/// <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.values(conversationReadStatus)
    .map(({ lastRead, lastMessage }) => {
      return !lastRead || lastRead < lastMessage ? 1 : 0;
    })
    .reduce((total, current) => total + current, 0);
}

self.addEventListener('push', (event) => {
  // 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(),
    }),
  );

  const data = event.data?.json();
  // Now we can do slower things that might fail:
  conversationReadStatus[data.conversationId] ||= { lastRead: null, lastMessage: null };
  conversationReadStatus[data.conversationId].lastMessage = new Date();
  event.waitUntil(
    (async () => {
      if (navigator.setAppBadge) {
        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) {
            navigator.setAppBadge(countUnreadChannels());
          }
        })(),
      );
      break;
    default:
      break;
  }
});