v0.0.4

cloudfunctions/nearbyPets/index.js

@@ -0,0 +1,70 @@
+const cloud = require('wx-server-sdk')
+
+cloud.init({ env: cloud.DYNAMIC_CURRENT_ENV })
+const db = cloud.database()
+
+function hashId(id) {
+  let h = 5381
+  for (let i = 0; i < id.length; i++) {
+    h = ((h << 5) + h) ^ id.charCodeAt(i)
+    h = h >>> 0 // keep as unsigned 32-bit
+  }
+  return h
+}
+
+// Generate a stable map pin position from pet id (fallback abstract layer)
+function stablePin(id) {
+  const h = hashId(id)
+  const left = 10 + (h % 70)
+  const top = 15 + ((h >> 8) % 55)
+  return { left, top }
+}
+
+// Scatter a pet deterministically within roughly ±0.9km of the user, so on a
+// real map markers cluster nearby (stable per pet id across requests).
+function syntheticCoord(id, userLoc) {
+  const h = hashId(id)
+  const dLat = ((h % 1600) - 800) / 100000 // ±0.008° ≈ ±0.9km
+  const dLng = (((h >> 8) % 1600) - 800) / 100000
+  return { latitude: userLoc.latitude + dLat, longitude: userLoc.longitude + dLng }
+}
+
+// Rough distance text from coordinate delta (fallback when no real distance)
+function distanceText(petLoc, userLoc) {
+  if (!petLoc || !userLoc) return null
+  const R = 6371000
+  const dLat = ((petLoc.latitude - userLoc.latitude) * Math.PI) / 180
+  const dLon = ((petLoc.longitude - userLoc.longitude) * Math.PI) / 180
+  const a =
+    Math.sin(dLat / 2) ** 2 +
+    Math.cos((userLoc.latitude * Math.PI) / 180) *
+      Math.cos((petLoc.latitude * Math.PI) / 180) *
+      Math.sin(dLon / 2) ** 2
+  const meters = Math.round(R * 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a)))
+  if (meters < 1000) return `${meters}m`
+  return `${(meters / 1000).toFixed(1)}km`
+}
+
+exports.main = async event => {
+  const filter = event.filters?.type || 'all'
+  const userLoc = event.location || null
+  const query = {}
+  if (filter === 'dog' || filter === 'cat') query.species = filter
+  if (filter === 'online') query.online = true
+
+  const res = await db.collection('pets').where(query).limit(50).get()
+
+  const list = res.data.map(pet => {
+    const realCoord = pet.location && typeof pet.location.latitude === 'number' ? pet.location : null
+    const coord = realCoord || (userLoc ? syntheticCoord(pet._id, userLoc) : null)
+    return {
+      ...pet,
+      latitude: coord ? coord.latitude : undefined,
+      longitude: coord ? coord.longitude : undefined,
+      distanceText: distanceText(coord, userLoc) || pet.distanceText || null,
+      pin: stablePin(pet._id)
+    }
+  })
+
+  return { list }
+}