<?php
/**
 * SPDX-FileCopyrightText: 2024 Sascha Nitsch (grumpydeveloper) https://contentnation.net/@grumpydevelop
 * SPDX-License-Identifier: GPL-3.0-or-later
 *
 * @author Sascha Nitsch <grumpydevelop@contentnation.net>
 **/

namespace Federator\Cache;

/**
 * Caching class using redis
 */
class RedisCache implements Cache
{
    /**
     * config data
     *
     * @var array<string, mixed> $config
     */
    private $config;

    /**
     * connection to redis open flag
     *
     * @var bool $connected
     */
    private $connected = false;

    /**
     * connection handle
     *
     * @var \Redis $redis
     */
    private $redis;

    /**
     * user cache time to live in secods
     *
     * @var int $userTTL
     */
    private $userTTL;

    /**
     * public key cache time to live in secods
     *
     * @var int $publicKeyPemTTL
     */
    private $publicKeyPemTTL;

    /**
     * constructor
     */
    public function __construct()
    {
        $config = parse_ini_file('../rediscache.ini');
        if ($config !== false) {
            $this->config = $config;
            $this->userTTL = array_key_exists('userttl', $config) ? intval($config['userttl'], 10) : 60;
            $this->publicKeyPemTTL = array_key_exists('publickeypemttl', $config)
              ? intval($config['publickeypemttl'], 10) : 3600;
        }
    }

    /**
     * connect to redis
     * @return void
     */
    private function connect()
    {
        $this->redis = new \Redis();
        $this->redis->pconnect($this->config['host'], intval($this->config['port'], 10));
        // @phan-suppress-next-line PhanTypeMismatchArgumentInternalProbablyReal
        $this->redis->auth([$this->config['username'], $this->config['password']]);

        // Set the Redis backend for Resque
        $redisUrl = sprintf(
            'redis://%s:%s@%s:%d',
            urlencode($this->config['username']),
            urlencode($this->config['password']),
            $this->config['host'],
            intval($this->config['port'], 10)
        );
        \Resque::setBackend($redisUrl);
    }

    /**
     * create key from session and user
     *
     * @param string $prefix prefix to create name spaces
     * @param string $input key name
     * @return string key
     */
    private static function createKey($prefix, $input)
    {
        return $prefix . '_' . md5($input);
    }

    /**
     * get followers of given user
     *
     * @param string $id user id @unused-param

     * @return \Federator\Data\FedUser[]|false
     */
    public function getFollowersByUser($id)
    {
        error_log("rediscache::getFollowersByUser not implemented");
        return false;
    }

    /**
     * get following of given user
     *
     * @param string $id user id @unused-param

     * @return \Federator\Data\FedUser[]|false
     */
    public function getFollowingByUser($id)
    {
        error_log("rediscache::getFollowingByUser not implemented");
        return false;
    }

    /**
     * Convert jsonData to Activity format
     *
     * @param array<string, mixed> $jsonData the json data from our platfrom @unused-param
     * @param string $articleId the original id of the article (if applicable)
     *                           (used to identify the article in the remote system) @unused-param
     * @return \Federator\Data\ActivityPub\Common\Activity|false
     */
    public function jsonToActivity(array $jsonData, &$articleId)
    {
        error_log("rediscache::jsonToActivity not implemented");
        return false;
    }

    /**
     * get posts by given user
     *
     * @param string $id user id @unused-param
     * @param int $min min timestamp @unused-param
     * @param int $max max timestamp @unused-param
     * @param int $limit limit results @unused-param

     * @return \Federator\Data\ActivityPub\Common\Activity[]|false
     */
    public function getRemotePostsByUser($id, $min, $max, $limit)
    {
        error_log("rediscache::getRemotePostsByUser not implemented");
        return false;
    }

    /**
     * get statistics from remote system
     *
     * @return \Federator\Data\Stats|false
     */
    public function getRemoteStats()
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = 'm_stats';
        $data = $this->redis->get($key);
        if ($data === false) {
            return false;
        }
        $stats = \Federator\Data\Stats::createFromJson($data);
        return $stats;
    }

    /**
     * get remote user by given name
     *
     * @param string $_name user/profile name
     * @return \Federator\Data\User | false
     */
    public function getRemoteUserByName(string $_name)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('u', $_name);
        $data = $this->redis->get($key);
        if ($data === false) {
            return false;
        }
        $user = \Federator\Data\User::createFromJson($data);
        return $user;
    }

    /**
     * get remote federation user by given name
     *
     * @param string $_name user/profile name
     * @return \Federator\Data\FedUser | false
     */
    public function getRemoteFedUserByName(string $_name)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('u', $_name);
        $data = $this->redis->get($key);
        if ($data === false) {
            return false;
        }
        $user = \Federator\Data\FedUser::createFromJson($data);
        return $user;
    }

    /**
     * get remote user by given session
     *
     * @param string $_session session id
     * @param string $_user user/profile name
     * @return \Federator\Data\User | false
     */
    public function getRemoteUserBySession($_session, $_user)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('s', $_session . $_user);
        $data = $this->redis->get($key);
        if ($data === false) {
            return false;
        }
        $user = \Federator\Data\User::createFromJson($data);
        return $user;
    }

    /**
     * Retrieve the public key for a given keyId
     *
     * @param string $keyId The keyId (e.g., actor URL + #main-key)
     * @return string|false The cached public key PEM or false if not found
     */
    public function getPublicKey(string $keyId)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('publickey', $keyId);
        return $this->redis->get($key);
    }

    /**
     * save remote followers by user
     *
     * @param string $user user name @unused-param
     * @param \Federator\Data\FedUser[]|false $followers user followers @unused-param
     * @return void
     */
    public function saveFollowersByUser($user, $followers)
    {
        error_log("rediscache::saveFollowersByUser not implemented");
    }

    /**
     * save remote following for user
     *
     * @param string $user user name @unused-param
     * @param \Federator\Data\FedUser[]|false $following user following @unused-param
     * @return void
     */
    public function saveFollowingByUser($user, $following)
    {
        error_log("rediscache::saveFollowingByUser not implemented");
    }

    /**
     * save remote posts by user
     *
     * @param string $user user name @unused-param
     * @param int $min min timestamp @unused-param
     * @param int $max max timestamp @unused-param
     * @param int $limit limit results @unused-param
     * @param \Federator\Data\ActivityPub\Common\APObject[]|false $posts user posts @unused-param
     * @return void
     */
    public function saveRemotePostsByUser($user, $min, $max, $limit, $posts)
    {
        error_log("rediscache::saveRemotePostsByUser not implemented");
    }

    /**
     * save remote stats
     *
     * @param \Federator\Data\Stats $stats stats to save
     * @return void
     */
    public function saveRemoteStats($stats)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = 'm_stats';
        $serialized = $stats->toJson();
        $this->redis->setEx($key, $this->config['statsttl'], $serialized);
    }

    /**
     * save remote user by name
     *
     * @param string $_name user/profile name
     * @param \Federator\Data\User $user user data
     * @return void
     */
    public function saveRemoteUserByName($_name, $user)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('u', $_name);
        $serialized = $user->toJson();
        $this->redis->setEx($key, $this->userTTL, $serialized);
    }

    /**
     * save remote federation user by given name
     *
     * @param string $_name user/profile name
     * @param \Federator\Data\FedUser $user user data
     * @return void
     */
    public function saveRemoteFedUserByName(string $_name, \Federator\Data\FedUser $user)
    {
        $key = self::createKey('u', $_name);
        $serialized = $user->toJson();
        $this->redis->setEx($key, $this->userTTL, $serialized);
    }

    /**
     * save remote user by given session
     *
     * @param string $_session session id
     * @param string $_user user/profile name
     * @param \Federator\Data\User $user user data
     * @return void
     */
    public function saveRemoteUserBySession($_session, $_user, $user)
    {
        $key = self::createKey('s', $_session . $_user);
        $serialized = $user->toJson();
        $this->redis->setEx($key, $this->userTTL, $serialized);
    }

    /**
     * Save the public key for a given keyId
     *
     * @param string $keyId The keyId (e.g., actor URL + #main-key)
     * @param string $publicKeyPem The public key PEM to cache
     * @return void
     */
    public function savePublicKey(string $keyId, string $publicKeyPem)
    {
        if (!$this->connected) {
            $this->connect();
        }
        $key = self::createKey('publickey', $keyId);
        $this->redis->setEx($key, $this->publicKeyPemTTL, $publicKeyPem);
    }

    /**
     * send target-friendly json from ActivityPub activity
     *
     * @param \Federator\Data\FedUser $sender the user of the sender @unused-param
     * @param \Federator\Data\ActivityPub\Common\Activity $activity the activity @unused-param
     * @return boolean did we successfully send the activity?
     */
    public function sendActivity($sender, $activity)
    {
        return false;
    }

    /**
     * check if the headers include a valid signature
     *
     * @param string[] $headers the headers @unused-param
     * @throws \Federator\Exceptions\PermissionDenied
     * @return string|\Federator\Exceptions\PermissionDenied
     */
    public function checkSignature($headers)
    {
        return new \Federator\Exceptions\PermissionDenied("RedisCache: no signature check");
    }
}

namespace Federator;

/**
 * Function to initialize plugin
 *
 * @param  \Federator\Main $main main instance
 * @return void
 */
function rediscache_load($main)
{
    $rc = new Cache\RedisCache();
    $main->setCache($rc);
}