<?php
namespace Thms\Config;

use Closure;

class Environment
{
	/**
	 * Root path where files are located.
	 * 
	 * @var string
	 */
	protected $path;

	/**
	 * Environments locations.
	 * 
	 * @var array|Closure
	 */
	protected $locations = [];

	/**
	 * Init the Environment class.
	 * 
	 * @param string $path The root path where environments files are located.
	 * @param array|Closure $locations Environment locations - Detection.
	 */ 
	public function __construct($path, $locations)
	{
		$this->path = $path;
		$this->locations = $locations;
	}

	/**
	 * Find which environment we are.
	 * 
	 * @return string
	 */
	public function which()
	{
        // Check if $locations is a closure.
        // This means we're checking for environment variables through the closure.
        if ($this->locations instanceof Closure)
        {
            $callback = $this->locations;
            return $callback();
        }

        // If not using closure, we're using the default detection
        // by comparing the hostname.
		$hostname = gethostname();

		foreach ($this->locations as $location => $name)
		{
			$name = is_array($name) ? $name : [$name];
			if (in_array($hostname, $name))
			{
				return $location;
			}
		}

        return '';
	}

	/**
	 * Load the .env.{$location}.php file.
	 * 
	 * @param string $location
	 * @return array
	 */
	public function load($location)
	{
		if (file_exists($path = $this->getFile($location)))
		{
            return require_once($path);
		}

		return [];
	}

	/**
	 * Check required values.
	 * 
	 * @param array $required The required values to check.
	 * @param array $values
	 * @return bool
	 */
	public function check(array $required, array $values)
	{
		foreach ($required as $key)
		{
			if (!array_key_exists($key, $values))
			{
				return false;
			}
		}

		return true;
	}

	/**
	 * Populate environment vars.
	 * 
	 * @param array $vars The loaded environments vars.
	 * @return void
	 */
	public function populate(array $vars)
	{
		foreach ($vars as $key => $value)
		{
			if (false === getenv($key))
			{
				$_ENV[$key] = $value;
				$_SERVER[$key] = $value;
				putenv("{$key}={$value}");
			}
		}
	}

	/**
	 * Return the .env file path.
	 * 
	 * @param string $location
	 * @return string
	 */
	protected function getFile($location)
	{
		return $this->path.'.env.'.$location.'.php';
	}
}