"""R610：排他落盘开封、不可覆盖首次判定；只使用独立临时目录。"""
from hashlib import sha256
import json
from pathlib import Path
from tempfile import TemporaryDirectory
from datetime import datetime, timezone


def digest(obj):
    return sha256(json.dumps(obj, sort_keys=True).encode()).hexdigest()


def create_json(path, obj):
    with path.open('x', encoding='utf-8') as stream:
        json.dump(obj, stream, sort_keys=True)


def evaluate(folder, ident, config, observations, fail=False):
    frozen = json.loads((folder / 'seal.json').read_text(encoding='utf-8'))
    if digest(config) != frozen['digest']:
        raise ValueError('seal changed')
    # 先保存已开封状态，后续失败不能把这次查看抹去。
    create_json(folder / f'{ident}.opened.json', {
        'seal': frozen['digest'], 'openedAt': datetime.now(timezone.utc).isoformat()
    })
    if fail:
        raise RuntimeError('injected execution failure')
    result = ('information_insufficient' if len(observations) < config['min_trades']
              else 'pass' if sum(observations) >= config['min_pnl'] else 'fail')
    record = {'status': result, 'pnl': sum(observations), 'n': len(observations)}
    create_json(folder / f'{ident}.result.json', record)
    return record


def main():
    candidate = {'code': 'frozen-v1', 'data': 'synthetic-v1', 'lookback': 3,
                 'min_trades': 2, 'min_pnl': 0}
    with TemporaryDirectory(prefix='r610-synthetic-') as temp:
        folder = Path(temp)
        create_json(folder / 'seal.json', {'config': candidate, 'digest': digest(candidate)})
        first = evaluate(folder, 'H1', candidate, [-1, .5])
        assert first == {'status': 'fail', 'pnl': -.5, 'n': 2}
        try:
            evaluate(folder, 'H1', candidate, [1, 1])
        except FileExistsError:
            pass
        else:
            raise AssertionError('same holdout opened twice')
        changed = dict(candidate, lookback=2)
        try:
            evaluate(folder, 'H2', changed, [1, 1])
        except ValueError:
            pass
        else:
            raise AssertionError('changed seal accepted')
        assert evaluate(folder, 'H3', candidate, [1])['status'] == 'information_insufficient'
        try:
            evaluate(folder, 'H4', candidate, [], fail=True)
        except RuntimeError:
            pass
        assert (folder / 'H4.opened.json').exists()
        assert not (folder / 'H4.result.json').exists()
        try:
            evaluate(folder, 'H4', candidate, [1, 1])
        except FileExistsError:
            pass
        else:
            raise AssertionError('failed opening silently reused')
        assert json.loads((folder / 'H1.result.json').read_text()) == first
        print('first=fail pnl=-0.5 repeat=rejected modified_seal=rejected')
        print('short_sample=information_insufficient failure_receipt=opened_without_result')
        print('exclusive_files_verified=True first_result_unchanged=True')


if __name__ == '__main__':
    main()