<?php
namespace Civi\CompilePlugin\Util;

class EnvHelper
{

    /**
     * @return string[]
     *   Key-value pairs.
     */
    public static function getAll()
    {
        // Huzza, PHP 7.1
        return getenv();
    }

    /**
     * Set the full environment, precisely.
     *
     * @param array $newEnv
     *   The new environment. Key-value pairs.
     *   All other environment variables will be removed.
     */
    public static function setAll($newEnv)
    {
        $currentEnv = self::getAll();
        $allKeys = array_unique(array_merge(array_keys($currentEnv), array_keys($newEnv)));
        foreach ($allKeys as $key) {
            if (!isset($currentEnv[$key])) {
                static::set($key, $newEnv[$key]);
            } elseif (!isset($newEnv[$key])) {
                static::remove($key);
            } elseif ($currentEnv[$key] !== $newEnv[$key]) {
                static::set($key, $newEnv[$key]);
            }
        }
    }

    /**
     * Add variables to the environment.
     *
     * @param array $vars
     *   The new environment. Key-value pairs.
     */
    public static function add($vars)
    {
        foreach ($vars as $key => $value) {
            static::set($key, $value);
        }
    }

    public static function set(string $key, string $value): void {
        putenv("$key=" . $value);
        $_SERVER[$key] = $_ENV[$key] = $value;
    }

    public static function remove(string $key) {
        putenv($key);
        unset($_SERVER[$key]);
        unset($_ENV[$key]);
    }

}
