feat: add with subcommand

src/main.rs

@@ -1,3 +1,60 @@
+use std::process::Command;
+use std::str;
+
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None)]
+#[command(propagate_version = true)]
+struct Cli {
+    #[command(subcommand)]
+    command: Commands,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    With { coauthor_keys: Option<Vec<String>> },
+}
+
 fn main() {
-    println!("Hello, world!");
+    let cli = Cli::parse();
+
+    match &cli.command {
+        Commands::With { coauthor_keys } => {
+            Command::new("git")
+                .arg("config")
+                .arg("--global")
+                .arg("--remove-section")
+                .arg(format!("co-authors.active"))
+                .output()
+                .expect("failed to execute process");
+
+            match coauthor_keys {
+                Some(keys) => {
+                    for key in keys {
+                        let output = Command::new("git")
+                            .arg("config")
+                            .arg("--global")
+                            .arg(format!("chums.{key}"))
+                            .output()
+                            .expect("failed to execute process");
+
+                        assert!(output.status.success());
+
+                        let status = Command::new("git")
+                            .arg("config")
+                            .arg("--global")
+                            .arg(format!("chums.active.{key}"))
+                            .arg(str::from_utf8(&output.stdout).unwrap().trim())
+                            .status()
+                            .expect("failed to execute process");
+
+                        assert!(status.success());
+                    }
+                    return;
+                }
+                None => println!("No co-author keys provided"),
+            }
+        }
+    }
 }