john
245 lines
7.9 KiB
JavaScript
245 lines
7.9 KiB
JavaScript
import crypto from 'node:crypto';
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import fs from 'node:fs';
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import path from 'node:path';
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import { fileURLToPath } from 'node:url';
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import { fetch as undiciFetch } from 'undici';
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import { buildPublicUrl, PUBLISH_ROOT_DIR, PUBLIC_ZONE_DIR } from './user-publish.mjs';
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const __dirname = path.dirname(fileURLToPath(import.meta.url));
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const DEFAULT_WECHAT_MEDIA_URL = 'https://api.weixin.qq.com/cgi-bin/media/get';
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const DEFAULT_MAX_IMAGE_BYTES = 10 * 1024 * 1024;
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const DEFAULT_MAX_ATTACHMENT_BYTES = 30 * 1024 * 1024;
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const ALLOWED_IMAGE_MIME_TYPES = new Map([
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['image/jpeg', 'jpg'],
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['image/png', 'png'],
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['image/webp', 'webp'],
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['image/gif', 'gif'],
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]);
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const ALLOWED_ATTACHMENT_EXTENSIONS = new Map([
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['.doc', 'application/msword'],
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['.docx', 'application/vnd.openxmlformats-officedocument.wordprocessingml.document'],
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['.xls', 'application/vnd.ms-excel'],
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['.xlsx', 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet'],
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]);
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function resolveImageExtension(contentType = '', fallbackUrl = '') {
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const normalized = String(contentType ?? '')
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.split(';')[0]
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.trim()
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.toLowerCase();
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if (ALLOWED_IMAGE_MIME_TYPES.has(normalized)) {
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return {
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mimeType: normalized,
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extension: ALLOWED_IMAGE_MIME_TYPES.get(normalized),
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};
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}
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const ext = path.extname(String(fallbackUrl ?? '').split('?')[0]).replace(/^\./, '').toLowerCase();
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if (ext === 'jpg' || ext === 'jpeg') return { mimeType: 'image/jpeg', extension: 'jpg' };
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if (ext === 'png') return { mimeType: 'image/png', extension: 'png' };
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if (ext === 'webp') return { mimeType: 'image/webp', extension: 'webp' };
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if (ext === 'gif') return { mimeType: 'image/gif', extension: 'gif' };
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return null;
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}
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function ensureImageWithinLimit(buffer, maxBytes) {
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if (!Buffer.isBuffer(buffer) || buffer.length === 0) {
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throw new Error('微信图片内容为空');
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}
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if (buffer.length > maxBytes) {
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throw new Error(`图片超过大小限制（${maxBytes} bytes）`);
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}
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}
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function sanitizeAttachmentFilename(filename = '') {
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const basename = path.basename(String(filename ?? '').trim()).replace(/[\u0000-\u001f\u007f]/g, '');
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if (!basename || basename === '.' || basename === '..') {
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throw new Error('微信文件缺少有效文件名');
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}
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const extension = path.extname(basename).toLowerCase();
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const mimeType = ALLOWED_ATTACHMENT_EXTENSIONS.get(extension);
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if (!mimeType) {
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throw new Error('当前服务号文件仅支持 Word（doc/docx）和 Excel（xls/xlsx）');
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}
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return {
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filename: basename.slice(0, 160),
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extension,
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mimeType,
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};
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}
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function ensureAttachmentWithinLimit(buffer, maxBytes) {
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if (!Buffer.isBuffer(buffer) || buffer.length === 0) {
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throw new Error('微信文件内容为空');
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}
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if (buffer.length > maxBytes) {
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throw new Error(`文件超过大小限制（${maxBytes} bytes）`);
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}
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}
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export async function downloadTemporaryMedia(accessToken, mediaId, { wechatFetch = undiciFetch } = {}) {
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if (!accessToken) throw new Error('缺少微信 access_token');
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if (!mediaId) throw new Error('缺少微信 mediaId');
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const url = new URL(DEFAULT_WECHAT_MEDIA_URL);
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url.searchParams.set('access_token', accessToken);
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url.searchParams.set('media_id', mediaId);
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const response = await wechatFetch(url.toString(), {
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method: 'GET',
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headers: { Accept: '*/*' },
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});
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if (!response.ok) {
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const text = await response.text().catch(() => '');
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throw new Error(text || `微信临时素材下载失败 (${response.status})`);
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}
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const contentType = response.headers.get('content-type') || '';
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const buffer = Buffer.from(await response.arrayBuffer());
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return { buffer, contentType };
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}
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export function buildWechatImagePublicUrl({
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publicBaseUrl,
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publishKey,
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filename,
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publicBasePath = `${PUBLIC_ZONE_DIR}/wechat-mp`,
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}) {
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if (!publicBaseUrl) throw new Error('缺少图片公网基础地址');
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if (!publishKey) throw new Error('缺少用户 publish key');
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if (!filename) throw new Error('缺少图片文件名');
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return buildPublicUrl(publicBaseUrl, publishKey, `${publicBasePath}/${filename}`);
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}
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export async function persistWechatImage(
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{
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userId,
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appId,
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openid,
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msgId,
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mediaId,
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picUrl,
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publicBaseUrl,
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maxImageBytes = DEFAULT_MAX_IMAGE_BYTES,
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},
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{
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wechatFetch = undiciFetch,
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accessToken,
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h5Root = __dirname,
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} = {},
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) {
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if (!userId) throw new Error('缺少 userId');
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const publishDir = path.join(h5Root, PUBLISH_ROOT_DIR, String(userId), PUBLIC_ZONE_DIR, 'wechat-mp');
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fs.mkdirSync(publishDir, { recursive: true });
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let source = 'wechat_media';
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let buffer;
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let contentType = '';
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if (mediaId && accessToken) {
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try {
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const downloaded = await downloadTemporaryMedia(accessToken, mediaId, { wechatFetch });
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buffer = downloaded.buffer;
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contentType = downloaded.contentType;
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} catch (error) {
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if (!picUrl) throw error;
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}
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}
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if (!buffer && picUrl) {
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source = 'wechat_pic_url';
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const response = await wechatFetch(picUrl, {
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method: 'GET',
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headers: { Accept: 'image/*,*/*;q=0.8' },
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});
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if (!response.ok) {
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const text = await response.text().catch(() => '');
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throw new Error(text || `微信图片下载失败 (${response.status})`);
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}
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contentType = response.headers.get('content-type') || contentType;
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buffer = Buffer.from(await response.arrayBuffer());
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}
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ensureImageWithinLimit(buffer, maxImageBytes);
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const resolved = resolveImageExtension(contentType, picUrl);
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if (!resolved) {
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throw new Error(`暂不支持的图片类型：${contentType || 'unknown'}`);
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}
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const timestamp = Date.now();
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const hash = crypto.createHash('sha1').update(buffer).digest('hex').slice(0, 12);
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const fileBase = [appId || 'wx', openid || 'openid', msgId || timestamp, mediaId || hash]
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.filter(Boolean)
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.join('-')
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.replace(/[^a-zA-Z0-9._-]+/g, '_')
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.slice(0, 120);
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const filename = `${fileBase}.${resolved.extension}`;
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const absolutePath = path.join(publishDir, filename);
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fs.writeFileSync(absolutePath, buffer);
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return {
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absolutePath,
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bytes: buffer.length,
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contentType: resolved.mimeType,
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filename,
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publicUrl: buildWechatImagePublicUrl({
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publicBaseUrl,
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publishKey: String(userId),
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filename,
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}),
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source,
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};
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}
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export async function persistWechatAttachment(
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{
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userId,
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appId,
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openid,
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msgId,
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mediaId,
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filename,
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publicBaseUrl,
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maxFileBytes = DEFAULT_MAX_ATTACHMENT_BYTES,
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},
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{
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wechatFetch = undiciFetch,
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accessToken,
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h5Root = __dirname,
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} = {},
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) {
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if (!userId) throw new Error('缺少 userId');
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const resolved = sanitizeAttachmentFilename(filename);
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const downloaded = await downloadTemporaryMedia(accessToken, mediaId, { wechatFetch });
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ensureAttachmentWithinLimit(downloaded.buffer, maxFileBytes);
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const publishDir = path.join(h5Root, PUBLISH_ROOT_DIR, String(userId), PUBLIC_ZONE_DIR, 'wechat-mp');
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fs.mkdirSync(publishDir, { recursive: true });
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const timestamp = Date.now();
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const hash = crypto.createHash('sha1').update(downloaded.buffer).digest('hex').slice(0, 12);
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const originalStem = path.basename(resolved.filename, resolved.extension)
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.replace(/[^\p{L}\p{N}._-]+/gu, '_')
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.replace(/^_+|_+$/g, '')
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.slice(0, 80) || 'attachment';
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const identity = [appId || 'wx', openid || 'openid', msgId || timestamp, mediaId || hash]
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.filter(Boolean)
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.join('-')
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.replace(/[^a-zA-Z0-9._-]+/g, '_')
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.slice(0, 100);
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const publicFilename = `${originalStem}-${identity}-${hash}${resolved.extension}`;
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const absolutePath = path.join(publishDir, publicFilename);
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fs.writeFileSync(absolutePath, downloaded.buffer);
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return {
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absolutePath,
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bytes: downloaded.buffer.length,
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contentType: resolved.mimeType,
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filename: resolved.filename,
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publicFilename,
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publicUrl: buildWechatImagePublicUrl({
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publicBaseUrl,
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publishKey: String(userId),
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filename: publicFilename,
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}),
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source: 'wechat_media',
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};
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}
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