Files

67 lines
1.9 KiB
JavaScript

const cloud = require('wx-server-sdk')
cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
const db = cloud.database()
const _ = db.command
function isCloudFileId(v) {
return typeof v === 'string' && v.startsWith('cloud://')
}
function extractMediaId(m) {
if (!m) return ''
if (typeof m === 'string') return m
return m.fileId || m.fileID || m.url || ''
}
// Remove all docs matching `where`, tolerating a collection that was never created.
async function safeRemoveWhere(collection, where) {
try {
await db.collection(collection).where(where).remove()
} catch (e) {
/* collection missing or nothing to remove */
}
}
exports.main = async event => {
const { OPENID } = cloud.getWXContext()
if (!OPENID) throw new Error('no openid in wx context')
if (!event.postId) throw new Error('postId is required')
let postRes
try {
postRes = await db.collection('posts').doc(event.postId).get()
} catch (_) {
return { ok: true } // already gone
}
const post = postRes.data
if (!post) return { ok: true }
if (post.authorOpenid !== OPENID) throw new Error('not allowed')
await db.collection('posts').doc(event.postId).remove()
// Decrement the author's post count (never below 0 in practice).
if (post.authorId) {
await db.collection('users').doc(post.authorId).update({
data: { 'stats.posts': _.inc(-1) }
}).catch(() => {})
}
// Best-effort cleanup of derived data so no orphans linger.
await Promise.all([
safeRemoveWhere('postLikes', { postId: event.postId }),
safeRemoveWhere('postFavorites', { postId: event.postId }),
safeRemoveWhere('comments', { postId: event.postId })
])
// Best-effort removal of the post's uploaded media from storage.
const fileList = (Array.isArray(post.media) ? post.media : [])
.map(extractMediaId)
.filter(isCloudFileId)
if (fileList.length) {
await cloud.deleteCloudFile({ fileList }).catch(() => {})
}
return { ok: true }
}