"""当前截面上预设顺序统计量截尾；检查不变成员与新同分换仓。"""
import json


def clip(scores, upper_count):
    values = sorted(scores.values())
    cap = values[-upper_count - 1]
    return {s: min(v, cap) for s, v in scores.items()}, cap


def top(scores, count):
    return sorted(scores, key=lambda s: (-scores[s], s))[:count]


same = {'A': 1, 'B': 2, 'C': 3, 'D': 4, 'E': 100}
same_clipped, same_cap = clip(same, 1)
assert same_cap == 4
assert set(top(same, 2)) == set(top(same_clipped, 2)) == {'D', 'E'}
changed = {'X': 100, 'A': 4, 'B': 3, 'C': 2, 'D': 1}
clipped, cap = clip(changed, 1)
assert cap == 4 and top(changed, 1) == ['X'] and top(clipped, 1) == ['A']


def account(target):
    cash, orders = 200, []
    if target != 'X':
        cash += 80 * 10 - 1
        cash -= 80 * 10 + 1
        orders = [['X', 'sell', 80, 10, 1], [target, 'buy', 80, 10, 1]]
    mark = {'X': 10.2, 'A': 10.1}[target]
    return {'cash': cash, 'orders': orders, 'fees': sum(order[4] for order in orders),
            'equity': round(cash + 80 * mark, 6)}


assert account('X')['equity'] == 1016 and account('A')['equity'] == 1006
assert account('X')['orders'] == []
assert account('A')['orders'] == [['X', 'sell', 80, 10, 1], ['A', 'buy', 80, 10, 1]]
assert account('X')['cash'] == 200 and account('A')['cash'] == 198
assert sum(order[4] for order in account('X')['orders']) == 0
assert sum(order[4] for order in account('A')['orders']) == 2
assert account('X')['fees'] == 0 and account('A')['fees'] == 2
print(json.dumps({'unchanged_members': {'before': top(same, 2), 'after': top(same_clipped, 2),
                                      'cap': same_cap},
                  'changed_scores': clipped, 'cap': cap, 'raw_account': account('X'),
                  'clipped_account': account('A')}))