<?php

declare(strict_types=1);

namespace App\Framework\Redis;

use Redis;
use RedisException;

/**
 * Managed Redis connection with health checking and reconnection using php-redis extension
 */
final class RedisConnection implements RedisConnectionInterface
{
    private Redis $client;

    private(set) bool $connected = false;

    public function __construct(
        private readonly RedisConfig $config,
        private readonly string $name = 'default'
    ) {
        $this->connect();
    }

    public function getClient(): Redis
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client;
    }

    public function getDatabase(): int
    {
        return $this->config->database;
    }

    public function getName(): string
    {
        return $this->name;
    }

    public function isConnected(): bool
    {
        if (! $this->connected) {
            return false;
        }

        try {
            return $this->client->ping() === '+PONG';
        } catch (RedisException) {
            $this->connected = false;

            return false;
        }
    }

    public function reconnect(): void
    {
        $this->connected = false;
        $this->connect();
    }

    private function connect(): void
    {
        if (! extension_loaded('redis')) {
            throw new RedisConnectionException(
                "Redis extension is not loaded. Please install php-redis extension or use alternative cache drivers."
            );
        }

        $this->client = new Redis();

        try {
            // Connect to Redis
            $success = $this->client->connect(
                $this->config->host,
                $this->config->port,
                $this->config->timeout,
                null, // reserved
                0, // retry_interval
                $this->config->readWriteTimeout
            );

            if (! $success) {
                throw new RedisConnectionException("Failed to connect to Redis server");
            }

            // Authenticate if a password is provided

            if ($this->client->auth($this->config->password) === false) {
                throw new RedisConnectionException("Redis authentication failed");
            }

            // Select database
            if ($this->config->database > 0) {
                if ($this->client->select($this->config->database) === false) {
                    throw new RedisConnectionException("Failed to select Redis database {$this->config->database}");
                }
            }

            // Set additional options
            foreach ($this->config->options as $option => $value) {
                $this->client->setOption($option, $value);
            }

            $this->connected = true;
        } catch (RedisException $e) {
            $this->connected = false;

            throw new RedisConnectionException(
                "Failed to connect to Redis ({$this->name}): " . $e->getMessage() . " with Host: {$this->config->host} and Password: {$this->config->password}",
                previous: $e
            );
        }
    }

    public function flush(): void
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        $this->client->flushDB();
    }

    public function get(string $key): string|false
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->get($key);
    }

    public function set(string $key, string $value, ?int $ttl = null): bool
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        if ($ttl === null) {
            return $this->client->set($key, $value);
        }

        return $this->client->setex($key, $ttl, $value);
    }

    public function delete(string ...$keys): int
    {
        if (empty($keys)) {
            return 0;
        }

        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->del($keys);
    }

    public function exists(string ...$keys): int
    {
        if (empty($keys)) {
            return 0;
        }

        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->exists(...$keys);
    }

    public function ttl(string $key): int
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->ttl($key);
    }

    public function expire(string $key, int $seconds): bool
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->expire($key, $seconds);
    }

    public function incr(string $key, int $by = 1): int
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $by === 1
            ? $this->client->incr($key)
            : $this->client->incrBy($key, $by);
    }

    public function decr(string $key, int $by = 1): int
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $by === 1
            ? $this->client->decr($key)
            : $this->client->decrBy($key, $by);
    }

    public function mGet(array $keys): array
    {
        if (empty($keys)) {
            return [];
        }

        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->mGet($keys);
    }

    public function mSet(array $keyValuePairs): bool
    {
        if (empty($keyValuePairs)) {
            return true;
        }

        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->mSet($keyValuePairs);
    }

    public function command(string $command, string|int ...$arguments): mixed
    {
        if (! $this->isConnected()) {
            $this->reconnect();
        }

        return $this->client->rawCommand($command, ...$arguments);
    }

    /**
     * Close the connection when the object is destroyed
     */
    public function __destruct()
    {
        if ($this->connected && isset($this->client)) {
            try {
                $this->client->close();
            } catch (RedisException) {
                // Ignore disconnection errors during destruction
            }
        }
    }
}