"""R640：规则版本独立封存、账户独立，不因新成交重写旧分支。"""
from decimal import Decimal as D
from pathlib import Path
from tempfile import TemporaryDirectory
import json,hashlib

def digest(value):return hashlib.sha256(json.dumps(value,sort_keys=True,separators=(',',':'),allow_nan=False).encode()).hexdigest()
def run(rule,initial,events):
    if set(rule)!={'version','entry','exit','cutoff'} or not isinstance(rule['version'],str) or not rule['version'].strip():raise ValueError('invalid frozen rule')
    if type(rule['cutoff']) is not int or any(not D(str(rule[k])).is_finite() or D(str(rule[k]))<=0 for k in ['entry','exit']):raise ValueError('invalid rule values')
    cash=D(initial['cash']);shares=initial['shares'];rows=[]
    if not cash.is_finite() or cash<0 or type(shares) is not int or shares<0:raise ValueError('invalid initial state')
    for t,observed,price in events:
        observed=D(str(observed));price=D(str(price))
        if t<=rule['cutoff'] or not observed.is_finite() or not price.is_finite() or observed<=0 or price<=0:raise ValueError('invalid future observation')
        before=cash+shares*price;side='hold'
        if shares and observed<D(rule['exit']):cash+=shares*price;shares=0;side='sell'
        elif not shares and observed>D(rule['entry']) and cash>=price:cash-=price;shares=1;side='buy'
        assert cash>=0 and cash+shares*price==before
        rows.append((t,side,str(cash),shares))
    return {'cash':cash,'shares':shares,'rows':rows,'ending':cash+shares*D(112)}

old={'version':'v1','entry':'100','exit':'100','cutoff':1}
new={'version':'v2','entry':'105','exit':'102','cutoff':3}
events=[(4,101,102),(5,107,108),(6,99,100),(7,110,111)]
with TemporaryDirectory() as tmp:
    p=Path(tmp)/'v1.json';p.write_text(json.dumps(old,sort_keys=True),encoding='utf-8');old_bytes=p.read_bytes()
    with (Path(tmp)/'v2.json').open('x',encoding='utf-8') as f:json.dump(new,f,sort_keys=True)
    a=run(json.loads(p.read_text(encoding='utf-8')),{'cash':'900','shares':1},events)
    b=run(new,{'cash':'1000','shares':0},events)
    common=run(old,{'cash':'1000','shares':0},events)
    assert p.read_bytes()==old_bytes and digest(old)!=digest(new)
    try:
        with (Path(tmp)/'v2.json').open('x',encoding='utf-8'):pass
    except FileExistsError:pass
    else:raise AssertionError('frozen version overwritten')
assert (a['ending'],b['ending'],common['ending'])==(D(1001),D(993),D(999))
assert a['rows'][0][1]=='hold' and b['rows'][0][1]=='hold' and common['rows'][0][1]=='buy'
try:run(new,{'cash':'1000','shares':0},[(3,101,102)])
except ValueError:pass
else:raise AssertionError('pre-freeze observation rewritten')
print('continuing_v1_ending=1001 fresh_v2_ending=993 fresh_common_v1_ending=999 mark=112 fees=0_synthetic')
print('v1_rows='+str(a['rows'])+' v2_rows='+str(b['rows']))
print('old_file_preserved=True exclusive_version=True historical_rewrite=rejected model_calls=0 independent_accounts=True')