// Package cli holds small command-line helpers shared by the sshtools binaries.
package cli

import "strings"

// Split reorders a raw argument list so that Go's flag package can parse it
// even when flags follow positional arguments, as in:
//
//	golink user@host -p secret -port 22 -command uptime
//
// flag.Parse stops at the first non-flag argument, so that raw order would
// otherwise leave every flag unset and silently do the wrong thing. Split walks
// the arguments once and collects flags (together with the value of any flag
// named in takesValue) into flags, and everything else into positional.
//
// The caller is expected to concatenate the results:
//
//	flags, positional := cli.Split(os.Args[1:], valueFlags)
//	fs.Parse(append(flags, positional...))
//
// A literal "--" ends flag processing; everything after it is positional.
func Split(args []string, takesValue map[string]bool) (flags, positional []string) {
	for i := 0; i < len(args); i++ {
		arg := args[i]
		if arg == "--" {
			positional = append(positional, args[i+1:]...)
			break
		}
		if !isFlag(arg) {
			positional = append(positional, arg)
			continue
		}
		flags = append(flags, arg)
		name := strings.TrimLeft(arg, "-")
		if strings.ContainsRune(name, '=') {
			continue // -port=22 carries its value inline
		}
		if takesValue[name] && i+1 < len(args) {
			i++
			flags = append(flags, args[i])
		}
	}
	return flags, positional
}

// isFlag reports whether arg looks like a flag rather than a positional value.
// A bare "-" and negative numbers are treated as positional.
func isFlag(arg string) bool {
	if len(arg) < 2 || arg[0] != '-' {
		return false
	}
	return arg[1] < '0' || arg[1] > '9'
}