const V='1'
const send=m=>self.clients.matchAll({type:'window',includeUncontrolled:true}).then(cs=>cs.forEach(c=>c.postMessage(m)))

self.addEventListener('install',e=>{
  self.skipWaiting()
})

self.addEventListener('activate',e=>{
  e.waitUntil((async()=>{await self.clients.claim();await send({type:'SW_ACTIVE',v:V,ts:Date.now()})})())
})

self.addEventListener('message',e=>{
  if(e.data&&e.data.type==='PING'){(e.source||null)?.postMessage({type:'PONG',v:V,ts:Date.now()})||send({type:'PONG',v:V,ts:Date.now()})}
})