"""港股每股lot生效元数据对照统一100股简化，含费用和数量现金桥。"""
from decimal import Decimal as D
import json

lots=[{'symbol':'HK:A','from':'2026-10-01','to':'2026-10-31','lot':500,'source':'synthetic_issuer_table_v1'},
      {'symbol':'HK:B','from':'2026-10-01','to':'2026-10-31','lot':1000,'source':'synthetic_issuer_table_v1'},
      {'symbol':'HK:B','from':'2026-11-01','to':'2026-12-31','lot':500,'source':'synthetic_issuer_table_v2'}]


def lot_at(symbol,day):
    rows=[r for r in lots if r['symbol']==symbol and r['from']<=day<=r['to']]
    if len(rows)!=1: raise ValueError('missing_or_ambiguous_lot_metadata')
    return rows[0]['lot']


def size(budget,price,lot):
    budget,price=D(str(budget)),D(str(price))
    if type(lot) is not int or lot<=0 or not budget.is_finite() or not price.is_finite() or budget<0 or price<=0:
        raise ValueError('invalid_sizing_input')
    quantity=max(0,int((budget-1)//(price*lot)))*lot
    fee=D(1) if quantity else D(0)
    return {'quantity':quantity,'fee':str(fee),'cash_left':str(budget-quantity*price-fee)}


def run(simplified):
    cash,fees,holdings,orders=D(20000),D(0),{},[]
    for symbol,price in [('HK:A',D('12.5')),('HK:B',D('7.2'))]:
        lot=100 if simplified else lot_at(symbol,'2026-10-26')
        plan=size(10000,price,lot);q=plan['quantity'];fee=D(plan['fee'])
        cash-=q*price+fee;fees+=fee;holdings[symbol]=q
        orders.append([symbol,'buy',q,str(price),str(fee),lot])
    opened_cash=cash
    assert cash+holdings['HK:A']*D('12.5')+holdings['HK:B']*D('7.2')==D(20000)-fees
    for symbol,price in [('HK:A',D(13)),('HK:B',D(7))]:
        q=holdings.pop(symbol);cash+=q*price-1;fees+=1
        orders.append([symbol,'sell',q,str(price),'1'])
    return {'entry_cash':str(opened_cash),'orders':orders,'ending_cash':str(cash),
            'fees':str(fees),'holdings':holdings}


actual,reference=run(False),run(True)
assert actual['orders'][:2]==[['HK:A','buy',500,'12.5','1',500],['HK:B','buy',1000,'7.2','1',1000]]
assert reference['orders'][:2]==[['HK:A','buy',700,'12.5','1',100],['HK:B','buy',1300,'7.2','1',100]]
assert actual['orders'][2:]==[['HK:A','sell',500,'13','1'],['HK:B','sell',1000,'7','1']]
assert reference['orders'][2:]==[['HK:A','sell',700,'13','1'],['HK:B','sell',1300,'7','1']]
assert D(actual['entry_cash'])==6548 and D(reference['entry_cash'])==1888
assert D(actual['ending_cash'])==20046 and D(reference['ending_cash'])==20086
assert actual['fees']==reference['fees']=='4' and not actual['holdings'] and not reference['holdings']
assert lot_at('HK:B','2026-11-02')==500 and lot_at('HK:B','2026-10-26')==1000
assert size(1000,12.5,500)=={'quantity':0,'fee':'0','cash_left':'1000.0'}
try: lot_at('HK:UNKNOWN','2026-10-26')
except ValueError: pass
else: raise AssertionError('没有逐股元数据不得默默回退100股')
lots.append(dict(lots[0],source='synthetic_conflicting_version'))
try: lot_at('HK:A','2026-10-26')
except ValueError: pass
else: raise AssertionError('重叠生效版本必须拒绝')
finally: lots.pop()
print(json.dumps({'lot_metadata':lots,'per_stock_model':actual,'uniform_100_reference':reference,
                  'scope':'synthetic HKD stocks and issuer metadata; no odd-lot or actual broker matching claim'}))