const DB_NAME = 'furumi-sw'
const STORE = 'auth'
const KEY = 'bearer'

function openDB() {
  return new Promise((resolve, reject) => {
    const req = indexedDB.open(DB_NAME, 1)
    req.onupgradeneeded = () => req.result.createObjectStore(STORE)
    req.onsuccess = () => resolve(req.result)
    req.onerror = () => reject(req.error)
  })
}

async function getToken() {
  try {
    const db = await openDB()
    return new Promise((resolve) => {
      const tx = db.transaction(STORE, 'readonly')
      const req = tx.objectStore(STORE).get(KEY)
      req.onsuccess = () => resolve(req.result || null)
      req.onerror = () => resolve(null)
    })
  } catch {
    return null
  }
}

self.addEventListener('fetch', (e) => {
  const url = new URL(e.request.url)
  if (url.origin !== self.location.origin || !url.pathname.startsWith('/api/')) return

  e.respondWith(
    (async () => {
      const token = await getToken()
      if (!token) return fetch(e.request)

      const headers = new Headers(e.request.headers)
      headers.set('Authorization', `Bearer ${token}`)
      return fetch(new Request(e.request, { headers }))
    })()
  )
})

self.addEventListener('install', () => self.skipWaiting())
self.addEventListener('activate', (e) => e.waitUntil(self.clients.claim()))