<?php

declare(strict_types=1);

namespace app\common\service;

use app\common\model\User;
use support\Redis;
use support\think\Db;
use Throwable;

/**
 * 热点数据 Redis 缓存：game_config、game_record、user 全行 JSON。
 * Redis 不可用时自动回退为直连数据库。
 */
final class GameHotDataRedis
{
    private const KEY_GC = 'dfw:v1:gc:';

    private const KEY_GR_ID = 'dfw:v1:gr:id:';

    private const KEY_GR_ACTIVE = 'dfw:v1:gr:active';

    private const KEY_GR_LATEST = 'dfw:v1:gr:latest';

    private const KEY_USER = 'dfw:v1:user:';

    public static function enabled(): bool
    {
        return config('game_hot_cache.enabled', true) === true;
    }

    /**
     * @return array<string, mixed>|null
     */
    public static function gameConfigRow(string $configKey): ?array
    {
        if ($configKey === '') {
            return null;
        }
        if (self::enabled()) {
            $cached = self::redisGet(self::KEY_GC . $configKey);
            if ($cached !== null && $cached !== '') {
                $decoded = json_decode($cached, true);
                if (is_array($decoded)) {
                    return $decoded;
                }
            }
        }
        $row = Db::name('game_config')->where('config_key', $configKey)->find();
        if (!$row) {
            return null;
        }
        if (self::enabled()) {
            $ttl = self::intConfig('ttl_game_config', 86400);
            self::redisSetEx(self::KEY_GC . $configKey, $ttl, json_encode($row, JSON_UNESCAPED_UNICODE));
        }
        return $row;
    }

    public static function gameConfigForget(string $configKey): void
    {
        if ($configKey === '') {
            return;
        }
        self::redisDel(self::KEY_GC . $configKey);
    }

    /**
     * @return array<string, mixed>|null
     */
    public static function gameRecordById(int $id): ?array
    {
        if ($id <= 0) {
            return null;
        }
        $key = self::KEY_GR_ID . $id;
        if (self::enabled()) {
            $cached = self::redisGet($key);
            if ($cached !== null && $cached !== '') {
                $decoded = json_decode($cached, true);
                if (is_array($decoded)) {
                    return $decoded;
                }
            }
        }
        $row = Db::name('game_record')->where('id', $id)->find();
        if (!$row) {
            return null;
        }
        if (self::enabled()) {
            $ttl = self::intConfig('ttl_game_record', 60);
            self::redisSetEx($key, $ttl, json_encode($row, JSON_UNESCAPED_UNICODE));
        }
        return $row;
    }

    /**
     * 当前未完全结束的对局（status ∈ 0,1,2,3 中 id 最大的一条）
     *
     * @return array<string, mixed>|null
     */
    public static function gameRecordActive(): ?array
    {
        if (self::enabled()) {
            $cached = self::redisGet(self::KEY_GR_ACTIVE);
            if ($cached !== null && $cached !== '') {
                $decoded = json_decode($cached, true);
                if (is_array($decoded)) {
                    return $decoded;
                }
            }
        }
        $row = Db::name('game_record')->whereIn('status', [0, 1, 2, 3])->order('id', 'desc')->find();
        if (!$row) {
            return null;
        }
        if (self::enabled()) {
            $ttl = self::intConfig('ttl_game_record', 60);
            self::redisSetEx(self::KEY_GR_ACTIVE, $ttl, json_encode($row, JSON_UNESCAPED_UNICODE));
        }
        return $row;
    }

    /**
     * 最新一条对局（含已结束），与 GameRecord::order('id','desc')->find() 一致
     *
     * @return array<string, mixed>|null
     */
    public static function gameRecordLatest(): ?array
    {
        if (self::enabled()) {
            $cached = self::redisGet(self::KEY_GR_LATEST);
            if ($cached !== null && $cached !== '') {
                $decoded = json_decode($cached, true);
                if (is_array($decoded)) {
                    return $decoded;
                }
            }
        }
        $row = Db::name('game_record')->order('id', 'desc')->find();
        if (!$row) {
            return null;
        }
        if (self::enabled()) {
            $ttl = self::intConfig('ttl_game_record', 60);
            self::redisSetEx(self::KEY_GR_LATEST, $ttl, json_encode($row, JSON_UNESCAPED_UNICODE));
        }
        return $row;
    }

    /**
     * 任意 game_record 变更后调用：删除活跃局、最新局及指定 id 缓存
     */
    public static function gameRecordForget(?int $id = null): void
    {
        $keys = [self::KEY_GR_ACTIVE, self::KEY_GR_LATEST];
        if ($id !== null && $id > 0) {
            $keys[] = self::KEY_GR_ID . $id;
        }
        self::redisDel(...$keys);
    }

    /**
     * @return array<string, mixed>|null
     */
    public static function userRow(int $userId): ?array
    {
        if ($userId <= 0) {
            return null;
        }
        $key = self::KEY_USER . $userId;
        if (self::enabled()) {
            $cached = self::redisGet($key);
            if ($cached !== null && $cached !== '') {
                $decoded = json_decode($cached, true);
                if (is_array($decoded)) {
                    return $decoded;
                }
            }
        }
        $row = Db::name('user')->where('id', $userId)->find();
        if (!$row) {
            return null;
        }
        if (self::enabled()) {
            $ttl = self::intConfig('ttl_user', 90);
            self::redisSetEx($key, $ttl, json_encode($row, JSON_UNESCAPED_UNICODE));
        }
        return $row;
    }

    public static function userRemember(User $user): void
    {
        if (!self::enabled()) {
            return;
        }
        $id = $user->getAttr('id');
        $uid = filter_var($id, FILTER_VALIDATE_INT);
        if ($uid === false || $uid <= 0) {
            return;
        }
        $ttl = self::intConfig('ttl_user', 90);
        self::redisSetEx(self::KEY_USER . $uid, $ttl, json_encode($user->toArray(), JSON_UNESCAPED_UNICODE));
    }

    public static function userForget(int $userId): void
    {
        if ($userId <= 0) {
            return;
        }
        self::redisDel(self::KEY_USER . $userId);
    }

    /**
     * 用缓存行构造已存在库的 User（供 Auth 等高频读）
     */
    public static function userModelFromCacheOrDb(int $userId): ?User
    {
        $row = self::userRow($userId);
        if ($row === null) {
            return null;
        }
        return (new User())->newInstance($row);
    }

    private static function intConfig(string $name, int $default): int
    {
        $v = config('game_hot_cache.' . $name, $default);
        if (is_int($v)) {
            return $v > 0 ? $v : $default;
        }
        if (is_numeric($v)) {
            $n = filter_var($v, FILTER_VALIDATE_INT);
            if ($n === false) {
                return $default;
            }

            return $n > 0 ? $n : $default;
        }

        return $default;
    }

    private static function redisGet(string $key): ?string
    {
        try {
            $v = Redis::get($key);
            if ($v === false || $v === null) {
                return null;
            }
            if (!is_string($v)) {
                return null;
            }
            return $v;
        } catch (Throwable) {
            return null;
        }
    }

    private static function redisSetEx(string $key, int $ttl, string $value): void
    {
        try {
            Redis::setEx($key, $ttl, $value);
        } catch (Throwable) {
        }
    }

    private static function redisDel(string ...$keys): void
    {
        if ($keys === []) {
            return;
        }
        try {
            Redis::del(...$keys);
        } catch (Throwable) {
        }
    }
}