From 08da5d685bd3a0ece9766359bacb9b49a1502bbb Mon Sep 17 00:00:00 2001
From: Oleksii Holub <Oleksii.Holub@3shape.com>
Date: Mon, 25 Jun 2018 17:11:52 +0300
Subject: [PATCH] Prevent choosing invalid from/to dates

---
 DiscordChatExporter.Gui/ViewModels/ExportSetupViewModel.cs | 6 ++++++
 DiscordChatExporter.Gui/Views/ExportSetupDialog.xaml       | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/DiscordChatExporter.Gui/ViewModels/ExportSetupViewModel.cs b/DiscordChatExporter.Gui/ViewModels/ExportSetupViewModel.cs
index 7bab525..12d80ed 100644
--- a/DiscordChatExporter.Gui/ViewModels/ExportSetupViewModel.cs
+++ b/DiscordChatExporter.Gui/ViewModels/ExportSetupViewModel.cs
@@ -93,6 +93,12 @@ namespace DiscordChatExporter.Gui.ViewModels
             // Save format
             _settingsService.LastExportFormat = SelectedFormat;
 
+            // Clamp 'from' and 'to' values
+            if (From > To)
+                From = To;
+            if (To < From)
+                To = From;
+
             // Start export
             MessengerInstance.Send(new StartExportMessage(Channel, FilePath, SelectedFormat, From, To));
         }
diff --git a/DiscordChatExporter.Gui/Views/ExportSetupDialog.xaml b/DiscordChatExporter.Gui/Views/ExportSetupDialog.xaml
index 5fb759c..e24f2ca 100644
--- a/DiscordChatExporter.Gui/Views/ExportSetupDialog.xaml
+++ b/DiscordChatExporter.Gui/Views/ExportSetupDialog.xaml
@@ -36,18 +36,22 @@
                 <ColumnDefinition Width="*" />
             </Grid.ColumnDefinitions>
             <DatePicker
+                x:Name="FromDatePicker"
                 Grid.Row="0"
                 Grid.Column="0"
                 Margin="16,20,8,8"
                 materialDesign:HintAssist.Hint="From (optional)"
                 materialDesign:HintAssist.IsFloating="True"
+                DisplayDateEnd="{Binding SelectedDate, ElementName=ToDatePicker}"
                 SelectedDate="{Binding From}" />
             <DatePicker
+                x:Name="ToDatePicker"
                 Grid.Row="0"
                 Grid.Column="1"
                 Margin="8,20,16,8"
                 materialDesign:HintAssist.Hint="To (optional)"
                 materialDesign:HintAssist.IsFloating="True"
+                DisplayDateStart="{Binding SelectedDate, ElementName=FromDatePicker}"
                 SelectedDate="{Binding To}" />
         </Grid>