<?php

namespace alveolata\conf;

// require_once(DIR_ALVEOLATA . '/definitions.php');
require_once(DIR_ALVEOLATA . '/file/functions.php');
require_once(DIR_ALVEOLATA . '/json/functions.php');
require_once(DIR_ALVEOLATA . '/cache/functions.php');


/**
 * @var \alveolata\cache\interface_cache
 * @author Christian Fraß <frass@greenscale.de>
 */
class _state
{
	public static $path = 'conf.json';
	public static $cache_kind = 'memory';
	public static $cache_parameters = [];
	public static $cache_instance = null;
}


/**
 * @author Christian Fraß <frass@greenscale.de>
 */
function set_cache(
	string $kind,
	array $parameters = []
) : void
{
	_state::$cache_kind = $kind;
	_state::$cache_parameters = $parameters;
}


/**
 * @author Christian Fraß <frass@greenscale.de>
 */
function set_path(
	string $path
) : void
{
	_state::$path = $path;
}


/**
 * @param string $path
 * @param any [$fallback] value to return in case no conf entry was found for the given path
 * @param boolean [$throw_exception] if true, do not return the fallback in case of a missing entry, but throw an exception
 * @return mixed
 * @throw \Exception
 * @author Christian Fraß <frass@greenscale.de>
 */
function get(
	string $path,
	$fallback = null,
	$throw_exception = false
)
{
	// prepare cache
	if (_state::$cache_instance === null) {
		_state::$cache_instance = \alveolata\cache\make(_state::$cache_kind, _state::$cache_parameters);
	}
	// get raw data
	$data = \alveolata\cache\get(
		_state::$cache_instance,
		'data',
		function () {
			$content = \alveolata\file\read(_state::$path);
			$data = \alveolata\json\decode($content);
			return $data;
		}
	);
	// get specific piece of information
	$steps = (($path === '') ? [] : explode('.', $path));
	$value = $data;
	foreach ($steps as $step) {
		if (! array_key_exists($step, $value)) {
			$report = \alveolata\report\make(
				'conf entry not set',
				[
					'path' => $path,
					'fallback' => $fallback,
				]
			);
			if ($throw_exception) {
				throw (\alveolata\report_as_exception($report));
			}
			else {
				\alveolata\log\warning_($report);
				return $fallback;
			}
		}
		else {
			$value = $value[$step];
		}
	}
	return $value;
}

 ?>