feat: Initial rewrite of python render tool

src/cli.rs

@@ -0,0 +1,52 @@
+use std::path::PathBuf;
+
+use clap::{Args, Parser, Subcommand};
+use gix_discover::repository::Path;
+
+#[derive(Debug, Parser)]
+#[command(version, about)]
+#[command(propagate_version = true)]
+pub struct Cli {
+    #[command(flatten)]
+    pub global_opts: GlobalOpts,
+
+    #[command(subcommand)]
+    pub command: Commands,
+}
+
+fn path_is_repo(path: &str) -> Result<PathBuf, String> {
+    let path = PathBuf::from(path);
+    let (repo, _trust) = gix_discover::upwards(&path).map_err(|err| err.to_string())?;
+
+    let work_dir = match repo {
+        Path::LinkedWorkTree { work_dir, .. } => work_dir,
+        Path::WorkTree(work_dir) => work_dir,
+        Path::Repository(git_dir) => {
+            return Err(format!(
+                "Repo '{}' has no working directory",
+                git_dir.to_string_lossy()
+            ));
+        }
+    };
+
+    Ok(work_dir)
+}
+
+#[derive(Debug, Args)]
+pub struct GlobalOpts {
+    #[arg(global = true, short, long, action = clap::ArgAction::Count)]
+    /// Use verbose output
+    pub verbose: u8,
+
+    #[arg(global = true, short, long, value_parser = path_is_repo, default_value_os_t = PathBuf::from("."))]
+    /// Path to the repo containing the config files
+    pub repo: PathBuf,
+}
+
+#[derive(Debug, Subcommand)]
+pub enum Commands {
+    /// Generate talos config file
+    Generate,
+    /// Generate completions for your current shell
+    ShellCompletions,
+}