/* Tells or toggles for any URL whether the extension should be enabled.
 * Groups URL by their origin; a whole origin is enabled or disabled.
 */

import browser from 'webextension-polyfill'

import listenableStorage from './listenableStorage'

const browserStorage = listenableStorage(browser.storage)

// Whichever is supported.
// XXX Causes data loss when the browser suddenly supports the sync storage area.
const storage = browserStorage.sync || browserStorage.local

const keyForUrl = url => {
  const origin = new URL(url).origin
  return `enable_on_origin_${origin}`
}

export async function disable(url) {
  await storage.set({ [keyForUrl(url)]: false })
}

export async function enable(url) {
  await storage.set({ [keyForUrl(url)]: true })
}

export async function toggleEnabled(url) {
  const enabled = await isEnabled(url)
  if (enabled) {
    await disable(url)
  } else {
    await enable(url)
  }
}

export async function isEnabled(url, defaultValue = true) {
  const key = keyForUrl(url)
  const result = await storage.get({ [key]: defaultValue })
  return result[key]
}

export function onEnabledChange(url, cb) {
  storage.onChanged(keyForUrl(url), cb)
}