"""Apply quote edits in chronological order, including derived carton quantities."""

from copy import deepcopy
from decimal import Decimal


QUANTITY_QUESTION='箱数已更改，请确认新的总重或各箱重量，原分箱明细不能直接套用。'


def merge_intent(current,previous):
    result=deepcopy(current)
    excluded={'mode','text','errors','dim_unit','quantity_note','quantity_uncertain','preserve_total'}
    if current.get('warehouse') or current.get('unknown_warehouses'):
        excluded.update(('postal','zone','zones'))
    elif current.get('postal'):
        excluded.update(('warehouse','warehouses','unknown_warehouses','zone','zones'))
    elif current.get('zone'):
        excluded.update(('warehouse','warehouses','unknown_warehouses','postal'))
    if any(current.get(k) for k in ('warehouse','postal','zone')) and not current.get('unknown_warehouses'):
        excluded.add('unknown_warehouses')
    if any(current.get(k) for k in ('warehouse','unknown_warehouses','postal','zone')) and not current.get('allocations'):
        excluded.add('allocations')
    if current.get('allocations'):excluded.update(('packages','boxes','dims','cbm'))
    if current['transport'] or current['kinds'] or current['services']:excluded.update(('air_only','air_requested'))
    if current['air_only'] or current['tax']=='excluded':excluded.add('kinds')
    if current['weight'] is not None:
        if not current.get('packages'):excluded.add('packages')
        if not current.get('allocations'):excluded.add('allocations')
    if current['dims']:excluded.add('cbm')
    if current['cbm'] is not None:excluded.add('dims')
    for key,value in previous.items():
        if result.get(key) is None and key not in excluded:result[key]=deepcopy(value)
    if current['dims'] is None and 'dims' not in excluded and previous['dims']:
        result['dim_unit']=previous['dim_unit']
    pieces=result.get('packages') or []
    if current['dims']:
        for piece in pieces:piece.update(dims=current['dims'],dim_unit=current['dim_unit'])
    elif current['cbm'] is not None:
        for piece in pieces:piece.update(dims=None,dim_unit='cm')
    if previous.get('quantity_uncertain') and current['weight'] is None and not current.get('preserve_total'):
        result['quantity_uncertain']=True
        result['errors'].append(QUANTITY_QUESTION)
    if pieces and result['boxes']!=sum(p['count'] for p in pieces):
        if current.get('preserve_total'):
            result['packages']=None
        elif len(pieces)==1:
            pieces[0]['count']=result['boxes']
            result['weight']=str(Decimal(pieces[0]['weight'])*result['boxes'])
            result['quantity_note']=f'按每箱{pieces[0]["weight"]}KG不变，更新为{result["boxes"]}箱。'
        else:
            result['packages']=None
            result['quantity_uncertain']=True
            result['errors'].append(QUANTITY_QUESTION)
    return result