"""Bounded quote matching and Decimal arithmetic, independent of Flask/models."""

from decimal import Decimal, ROUND_HALF_UP
import re

from .pricing import dims_to_cm


from .quote_intent import US, QUOTE_WORDS, parse_intent, is_followup


def broad_zone(postal):
    if not postal:
        return None
    if postal.startswith(('8','9')):
        return '美西'
    if postal.startswith('46') or postal[0] in '0123':
        return '美东'
    return '美中'


def variants(intent, book):
    if intent.get('allocations'):
        return [{**destination,'allocation':part} for part in intent['allocations']
                for destination in variants({**intent,'allocations':None,'warehouse':part['warehouse'],
                    'warehouses':None,'postal':None},book)]
    if len(intent.get('warehouses') or [])>1:
        return [variant for warehouse in intent['warehouses'] for variant in
                variants({**intent,'warehouse':warehouse,'warehouses':None,'postal':None},book)]
    if not intent['warehouse'] and len(intent.get('zones') or [])>1:
        return [variant for zone in intent['zones'] for variant in
                variants({**intent,'zone':zone,'zones':None},book)]
    warehouse = intent['warehouse']
    found = [r for r in book['warehouses'] if r['code'] == warehouse] if warehouse else []
    zoned = [r for r in found if r['zone']]
    selected_destination=intent.get('plan_destination')
    if selected_destination and selected_destination['warehouse']==warehouse:
        zoned=[row for row in zoned if row['zone']==selected_destination['zone']]
    if zoned:
        unique = {}
        for row in zoned:
            postal = intent['postal'] or row['postal'][:5]
            key = (row['zone'], postal)
            unique.setdefault(key, {'label':f"{warehouse} · {row['zone']}", 'postal':postal,
                'zone':broad_zone(postal), 'warehouse':warehouse})
        return list(unique.values())
    postal = intent['postal']
    if not postal and found:
        match = re.search(r'(?<![0-9])([0-9]{5})(?:-[0-9]{4})?(?![0-9])', found[0]['address'])
        postal = match.group(1) if match else None
    zone = intent['zone']
    if zone and zone[0] in '东中西':
        zone = {'东':'美东','中':'美中','西':'美西'}[zone[0]]
    return [{'label':warehouse or postal or zone or '美国', 'postal':postal, 'zone':zone or broad_zone(postal), 'warehouse':warehouse}]


def quantity(intent, rate):
    real = Decimal(intent['weight'] or '0')
    volume = Decimal(intent['cbm']) if intent['cbm'] else None
    if volume is None and intent['dims']:
        cm = [Decimal(str(value)) for value in dims_to_cm(intent['dims'], intent['dim_unit'])]
        volume = cm[0]*cm[1]*cm[2]/Decimal(1000000)*(intent['boxes'] or 1)
    package_charge=Decimal(0)
    if intent.get('packages'):
        package_volume=Decimal(0)
        all_dimensions=True
        for package in intent['packages']:
            dims=package.get('dims') or intent['dims']
            cm=[Decimal(str(value)) for value in dims_to_cm(dims,package.get('dim_unit') or intent['dim_unit'])] if dims else None
            box_volume=cm[0]*cm[1]*cm[2]/1000000 if cm else Decimal(0)
            all_dimensions=all_dimensions and bool(cm)
            package_volume+=box_volume*package['count']
            piece=max(Decimal(package['weight']),box_volume*1000000/6000 if rate['kind']=='parcel' else box_volume*167)
            package_charge+=max(piece,Decimal(12) if rate['kind']=='parcel' else Decimal(0))*package['count']
        if all_dimensions and not intent['cbm']:volume=package_volume
    if rate['unit'] == 'cbm':
        if volume is None:
            return None
        result=max(volume, real/Decimal(363))
        if rate['service']=='洛杉矶普船海卡':
            result=result.quantize(Decimal('.01'),rounding=ROUND_HALF_UP)
        return result if result>0 else None
    volume_weight = ((volume or Decimal(0))*1000000/6000 if rate['kind']=='parcel'
                     else (volume or Decimal(0))*167)
    charge = max(real, volume_weight,package_charge)
    if rate['kind'] == 'parcel':
        charge = max(charge, Decimal(12)*(intent['boxes'] or 1))
    return charge if real or volume else None


def match_rates(intent, book, variant):
    selected = []
    kinds = intent['kinds'] or (['truck','parcel'] if variant['warehouse'] else ['parcel'])
    for rate in book['rates']:
        if intent.get('plan_unit') and rate['unit']!=intent['plan_unit']:continue
        if rate['kind'] not in kinds or (intent['origin'] and intent['origin'] != rate['origin']):
            continue
        if intent['services'] and not any(name in rate['service'] for name in intent['services']):
            continue
        if any(name in rate['service'] for name in intent.get('excluded_services') or []):
            continue
        if intent['tax'] and rate['tax'] != intent['tax']:
            continue
        if rate['kind'] == 'truck':
            if not variant['warehouse'] or variant['warehouse'] not in [value.upper() for value in rate['destinations']]:
                continue
        elif variant['zone'] and rate['zone'] != variant['zone']:
            continue
        selected.append(rate)
    groups = {}
    for rate in selected:
        key = (rate['service'],rate['origin'],rate['zone'],rate['unit'],rate['tax'])
        charge = quantity(intent,rate)
        if rate['kind'] == 'parcel' and Decimal(rate['min_weight']) > (charge or Decimal(12)):
            continue
        if key not in groups or Decimal(rate['min_weight']) > Decimal(groups[key]['min_weight']):
            groups[key] = rate
    return list(groups.values())


def number(value, places=2):
    return format(Decimal(value).quantize(Decimal(10)**-places, rounding=ROUND_HALF_UP), 'f').rstrip('0').rstrip('.') if places else str(value)


def exact_number(value):
    text=format(Decimal(value),'f')
    return text.rstrip('0').rstrip('.') if '.' in text else text


def quantity_number(value,intent):
    if Decimal(value)==Decimal(intent.get('weight') or '0') or Decimal(value).as_tuple().exponent>=-6:
        return exact_number(value)
    return '约'+number(value,6)


def reference_days(rate):
    match=re.search(r'(?<![\d.])(\d+(?:\.\d+)?)\s*(?:[-—–~～至]\s*(\d+(?:\.\d+)?))?\s*(?:天|days?)',rate['eta'],re.I)
    if not match:return None
    low=Decimal(match[1])
    high=Decimal(match[2] or match[1])
    return (low,high) if low>0 and high>=low else None


def select_timed_rates(rates,slowest=False,by_origin=False):
    """Compare numeric day ranges within one region, service kind and billing basis."""
    ranked=[]
    best={}
    for rate in rates:
        days=reference_days(rate)
        if not days:continue
        low,high=days
        key=(rate['zone'],rate['kind'],rate['unit'],rate['tax'])
        if by_origin:key+=(rate['origin'],)
        timing=(high,low) if slowest else (low,high)
        ranked.append((rate,key,timing))
        choose=max if slowest else min
        best[key]=choose(best.get(key,timing),timing)
    return [rate for rate,key,timing in ranked if timing==best[key]]


def select_cheapest_rates(intent,book,rates,fees,zone=None):
    from .quote_fees import charge_details

    ranked=[]
    best={}
    for rate in rates:
        amount=quantity(intent,rate)
        if amount is None:continue
        key=(zone or rate['zone'],rate['unit'],rate['tax'])
        value=amount*Decimal(rate['price'])+charge_details(intent,rate,fees,book)['cny']
        ranked.append((rate,key,value))
        best[key]=min(best.get(key,value),value)
    return [rate for rate,key,value in ranked if value==best[key]]


def render_rates(intent, book, destinations, remote_fees):
    from .quote_fees import charge_details
    from .quote_language import translate_quote

    lines = []
    plan_number=0
    rate_selection=intent.get('selection') or intent.get('mode')
    if intent.get('mode')=='time':
        lines.append('美国线路参考时效：')
    elif intent['weight']:
        lines.append(f"美国 {exact_number(intent['weight'])}KG 基础运费：")
    else:
        lines.append('美国线路报价：')
    if intent.get('quantity_note'):lines.append(intent['quantity_note'])
    if intent.get('selected_plan_number'):lines.append(f'当前按方案{intent["selected_plan_number"]}继续核算。')
    if intent.get('mode')=='recommend':
        lines.append({'fastest':'按您优先时效的要求，可考虑下面的较快方案。',
                      'cheapest':'按您优先运费的要求，可考虑下面的较低价方案。'}.get(rate_selection,
                     '更看重时效可选下面的较快方案，更看重运费可选较低价方案。'))
    if intent.get('allocations'):
        lines.append('按各目的仓分票计算，箱规需逐票核对：')
        if intent.get('metal_chargeable_weight') is not None:
            lines.append('请分别提供各目的仓的铁铝货物计费重，整票铁铝基数不能重复套用到每个仓。')
    elif len(intent.get('warehouses') or [])>1:
        lines.append('以下按各目的仓分别比较；实际分票请提供每个仓的重量。')
    if intent.get('air_requested') and not intent.get('air_only'):
        lines.append('当前资料没有美国空运费率，下面列出海运方案。')
    if intent.get('mode')=='difference':
        from .quote_comparison import render_difference
        return render_difference(intent,book,destinations,remote_fees)
    for destination, fees in zip(destinations, remote_fees):
        part=destination.get('allocation')
        billing=({**intent,'weight':part['weight'],'packages':part.get('packages'),'dims':None,'cbm':None,'boxes':part.get('boxes')}
                 if part else intent)
        if part and intent.get('metal_chargeable_weight') is not None:
            billing.update(metal_chargeable_weight=None,metal_scope='partial')
        rates = match_rates(billing, book, destination)
        if rate_selection=='cheapest' and rates:
            rates=select_cheapest_rates(billing,book,rates,fees,zone=destination['zone']) or rates
            lines.append('按相同区域、计费单位及税费方式比较的较低价方案：')
        if not rates:
            lines.append(f"{destination['label']}：当前资料没有匹配的线路价格，提供目的仓码或邮编可继续查询。")
            continue
        if destination['label'] != '美国':
            lines.append(destination['label']+'：')
        selections=[('',rates)]
        if rate_selection in ('fastest','slowest','speed_compare','fastest_cheapest'):
            selections=[]
            if rate_selection in ('fastest','speed_compare','fastest_cheapest'):
                selections.append(('最快参考方案',select_timed_rates(rates,by_origin=intent.get('mode')=='quote_detail')))
            if rate_selection in ('slowest','speed_compare'):
                selections.append(('最慢参考方案',select_timed_rates(rates,slowest=True,by_origin=intent.get('mode')=='quote_detail')))
            if rate_selection=='fastest_cheapest':
                selections.append(('最便宜参考方案',select_cheapest_rates(billing,book,rates,fees,zone=destination['zone'])))
            lines.append('按相同区域、运输方式、计费单位及税费方式比较。' if rate_selection=='fastest_cheapest'
                         else '按相同区域、运输方式、计费单位及税费方式比较参考时效。最快按天数下限、最慢按天数上限选择。')
        grouped = {}
        for selection,selected_rates in selections:
            if selection and not selected_rates:
                plan_number+=1
                lines.append(f'方案{plan_number} · '+selection+('暂时无法确定，请提供货物重量和箱规。' if selection=='最便宜参考方案' else '暂时无法确定，匹配线路未列明可比较的天数。'))
            for rate in selected_rates:
                key = (selection, rate['service'], rate['origin'], rate['unit'], rate['tax'], rate['eta'])
                grouped.setdefault(key, []).append(rate)
        last_selection=None
        for (selection,service, origin, unit, tax,eta_source), rows in grouped.items():
            if selection and selection!=last_selection:
                plan_number+=1
                lines.append(f'方案{plan_number} · '+selection)
                last_selection=selection
            eta = re.sub(r'\s*无时效赔偿', '', eta_source).strip()
            if rows[0]['kind']=='parcel' and eta and '提取' not in eta:eta+='提取'
            elif rows[0]['kind']=='truck' and eta and '船开' not in eta:eta='开船后参考'+eta
            if intent.get('mode')=='time':
                lines.append(f'- {service} · {origin}，{eta or "当前资料未列明时效"}。')
                continue
            parts = []
            for rate in rows:
                amount = quantity(billing,rate)
                price = Decimal(rate['price'])
                rate_text = f"{rate['zone']} " if rate['zone'] and not destination['zone'] else ''
                rate_text += f"{number(price)}元/{'KG' if unit == 'kg' else 'CBM'}"
                if amount is not None:
                    total = amount*price
                    details=charge_details(billing,rate,fees,book)
                    total+=details['cny']
                    rate_text += f"，{quantity_number(amount,billing)}{'KG' if unit == 'kg' else 'CBM'} = {number(total)}元"
                    if details['items']:rate_text+='（'+ '；'.join(details['items'])+'）'
                    for note in details['notes']:
                        if note not in lines:lines.append(note)
                elif intent.get('cbm') and rate['unit']=='cbm':
                    lines.append('计费体积四舍五入后不足0.01CBM，最低计费体积需人工确认，不能按零费用出价。')
                parts.append(rate_text)
            prefix=''
            if not selection and not intent.get('selected_plan_number'):
                plan_number+=1
                prefix=f'方案{plan_number} · '
            lines.append(f"- {prefix}{service} · {origin} · {'包税' if tax=='included' else '不包税'}："+'；'.join(parts)
                         + (f'（{eta}）' if eta else ''))
        if fees:
            if fees['fee'] is None:
                lines.append('该邮编属于遥远地址，派送附加费需单独确认。')
            else:
                lines.append(f"海派已计入偏远附加费 {number(fees['fee'])}元/KG。")
    if intent.get('mode')=='time' and not any(intent.get(key) for key in ('warehouse','postal')):
        lines.append('发我目的仓码或邮编，可继续匹配到仓线路。')
    if intent.get('mode')=='time':
        lines.append('以上时效按开船后到提取计算，送达时间需结合末端派送进度核对。')
        if re.search(r'哪天|几号|什么时候|何时|收到',intent['text']):
            lines.append('请补充预计开船日期和目的仓码或邮编，再核对具体到货日期。')
    elif not (intent.get('mode')=='recommend' and rate_selection=='fastest_cheapest'):
        from .quote_followup_fields import missing_fields
        question=missing_fields(intent)
        if question:lines.append(question)
    if intent.get('mode')=='calculation':
        lines.append('计算过程：各箱实重与体积重取大；海派每箱不足12KG按12KG计费，再按整票计费重选择重量档位，乘对应单价，并单列已知附加费。')
    if intent.get('mode')=='recommend' and rate_selection=='fastest_cheapest':
        lines.append('您更看重预算还是时效？')
    text='\n'.join(lines)
    return translate_quote(text) if intent.get('english') else text