<?php
/**
 * User Configuration Class
 *
 * @file include/Core/PConfig.php
 *
 * @brief Contains the class with methods for user configuration
 */
namespace Friendica\Core;

use Friendica\App;
use Friendica\BaseObject;

/**
 * @brief Management of user configuration storage
 * Note:
 * Please do not store booleans - convert to 0/1 integer values
 * The PConfig::get() functions return boolean false for keys that are unset,
 * and this could lead to subtle bugs.
 */
class PConfig extends BaseObject
{
	private static $config;

	/**
	 * @var \Friendica\Core\Config\IPConfigAdapter
	 */
	private static $adapter = null;

	public static function init($uid)
	{
		$a = self::getApp();

		// Database isn't ready or populated yet
		if (!$a->getMode()->has(App\Mode::DBCONFIGAVAILABLE)) {
			return;
		}

		if (Config::getConfigValue('system', 'config_adapter') == 'preload') {
			self::$adapter = new Config\PreloadPConfigAdapter($uid);
		} else {
			self::$adapter = new Config\JITPConfigAdapter();
		}
	}

	/**
	 * @brief Loads all configuration values of a user's config family into a cached storage.
	 *
	 * All configuration values of the given user are stored in global cache
	 * which is available under the global variable self::$config[$uid].
	 *
	 * @param string $uid    The user_id
	 * @param string $family The category of the configuration value
	 *
	 * @return void
	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
	 */
	public static function load($uid, $family)
	{
		// Database isn't ready or populated yet
		if (!self::getApp()->getMode()->has(App\Mode::DBCONFIGAVAILABLE)) {
			return;
		}

		if (empty(self::$adapter)) {
			self::init($uid);
		}

		self::$adapter->load($uid, $family);
	}

	/**
	 * @brief Get a particular user's config variable given the category name
	 * ($family) and a key.
	 *
	 * Get a particular user's config value from the given category ($family)
	 * and the $key from a cached storage in self::$config[$uid].
	 *
	 * @param string  $uid           The user_id
	 * @param string  $family        The category of the configuration value
	 * @param string  $key           The configuration key to query
	 * @param mixed   $default_value optional, The value to return if key is not set (default: null)
	 * @param boolean $refresh       optional, If true the config is loaded from the db and not from the cache (default: false)
	 *
	 * @return mixed Stored value or null if it does not exist
	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
	 */
	public static function get($uid, $family, $key, $default_value = null, $refresh = false)
	{
		// Database isn't ready or populated yet
		if (!self::getApp()->getMode()->has(App\Mode::DBCONFIGAVAILABLE)) {
			return;
		}

		if (empty(self::$adapter)) {
			self::init($uid);
		}

		return self::$adapter->get($uid, $family, $key, $default_value, $refresh);
	}

	/**
	 * @brief Sets a configuration value for a user
	 *
	 * Stores a config value ($value) in the category ($family) under the key ($key)
	 * for the user_id $uid.
	 *
	 * @note  Please do not store booleans - convert to 0/1 integer values!
	 *
	 * @param string $uid    The user_id
	 * @param string $family The category of the configuration value
	 * @param string $key    The configuration key to set
	 * @param mixed  $value  The value to store
	 *
	 * @return bool Operation success
	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
	 */
	public static function set($uid, $family, $key, $value)
	{
		// Database isn't ready or populated yet
		if (!self::getApp()->getMode()->has(App\Mode::DBCONFIGAVAILABLE)) {
			return false;
		}

		if (empty(self::$adapter)) {
			self::init($uid);
		}

		return self::$adapter->set($uid, $family, $key, $value);
	}

	/**
	 * @brief Deletes the given key from the users's configuration.
	 *
	 * Removes the configured value from the stored cache in self::$config[$uid]
	 * and removes it from the database.
	 *
	 * @param string $uid    The user_id
	 * @param string $family The category of the configuration value
	 * @param string $key    The configuration key to delete
	 *
	 * @return mixed
	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
	 */
	public static function delete($uid, $family, $key)
	{
		// Database isn't ready or populated yet
		if (!self::getApp()->getMode()->has(App\Mode::DBCONFIGAVAILABLE)) {
			return false;
		}

		if (empty(self::$adapter)) {
			self::init($uid);
		}

		return self::$adapter->delete($uid, $family, $key);
	}


	/**
	 * Retrieves a value from the user config cache
	 *
	 * @param int    $uid     User Id
	 * @param string $cat     Config category
	 * @param string $k       Config key
	 * @param mixed  $default Default value if key isn't set
	 *
	 * @return string The value of the config entry
	 */
	public static function getPConfigValue($uid, $cat, $k = null, $default = null)
	{
		$return = $default;

		if (isset(self::$config[$uid][$cat][$k])) {
			$return = self::$config[$uid][$cat][$k];
		} elseif ($k == null && isset(self::$config[$uid][$cat])) {
			$return = self::$config[$uid][$cat];
		}

		return $return;
	}

	/**
	 * Sets a value in the user config cache
	 *
	 * Accepts raw output from the pconfig table
	 *
	 * @param int    $uid User Id
	 * @param string $cat Config category
	 * @param string $k   Config key
	 * @param mixed  $v   Value to set
	 */
	public static function setPConfigValue($uid, $cat, $k, $v)
	{
		// Only arrays are serialized in database, so we have to unserialize sparingly
		$value = is_string($v) && preg_match("|^a:[0-9]+:{.*}$|s", $v) ? unserialize($v) : $v;

		if (!isset(self::$config[$uid]) || !is_array(self::$config[$uid])) {
			self::$config[$uid] = [];
		}

		if (!isset(self::$config[$uid][$cat]) || !is_array(self::$config[$uid][$cat])) {
			self::$config[$uid][$cat] = [];
		}

		self::$config[$uid][$cat][$k] = $value;
	}

	/**
	 * Deletes a value from the user config cache
	 *
	 * @param int    $uid User Id
	 * @param string $cat Config category
	 * @param string $k   Config key
	 */
	public static function deletePConfigValue($uid, $cat, $k)
	{
		if (isset(self::$config[$uid][$cat][$k])) {
			unset(self::$config[$uid][$cat][$k]);
		}
	}
}