"""含费用的整篮共同缩放；标准库合成账户，不运行产品撮合器。"""
from decimal import Decimal as D
from fractions import Fraction as F
from itertools import permutations
import json


def fit(plans,cash):
    cash=D(str(cash))
    if not cash.is_finite() or cash<0: raise ValueError('invalid_available_cash')
    if len({p['symbol'] for p in plans})!=len(plans): raise ValueError('duplicate_symbol')
    for p in plans:
        if type(p['quantity']) is not int or p['quantity']<=0 or type(p['lot']) is not int or p['lot']<=0:
            raise ValueError('invalid_quantity_or_lot')
        if p['quantity']%p['lot']!=0:raise ValueError('plan_not_board_lot_multiple')
        if not D(str(p['price'])).is_finite() or D(str(p['price']))<=0: raise ValueError('invalid_price')
    def at(scale):
        rows=[]
        for p in sorted(plans,key=lambda p:p['symbol']):
            q=(p['quantity']*scale//p['lot'])*p['lot']
            if q:
                rows.append({'symbol':p['symbol'],'quantity':q,'price':str(p['price']),
                             'fee':'1','cost':str(q*D(str(p['price']))+1)})
        return rows
    full=at(F(1));low,high=F(0),F(1);trials=0
    if sum(D(r['cost']) for r in full)<=cash: chosen=full;low=F(1)
    else:
        chosen=[]
        for _ in range(50):
            trials+=1;mid=(low+high)/2;candidate=at(mid)
            if sum(D(r['cost']) for r in candidate)<=cash: low,chosen=mid,candidate
            else: high=mid
    filled={r['symbol']:r['quantity'] for r in chosen}
    shortfalls=[{'symbol':p['symbol'],'requested':p['quantity'],'filled':filled.get(p['symbol'],0),
                 'unfilled':p['quantity']-filled.get(p['symbol'],0)} for p in sorted(plans,key=lambda p:p['symbol'])]
    rejected=[{'symbol':r['symbol'],'reason':'insufficient_capital'} for r in full if r['symbol'] not in filled]
    return {'full_cost':str(sum(D(r['cost']) for r in full)),'scale':str(low),'trials':trials,
            'orders':chosen,'shortfalls':shortfalls,'rejected':rejected,
            'cash_after':str(cash-sum(D(r['cost']) for r in chosen))}


plans=[{'symbol':'A','quantity':8,'price':10,'lot':1},
       {'symbol':'B','quantity':8,'price':10,'lot':1},
       {'symbol':'C','quantity':1,'price':20,'lot':1}]
cash,fees=D(50),D(0);holdings={'OLD':10};orders=[]
cash+=holdings.pop('OLD')*D(10)-1;fees+=1;orders.append(['OLD','sell',10,'10','1'])
assert cash==149 and fees==1 and not holdings
result=fit(plans,cash)
assert result['full_cost']=='183' and F(7,8)<=F(result['scale'])<1 and result['trials']==50
assert result['orders']==[{'symbol':s,'quantity':7,'price':'10','fee':'1','cost':'71'} for s in ['A','B']]
assert result['rejected']==[{'symbol':'C','reason':'insufficient_capital'}]
assert result['shortfalls']==[{'symbol':'A','requested':8,'filled':7,'unfilled':1},
                             {'symbol':'B','requested':8,'filled':7,'unfilled':1},
                             {'symbol':'C','requested':1,'filled':0,'unfilled':1}]
for r in result['orders']:
    cash-=D(r['cost']);fees+=D(r['fee']);holdings[r['symbol']]=r['quantity']
    orders.append([r['symbol'],'buy',r['quantity'],r['price'],r['fee']])
assert cash==7 and fees==3 and holdings=={'A':7,'B':7}
assert cash+sum(holdings.values())*10==150-fees
for ordering in permutations(plans): assert fit(list(ordering),149)==result
empty=fit(plans,0)
assert empty['orders']==[] and empty['cash_after']=='0' and len(empty['rejected'])==3
assert fit(plans,183)['scale']=='1' and len(fit(plans,183)['orders'])==3
for requested in [1,150]:
    try:fit([{'symbol':'LOT','quantity':requested,'price':10,'lot':100}],1000)
    except ValueError as error:assert str(error)=='plan_not_board_lot_multiple'
    else:raise AssertionError('完整计划必须已在lot网格；非法计划不是资金不足')
# 顺序现金截断是另一机制：首个名字获得8股，第二个仅6股。
def greedy(ordering):
    remaining,quantities=D(149),{}
    for p in ordering:
        q=min(p['quantity'],max(0,int((remaining-1)//D(str(p['price'])))))
        if q: remaining-=q*D(str(p['price']))+1
        quantities[p['symbol']]=q
    return quantities
assert greedy(plans)=={'A':8,'B':6,'C':0}
assert greedy(list(reversed(plans)))!=greedy(plans)
for symbol,price in [('A',D(11)),('B',D(9))]:
    q=holdings.pop(symbol);cash+=q*price-1;fees+=1;orders.append([symbol,'sell',q,str(price),'1'])
assert orders==[['OLD','sell',10,'10','1'],['A','buy',7,'10','1'],['B','buy',7,'10','1'],
                ['A','sell',7,'11','1'],['B','sell',7,'9','1']]
assert cash==145 and fees==5 and not holdings and cash==150-fees
print(json.dumps({'initial_cash':'50','initial_OLD_market_value':'100','sale_released_cash':'99',
                  'available_after_sale':'149','fit':result,'completed_orders':orders,
                  'ending_cash':str(cash),'fees':str(fees),'holdings':holdings,
                  'scope':'synthetic common-factor planning and cash; not real broker partial fills or live Vibe'}))