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