修复动态发布与互动问题

cloudfunctions/postDelete/index.js

@@ -0,0 +1,66 @@
+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 }
+}