<?php
declare(strict_types=1);

namespace Fendx\Cache;

use Redis;
use RedisException;
use Fendx\Core\Config\Config;
use Fendx\Common\Exception\BusinessException;

final class Cache
{
    private static ?Redis $redis = null;
    private static array $config = [];
    private static array $localCache = [];
    private static bool $localCacheEnabled = false;

    public static function configure(array $config): void
    {
        self::$config = $config;
        self::$localCacheEnabled = $config['local_cache'] ?? false;
    }

    private static function getRedis(): Redis
    {
        if (self::$redis === null) {
            self::$redis = self::createRedisConnection();
        }
        return self::$redis;
    }

    private static function createRedisConnection(): Redis
    {
        $redis = new Redis();
        
        $host = self::$config['host'] ?? '127.0.0.1';
        $port = self::$config['port'] ?? 6379;
        $password = self::$config['password'] ?? null;
        $database = self::$config['database'] ?? 0;
        $timeout = self::$config['timeout'] ?? 3.0;

        try {
            $redis->connect($host, $port, $timeout);
            
            if ($password) {
                $redis->auth($password);
            }
            
            $redis->select($database);
            
            return $redis;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'REDIS_CONNECT_FAILED', [
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function get(string $key, mixed $default = null): mixed
    {
        // 先检查本地缓存
        if (self::$localCacheEnabled && isset(self::$localCache[$key])) {
            $item = self::$localCache[$key];
            if ($item['expires'] > time()) {
                return $item['value'];
            }
            unset(self::$localCache[$key]);
        }

        try {
            $value = self::getRedis()->get($key);
            
            if ($value === false) {
                return $default;
            }

            $decoded = json_decode($value, true);
            $result = is_array($decoded) ? $decoded : $value;

            // 更新本地缓存
            if (self::$localCacheEnabled) {
                $ttl = self::getRedis()->ttl($key);
                if ($ttl > 0) {
                    self::$localCache[$key] = [
                        'value' => $result,
                        'expires' => time() + $ttl
                    ];
                }
            }

            return $result;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_GET_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function set(string $key, mixed $value, int $ttl = 3600): bool
    {
        try {
            $serialized = is_scalar($value) ? $value : json_encode($value);
            
            $result = self::getRedis()->setex($key, $ttl, $serialized);

            // 更新本地缓存
            if (self::$localCacheEnabled && $result) {
                self::$localCache[$key] = [
                    'value' => $value,
                    'expires' => time() + $ttl
                ];
            }

            return $result;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_SET_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function delete(string $key): bool
    {
        try {
            $result = self::getRedis()->del($key);
            
            // 清除本地缓存
            if (self::$localCacheEnabled) {
                unset(self::$localCache[$key]);
            }

            return $result > 0;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_DELETE_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function has(string $key): bool
    {
        try {
            return self::getRedis()->exists($key) > 0;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_HAS_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function clear(): bool
    {
        try {
            $result = self::getRedis()->flushDB();
            
            // 清除本地缓存
            if (self::$localCacheEnabled) {
                self::$localCache = [];
            }

            return $result;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_CLEAR_FAILED', [
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function increment(string $key, int $value = 1): int
    {
        try {
            $result = self::getRedis()->incrBy($key, $value);
            
            // 清除本地缓存
            if (self::$localCacheEnabled) {
                unset(self::$localCache[$key]);
            }

            return $result;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_INCREMENT_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function decrement(string $key, int $value = 1): int
    {
        try {
            $result = self::getRedis()->decrBy($key, $value);
            
            // 清除本地缓存
            if (self::$localCacheEnabled) {
                unset(self::$localCache[$key]);
            }

            return $result;
        } catch (RedisException $e) {
            throw new BusinessException(500, 'CACHE_DECREMENT_FAILED', [
                'key' => $key,
                'message' => $e->getMessage()
            ]);
        }
    }

    public static function remember(string $key, callable $callback, int $ttl = 3600): mixed
    {
        $value = self::get($key);
        
        if ($value === null) {
            $value = $callback();
            self::set($key, $value, $ttl);
        }
        
        return $value;
    }

    public static function close(): void
    {
        if (self::$redis !== null) {
            self::$redis->close();
            self::$redis = null;
        }
        self::$localCache = [];
    }
}