v0.0.4

cloudfunctions/followToggle/index.js

@@ -0,0 +1,47 @@
+const cloud = require('wx-server-sdk')
+
+cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
+const db = cloud.database()
+
+exports.main = async event => {
+  const { OPENID } = cloud.getWXContext()
+  if (!OPENID) throw new Error('no openid in wx context')
+  const { targetUserId, follow } = event
+  if (!targetUserId) throw new Error('targetUserId is required')
+
+  const meRes = await db.collection('users').where({ openid: OPENID }).limit(1).get()
+  if (!meRes.data.length) throw new Error('user not found')
+  const meId = meRes.data[0]._id
+  if (meId === targetUserId) throw new Error('cannot follow yourself')
+
+  const targetRes = await db.collection('users').doc(targetUserId).get().catch(() => null)
+  const target = targetRes && targetRes.data
+  if (!target) throw new Error('target user not found')
+
+  const existing = await db.collection('follows')
+    .where({ followerId: meId, followeeId: targetUserId })
+    .limit(1)
+    .get()
+
+  if (follow && !existing.data.length) {
+    await db.collection('follows').add({
+      data: {
+        followerId: meId,
+        followerOpenid: OPENID,
+        followeeId: targetUserId,
+        followeeOpenid: target.openid,
+        createdAt: Date.now()
+      }
+    })
+  } else if (!follow && existing.data.length) {
+    await db.collection('follows').doc(existing.data[0]._id).remove()
+  }
+
+  // A friendship (汪友) is a mutual follow.
+  const back = await db.collection('follows')
+    .where({ followerId: targetUserId, followeeId: meId })
+    .limit(1)
+    .get()
+
+  return { following: Boolean(follow), mutual: Boolean(follow) && back.data.length > 0 }
+}