1 files changed, 39 insertions, 0 deletions
diff --git a/src/Agent.App/Cli/CommandLine.cs b/src/Agent.App/Cli/CommandLine.cs
new file mode 100644
index 0000000..df65080
--- /dev/null
+++ b/src/Agent.App/Cli/CommandLine.cs
@@ -0,0 +1,39 @@
+namespace Agent.App.Cli;
+
+public enum AppCommand { Serve, Check }
+
+public sealed record CommandLine(AppCommand Command, string? ConfigPath, string? Language, string? Transport)
+{
+    public static CommandLine Parse(string[] args)
+    {
+        if (args.Length == 0) throw new CommandLineException("Expected 'serve' or 'check'.");
+        AppCommand command = args[0] switch
+        {
+            "serve" => AppCommand.Serve,
+            "check" => AppCommand.Check,
+            _ => throw new CommandLineException("Expected 'serve' or 'check'.")
+        };
+
+        string? config = null;
+        string? language = null;
+        string? transport = null;
+        for (int i = 1; i < args.Length; i++)
+        {
+            string option = args[i];
+            if (i + 1 >= args.Length) throw new CommandLineException($"Missing value for '{option}'.");
+            string value = args[++i];
+            switch (option)
+            {
+                case "--config" when config is null: config = value; break;
+                case "--lang" when language is null: language = value; break;
+                case "--transport" when command == AppCommand.Serve && transport is null && value is "stdio" or "http": transport = value; break;
+                case "--transport" when command == AppCommand.Check: throw new CommandLineException("--transport is only valid for serve.");
+                case "--transport": throw new CommandLineException("Transport must be stdio or http.");
+                default: throw new CommandLineException($"Unknown or duplicate option '{option}'.");
+            }
+        }
+        return new CommandLine(command, config, language, transport);
+    }
+}
+
+public sealed class CommandLineException(string message) : Exception(message);