Validate input arguments and improve file upload handling

Added validation to ensure at least one input file is provided. Simplified format argument parsing and modified upload logic to include indexed file names in form data. Minor code formatting adjustments for readability.

Author: Tomas Rutkauskas

ConvertApi.Cli/Program.cs

@@ -31,11 +31,19 @@ public static async Task Main(string[] args)
             {
                 pipeInput.Add(line);
             }
+
             inputFiles = pipeInput.ToArray();
         }
         else
         {
-            inputFiles = args.Skip(2).TakeWhile(arg => !arg.Contains('=')).ToArray();
+            int inputFilesCount = args.Length - 4; // Exclude API token, output file, from-format, and to-format
+            if (inputFilesCount < 1)
+            {
+                Console.WriteLine("Error: At least one input file is required.");
+                return;
+            }
+
+            inputFiles = args.Skip(2).Take(inputFilesCount).ToArray();
         }
 
         // Validate input files
@@ -48,8 +56,8 @@ public static async Task Main(string[] args)
             }
         }
 
-        string fromFormat = Directory.Exists(outputFile) ? (args.Length > 3 ? args[^2] : throw new ArgumentException("[from-format] is required when output path is a folder.")) : Path.GetExtension(inputFiles[0]).Trim('.').ToLower();
-        string toFormat = Directory.Exists(outputFile) ? (args.Length > 4 ? args[^1] : throw new ArgumentException("[to-format] is required when output path is a folder.")) : Path.GetExtension(outputFile).Trim('.').ToLower();
+        string fromFormat = args[^2];
+        string toFormat = args[^1];
 
         var dynamicProperties = args.Skip(2 + inputFiles.Length).Where(arg => arg.Contains('=')).ToDictionary(
             arg => arg.Split('=')[0],
@@ -108,12 +116,17 @@ static async Task ConvertFiles(string apiToken, string fromFormat, string toForm
             }
             else
             {
+                int fileIndex = 0;
                 foreach (var inputFile in inputFiles)
                 {
                     form.Add(new StreamContent(File.OpenRead(inputFile))
                     {
-                        Headers = { ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data") { Name = "files", FileName = Path.GetFileName(inputFile) } }
+                        Headers =
+                        {
+                            ContentDisposition = new System.Net.Http.Headers.ContentDispositionHeaderValue("form-data") { Name = $"files[{fileIndex}]", FileName = Path.GetFileName(inputFile) }
+                        }
                     });
+                    fileIndex++;
                 }
             }
 
@@ -137,7 +150,8 @@ static async Task ConvertFiles(string apiToken, string fromFormat, string toForm
 
                 while ((section = await multipartReader.ReadNextSectionAsync()) != null)
                 {
-                    if (Microsoft.Net.Http.Headers.ContentDispositionHeaderValue.TryParse(section.ContentDisposition, out var contentDisposition) && (contentDisposition.FileName != null || contentDisposition.FileNameStar.HasValue))
+                    if (Microsoft.Net.Http.Headers.ContentDispositionHeaderValue.TryParse(section.ContentDisposition, out var contentDisposition) &&
+                        (contentDisposition.FileName != null || contentDisposition.FileNameStar.HasValue))
                     {
                         var fileName = contentDisposition.FileNameStar.HasValue ? contentDisposition.FileNameStar.Value : contentDisposition.FileName.Value.Trim('"');
                         var filePath = Directory.Exists(outputPath) ? Path.Combine(outputPath, fileName) : Path.Combine(Path.GetDirectoryName(outputPath), fileName);
@@ -157,12 +171,12 @@ static async Task ConvertFiles(string apiToken, string fromFormat, string toForm
                 var errorContent = await response.Content.ReadAsStringAsync();
                 Console.WriteLine($"Error: {response.StatusCode}. Response message: {errorContent}");
             }
-        } 
-    } 
-  
-  static string GetVersion()
+        }
+    }
+
+    static string GetVersion()
     {
         var version = FileVersionInfo.GetVersionInfo(Assembly.GetExecutingAssembly().Location).FileVersion;
         return version ?? "unknown";
     }
-}
+}