// Typed text in a field that applies on change, so unsaved work includes text not applied yet.

import type { ActionReturn } from 'svelte/action'

export interface DraftOptions {
  /** The value the field shows when nothing is typed: the applied one. */
  value: string
  ondraft: (pending: boolean) => void
}

/** Action reporting whether a text field holds typed text that differs from its applied value. */
export function draft(node: HTMLInputElement | HTMLTextAreaElement, opts: DraftOptions): ActionReturn<DraftOptions> {
  let o = opts
  const check = () => o.ondraft(node.value !== o.value)
  node.addEventListener('input', check)
  return {
    update(next) {
      o = next
      check()
    },
    destroy() {
      node.removeEventListener('input', check)
      o.ondraft(false)
    },
  }
}

/** Applies the focused field's typed text by ending its edit, which fires its change event, then refocuses it. */
export function commitFocused(): void {
  const el = document.activeElement
  if (!(el instanceof HTMLInputElement || el instanceof HTMLTextAreaElement)) return
  el.blur()
  el.focus()
}