package cli

import (
	"flag"
	"fmt"
)

type CLIOptions struct {
	Input       string
	Verbose     bool
	Explanation bool
}

func ParseOptions(args []string) (*CLIOptions, error) {
	// Parse flags and arguments.
	verbose := flag.Bool("v", false, "Verbosity. If set, the program will print logs.")
	explanation := flag.Bool("x", false, "Explanation. Whether or not to show all reduction steps.")
	flag.Parse()

	if flag.NArg() == 0 {
		return nil, fmt.Errorf("No input given.")
	} else if flag.NArg() > 1 {
		return nil, fmt.Errorf("More than 1 command-line argument.")
	}

	return &CLIOptions{
		Input:       flag.Arg(0),
		Verbose:     *verbose,
		Explanation: *explanation,
	}, nil
}