package cli

import (
	"context"
	"flag"
	"fmt"
	"io"
)

const helpText = `weatherreporter prepares weather reports from normalized forecast data.

Usage:
  weatherreporter --help

Options:
  -h, --help    Show this help message.
`

// Run parses the root command and executes the selected behavior.
func Run(ctx context.Context, args []string, stdout io.Writer, stderr io.Writer) error {
	_ = ctx
	_ = stderr

	fs := flag.NewFlagSet("weatherreporter", flag.ContinueOnError)
	fs.SetOutput(io.Discard)

	help := fs.Bool("help", false, "show help")
	fs.BoolVar(help, "h", false, "show help")

	if err := fs.Parse(args); err != nil {
		return err
	}

	if *help {
		_, err := fmt.Fprint(stdout, helpText)
		return err
	}

	if fs.NArg() > 0 {
		return fmt.Errorf("unknown argument %q", fs.Arg(0))
	}

	_, err := fmt.Fprint(stdout, helpText)
	return err
}