checkpoint: pre-refactor state before fixing P0/P1 issues

cloudfunctions/getPosts/index.js

@@ -2,49 +2,119 @@ const cloud = require('wx-server-sdk')
 cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
 const db = cloud.database()
 const _ = db.command
+const $ = db.command.aggregate
 const PAGE_SIZE = 10
 
+// 按 where 条件取一页，时间倒序（关注流 / 个人主页 / 附近兜底共用）
+async function listByWhere(where, skip) {
+  const col = db.collection('posts').where(where)
+  const countRes = await col.count()
+  const res = await col
+    .orderBy('createdAt', 'desc')
+    .skip(skip)
+    .limit(PAGE_SIZE)
+    .get()
+  return {
+    posts: res.data,
+    total: countRes.total,
+    hasMore: skip + res.data.length < countRes.total,
+  }
+}
+
+// 热门：热度分 = (点赞×3 + 评论×5 + 1) / (帖龄小时数 + 2)^1.5
+// 类 Hacker News 的重力衰减，互动加分、随时间下沉；同分按发布时间倒序
+async function listHot(skip) {
+  const countRes = await db.collection('posts').count()
+  const res = await db.collection('posts').aggregate()
+    .addFields({
+      hotScore: $.divide([
+        $.add([
+          $.multiply([$.ifNull(['$likeCount', 0]), 3]),
+          $.multiply([$.ifNull(['$commentCount', 0]), 5]),
+          1,
+        ]),
+        $.pow([
+          $.add([
+            $.divide([$.subtract([new Date(), '$createdAt']), 3600000]),
+            2,
+          ]),
+          1.5,
+        ]),
+      ]),
+    })
+    .sort({ hotScore: -1, createdAt: -1 })
+    .skip(skip)
+    .limit(PAGE_SIZE)
+    .end()
+  return {
+    posts: res.list,
+    total: countRes.total,
+    hasMore: skip + res.list.length < countRes.total,
+  }
+}
+
+// 附近：geo.near 按距离由近到远，依赖 posts.geo 的地理位置索引；
+// 索引未建或查询失败时回退为矩形围栏 + 时间倒序。
+// $near 不支持 count，用多取一条判断 hasMore，total 为近似值
+async function listNearby(latitude, longitude, skip) {
+  try {
+    const res = await db.collection('posts')
+      .where({
+        geo: _.geoNear({
+          geometry: db.Geo.Point(longitude, latitude),
+          maxDistance: 10000,
+        }),
+      })
+      .skip(skip)
+      .limit(PAGE_SIZE + 1)
+      .get()
+    const hasMore = res.data.length > PAGE_SIZE
+    const posts = hasMore ? res.data.slice(0, PAGE_SIZE) : res.data
+    return { posts, total: skip + posts.length + (hasMore ? 1 : 0), hasMore }
+  } catch (e) {
+    return listByWhere(
+      _.and([
+        { 'location.latitude': _.gt(latitude - 0.1) },
+        { 'location.latitude': _.lt(latitude + 0.1) },
+        { 'location.longitude': _.gt(longitude - 0.15) },
+        { 'location.longitude': _.lt(longitude + 0.15) },
+      ]),
+      skip
+    )
+  }
+}
+
 exports.main = async (event, context) => {
   const { OPENID } = cloud.getWXContext()
   const { page = 0, type = 'hot', userId, latitude, longitude } = event
+  const skip = page * PAGE_SIZE
 
   try {
-    let query = db.collection('posts')
-    const skip = page * PAGE_SIZE
+    let result
 
     if (userId) {
       // 某用户的帖子
-      query = query.where({ authorId: userId })
+      result = await listByWhere({ authorId: userId }, skip)
     } else if (type === 'feed') {
-      // 关注的用户帖子
+      // 关注流：我关注的人 + 自己
       const followsRes = await db.collection('follows')
         .where({ followerId: OPENID })
         .field({ followeeId: true })
         .get()
       const followeeIds = followsRes.data.map(f => f.followeeId)
       followeeIds.push(OPENID)
-      query = query.where({ authorId: _.in(followeeIds) })
+      result = await listByWhere({ authorId: _.in(followeeIds) }, skip)
     } else if (type === 'nearby' && latitude && longitude) {
-      // 附近帖子：使用地理围栏查询（简化版，用 geo_near）
-      query = query.where(
-        _.and([
-          { 'location.latitude': _.gt(latitude - 0.1) },
-          { 'location.latitude': _.lt(latitude + 0.1) },
-          { 'location.longitude': _.gt(longitude - 0.15) },
-          { 'location.longitude': _.lt(longitude + 0.15) },
-        ])
-      )
+      result = await listNearby(latitude, longitude, skip)
+    } else {
+      result = await listHot(skip)
     }
-    // type === 'hot' 全量按热度排序
 
-    const total = await query.count()
-    const postsRes = await query
-      .orderBy('createdAt', 'desc')
-      .skip(skip)
-      .limit(PAGE_SIZE)
-      .get()
+    const { posts, total, hasMore } = result
 
-    const posts = postsRes.data
+    if (posts.length === 0) {
+      return { code: 0, data: { list: [], total, hasMore: false } }
+    }
 
     // 批量获取作者信息
     const authorIds = [...new Set(posts.map(p => p.authorId))]
@@ -71,11 +141,7 @@ exports.main = async (event, context) => {
 
     return {
       code: 0,
-      data: {
-        list: enriched,
-        total: total.total,
-        hasMore: skip + posts.length < total.total,
-      },
+      data: { list: enriched, total, hasMore },
     }
   } catch (e) {
     return { code: -1, message: e.message }