package bonfire

import (
	"errors"
	"fmt"
	"io"
	"strings"
)

// UsageError marks a mistake in how a command was called: an unknown
// command or flag, or a wrong number of arguments. Execute returns ExitUsage
// for it.
type UsageError struct {
	Err error
}

func (e *UsageError) Error() string { return e.Err.Error() }

func (e *UsageError) Unwrap() error { return e.Err }

// Usage wraps err as a UsageError; nil stays nil.
func Usage(err error) error {
	if err == nil {
		return nil
	}
	var ue *UsageError
	if errors.As(err, &ue) {
		return err
	}
	return &UsageError{Err: err}
}

// isUsage reports a UsageError in the chain or cobra's unknown command error.
func isUsage(err error) bool {
	var ue *UsageError
	if errors.As(err, &ue) {
		return true
	}
	return strings.HasPrefix(err.Error(), "unknown command")
}

// RenderError writes err to w as the console error block: a blank line,
// "  ERROR  <message>" and a blank line. name is the root name of the binary
// (summer, or the application binary's name).
func RenderError(w io.Writer, name string, err error, g Globals) {
	if err == nil || w == nil {
		return
	}
	_ = name
	_ = g
	fmt.Fprintf(w, "\n  ERROR  %s\n\n", err.Error())
}