// Shell/Process example - demonstrates the Process effect
//
// This script runs shell commands and uses environment variables

fn main(): Unit with {Process, Console} = {
    Console.print("=== Lux Shell Example ===")
    Console.print("")

    // Get current working directory
    let cwd = Process.cwd()
    Console.print("Current directory: " + cwd)
    Console.print("")

    // Get environment variables
    Console.print("Environment variables:")
    match Process.env("USER") {
        Some(user) => Console.print("  USER: " + user),
        None => Console.print("  USER: (not set)")
    }
    match Process.env("HOME") {
        Some(home) => Console.print("  HOME: " + home),
        None => Console.print("  HOME: (not set)")
    }
    match Process.env("SHELL") {
        Some(shell) => Console.print("  SHELL: " + shell),
        None => Console.print("  SHELL: (not set)")
    }
    Console.print("")

    // Run shell commands
    Console.print("Running shell commands:")

    let date = Process.exec("date")
    Console.print("  date: " + String.trim(date))

    let kernel = Process.exec("uname -r")
    Console.print("  kernel: " + String.trim(kernel))

    let files = Process.exec("ls examples/*.lux | wc -l")
    Console.print("  .lux files in examples/: " + String.trim(files))
    Console.print("")

    // Command line arguments
    Console.print("Command line arguments:")
    let args = Process.args()
    let argCount = List.length(args)
    if argCount == 0 then {
        Console.print("  (no arguments)")
    } else {
        Console.print("  Count: " + toString(argCount))
        match List.head(args) {
            Some(first) => Console.print("  First: " + first),
            None => Console.print("  First: (empty)")
        }
    }
}

let result = run main() with {}