From 2f29be6222835d3d4e9b001a7d595f5e0ba72761 Mon Sep 17 00:00:00 2001
From: PurpleCreativity <thepurplecreativity@gmail.com>
Date: Wed, 17 Jun 2026 22:40:18 +0200
Subject: [PATCH] Better argument handling, make output-dir optional

---
 Program.cs | 56 ++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 37 insertions(+), 19 deletions(-)

diff --git a/Program.cs b/Program.cs
index 675566d..d17f40f 100644
--- a/Program.cs
+++ b/Program.cs
@@ -7,9 +7,9 @@ namespace WSiPBookDownloader;
 
 internal class BookMissingException : Exception
 {
-    public int BookId { get; }
+    public uint BookId { get; }
 
-    public BookMissingException(int bookId)
+    public BookMissingException(uint bookId)
         : base($"Book with ID {bookId} does not exist.")
     {
         BookId = bookId;
@@ -45,28 +45,46 @@ internal class Program
 
     static async Task Main(string[] args)
     {
-        if (args.Length < 2 || args.Length > 4)
+        var onlyCovers = args.Any(arg => arg.Equals("--only-covers", StringComparison.OrdinalIgnoreCase));
+
+        var outputDirectory = Directory.GetCurrentDirectory();
+        var outputDirectoryIndex = Array.FindIndex(args, arg => arg.Equals("--output-dir", StringComparison.OrdinalIgnoreCase));
+        if (outputDirectoryIndex > -1)
         {
-            Log("Usage: [outputDirectory] [startBookId] [endBookId] [--only-covers]", ConsoleColor.DarkRed);
-            return;
+            if (outputDirectoryIndex + 1 >= args.Length)
+            {
+                Log("--output-dir requires a value.", ConsoleColor.DarkRed);
+                return;
+            }
+
+            outputDirectory = args[outputDirectoryIndex + 1];
+
+            if (!Directory.Exists(outputDirectory))
+            {
+                Log($"Output directory \"{outputDirectory}\" does not exist.", ConsoleColor.DarkRed);
+                return;
+            }
         }
 
-        var outputDirectory = args[0];
-        if (!Path.Exists(outputDirectory))
-        {
-            Log($"Output directory \"{outputDirectory}\" does not exist.", ConsoleColor.DarkRed);
-            return;
-        }
+        var positionalArgs = args
+            .Except(
+            [
+                "--only-covers",
+                "--output-dir",
+                outputDirectory
+            ], StringComparer.OrdinalIgnoreCase)
+            .ToArray();
 
-        var startBookId = int.Parse(args[1]);
-        var endBookId = (args.Length >= 3 && int.TryParse(args[2], out var parsedEndBookId))
-            ? parsedEndBookId
+        var startBookId = int.Parse(positionalArgs[0]);
+        var endBookId = positionalArgs.Length > 1
+            ? int.Parse(positionalArgs[1])
             : startBookId;
-        var onlyCovers = args.FirstOrDefault(arg => arg.Equals("--only-covers", StringComparison.OrdinalIgnoreCase)) != null;
 
-        var bookIds = Enumerable.Range(startBookId, endBookId - startBookId + 1);
+        var bookIds = Enumerable.Range(startBookId, endBookId - startBookId + 1).Select(bookId => (uint)bookId);
         var parallelOptions = new ParallelOptions { MaxDegreeOfParallelism = onlyCovers ? 100 : 10 };
 
+        Log($"Output directory: \"{outputDirectory}\"");
+
         await Parallel.ForEachAsync(bookIds, parallelOptions, async (bookId, cancellationToken) =>
         {
             var outputPath = Path.Combine(outputDirectory, $"{bookId}.pdf");
@@ -104,7 +122,7 @@ internal class Program
         });
     }
 
-    private static async Task DownloadBookCoverJpg(int bookId, string outputDir, CancellationToken cancellationToken = default)
+    private static async Task DownloadBookCoverJpg(uint bookId, string outputDir, CancellationToken cancellationToken = default)
     {
         var outputPath = Path.Combine(outputDir, $"{bookId}.jpg");
         if (File.Exists(outputPath))
@@ -126,7 +144,7 @@ internal class Program
         Debug.WriteLine($"Downloaded cover for book {bookId}");
     }
 
-    private static async Task DownloadBookJpg(int bookId, string outputDir, CancellationToken cancellationToken = default)
+    private static async Task DownloadBookJpg(uint bookId, string outputDir, CancellationToken cancellationToken = default)
     {
         var currentPage = 1;
         while (true)
@@ -163,7 +181,7 @@ internal class Program
         }
     }
 
-    private static void BuildPdf(int bookId, string jpgDir, string outputPath)
+    private static void BuildPdf(uint bookId, string jpgDir, string outputPath)
     {
         var pages = Directory.GetFiles(jpgDir, "*.jpg")
             .OrderBy(file => int.Parse(Path.GetFileNameWithoutExtension(file)))