/// <reference types="@sveltejs/kit" />
/// <reference no-default-lib="true"/>
/// <reference lib="esnext" />
/// <reference lib="webworker" />

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

self.addEventListener('activate', (event) => {
  event.waitUntil(self.clients.claim());
});

// ###### Handle unread badge:
const conversationReadStatus = {
  // Format:
  // conversationId: { lastRead: Optional(Datetime), lastMessage: Datetime }
};

function countUnreadChannels() {
  return Object.entries(conversationReadStatus)
    .map(([conversationId, { lastRead, lastMessage }]) => {
      return !lastRead || lastRead < lastMessage ? 1 : 0;
    })
    .reduce((total, current) => total + current, 0);
}

self.addEventListener('push', (event) => {
  const data = event.data.json();
  if (data.type === 'heartbeat') {
    // Let's show a notification right away so Safari doesn't tell Apple to be
    // mad at us:
    event.waitUntil(
      self.registration.showNotification('Test notification', {
        actions: [],
        body: event.data.text(),
      }),
    );
  }

  if (data.type === 'message' && data.event === 'sent') {
    // Now we can do slower things that might fail:
    conversationReadStatus[data.conversation] ||= { lastRead: null, lastMessage: null };
    conversationReadStatus[data.conversation].lastMessage = new Date();
    event.waitUntil(
      (async () => {
        if (navigator.setAppBadge) {
          await navigator.setAppBadge(countUnreadChannels());
        }
      })(),
    );
  }
});

// The client has to tell us when it has read a conversation:
self.addEventListener('message', (event) => {
  const data = event.data;
  switch (data.type) {
    case 'CONVERSATION_READ':
      conversationReadStatus[data.conversationId] ||= { lastRead: null, lastMessage: null };
      if (data.at) {
        conversationReadStatus[data.conversationId].lastRead = new Date(data.at.ts);
      } else {
        conversationReadStatus[data.conversationId].lastRead = new Date();
      }
      event.waitUntil(
        (async () => {
          if (navigator.setAppBadge) {
            await navigator.setAppBadge(countUnreadChannels());
          }
        })(),
      );
      break;
    default:
      break;
  }
});