroupsUrl;

            ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;

            var client = new RestClient(url);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                var groups = JsonConvert.DeserializeObject<ChatGruppenDaten>(response.Content);

                callback?.Invoke(groups);
            });
        }

        public List<Contact> UpdateContacts(ChatGruppenDaten chatDaten)
        {
            _Contacts.Clear();
            
            if(!(chatDaten?.Response is null))
            {
                _Contacts.AddRange(GenerateContactsFromServerResponse(chatDaten.Response.Groups.ToArray()));
            }

            return _Contacts;
        }

        public List<Contact> GenerateContactsFromServerResponse(GroupInput[] pGroupInputs, bool pShouldUpdateLastTimeStamp = false)
        {
            var contacts = new List<Contact>();
            
            foreach(var groupInput in pGroupInputs)
            {
                var formattedTime = new DateTime();

                var latestMessage = groupInput.LastMessage;

                if(latestMessage?.Text != null)// && latestMessage?.Timestamp != null)
                {
                    var timeStamp = DateTime.Parse(latestMessage.Timestamp.Date);

                    var clientZone = TimeZoneInfo.Local;

                    formattedTime = TimeZoneInfo.ConvertTimeFromUtc(timeStamp, clientZone);
                }

                string userIdManage = null;

                foreach(var user in groupInput.Users)
                {
                    if(user.Oid != ChatDaten.Userid)
                    {
                        if(!user.Is_Employee && !string.IsNullOrEmpty(user.Userid_Manage))
                        {
                            userIdManage = user.Userid_Manage;
                        }
                    }
                }

                var key = $"group-{groupInput.Oid}";
                
                contacts.Add(new Contact(
                    groupInput.Name, 
                    groupInput.LastMessage, 
                    formattedTime, 
                    groupInput.Oid, 
                    userIdManage, 
                    groupInput.OnlyEmployees, 
                    groupInput.Users.Length, 
                    groupInput.CanWrite, 
                    groupInput.AccentColor, 
                    groupInput.Avatar,
                    key, groupInput.Users.ToDictionary(user => user.Oid, user => user.Picture)));

                if(!pShouldUpdateLastTimeStamp || latestMessage?.Timestamp?.Date is null)
                {
                    continue;
                }

                var time = DateTime.Parse(latestMessage.Timestamp.Date);
                
                //var unixTimeStamp = latestMessage.Timestamp.Value.GetUnixTimeStamp();
                var unixTimeStamp = time.GetUnixTimeStamp();

                if(LastTimeStamp < unixTimeStamp)
                {
                    LastTimeStamp = unixTimeStamp;
                }
            }

            Task.Run(() =>
            {
                var userId2Uris = new Dictionary<long, string>();
                foreach(var contact in contacts)
                {
                    foreach(var test in contact.UserId2Uri)
                    {
                        userId2Uris.AddAndIgnoreDuplicates(test.Key, test.Value);
                    }
                }

                Utils.DownloadUserProfilePicturesSync(userId2Uris);

                foreach(var contact in contacts)
                {
                    contact.Image = Utils.DownloadImageSync(contact.ProfilePicturePath, null, contact.GroupId);
                }
            });
            
            return contacts;
        }

        public List<ChatMessage> AddMessagesFromServerResponse(OwnChatMessage[] pMessages, ChatMessage previousMessage)
        {
            var result = new List<ChatMessage>();

            foreach(var message in pMessages ?? new OwnChatMessage[0])
            {
                var time = DateTime.Parse(message.Timestamp.Date);

                var clientZone             = TimeZoneInfo.Local;
                var formattedTime          = TimeZoneInfo.ConvertTimeFromUtc(time, clientZone);
                
                var isLoggedInUsersMessage = !(ChatDaten.Userid is null) && message.UserId == ChatDaten.Userid.Value;
                var messageText      = message.Text ?? (string.IsNullOrEmpty(message.File) ? string.Empty : message.OriginalFilename);

                if(!string.IsNullOrEmpty(message.File))
                {
                    var message2Add = Constants.ImageFileExtensions.Contains(Path.GetExtension(message.File).ToUpperInvariant()) ? //SmallerImage ist null
                        new ChatMessage(message.GroupId, message.Id, message.UserName, messageText, formattedTime, isLoggedInUsersMessage, message.FileSize, message.SmallerImage, message.File, message.OriginalFilename, null, null, ChatMessageType.Image, message.UserId) :
                        new ChatMessage(message.GroupId, message.Id, message.UserName, messageText, formattedTime, isLoggedInUsersMessage, 0, message.File, null, null, message.SmallerImage, null, ChatMessageType.Document, message.UserId);

                    result.AddIfNotIn(message2Add);
                }
                else
                {
                    var chatMessage = new ChatMessage(message.GroupId, message.Id, message.UserName, message.Text, formattedTime, isLoggedInUsersMessage, message.FileSize, null, null, null, null, null, ChatMessageType.Message, message.UserId);
                    
                    result.AddIfNotIn(chatMessage);
                }
            }

            return AddSeparators(result);
        }

        private static List<ChatMessage> AddSeparators(List<ChatMessage> chatMessages)
        {
            if(chatMessages is null)
            {
                chatMessages = new List<ChatMessage>();
            }

            var test = chatMessages.Any(a => a is null);

            var messagesWithoutSeparators = chatMessages.Where(message => !message.IsSeparator).OrderBy(message => message.SendTime).ToList();

            var separators = new List<ChatMessage>();

            var previousMessage = messagesWithoutSeparators.OrderBy(message => message.SendTime).FirstOrDefault();

            foreach(var message in messagesWithoutSeparators.OrderBy(message => message.SendTime))
            {
                if(!message.Equals(previousMessage) && !(previousMessage is null))
                {
                    if(message.SendTime.Date != previousMessage.SendTime.Date)
                    {
                        var separatorMessage = new ChatMessage(0, -1, null, null, message.SendTime.Date, false, 0, null, null, null, null, null, ChatMessageType.Separator, 0);

                        separators.Add(separatorMessage);

                        previousMessage = message;
                    }
                }
            }

            chatMessages.AddRange(separators);

            return chatMessages;
        }

        public void DownloadFileAsync(string uri, string path, Action callback)
        {
            var client = new RestClient(uri);
            var request = new RestRequest();

            request.AddHeader(Constants.Token, ChatDaten.AuthToken);
            request.AddHeader(Constants.CustomerId, ChatDaten.Kundennummer);

            client.ExecuteAsync(request, response =>
            {
                if(response.StatusCode == HttpStatusCode.OK)
                {
                    response.RawBytes.SaveAs(path);
                }
                else
                {
                    throw new Exception("Die Datei konnte nicht heruntergeladen werden.");
                }

                callback?.Invoke();
            });
        }

        private bool _IsInBroadcastMode;

        public bool IsInBroadcastMode
        {
            get => _IsInBroadcastMode;
            set
            {
                _IsInBroadcastMode = value;
                OnPropertyChanged(nameof(IsInBroadcastMode));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        [NotifyPropertyChangedInvocator]
        protected virtual void OnPropertyChanged([CallerMemberName] string propertyName = null)
        {
            PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
        }
    }

    public class ChatMessageComparer : IComparer
    {
        public int Compare(object x, object y)
        {
            return x is ChatMessage message1 && y is ChatMessage message2 ? message1.SendTime.CompareTo(message2.SendTime) : 0;
        }
    }
}