// Copyright IBM Corp. 2020, 2026
// SPDX-License-Identifier: BUSL-1.1

package cmd

import (
	"path/filepath"
	"strings"
)

// legacyBinaryName is the name of the upstream HashiCorp Boundary binary. A
// "boundary" symlink to the threshold binary is shipped in packages and
// container images so existing scripts keep working.
const legacyBinaryName = "boundary"

// envNoLegacyNameNotice, when set to a non-empty value, silences the
// deprecation notice printed when the binary is invoked as "boundary".
const envNoLegacyNameNotice = "THRESHOLD_NO_DEPRECATION_NOTICE"

// invokedAsLegacyName reports whether argv0 refers to the legacy "boundary"
// binary name. Directory components and a Windows ".exe" suffix are ignored.
func invokedAsLegacyName(argv0 string) bool {
	// Normalize Windows separators too, since filepath.Base on unix does not
	// treat backslash as a separator.
	argv0 = strings.ReplaceAll(argv0, `\`, "/")
	base := strings.ToLower(filepath.Base(argv0))
	base = strings.TrimSuffix(base, ".exe")
	return base == legacyBinaryName
}

// LegacyNameNotice returns the one-line deprecation notice (including a
// trailing newline) to write to stderr when the binary was invoked as
// "boundary", or an empty string when no notice should be shown. No notice is
// shown for any other invocation name, when shell completion is running
// (COMP_LINE is set, so that a notice never corrupts the user's prompt), or
// when THRESHOLD_NO_DEPRECATION_NOTICE is set. The notice is only ever written
// to stderr so that machine-readable stdout output is unaffected.
//
// getenv is typically os.Getenv.
func LegacyNameNotice(argv0 string, getenv func(string) string) string {
	if !invokedAsLegacyName(argv0) {
		return ""
	}
	if getenv("COMP_LINE") != "" || getenv(envNoLegacyNameNotice) != "" {
		return ""
	}
	return "Note: the 'boundary' command name is deprecated; use 'threshold' instead. " +
		"(Set " + envNoLegacyNameNotice + "=1 to silence this notice.)\n"
}