// Browser notifications for contact messaging (docs/messages.md): the
// visitor is notified of admin replies, the admin of new visitor
// messages. Permission is requested at one entry point only — right
// after the first message of a fresh thread (the Notification API
// requires a user gesture). A denied permission is permanent in the
// browser, so we never re-ask; a dismissed prompt stays "default" and is
// asked again on the next fresh thread.

export function askNotifyPermission() {
  if (!('Notification' in window) || Notification.permission !== 'default') return
  Notification.requestPermission()
}

// Fire a notification (a no-op without a granted permission). Clicking
// it focuses the site tab and runs onclick (opening the thread/inbox
// view), so the user reliably lands on what was new.
export function notifyMessage(title, body, onclick) {
  if (!('Notification' in window) || Notification.permission !== 'granted') return
  const n = new Notification(title, { body, icon: '/favicon.ico' })
  n.onclick = () => {
    window.focus()
    onclick?.()
    n.close()
  }
}

// The visible text of a server-rendered strict-markdown message (safe to
// parse: the stored html is markdown-it output, never user markup).
export function messageText(html) {
  const div = document.createElement('div')
  div.innerHTML = html
  return (div.textContent || '').trim()
}