package cli

import (
	"fmt"
	"io"
)

const usage = "Usage:\n  notarius help\n"

// Run executes the command-line interface and returns a process exit code.
func Run(args []string, stdout, stderr io.Writer) int {
	if len(args) == 0 {
		writeUsage(stdout)
		return 0
	}

	switch args[0] {
	case "help", "--help", "-h":
		writeUsage(stdout)
		return 0
	default:
		fmt.Fprintf(stderr, "notarius: unknown command %q\n", args[0])
		writeUsage(stderr)
		return 2
	}
}

func writeUsage(w io.Writer) {
	fmt.Fprint(w, usage)
}