/**
 * The service worker, which exists only so a push can arrive when no tab is
 * open. There is deliberately no `fetch` handler and nothing is cached: the
 * page this app is served from carries a credential and is sent `no-store`,
 * so caching it would hand the next visitor somebody else's session.
 *
 * `registration.scope` is the app's root in both places it runs — `/` on an
 * instance of its own, `/i/{id}/` through the portal — which is why the
 * push payload does not carry a URL.
 */

self.addEventListener("push", (event) => {
  const alert = event.data ? event.data.json() : {}
  const scope = new URL(self.registration.scope)
  event.waitUntil(
    self.registration.showNotification(alert.title || "Fluksio", {
      body: alert.body || "",
      // Under the portal the icons are the shared bundle's, not this
      // instance's path.
      icon: scope.pathname.startsWith("/i/")
        ? "/app-shell/icon-192.png"
        : `${scope.pathname}icon-192.png`,
      // The same fault repeating replaces its notification rather than
      // stacking another one up.
      tag: alert.flow || alert.title || "fluksio",
      timestamp: Date.now(),
    }),
  )
})

self.addEventListener("notificationclick", (event) => {
  event.notification.close()
  const scope = self.registration.scope
  event.waitUntil(
    self.clients
      .matchAll({ type: "window", includeUncontrolled: true })
      .then((clients) => {
        // A tab on this instance is already open: raise it rather than
        // opening a second one.
        const open = clients.find((client) => client.url.startsWith(scope))
        if (open) return open.focus()
        return self.clients.openWindow(scope)
      }),
  )
})