<?php

namespace authkit2;

class Authkit2
{
	const LIB_PREFIX = 'authkit2.';

	protected $callbacks;

	protected function __construct()
	{
		if (defined('LARAVEL_START'))
		{
			$this->initializeLaravel();
		}
		else
		{
			$this->initializeNative();
		}
	}

	public static function get()
	{
		static $authkit2;
		if (!isset($authkit2))
		{
			$authkit2 = new Authkit2();
		}
		return $authkit2;
	}

	public function __set(string $name, $value)
	{
		if (!array_key_exists($name, $this->callbacks))
		{
			trigger_error('Undefined property: '.__CLASS__.'::$'.$name, E_USER_WARNING);
			return;
		}

		if (!is_callable($value))
		{
			throw new \Exception('Authkit2::'.$name.' value must be callable');
		}

		$this->callbacks[$name] = $value;
	}

	public static function __callStatic(string $name, array $arguments)
	{
		$authkit2 = static::get();
		if (!isset($authkit2->callbacks[$name]))
		{
			trigger_error('Call to undefined method '.__CLASS__.'::'.$name.'()', E_USER_ERROR);
			return;
		}

		return call_user_func_array($authkit2->callbacks[$name], $arguments);
	}

	protected function cache(string $key, callable $generator)
	{
		$value = static::cache_get($key, null);
		if (!isset($value))
		{
			$value = $generator();
			static::cache_set($key, $value);
		}
		return $value;
	}

	protected function initializeNative()
	{
		$this->callbacks = [
			'session_get' => [$this, 'native_session_get'],
			'session_set' => [$this, 'native_session_set'],
			'cache_get' => [$this, 'native_cache_get'],
			'cache_set' => [$this, 'native_cache_set'],
			'cache' => [$this, 'cache']
		];
	}

	protected function initializeLaravel()
	{
		throw new \Exception('TODO: Implement laravel support');
	}

	protected function native_session_get($key)
	{
		$this->native_session_check();
		return $_SESSION[static::LIB_PREFIX.$key] ?? null;
	}

	protected function native_session_set($key, $value)
	{
		$this->native_session_check();
		$_SESSION[static::LIB_PREFIX.$key] = $value;
	}

	protected function native_session_check()
	{
		if (session_status() == \PHP_SESSION_NONE)
			session_start();
		else if (session_status() == \PHP_SESSION_DISABLED)
			throw new \Exception("Authkit2 requires PHP sessions are enabled");
	}

	protected function native_cache_get($key, $default = null)
	{
		return $default;
	}

	protected function native_cache_set($key, $value)
	{
	}


}