Initial commit

cloudfunctions/getNearbyPets/index.js

@@ -0,0 +1,76 @@
+const cloud = require('wx-server-sdk')
+cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
+const db = cloud.database()
+const _ = db.command
+
+// 粗略经纬度范围换算（1度≈111km）
+function latDelta(km) { return km / 111 }
+function lngDelta(km, lat) { return km / (111 * Math.cos(lat * Math.PI / 180)) }
+
+function calcDistance(lat1, lng1, lat2, lng2) {
+  const R = 6371
+  const dLat = (lat2 - lat1) * Math.PI / 180
+  const dLng = (lng2 - lng1) * Math.PI / 180
+  const a = Math.sin(dLat / 2) ** 2 +
+    Math.cos(lat1 * Math.PI / 180) * Math.cos(lat2 * Math.PI / 180) * Math.sin(dLng / 2) ** 2
+  return R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)) * 1000 // meters
+}
+
+exports.main = async (event, context) => {
+  const { OPENID } = cloud.getWXContext()
+  const { latitude, longitude, radiusKm = 5 } = event
+
+  if (!latitude || !longitude) {
+    return { code: -1, message: '缺少位置信息' }
+  }
+
+  // 在线判断：60秒内更新过位置的用户为在线
+  const onlineThreshold = new Date(Date.now() - 60 * 1000).toISOString()
+
+  try {
+    const dLat = latDelta(radiusKm)
+    const dLng = lngDelta(radiusKm, latitude)
+
+    const usersRes = await db.collection('users')
+      .where(
+        _.and([
+          { openid: _.neq(OPENID) },  // 排除自己
+          { 'lastLocation.latitude': _.gt(latitude - dLat).and(_.lt(latitude + dLat)) },
+          { 'lastLocation.longitude': _.gt(longitude - dLng).and(_.lt(longitude + dLng)) },
+          { pets: _.exists(true) },
+        ])
+      )
+      .field({
+        openid: true, nickName: true, avatarUrl: true,
+        lastLocation: true, lastSeen: true, isOnline: true,
+        pets: true, location: true, bio: true,
+      })
+      .limit(30)
+      .get()
+
+    const nearby = usersRes.data
+      .map(user => {
+        const userLat = user.lastLocation?.latitude
+        const userLng = user.lastLocation?.longitude
+        if (!userLat || !userLng) return null
+
+        const distance = calcDistance(latitude, longitude, userLat, userLng)
+        if (distance > radiusKm * 1000) return null
+
+        return {
+          userId: user.openid,
+          user,
+          pet: user.pets?.[0] || null,
+          distance,
+          isOnline: user.isOnline && user.lastSeen > onlineThreshold,
+          location: { latitude: userLat, longitude: userLng },
+        }
+      })
+      .filter(Boolean)
+      .sort((a, b) => a.distance - b.distance)
+
+    return { code: 0, data: nearby }
+  } catch (e) {
+    return { code: -1, message: e.message }
+  }
+}