"""Separate metal chargeable-weight declarations from the shipment's gross weight."""

import re
from decimal import Decimal


def material_intent(text,weight_pattern,to_kg):
    declarations=re.sub(r'铁铝(?:附加费|加费|费用)','',text)
    metal=bool(re.search(r'铁制|钢制|铝制|铁铝|不锈钢|(?:铁|钢|铝)(?:件|货|扣|罐|盒|板|管|架|材)',declarations))
    generic='金属' in text
    ordinary=bool(re.search(r'普通货|普货|非铁铝',text))
    partial=bool(re.search(r'只有|部分|其中|有些|只是|一部分',text) or
                 metal and re.search(r'塑料|木制|布料',text))
    scope='partial' if partial and (metal or generic) else ('all' if re.search(r'全是|全部是|都是|整票是|货物是|换成|改成',text) and metal else None)
    material=('ordinary' if '非铁铝' in text else 'metal' if metal else 'unknown_metal' if generic
              else 'ordinary' if ordinary or re.search(r'塑料|木制',text) else None)
    name=r'(?:铁铝|铁制品|钢制品|铝制品|铁件|钢件|铝件|金属)(?:部分|货物)?(?:的)?'
    patterns=(name+r'\s*计费重(?:量)?\s*(?:为|是|[:：])?\s*'+weight_pattern.pattern,
              name+r'\s*按\s*'+weight_pattern.pattern+r'\s*计费',
              r'(?:铁铝|铁制品|钢制品|铝制品|铁件|钢件|铝件|金属)部分(?:的计费重(?:量)?)?\s*'
              r'(?:还是|仍然是|仍是|改为|改成|换成)\s*'+weight_pattern.pattern)
    charged=None;cleaned=text;errors=[];oral=False
    for index,pattern in enumerate(patterns):
        matches=list(re.finditer(pattern,text,re.I))
        for match in matches:
            value=to_kg(*match.groups())
            if charged is not None and Decimal(charged)!=value:errors.append('铁铝货物的计费重不一致，请确认。')
            charged=str(value);scope='partial'
            oral=oral or (index==2 and '计费重' not in match[0])
            if not 0<value<=1000000:errors.append('请提供大于0的有效铁铝货物计费重。')
            cleaned=cleaned[:match.start()]+' '*(match.end()-match.start())+cleaned[match.end():]
    return {'material':material,'metal_scope':scope,'metal_chargeable_weight':charged,
            'quantity_text':cleaned,'errors':errors,'metal_weight_update':True if oral else None}