<?php
/**
 * 存储门面：全站**唯一**的附件读写出口。
 *
 * 三条纪律（照 MovieLog 的教训定，别绕过）：
 *   ① 数据库只存「相对键」（如 avatars/ab12.jpg），绝不存完整 URL ——
 *      换域名、换桶、换前缀都不用改历史数据。
 *   ② 页面绝不手拼路径，一律走 url()。
 *   ③ 云端失败**自动回退本地**，绝不因云配置问题丢用户的文件。
 */

declare(strict_types=1);

namespace App\Storage;

use App\Setting;

final class Storage
{
    public const AVATAR_DIR = 'avatars';

    /** OSS 默认配置模板 */
    public static function ossDefaults(): array
    {
        return [
            'auth_mode'         => 'ak',   // ak | ecs_role
            'access_key_id'     => '',
            'access_key_secret' => '',
            'bucket'            => '',
            'endpoint'          => '',     // 例：oss-cn-beijing.aliyuncs.com（不带 https://）
            'prefix'            => '',     // 桶内前缀，一个桶放多个站点时用
            'ram_role_name'     => '',     // 留空 = 自动取实例绑定的角色
            'custom_domain'     => '',     // 可选，CDN / 自定义域名
            'internal_endpoint' => '1',    // 服务端读取优先走内网
            'https'             => '1',
        ];
    }

    // ---------------- 配置读写 ----------------

    public static function driver(int $familyId): string
    {
        $d = (string)Setting::get($familyId, 'storage_driver', 'local');
        return in_array($d, ['local', 'oss'], true) ? $d : 'local';
    }

    public static function config(int $familyId): array
    {
        $raw = json_decode((string)Setting::get($familyId, 'storage_config_oss', ''), true);
        $saved = is_array($raw) ? $raw : [];
        return array_merge(self::ossDefaults(), $saved);
    }

    public static function saveConfig(int $familyId, string $driver, array $oss): void
    {
        $driver = in_array($driver, ['local', 'oss'], true) ? $driver : 'local';
        Setting::set($familyId, 'storage_driver', $driver);
        Setting::set($familyId, 'storage_config_oss',
            json_encode(array_merge(self::ossDefaults(), $oss), JSON_UNESCAPED_UNICODE));
        EcsMeta::clearCache($familyId);
    }

    /** 配置是否填齐 —— 没填齐就强制退回本地，避免「传到云端、地址却按本地算」的错配 */
    public static function configComplete(int $familyId): bool
    {
        if (self::driver($familyId) !== 'oss') {
            return true;
        }
        $c = self::config($familyId);
        $auth = ($c['auth_mode'] === 'ecs_role')
            || (trim((string)$c['access_key_id']) !== '' && trim((string)$c['access_key_secret']) !== '');
        return $auth && trim((string)$c['bucket']) !== '' && trim((string)$c['endpoint']) !== '';
    }

    /** 实际生效的驱动（配置不全时是 local） */
    public static function effectiveDriver(int $familyId): string
    {
        $want = self::driver($familyId);
        if ($want !== 'local' && !self::configComplete($familyId)) {
            return 'local';
        }
        return $want;
    }

    private static ?StorageDriver $instance = null;
    private static ?int $instanceFor = null;

    public static function disk(int $familyId): StorageDriver
    {
        $id = self::effectiveDriver($familyId);
        if (self::$instance === null || self::$instanceFor !== $familyId || self::$instance->id() !== $id) {
            self::$instance = $id === 'oss'
                ? new OssDriver($familyId, self::config($familyId))
                : new LocalDriver(FB_UPLOADS);
            self::$instanceFor = $familyId;
        }
        return self::$instance;
    }

    // ---------------- 读写 ----------------

    /** 存一个上传的文件；云端失败自动回退本地 */
    public static function putFile(int $familyId, string $srcPath, string $key, ?string $mime = null): array
    {
        $disk = self::disk($familyId);
        $r = $disk->putFile($srcPath, $key, $mime);
        if (!empty($r['ok'])) {
            return $r;
        }
        if ($disk->id() !== 'local') {
            $local = new LocalDriver(FB_UPLOADS);
            $l = $local->putFile($srcPath, $key, $mime);
            if (!empty($l['ok'])) {
                return ['ok' => true, 'error' => '', 'note' => '云端上传失败，已自动存到本地：' . $r['error']];
            }
        }
        return $r;
    }

    public static function putContents(int $familyId, string $binary, string $key, ?string $mime = null): array
    {
        $disk = self::disk($familyId);
        $r = $disk->putContents($binary, $key, $mime);
        if (!empty($r['ok'])) {
            return $r;
        }
        if ($disk->id() !== 'local') {
            $local = new LocalDriver(FB_UPLOADS);
            $l = $local->putContents($binary, $key, $mime);
            if (!empty($l['ok'])) {
                return ['ok' => true, 'error' => '', 'note' => '云端上传失败，已自动存到本地：' . $r['error']];
            }
        }
        return $r;
    }

    public static function delete(int $familyId, string $key): void
    {
        if ($key === '') {
            return;
        }
        // 两个地方都试一遍：历史文件可能只在本地
        self::disk($familyId)->delete($key);
        if (self::effectiveDriver($familyId) !== 'local') {
            (new LocalDriver(FB_UPLOADS))->delete($key);
        }
    }

    /** 读取内容（导出、代理等场景） */
    public static function read(int $familyId, string $key): array
    {
        return self::disk($familyId)->get($key);
    }

    public static function exists(int $familyId, string $key): bool
    {
        if ($key === '') {
            return false;
        }
        if (is_file(FB_UPLOADS . '/' . $key)) {
            return true;    // 本地优先（迁移期两者并存）
        }
        return self::disk($familyId)->exists($key);
    }

    /**
     * **唯一出口**：把相对键变成可访问地址。
     *
     * 读取顺序刻意设计成「本地优先」：
     *   ① 已是绝对地址 → 原样返回
     *   ② 本地有文件 → 走本地（迁移期老文件仍可访问，随时可回滚）
     *   ③ 交给当前驱动
     */
    public static function url(int $familyId, ?string $key): string
    {
        $key = trim((string)$key);
        if ($key === '') {
            return asset('/assets/avatar-default.svg');
        }
        if (preg_match('#^https?://#i', $key)) {
            return $key;
        }
        $key = ltrim($key, '/');
        $local = FB_UPLOADS . '/' . $key;
        if (is_file($local)) {
            return asset('/uploads/' . $key);
        }
        $disk = self::disk($familyId);
        if ($disk->id() === 'local') {
            return asset('/uploads/' . $key);   // 本地也没有 → 让默认头像逻辑兜住
        }
        return $disk->url($key);
    }
}