// Copyright 2022 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package internal

import (
	"encoding/json"
	"os"
	"os/exec"
)

// GoEnv returns the value for key in `go env`.
func GoEnv(key string) (string, error) {
	if key == "GOVERSION" {
		if v := os.Getenv(key); v != "" {
			return v, nil
		}
	}
	out, err := exec.Command("go", "env", "-json", key).Output()
	if err != nil {
		return "", err
	}
	env := make(map[string]string)
	if err := json.Unmarshal(out, &env); err != nil {
		return "", err
	}
	return env[key], nil
}