Fix media downloading

DiscordChatExporter.Domain/Exporting/ExportContext.cs

@@ -8,6 +8,7 @@ using System.Net.Http;
 using System.Threading.Tasks;
 using DiscordChatExporter.Domain.Discord.Models;
 using DiscordChatExporter.Domain.Internal.Extensions;
+using Tyrrrz.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting
 {
@@ -72,7 +73,13 @@ namespace DiscordChatExporter.Domain.Exporting
                 // We want relative path so that the output files can be copied around without breaking
                 var relativeFilePath = Path.GetRelativePath(Request.OutputBaseDirPath, filePath);
 
-                return $"file:///./{Uri.EscapeDataString(relativeFilePath)}";
+                // Need to properly escape each path segment while keeping the slashes
+                var escapedRelativeFilePath = relativeFilePath
+                    .Split(Path.DirectorySeparatorChar, Path.AltDirectorySeparatorChar)
+                    .Select(Uri.EscapeDataString)
+                    .JoinToString(Path.AltDirectorySeparatorChar.ToString());
+
+                return escapedRelativeFilePath;
             }
             catch (HttpRequestException)
             {

DiscordChatExporter.Domain/Exporting/MediaDownloader.cs

@@ -9,7 +9,7 @@ using DiscordChatExporter.Domain.Internal.Extensions;
 
 namespace DiscordChatExporter.Domain.Exporting
 {
-    internal class MediaDownloader
+    internal partial class MediaDownloader
     {
         private readonly HttpClient _httpClient = Singleton.HttpClient;
         private readonly string _workingDirPath;
@@ -21,33 +21,35 @@ namespace DiscordChatExporter.Domain.Exporting
             _workingDirPath = workingDirPath;
         }
 
-        private string GetRandomSuffix() => Guid.NewGuid().ToString().Replace("-", "").Substring(0, 8);
-
-        private string GetFileNameFromUrl(string url)
-        {
-            var originalFileName = Regex.Match(url, @".+/([^?]*)").Groups[1].Value;
-
-            var fileName = !string.IsNullOrWhiteSpace(originalFileName) ?
-                $"{Path.GetFileNameWithoutExtension(originalFileName)}-{GetRandomSuffix()}{Path.GetExtension(originalFileName)}" :
-                GetRandomSuffix();
-
-            return PathEx.EscapePath(fileName);
-        }
-
-        // HACK: ConfigureAwait() is crucial here to enable sync-over-async in HtmlMessageWriter
         public async ValueTask<string> DownloadAsync(string url)
         {
             if (_pathMap.TryGetValue(url, out var cachedFilePath))
                 return cachedFilePath;
 
             var fileName = GetFileNameFromUrl(url);
-            var filePath = Path.Combine(_workingDirPath, fileName);
+            var filePath = PathEx.MakeUniqueFilePath(Path.Combine(_workingDirPath, fileName));
 
             Directory.CreateDirectory(_workingDirPath);
 
-            await _httpClient.DownloadAsync(url, filePath).ConfigureAwait(false);
+            await _httpClient.DownloadAsync(url, filePath);
 
             return _pathMap[url] = filePath;
         }
     }
+
+    internal partial class MediaDownloader
+    {
+        private static string GetRandomFileName() => Guid.NewGuid().ToString().Replace("-", "").Substring(0, 16);
+
+        private static string GetFileNameFromUrl(string url)
+        {
+            var originalFileName = Regex.Match(url, @".+/([^?]*)").Groups[1].Value;
+
+            var fileName = !string.IsNullOrWhiteSpace(originalFileName)
+                ? originalFileName
+                : GetRandomFileName();
+
+            return PathEx.EscapePath(fileName);
+        }
+    }
 }

DiscordChatExporter.Domain/Internal/Extensions/HttpClientExtensions.cs

@@ -7,14 +7,13 @@ namespace DiscordChatExporter.Domain.Internal.Extensions
 {
     internal static class HttpClientExtensions
     {
-        // HACK: ConfigureAwait() is crucial here to enable sync-over-async in HtmlMessageWriter
         public static async ValueTask DownloadAsync(this HttpClient httpClient, string uri, string outputFilePath)
         {
-            await using var input = await httpClient.GetStreamAsync(uri).ConfigureAwait(false);
+            await using var input = await httpClient.GetStreamAsync(uri);
             var output = File.Create(outputFilePath);
 
-            await input.CopyToAsync(output).ConfigureAwait(false);
+            await input.CopyToAsync(output);
-            await output.DisposeAsync().ConfigureAwait(false);
+            await output.DisposeAsync();
         }
 
         public static async ValueTask<JsonElement> ReadAsJsonAsync(this HttpContent content)

DiscordChatExporter.Domain/Internal/PathEx.cs

@@ -14,5 +14,27 @@ namespace DiscordChatExporter.Domain.Internal
         }
 
         public static string EscapePath(string path) => EscapePath(new StringBuilder(path)).ToString();
+
+        public static string MakeUniqueFilePath(string baseFilePath, int maxAttempts = 100)
+        {
+            if (!File.Exists(baseFilePath))
+                return baseFilePath;
+
+            var baseDirPath = Path.GetDirectoryName(baseFilePath);
+            var baseFileNameWithoutExtension = Path.GetFileNameWithoutExtension(baseFilePath);
+            var baseFileExtension = Path.GetExtension(baseFilePath);
+
+            for (var i = 1; i <= maxAttempts; i++)
+            {
+                var filePath = $"{baseFileNameWithoutExtension} ({i}){baseFileExtension}";
+                if (!string.IsNullOrWhiteSpace(baseDirPath))
+                    filePath = Path.Combine(baseDirPath, filePath);
+
+                if (!File.Exists(filePath))
+                    return filePath;
+            }
+
+            return baseFilePath;
+        }
     }
 }