Move thewithn CLI definition to a library.

src/bin/thewithn.rs

@@ -4,11 +4,14 @@
 //! thebacknd. The different commands are supposed to be symlinks to this single binary, which acts
 //! differently depending on the symlink name.
 
-use clap::{Parser, Subcommand};
+use clap::{Parser};
 use std::env;
 use std::fs;
 use std::path::Path;
 
+use thebacknd::agent::cli::{Cli, Commands};
+use thebacknd::agent::cli;
+
 /// Thewithn single binary main entry point.
 fn main() {
     let invoked_as = env::args().nth(0).unwrap_or_else(|| String::from("unknown"));
@@ -36,84 +39,46 @@ fn main() {
 
         match invoked_as {
             "current-system" => {
-                let sub_args = CurrentSystemCmd::parse_from(args);
+                let sub_args = cli::CurrentSystemCmd::parse_from(args);
                 handle_current_system(&sub_args);
             }
             "desired-system" => {
-                let sub_args = DesiredSystemCmd::parse_from(args);
+                let sub_args = cli::DesiredSystemCmd::parse_from(args);
                 handle_desired_system(&sub_args);
             }
             "destroy-system" => {
-                let sub_args = DestroySystemCmd::parse_from(args);
+                let sub_args = cli::DestroySystemCmd::parse_from(args);
                 handle_destroy_system(&sub_args);
             }
             "update-system" => {
-                let sub_args = UpdateSystemCmd::parse_from(args);
+                let sub_args = cli::UpdateSystemCmd::parse_from(args);
                 handle_update_system(&sub_args);
             }
             _ => println!("Unknown symlink name: {}", invoked_as),
         }
     }
 }
 
-#[derive(Parser)]
-#[command(name = "thewithn")]
-#[command(about = "A program that behaves differently based on the symlink name or subcommands")]
-struct Cli {
-    #[command(subcommand)]
-    command: Option<Commands>,
-}
-
-#[derive(Subcommand)]
-enum Commands {
-    CurrentSystem(CurrentSystemCmd),
-    DesiredSystem(DesiredSystemCmd),
-    DestroySystem(DestroySystemCmd),
-    UpdateSystem(UpdateSystemCmd),
-}
-
-#[derive(Parser)]
-struct CurrentSystemCmd {
-}
-
-#[derive(Parser)]
-struct DesiredSystemCmd {
-    /// Provide a custom message
-    #[arg(short, long, default_value = "Called as 'desired-system'.")]
-    message: String,
-}
-
-#[derive(Parser)]
-struct DestroySystemCmd {
-    /// Print extra details
-    #[arg(short, long)]
-    details: bool,
-}
-
-#[derive(Parser)]
-struct UpdateSystemCmd {
-}
-
-fn handle_current_system(_args: &CurrentSystemCmd) {
+fn handle_current_system(_args: &cli::CurrentSystemCmd) {
     let current_system_link = "/run/current-system";
     match fs::read_link(current_system_link) {
         Ok(path) => println!("{}", path.display()),
         Err(e) => eprintln!("Failed to read link {}: {}", current_system_link, e),
     }
 }
 
-fn handle_desired_system(args: &DesiredSystemCmd) {
+fn handle_desired_system(args: &cli::DesiredSystemCmd) {
     println!("{}", args.message);
 }
 
-fn handle_destroy_system(args: &DestroySystemCmd) {
+fn handle_destroy_system(args: &cli::DestroySystemCmd) {
     if args.details {
         println!("Called as 'destroy-system' with extra details.");
     } else {
         println!("Called as 'destroy-system'.");
     }
 }
 
-fn handle_update_system(_args: &UpdateSystemCmd) {
+fn handle_update_system(_args: &cli::UpdateSystemCmd) {
     println!("Called as 'update-system'.");
 }

src/lib/thebacknd/agent/cli.rs

@@ -0,0 +1,40 @@
+/// Command-line definition for thebacknd agent binary (called thewithn).
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(name = "thewithn")]
+#[command(about = "A program that behaves differently based on the symlink name or subcommands")]
+pub struct Cli {
+    #[command(subcommand)]
+    pub command: Option<Commands>,
+}
+
+#[derive(Subcommand)]
+pub enum Commands {
+    CurrentSystem(CurrentSystemCmd),
+    DesiredSystem(DesiredSystemCmd),
+    DestroySystem(DestroySystemCmd),
+    UpdateSystem(UpdateSystemCmd),
+}
+
+#[derive(Parser)]
+pub struct CurrentSystemCmd {
+}
+
+#[derive(Parser)]
+pub struct DesiredSystemCmd {
+    /// Provide a custom message
+    #[arg(short, long, default_value = "Called as 'desired-system'.")]
+    pub message: String,
+}
+
+#[derive(Parser)]
+pub struct DestroySystemCmd {
+    /// Print extra details
+    #[arg(short, long)]
+    pub details: bool,
+}
+
+#[derive(Parser)]
+pub struct UpdateSystemCmd {
+}

src/lib/thebacknd/agent/mod.rs

@@ -0,0 +1 @@
+pub mod cli;

src/lib/thebacknd/lib.rs

@@ -1 +1,2 @@
+pub mod agent;
 pub mod client;