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

from copy import deepcopy
from decimal import Decimal

from .quote_intent import kg,MISSING_WEIGHT_UNIT
from .quote_edits import ADJUSTMENT_QUESTION,VOLUME_QUESTION


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 apply_quantity_change(result,current,previous):
    from .quote_engine import exact_number

    change=current.get('quantity_change')
    if not change:return False
    if change['kind']=='volume':
        updated=Decimal(current['cbm']) if current['cbm'] is not None else None
        mismatch=False
        if not change['uncertain'] and previous['cbm'] is not None and not previous.get('volume_pending'):
            expected=Decimal(previous['cbm'])+Decimal(change['delta'])
            if updated is not None and updated!=expected:
                mismatch=True
                result['errors'].append('增减体积与您提供的新总体积不一致，请确认调整后的总体积。')
            else:updated=expected
        if change['uncertain'] or updated is None or updated<=0 or mismatch:
            result['volume_pending']=True
            result['errors'].append(VOLUME_QUESTION)
        else:
            result['cbm']=str(updated)
            result['volume_pending']=False
            result['quantity_note']=f'按本次增减更新，总体积为{exact_number(updated)}CBM。'
        return False
    question=ADJUSTMENT_QUESTION
    result['quantity_question']=question
    result['quantity_uncertain']=True
    if change['kind']=='boxes' and (previous['cbm'] is not None or previous.get('volume_pending') or current['cbm'] is not None):
        result['volume_pending']=True
    if change['uncertain'] or previous.get('allocations'):
        result['errors'].append(question)
        return False
    if change['kind']=='weight':
        if previous.get('weight') is None or previous.get('quantity_uncertain') or previous.get('pending_weight'):
            if current['weight'] is None:
                result['errors'].append(question)
                return False
            updated=Decimal(current['weight'])
        else:
            updated=Decimal(previous['weight'])+Decimal(change['delta'])
            if current['weight'] is not None and Decimal(current['weight'])!=updated:
                result['errors'].append('增减量与您提供的新总重不一致，请确认调整后的总重。')
                return False
        if updated<=0:
            result['errors'].append('调整后的总重需要大于0，请确认增减量或新的总重。')
            return False
        result['weight']=str(updated)
    else:
        pieces=deepcopy(previous.get('packages') or [])
        if not pieces or previous.get('quantity_uncertain') or previous.get('pending_weight'):
            result['errors'].append(question)
            return False
        for piece in pieces:
            if not piece.get('dims') and previous['dims']:
                piece.update(dims=previous['dims'],dim_unit=previous['dim_unit'])
        first=pieces[0]
        uniform=all(Decimal(piece['weight'])==Decimal(first['weight'])
                    and all(piece.get(key)==first.get(key) for key in ('dims','dim_unit')) for piece in pieces)
        if uniform:
            first['count']=sum(piece['count'] for piece in pieces)
            pieces=[first]
        delta=change['delta']
        additions=deepcopy(current.get('packages') or [])
        target_count=sum(piece['count'] for piece in pieces)+delta
        declared_count=change.get('declared_boxes')
        if declared_count is not None and declared_count!=target_count:
            result['errors'].append('增减箱数与您提供的新总箱数不一致，请确认调整后的箱数。')
            return False
        if declared_count is not None and additions and sum(piece['count'] for piece in additions)==target_count:
            pieces=additions
        elif delta>0 and additions:
            if sum(piece['count'] for piece in additions)!=delta:
                result['errors'].append(question)
                return False
            pieces.extend(additions)
        elif uniform:
            if delta<0 and additions and any(Decimal(piece['weight'])!=Decimal(first['weight'])
                    or piece.get('dims') and (piece['dims']!=first.get('dims') or piece['dim_unit']!=first.get('dim_unit')) for piece in additions):
                result['errors'].append('减少箱子的重量与原分箱明细不一致，请提供更新后的逐箱明细。')
                return False
            first['count']+=delta
            if first['count']<=0:
                result['errors'].append('调整后的箱数需要大于0，请确认增减量或新的箱数。')
                return False
        else:
            result['errors'].append('原货物包含不同箱规，请提供更新后的逐箱数量和重量。')
            return False
        result['packages']=pieces
        result['boxes']=sum(piece['count'] for piece in pieces)
        result['weight']=str(sum(Decimal(piece['weight'])*piece['count'] for piece in pieces))
        result['dims']=None
        result['cbm']=None
        if result['boxes']<=0 or any(piece['count']<=0 for piece in pieces):
            result['errors'].append('调整后的箱数需要大于0，请确认增减量或新的箱数。')
            return False
        if change.get('declared_weight') is not None and Decimal(change['declared_weight'])!=Decimal(result['weight']):
            result['errors'].append('增减箱数推算的总重与您提供的新总重不一致，请确认更新后的分箱明细。')
            return False
    result['quantity_uncertain']=False
    result['quantity_question']=None
    verb='增加' if Decimal(change['delta'])>0 else '减少'
    delta=exact_number(abs(Decimal(change['delta'])))
    if change['kind']=='boxes':
        old_count=sum(piece['count'] for piece in previous['packages'])
        result['quantity_note']=f'按原{old_count}箱{verb}{delta}箱核算，共{result["boxes"]}箱。'
    elif previous['weight'] is not None and not previous.get('quantity_uncertain'):
        result['quantity_note']=f'按原总重{exact_number(previous["weight"])}KG{verb}{delta}KG核算。'
    else:result['quantity_note']='按您确认的新总重核算。'
    return True


def merge_intent(current,previous):
    from .quote_plans import selected_intent
    current=selected_intent(current,previous)
    result=deepcopy(current)
    excluded={'mode','selection','clear_selection','clear_choice','compare_services','choice_pending','excluded_services','quantity_change','tax_pending','volume_pending','quantity_question',
              'text','errors','dim_unit','quantity_note','quantity_uncertain','preserve_total','metal_weight_update','pending_weight','weight_unit',
              'plan_reference','plan_option','plan_handled'}
    if (current.get('selection') or current.get('clear_selection') or current.get('clear_choice') or current.get('services')) and not current.get('selected_plan_number'):
        excluded.update(('selected_plan_number','plan_unit','plan_destination'))
    if current.get('plan_reference') is not None:excluded.add('plan_unit')
    if current.get('plan_reference') is not None and current.get('warehouse') and previous.get('allocations'):
        excluded.update(('cbm','dims'))
    if any(current.get(key) for key in ('warehouse','postal','zone')) and not current.get('plan_destination'):
        excluded.add('plan_destination')
    unit=current.get('weight_unit')
    pending=previous.get('pending_weight')
    weight_change=current['weight'] is not None or bool(unit and pending is not None)
    weight_change=apply_quantity_change(result,current,previous) or weight_change
    change=current.get('quantity_change')
    if change and change['kind']=='boxes':excluded.update(('dims','cbm','allocations'))
    if change and change['kind']=='volume':excluded.add('dims')
    volume_confirmed=not (change and change['kind']=='boxes') and (current['cbm'] is not None or current['dims']
                      or current.get('packages') and all(piece.get('dims') for piece in current['packages']))
    if previous.get('volume_pending') and not volume_confirmed:result['volume_pending']=True
    if result.get('volume_pending'):
        result['cbm']=None
        excluded.add('cbm')
        result['errors'].append(VOLUME_QUESTION)
    if unit:
        if pending is None:result['errors'].append('请同时提供重量数值和单位，例如800KG。')
        else:result['weight']=str(kg(pending,unit))
    elif pending is not None and current['weight'] is None and current.get('pending_weight') is None:
        result['pending_weight']=pending
        result['errors'].append(MISSING_WEIGHT_UNIT)
    if not current.get('selection') and not current.get('clear_selection') and not current.get('clear_choice') and not current.get('services'):
        result['selection']=previous.get('selection')
    if current.get('clear_selection'):
        excluded.update(('services','kinds','transport','air_only','air_requested'))
    if current.get('compare_services'):excluded.add('services')
    if previous.get('selected_plan_number') and current.get('selection') and not current.get('services'):
        excluded.add('services')
    blocked=[] if current.get('clear_selection') else previous.get('excluded_services') or []
    blocked=list(dict.fromkeys(blocked+(current.get('excluded_services') or [])))
    if current.get('excluded_services'):
        excluded.add('services')
        if any(name in ('海派','海卡','海铁') for name in current['excluded_services']):excluded.add('kinds')
    positives=(current.get('services') or [])+[name for name in ('海派','海卡','海铁') if name in current['text']]
    result['excluded_services']=[name for name in blocked if not any(name in choice or choice in name for choice in positives)] or None
    if current.get('tax_pending') or previous.get('tax_pending') and current['tax'] is None:
        result['tax_pending']=True
        result['tax']=None
        excluded.add('tax')
        result['errors'].append('请明确选择包税或不包税方案。')
    if current.get('choice_pending') or (previous.get('choice_pending') and not current.get('selection')
            and not current.get('services') and not current.get('clear_selection')):
        result['choice_pending']=True
        result['selection']=None
        result['errors'].append('请指定希望使用的渠道，或选择最快、最慢、最便宜方案。')
    if current.get('metal_weight_update') and previous.get('metal_chargeable_weight') is None:
        result['metal_chargeable_weight']=None
        result['errors'].append('请确认铁铝部分的计费重，不能把毛重直接当作计费重。')
    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 weight_change:
        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')
    if (weight_change or any(current.get(k) is not None for k in ('dims','cbm','boxes','packages','allocations','transport','kinds','services','tax'))) and current.get('metal_chargeable_weight') is None:
        excluded.add('metal_chargeable_weight')
    if current.get('material')=='ordinary':excluded.update(('metal_scope','metal_chargeable_weight'))
    if current.get('metal_scope')=='all' and current.get('metal_chargeable_weight') is None:
        excluded.add('metal_chargeable_weight')
    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'] and not (change and change['kind']=='boxes'):
        for piece in pieces:piece.update(dims=current['dims'],dim_unit=current['dim_unit'])
    elif (current['cbm'] is not None or change and change['kind']=='volume') and not (change and change['kind']=='boxes'):
        for piece in pieces:piece.update(dims=None,dim_unit='cm')
    if previous.get('quantity_uncertain') and not weight_change and not current.get('preserve_total'):
        result['quantity_uncertain']=True
        result['quantity_question']=previous.get('quantity_question') or QUANTITY_QUESTION
        result['errors'].append(result['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)
    result['errors']=list(dict.fromkeys(result['errors']))
    return result