"""Ask only for shipment fields absent from the current effective quote."""


def missing_fields(intent):
    fields=[]
    if not (intent['warehouse'] or intent['postal']):fields.append('目的仓码或邮编')
    packages=intent.get('packages') or []
    allocations=intent.get('allocations') or []
    boxes=intent.get('boxes') or packages or allocations and all(part.get('boxes') or part.get('packages') for part in allocations)
    if not boxes:fields.append('箱数')
    if not intent['weight'] and not allocations:
        fields.append('总重或各箱重量')
    elif not packages and not (intent.get('boxes')==1 and intent['weight']) and not (
            allocations and all(part.get('packages') or part.get('boxes')==1 for part in allocations)):
        fields.append('各箱重量')
    dimensions=(intent['dims'] or packages and all(part.get('dims') for part in packages)
                or allocations and all(part.get('packages') and all(box.get('dims') for box in part['packages']) for part in allocations))
    if not dimensions:fields.append('每箱长宽高')
    if intent.get('english'):
        names={'目的仓码或邮编':'destination warehouse code or ZIP code','箱数':'carton count',
               '总重或各箱重量':'total weight or each carton weight','各箱重量':'each carton weight','每箱长宽高':'each carton dimensions'}
        return 'Please provide '+', '.join(names[field] for field in fields)+'.' if fields else None
    return '请补充'+'、'.join(fields)+'，继续核对到仓运费和箱规费用。' if fields else None