"""入场事件、持续持有、退出优先与两个完整冷却期的状态路径。"""
import json
from enum import Enum


class State(Enum):
    FLAT = 'flat'
    LONG = 'long'
    COOLING = 'cooling'


def generate(events):
    state, remaining, result = State.FLAT, 0, []
    for i, event in enumerate(events):
        previous, before = state, remaining
        if state == State.LONG:
            if event['exit']:
                state, remaining, reason = State.COOLING, 2, 'exit_priority'
            else:
                reason = 'hold_without_reentering'
        elif state == State.COOLING:
            remaining -= 1
            reason = 'cooldown'
            if remaining == 0:
                state = State.FLAT
        elif event['exit']:
            reason = 'flat_exit_blocks_entry'
        elif event['enter']:
            state, reason = State.LONG, 'entry'
        else:
            reason = 'wait'
        result.append({'i': i, 'before': previous.value, 'cooldown_before': before,
                       'enter': event['enter'], 'exit': event['exit'],
                       'after': state.value, 'remaining': remaining,
                       'target': int(state == State.LONG), 'reason': reason})
    return result


events = [{'enter': i not in (1, 7), 'exit': i in (3, 7)} for i in range(11)]
rows = generate(events)
targets = [r['target'] for r in rows]
assert targets == [1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 1]
assert rows[1]['reason'] == 'hold_without_reentering'
assert rows[2]['reason'] == 'hold_without_reentering'
assert rows[3]['enter'] and rows[3]['reason'] == 'exit_priority'
assert [r['reason'] for r in rows[4:6]] == ['cooldown', 'cooldown']
assert rows[6]['reason'] == 'entry' and rows[10]['reason'] == 'entry'
assert sum(r['reason'] == 'entry' for r in rows) == 3
flat_conflict = generate([{'enter': True, 'exit': True}])[0]
assert flat_conflict['target'] == 0 and flat_conflict['reason'] == 'flat_exit_blocks_entry'
for cutoff in range(1, len(events)):
    assert generate(events[:cutoff]) == rows[:cutoff]
assert [int(e['enter']) for e in events] != targets
print(json.dumps({'path': rows, 'targets': targets, 'entry_events': 3,
                  'scope': 'desired state only, no asserted fills'}))