Add from/to date pickers

Fixes #6

DiscordChatExporter/Messages/StartExportMessage.cs

@@ -1,4 +1,5 @@
-using DiscordChatExporter.Models;
+using System;
+using DiscordChatExporter.Models;
 
 namespace DiscordChatExporter.Messages
 {
@@ -10,11 +11,18 @@ namespace DiscordChatExporter.Messages
 
         public ExportFormat Format { get; }
 
-        public StartExportMessage(Channel channel, string filePath, ExportFormat format)
+        public DateTime? From { get; }
+
+        public DateTime? To { get; }
+
+        public StartExportMessage(Channel channel, string filePath, ExportFormat format,
+            DateTime? from, DateTime? to)
         {
             Channel = channel;
             FilePath = filePath;
             Format = format;
+            From = from;
+            To = to;
         }
     }
 }

DiscordChatExporter/Services/DataService.cs

@@ -71,7 +71,7 @@ namespace DiscordChatExporter.Services
             return channels;
         }
 
-        public async Task<IReadOnlyList<Message>> GetChannelMessagesAsync(string token, string channelId)
+        public async Task<IReadOnlyList<Message>> GetChannelMessagesAsync(string token, string channelId, DateTime? from, DateTime? to)
         {
             var result = new List<Message>();
 
@@ -102,6 +102,9 @@ namespace DiscordChatExporter.Services
                 // If no messages - break
                 if (currentMessageId == null) break;
 
+                // If last message is older than from date - break
+                if (from != null && result.Last().TimeStamp < from) break;
+
                 // Otherwise offset the next request
                 beforeId = currentMessageId;
             }
@@ -109,6 +112,12 @@ namespace DiscordChatExporter.Services
             // Messages appear newest first, we need to reverse
             result.Reverse();
 
+            // Filter
+            if (from != null)
+                result.RemoveAll(m => m.TimeStamp < from);
+            if (to != null)
+                result.RemoveAll(m => m.TimeStamp > to);
+
             return result;
         }
 

DiscordChatExporter/Services/IDataService.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Threading.Tasks;
 using DiscordChatExporter.Models;
 
@@ -12,6 +13,7 @@ namespace DiscordChatExporter.Services
 
         Task<IReadOnlyList<Channel>> GetGuildChannelsAsync(string token, string guildId);
 
-        Task<IReadOnlyList<Message>> GetChannelMessagesAsync(string token, string channelId);
+        Task<IReadOnlyList<Message>> GetChannelMessagesAsync(string token, string channelId,
+            DateTime? from, DateTime? to);
     }
 }

DiscordChatExporter/ViewModels/ExportSetupViewModel.cs

@@ -17,6 +17,8 @@ namespace DiscordChatExporter.ViewModels
 
         private string _filePath;
         private ExportFormat _format;
+        private DateTime? _from;
+        private DateTime? _to;
 
         public Guild Guild { get; private set; }
 
@@ -40,6 +42,18 @@ namespace DiscordChatExporter.ViewModels
             set => Set(ref _format, value);
         }
 
+        public DateTime? From
+        {
+            get => _from;
+            set => Set(ref _from, value);
+        }
+
+        public DateTime? To
+        {
+            get => _to;
+            set => Set(ref _to, value);
+        }
+
         // Commands
         public RelayCommand ExportCommand { get; }
 
@@ -59,14 +73,17 @@ namespace DiscordChatExporter.ViewModels
                 Guild = m.Guild;
                 Channel = m.Channel;
                 SelectedFormat = _settingsService.LastExportFormat;
-                FilePath = Path.Combine($"{Guild} - {Channel}.{SelectedFormat.GetFileExtension()}");
+                FilePath = $"{Guild} - {Channel}.{SelectedFormat.GetFileExtension()}"
+                    .Replace(Path.GetInvalidFileNameChars(), '_');
+                From = null;
+                To = null;
             });
         }
 
         private void Export()
         {
             _settingsService.LastExportFormat = SelectedFormat;
-            MessengerInstance.Send(new StartExportMessage(Channel, FilePath, SelectedFormat));
+            MessengerInstance.Send(new StartExportMessage(Channel, FilePath, SelectedFormat, From, To));
         }
     }
 }

DiscordChatExporter/ViewModels/IExportSetupViewModel.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using DiscordChatExporter.Models;
 using GalaSoft.MvvmLight.CommandWpf;
 
@@ -11,6 +12,8 @@ namespace DiscordChatExporter.ViewModels
         string FilePath { get; set; }
         IReadOnlyList<ExportFormat> AvailableFormats { get; }
         ExportFormat SelectedFormat { get; set; }
+        DateTime? From { get; set; }
+        DateTime? To { get; set; }
 
         RelayCommand ExportCommand { get; }
     }

DiscordChatExporter/ViewModels/MainViewModel.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using System.Net;
@@ -104,7 +105,7 @@ namespace DiscordChatExporter.ViewModels
             // Messages
             MessengerInstance.Register<StartExportMessage>(this, m =>
             {
-                Export(m.Channel, m.FilePath, m.Format);
+                Export(m.Channel, m.FilePath, m.Format, m.From, m.To);
             });
         }
 
@@ -161,14 +162,14 @@ namespace DiscordChatExporter.ViewModels
             MessengerInstance.Send(new ShowExportSetupMessage(SelectedGuild, channel));
         }
 
-        private async void Export(Channel channel, string filePath, ExportFormat format)
+        private async void Export(Channel channel, string filePath, ExportFormat format, DateTime? from, DateTime? to)
         {
             IsBusy = true;
 
             try
             {
                 // Get messages
-                var messages = await _dataService.GetChannelMessagesAsync(_cachedToken, channel.Id);
+                var messages = await _dataService.GetChannelMessagesAsync(_cachedToken, channel.Id, from, to);
 
                 // Group them
                 var messageGroups = _messageGroupService.GroupMessages(messages);

DiscordChatExporter/Views/ExportSetupDialog.ammy

@@ -33,6 +33,27 @@ UserControl "DiscordChatExporter.Views.ExportSetupDialog" {
       }
     }
 
+    // Date range
+    Grid {
+      #TwoColumns("*", "*")
+
+      DatePicker {
+        Grid.Column: 0
+        Margin: "16 16 8 8"
+        HintAssist.Hint: "From"
+        HintAssist.IsFloating: true
+        SelectedDate: bind From
+      }
+
+      DatePicker {
+        Grid.Column: 1
+        Margin: "8 16 16 8"
+        HintAssist.Hint: "To"
+        HintAssist.IsFloating: true
+        SelectedDate: bind To
+      }
+    }
+
     // Buttons
     @StackPanelHorizontal {
       HorizontalAlignment: Right