WIP Loading older messages

WindowsAppCommunity · May 10, 2022 · ae1b666 · ae1b666
1 parent 4387fa6
commit ae1b666
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Showing 6 changed files with 63 additions and 22 deletions.
diff --git a/src/API/Discord.API/Rest/IChannelService.cs b/src/API/Discord.API/Rest/IChannelService.cs
@@ -11,6 +11,9 @@ internal interface IChannelService
         [Get("/v9/channels/{channelId}/messages?limit={limit}")]
         Task<JsonMessage[]> GetChannelMessages([AliasAs("channelId")] ulong channelId, [AliasAs("limit")] int limit = 50);
 
+        [Get("/v9/channels/{channelId}/messages?limit={limit}&before={before}")]
+        Task<JsonMessage[]> GetChannelMessagesBefore([AliasAs("channelId")] ulong channelId, [AliasAs("before")] ulong before, [AliasAs("limit")] int limit = 50);
+
         [Post("/v9/channels/{channelId}/messages")]
         Task<JsonMessage> CreateMessage([AliasAs("channelId")] ulong channelId, [Body] JsonMessageUpsert message);
     }

diff --git a/src/Quarrel.Client/QuarrelClient.Methods.cs b/src/Quarrel.Client/QuarrelClient.Methods.cs
@@ -41,11 +41,19 @@ public partial class QuarrelClient
         /// Gets messages in a channel.
         /// </summary>
         /// <param name="channelId">The channel's id.</param>
-        public async Task<Message[]> GetMessagesAsync(ulong channelId, ulong? guildId = null)
+        /// <param name="guildId">The id of the guild the channel belongs to.</param>
+        /// <param name="beforeId">The message to get the messages from before.</param>
+        public async Task<Message[]> GetMessagesAsync(ulong channelId, ulong? guildId = null, ulong? beforeId = null)
         {
             Guard.IsNotNull(_channelService, nameof(_channelService));
 
-            JsonMessage[]? jsonMessages = await MakeRefitRequest(() => _channelService.GetChannelMessages(channelId));
+            Func<Task<JsonMessage[]>> request = () => _channelService.GetChannelMessages(channelId);
+            if (beforeId.HasValue)
+            {
+                request = () => _channelService.GetChannelMessagesBefore(channelId, beforeId.Value);
+            }
+
+            JsonMessage[]? jsonMessages = await MakeRefitRequest(request);
             Guard.IsNotNull(jsonMessages, nameof(jsonMessages));
 
             Message[] messages = new Message[jsonMessages.Length];

diff --git a/src/Quarrel.ViewModels/Services/Discord/DiscordService.Methods.cs b/src/Quarrel.ViewModels/Services/Discord/DiscordService.Methods.cs
@@ -74,9 +74,9 @@ public BindableGuildFolder[] GetMyGuildFolders()
         }
 
         /// <inheritdoc/>
-        public async Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel)
+        public async Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel, ulong? beforeId = null)
         {
-            var rawMessages = await _quarrelClient.GetMessagesAsync(channel.Id, channel.GuildId);
+            var rawMessages = await _quarrelClient.GetMessagesAsync(channel.Id, channel.GuildId, beforeId);
             Guard.IsNotNull(rawMessages, nameof(rawMessages));
             return rawMessages;
         }

diff --git a/src/Quarrel.ViewModels/Services/Discord/IDiscordService.cs b/src/Quarrel.ViewModels/Services/Discord/IDiscordService.cs
@@ -50,13 +50,14 @@ public interface IDiscordService
         /// </remarks>
         /// <returns>The array of <see cref="BindableGuildFolder"/>s that the current user has.</returns>
         BindableGuildFolder[] GetMyGuildFolders();
-        
+
         /// <summary>
         /// Gets the messages in a channel.
         /// </summary>
         /// <param name="channel">The channel to get the messages for.</param>
+        /// <param name="beforeId">The if of the last message to load messages before, or null.</param>
         /// <returns>An array of <see cref="BindableMessage"/>s from the channel.</returns>
-        Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel);
+        Task<Message[]> GetChannelMessagesAsync(IBindableMessageChannel channel, ulong? beforeId = null);
 
         /// <summary>
         /// Gets the channels in a guild.

diff --git a/src/Quarrel.ViewModels/ViewModels/Panels/MessagesViewModel.cs b/src/Quarrel.ViewModels/ViewModels/Panels/MessagesViewModel.cs
@@ -72,12 +72,25 @@ public bool IsLoading
             private set => SetProperty(ref _isLoading, value);
         }
 
-        private void LoadChannel()
+        /// <remarks>
+        /// Must be called on the UI thread.
+        /// </remarks>
+        public async void LoadOlderMessages()
         {
-            if (SelectedChannel is IBindableMessageChannel)
-            {
-                LoadInitialMessages();
-            }
+            if (Source.Count == 0) return;
+
+            ulong beforeId = Source[0].Message.Id;
+            IBindableMessageChannel? channel = SelectedChannel as IBindableMessageChannel;
+            Guard.IsNotNull(channel, nameof(channel));
+
+            // Load messages
+            IsLoading = true;
+            var messages = await _discordService.GetChannelMessagesAsync(channel, beforeId);
+            var bindableMessages = ParseMessages(messages);
+
+            // Add messages to the UI and mark loading as finished
+            Source.InsertRange(0, bindableMessages);
+            IsLoading = false;
         }
 
         /// <remarks>
@@ -89,25 +102,38 @@ private async void LoadInitialMessages()
             Guard.IsNotNull(channel, nameof(channel));
             // Clear the messages and begin loading
             Source.Clear();
-            IsLoading = true;
 
             // Load messages
+            IsLoading = true;
             var messages = await _discordService.GetChannelMessagesAsync(channel);
-            BindableMessage[] bindableMessages = new BindableMessage[messages.Length];
-            if (bindableMessages.Length > 0)
-            {
-                bindableMessages[0] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1]);
-                for (int i = 1; i < messages.Length; i++)
-                {
-                    bindableMessages[i] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1 - i], messages[messages.Length - i]);
-                }
-            }
+            var bindableMessages = ParseMessages(messages);
 
             // Add messages to the UI and mark loading as finished
             Source.AddRange(bindableMessages);
             IsLoading = false;
         }
 
+        private void LoadChannel()
+        {
+            if (SelectedChannel is IBindableMessageChannel)
+            {
+                LoadInitialMessages();
+            }
+        }
+
+        private BindableMessage[] ParseMessages(Message[] messages)
+        {
+            BindableMessage[] bindableMessages = new BindableMessage[messages.Length];
+            if (bindableMessages.Length == 0) return bindableMessages;
+
+            bindableMessages[0] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1]);
+            for (int i = 1; i < messages.Length; i++)
+            {
+                bindableMessages[i] = new BindableMessage(_messenger, _discordService, _dispatcherService, messages[messages.Length - 1 - i], messages[messages.Length - i]);
+            }
+            return bindableMessages;
+        }
+
         /// <remarks>
         /// Must be called on the UI thread.
         /// </remarks>

diff --git a/src/Quarrel/Controls/Panels/Messages/MessagePanel.xaml.cs b/src/Quarrel/Controls/Panels/Messages/MessagePanel.xaml.cs
@@ -32,7 +32,10 @@ private void OnViewChanged(object sender, ScrollViewerViewChangedEventArgs e)
             var viewer = (ScrollViewer)sender;
             if (viewer.VerticalOffset <= ScrollPadding)
             {
-                // TODO: Scrolled to top
+                if (!ViewModel.IsLoading)
+                {
+                    ViewModel.LoadOlderMessages();
+                }
             }
             else if (viewer.VerticalOffset >= viewer.ScrollableHeight - ScrollPadding)
             {