<?php

/**
 * This file is part of CodeIgniter 4 framework.
 *
 * (c) CodeIgniter Foundation <admin@codeigniter.com>
 *
 * For the full copyright and license information, please view
 * the LICENSE file that was distributed with this source code.
 */

namespace CodeIgniter\Cache\Handlers;

use CodeIgniter\Exceptions\CriticalError;
use CodeIgniter\I18n\Time;
use Config\Cache;
use Exception;
use Predis\Client;
use Predis\Collection\Iterator\Keyspace;

/**
 * Predis cache handler
 *
 * @see \CodeIgniter\Cache\Handlers\PredisHandlerTest
 */
class PredisHandler extends BaseHandler
{
    /**
     * Default config
     *
     * @var array
     */
    protected $config = [
        'scheme'   => 'tcp',
        'host'     => '127.0.0.1',
        'password' => null,
        'port'     => 6379,
        'timeout'  => 0,
    ];

    /**
     * Predis connection
     *
     * @var Client
     */
    protected $redis;

    /**
     * Note: Use `CacheFactory::getHandler()` to instantiate.
     */
    public function __construct(Cache $config)
    {
        $this->prefix = $config->prefix;

        if (isset($config->redis)) {
            $this->config = array_merge($this->config, $config->redis);
        }
    }

    /**
     * {@inheritDoc}
     */
    public function initialize()
    {
        try {
            $this->redis = new Client($this->config, ['prefix' => $this->prefix]);
            $this->redis->time();
        } catch (Exception $e) {
            throw new CriticalError('Cache: Predis connection refused (' . $e->getMessage() . ').');
        }
    }

    /**
     * {@inheritDoc}
     */
    public function get(string $key)
    {
        $key = static::validateKey($key);

        $data = array_combine(
            ['__ci_type', '__ci_value'],
            $this->redis->hmget($key, ['__ci_type', '__ci_value'])
        );

        if (! isset($data['__ci_type'], $data['__ci_value']) || $data['__ci_value'] === false) {
            return null;
        }

        switch ($data['__ci_type']) {
            case 'array':
            case 'object':
                return unserialize($data['__ci_value']);

            case 'boolean':
            case 'integer':
            case 'double': // Yes, 'double' is returned and NOT 'float'
            case 'string':
            case 'NULL':
                return settype($data['__ci_value'], $data['__ci_type']) ? $data['__ci_value'] : null;

            case 'resource':
            default:
                return null;
        }
    }

    /**
     * {@inheritDoc}
     */
    public function save(string $key, $value, int $ttl = 60)
    {
        $key = static::validateKey($key);

        switch ($dataType = gettype($value)) {
            case 'array':
            case 'object':
                $value = serialize($value);
                break;

            case 'boolean':
            case 'integer':
            case 'double': // Yes, 'double' is returned and NOT 'float'
            case 'string':
            case 'NULL':
                break;

            case 'resource':
            default:
                return false;
        }

        if (! $this->redis->hmset($key, ['__ci_type' => $dataType, '__ci_value' => $value])) {
            return false;
        }

        if ($ttl !== 0) {
            $this->redis->expireat($key, Time::now()->getTimestamp() + $ttl);
        }

        return true;
    }

    /**
     * {@inheritDoc}
     */
    public function delete(string $key)
    {
        $key = static::validateKey($key);

        return $this->redis->del($key) === 1;
    }

    /**
     * {@inheritDoc}
     *
     * @return int
     */
    public function deleteMatching(string $pattern)
    {
        $matchedKeys = [];

        foreach (new Keyspace($this->redis, $pattern) as $key) {
            $matchedKeys[] = $key;
        }

        return $this->redis->del($matchedKeys);
    }

    /**
     * {@inheritDoc}
     */
    public function increment(string $key, int $offset = 1)
    {
        $key = static::validateKey($key);

        return $this->redis->hincrby($key, 'data', $offset);
    }

    /**
     * {@inheritDoc}
     */
    public function decrement(string $key, int $offset = 1)
    {
        $key = static::validateKey($key);

        return $this->redis->hincrby($key, 'data', -$offset);
    }

    /**
     * {@inheritDoc}
     */
    public function clean()
    {
        return $this->redis->flushdb()->getPayload() === 'OK';
    }

    /**
     * {@inheritDoc}
     */
    public function getCacheInfo()
    {
        return $this->redis->info();
    }

    /**
     * {@inheritDoc}
     */
    public function getMetaData(string $key)
    {
        $key = static::validateKey($key);

        $data = array_combine(['__ci_value'], $this->redis->hmget($key, ['__ci_value']));

        if (isset($data['__ci_value']) && $data['__ci_value'] !== false) {
            $time = Time::now()->getTimestamp();
            $ttl  = $this->redis->ttl($key);

            return [
                'expire' => $ttl > 0 ? $time + $ttl : null,
                'mtime'  => $time,
                'data'   => $data['__ci_value'],
            ];
        }

        return null;
    }

    /**
     * {@inheritDoc}
     */
    public function isSupported(): bool
    {
        return class_exists(Client::class);
    }
}