working v1.

extension/common.js

@@ -0,0 +1,74 @@
+import browser from 'webextension-polyfill'
+
+export const PERMISSIONS_REQUIRED = {
+  getPublicKey: 1,
+  signEvent: 10
+}
+
+const ORDERED_PERMISSIONS = [
+  [1, ['getPublicKey']],
+  [10, ['signEvent']]
+]
+
+const PERMISSION_NAMES = {
+  getPublicKey: 'read your public key',
+  signEvent: 'sign events using your private key'
+}
+
+export function getAllowedCapabilities(permission) {
+  let requestedMethods = []
+  for (let i = 0; i < ORDERED_PERMISSIONS.length; i++) {
+    let [perm, methods] = ORDERED_PERMISSIONS[i]
+    if (perm > permission) break
+    requestedMethods = requestedMethods.concat(methods)
+  }
+
+  if (requestedMethods.length === 0) return 'nothing'
+
+  return requestedMethods.map(method => PERMISSION_NAMES[method])
+}
+
+export function getPermissionsString(permission) {
+  let capabilities = getAllowedCapabilities(permission)
+
+  return (
+    capabilities.slice(0, -1).join(', ') +
+    ' and ' +
+    capabilities[capabilities.length - 1]
+  )
+}
+
+export async function readPermissions() {
+  let {permissions = {}} = await browser.storage.local.get('permissions')
+
+  // delete expired
+  var needsUpdate = false
+  for (let host in permissions) {
+    if (
+      permissions[host].condition === 'expirable' &&
+      permissions[host].created_at < Date.now() / 1000 - 5 * 60
+    ) {
+      delete permissions[host]
+      needsUpdate = true
+    }
+  }
+  if (needsUpdate) browser.storage.local.set({permissions})
+
+  return permissions
+}
+
+export async function readPermissionLevel(host) {
+  return (await readPermissions())[host]?.level || 0
+}
+
+export async function updatePermission(host, permission) {
+  browser.storage.local.set({
+    permissions: {
+      ...((await browser.storage.local.get('permissions').permissions) || {}),
+      [host]: {
+        ...permission,
+        created_at: Math.round(Date.now() / 1000)
+      }
+    }
+  })
+}