Add option to specify download directory for assets (#989)

Co-authored-by: Oleksii Holub <1935960+Tyrrrz@users.noreply.github.com>

DiscordChatExporter.Cli/Commands/Base/ExportCommandBase.cs

@@ -98,6 +98,20 @@ public abstract class ExportCommandBase : TokenCommandBase
     )]
     public bool ShouldReuseAssets { get; init; }
 
+    private readonly string? _assetsPath;
+
+    [CommandOption(
+        "media-dir",
+        Description = "Download assets to this directory."
+    )]
+    public string? AssetsPath
+    {
+        get => _assetsPath;
+        // Handle ~/ in paths on Unix systems
+        // https://github.com/Tyrrrz/DiscordChatExporter/pull/903
+        init => _assetsPath = value is not null ? Path.GetFullPath(value) : null;
+    }
+    
     [CommandOption(
         "dateformat",
         Description = "Format used when writing dates."
@@ -124,6 +138,14 @@ public abstract class ExportCommandBase : TokenCommandBase
             );
         }
 
+        // Assets directory should only be specified when the download assets option is set
+        if (!string.IsNullOrWhiteSpace(AssetsPath) && !ShouldDownloadAssets)
+        {
+            throw new CommandException(
+                "Option --media-dir cannot be used without --media."
+            );
+        }
+
         // Make sure the user does not try to export all channels into a single file.
         // Output path must either be a directory, or contain template tokens.
         // https://github.com/Tyrrrz/DiscordChatExporter/issues/799
@@ -172,6 +194,7 @@ public abstract class ExportCommandBase : TokenCommandBase
                                     guild,
                                     channel,
                                     OutputPath,
+                                    AssetsPath,
                                     ExportFormat,
                                     After,
                                     Before,

DiscordChatExporter.Core/Exporting/ExportContext.cs

@@ -92,13 +92,19 @@ internal class ExportContext
 
         try
         {
-            var filePath = await _assetDownloader.DownloadAsync(url, cancellationToken);
+            var absoluteFilePath = await _assetDownloader.DownloadAsync(url, cancellationToken);
 
             // We want relative path so that the output files can be copied around without breaking.
             // Base directory path may be null if the file is stored at the root or relative to working directory.
             var relativeFilePath = !string.IsNullOrWhiteSpace(Request.OutputBaseDirPath)
-                ? Path.GetRelativePath(Request.OutputBaseDirPath, filePath)
+                ? Path.GetRelativePath(Request.OutputBaseDirPath, absoluteFilePath)
-                : filePath;
+                : absoluteFilePath;
+
+            // If the assets path is outside of the export directory, fall back to absolute path
+            var filePath = relativeFilePath.StartsWith("..")
+                ? absoluteFilePath
+                : relativeFilePath;
+
 
             // HACK: for HTML, we need to format the URL properly
             if (Request.Format is ExportFormat.HtmlDark or ExportFormat.HtmlLight)
@@ -106,13 +112,14 @@ internal class ExportContext
                 // Need to escape each path segment while keeping the directory separators intact
                 return string.Join(
                     Path.AltDirectorySeparatorChar,
-                    relativeFilePath
+                    filePath
                         .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
                         .Select(Uri.EscapeDataString)
+                        .Select(x => x.Replace("%3A", ":"))
                 );
             }
 
-            return relativeFilePath;
+            return filePath;
         }
         // Try to catch only exceptions related to failed HTTP requests
         // https://github.com/Tyrrrz/DiscordChatExporter/issues/332

DiscordChatExporter.Core/Exporting/ExportRequest.cs

@@ -14,6 +14,7 @@ public partial record ExportRequest(
     Guild Guild,
     Channel Channel,
     string OutputPath,
+    string? AssetsPath,
     ExportFormat Format,
     Snowflake? After,
     Snowflake? Before,
@@ -36,7 +37,18 @@ public partial record ExportRequest(
 
     public string OutputBaseDirPath => Path.GetDirectoryName(OutputBaseFilePath) ?? OutputPath;
 
-    public string OutputAssetsDirPath => $"{OutputBaseFilePath}_Files{Path.DirectorySeparatorChar}";
+    private string? _outputAssetsDirPath;
+    public string OutputAssetsDirPath => _outputAssetsDirPath ??= (
+        AssetsPath is not null
+            ? EvaluateTemplateTokens(
+                    AssetsPath,
+                    Guild,
+                    Channel,
+                    After,
+                    Before
+                  )
+            : $"{OutputBaseFilePath}_Files{Path.DirectorySeparatorChar}"
+        );
 }
 
 public partial record ExportRequest
@@ -83,17 +95,15 @@ public partial record ExportRequest
         return PathEx.EscapeFileName(buffer.ToString());
     }
 
-    private static string GetOutputBaseFilePath(
+    private static string EvaluateTemplateTokens(
+        string path,
         Guild guild,
         Channel channel,
-        string outputPath,
+        Snowflake? after,
-        ExportFormat format,
+        Snowflake? before)
-        Snowflake? after = null,
-        Snowflake? before = null)
     {
-        // Format path
+        return Regex.Replace(
-        var actualOutputPath = Regex.Replace(
+            path,
-            outputPath,
             "%.",
             m => PathEx.EscapeFileName(m.Value switch
             {
@@ -110,8 +120,18 @@ public partial record ExportRequest
                 "%d" => DateTimeOffset.Now.ToString("yyyy-MM-dd"),
                 "%%" => "%",
                 _ => m.Value
-            })
+            }));
-        );
+    }
+
+    private static string GetOutputBaseFilePath(
+        Guild guild,
+        Channel channel,
+        string outputPath,
+        ExportFormat format,
+        Snowflake? after = null,
+        Snowflake? before = null)
+    {
+        var actualOutputPath = EvaluateTemplateTokens(outputPath, guild, channel, after, before);
 
         // Output is a directory
         if (Directory.Exists(actualOutputPath) || string.IsNullOrWhiteSpace(Path.GetExtension(actualOutputPath)))

DiscordChatExporter.Gui/ViewModels/Components/DashboardViewModel.cs

@@ -186,6 +186,7 @@ public class DashboardViewModel : PropertyChangedBase
                             dialog.Guild!,
                             channel,
                             dialog.OutputPath!,
+                            null,
                             dialog.SelectedFormat,
                             dialog.After?.Pipe(Snowflake.FromDate),
                             dialog.Before?.Pipe(Snowflake.FromDate),