<?php

namespace app\common\service;

use app\common\enum\FileEnum;
use app\common\model\file\File;
use app\common\service\storage\engine\Qcloud as QcloudEngine;
use Exception;

/**
 * 浏览器直传 OSS 服务
 * - 目前仅支持腾讯云 COS（qcloud）
 * - 其他 driver 返回 fallback=true，由前端降级到老链路
 *
 * Class DirectUploadService
 * @package app\common\service
 */
class DirectUploadService
{
    /** 视频允许的扩展名（沿用 config/project.file_video） */
    public const TYPE_VIDEO = 'video';
    public const TYPE_VOICE = 'voice';

    /** 默认凭证有效期 30 分钟 */
    public const DEFAULT_DURATION = 1800;

    /** 允许扩展类型 → 大小上限（字节） */
    private const MAX_SIZE = [
        self::TYPE_VIDEO => 2 * 1024 * 1024 * 1024, // 2GB
        self::TYPE_VOICE => 500 * 1024 * 1024, // 500MB
    ];

    /**
     * @notes 签发临时凭证
     * @param string $type
     * @return array
     * @throws Exception
     */
    public static function issueCredentials(string $type): array
    {
        if (!isset(self::MAX_SIZE[$type])) {
            throw new Exception('不支持的上传类型: ' . $type);
        }

        $default = ConfigService::get('storage', 'default', 'local');
        if ($default !== 'qcloud') {
            // 其他 driver 不支持直传，前端降级
            return ['provider' => $default, 'fallback' => true];
        }

        $storageConfig = ConfigService::get('storage', 'qcloud');
        if (empty($storageConfig['bucket']) || empty($storageConfig['region'])
            || empty($storageConfig['access_key']) || empty($storageConfig['secret_key'])) {
            throw new Exception('腾讯云 COS 配置不完整');
        }

        $keyPrefix = self::buildKeyPrefix($type);
        $engine = new QcloudEngine($storageConfig);
        $sts = $engine->getStsCredentials($keyPrefix, self::MAX_SIZE[$type], self::DEFAULT_DURATION);

        return [
            'provider' => 'qcloud',
            'fallback' => false,
            'bucket' => $sts['bucket'],
            'region' => $sts['region'],
            'host' => $sts['host'],
            'cdn_domain' => rtrim((string)($storageConfig['domain'] ?? ''), '/'),
            'key_prefix' => $keyPrefix,
            'max_size' => self::MAX_SIZE[$type],
            'duration' => self::DEFAULT_DURATION,
            'expired_time' => $sts['expiredTime'],
            'start_time' => $sts['startTime'],
            'credentials' => $sts['credentials'],
        ];
    }

    /**
     * @notes 直传完成后的回执：HEAD 校验 + 写 file 表
     * @param array $params {key, type, name, size, content_type, cid, admin_id}
     * @return array {id, cid, type, name, uri, url}
     * @throws Exception
     */
    public static function confirm(array $params): array
    {
        $type = (string)($params['type'] ?? '');
        if (!isset(self::MAX_SIZE[$type])) {
            throw new Exception('不支持的上传类型');
        }

        $default = ConfigService::get('storage', 'default', 'local');
        if ($default !== 'qcloud') {
            throw new Exception('当前存储驱动不支持直传回执');
        }

        $key = ltrim((string)($params['key'] ?? ''), '/');
        $allowedPrefix = self::buildKeyPrefix($type);
        if ($key === '' || strpos($key, $allowedPrefix) !== 0) {
            throw new Exception('对象 Key 非法');
        }

        $storageConfig = ConfigService::get('storage', 'qcloud');
        $engine = new QcloudEngine($storageConfig);
        $head = $engine->headObject($key);
        if ($head === false) {
            throw new Exception('对象未找到，请确认上传是否完成');
        }
        if ($head['size'] <= 0 || $head['size'] > self::MAX_SIZE[$type]) {
            throw new Exception('文件大小超出限制');
        }

        $name = trim((string)($params['name'] ?? ''));
        if ($name === '') {
            $name = basename($key);
        }
        if (strlen($name) > 128) {
            $name = substr($name, 0, 123) . substr($name, -5);
        }

        $file = File::create([
            'cid' => (int)($params['cid'] ?? 0),
            'type' => self::resolveFileType($type),
            'name' => $name,
            'uri' => $key,
            'source' => FileEnum::SOURCE_ADMIN,
            'source_id' => (int)($params['admin_id'] ?? 0),
            'create_time' => time(),
        ]);

        $url = FileService::getFileUrl($key);
        return [
            'id' => $file['id'],
            'cid' => $file['cid'],
            'type' => $file['type'],
            'name' => $file['name'],
            'uri' => $url,
            'url' => $url,
        ];
    }

    private static function buildKeyPrefix(string $type): string
    {
        return 'uploads/' . $type . '/' . date('Ymd') . '/';
    }

    private static function resolveFileType(string $type): int
    {
        return match ($type) {
            self::TYPE_VIDEO => FileEnum::VIDEO_TYPE,
            self::TYPE_VOICE => FileEnum::FILE_TYPE,
            default => FileEnum::FILE_TYPE,
        };
    }
}