"""dcy-019 / BAT-025: buy admission reallocates closed slots (REQ-007).

When no idle slot remains, _admit_buy must admit into a CLOSED slot via the new
closed→pending_buy transition, ordered by entry_count (least-entered first).
"""
from __future__ import annotations

from datetime import date

from trex_core.adapters.persistence.in_memory_intent_store import InMemoryIntentStore
from trex_core.application.intents import BuyIntent, IntentService
from trex_core.domain.slot import SlotService, SlotState
from trex_core.domain.slot.in_memory_repository import InMemorySlotRepository

DAY = date(2026, 6, 9)


def _cycle_to_closed(svc, slot_id):
    svc.transit_slot(slot_id, SlotState.IDLE, SlotState.PENDING_BUY,
                     reason="r", actor="a", symbol="005930")
    svc.transit_slot(slot_id, SlotState.PENDING_BUY, SlotState.HOLDING,
                     reason="r", actor="a", avg_price=70_000)
    svc.transit_slot(slot_id, SlotState.HOLDING, SlotState.PENDING_SELL,
                     reason="r", actor="a")
    svc.transit_slot(slot_id, SlotState.PENDING_SELL, SlotState.CLOSED,
                     reason="r", actor="a")


def test_admits_into_closed_slot_when_no_idle_remains():
    repo = InMemorySlotRepository()
    svc = SlotService(repo)
    intents = IntentService(svc, repo, InMemoryIntentStore())
    svc.preallocate_daily_slots(DAY, 1)
    slot = repo.find_idle_slot(DAY)
    _cycle_to_closed(svc, slot.slot_id)
    assert repo.find_idle_slot(DAY) is None  # nothing idle

    d = intents.submit_buy(BuyIntent(
        intent_id="buy-realloc", trading_date=DAY,
        symbol="000660", qty=3, portfolio_id="PF-1",
    ))
    assert d.status == "admitted"
    realloc = repo.fetch_slot(d.slot_id)
    assert realloc.status is SlotState.PENDING_BUY
    assert realloc.symbol == "000660"
    # second entry into the same physical slot
    assert realloc.entry_count == 2


def test_rejects_when_no_idle_and_no_closed():
    repo = InMemorySlotRepository()
    svc = SlotService(repo)
    intents = IntentService(svc, repo, InMemoryIntentStore())
    svc.preallocate_daily_slots(DAY, 1)
    slot = repo.find_idle_slot(DAY)
    # take it to holding (not closed, not idle → not allocatable)
    svc.transit_slot(slot.slot_id, SlotState.IDLE, SlotState.PENDING_BUY,
                     reason="r", actor="a", symbol="005930")
    svc.transit_slot(slot.slot_id, SlotState.PENDING_BUY, SlotState.HOLDING,
                     reason="r", actor="a", avg_price=70_000)

    d = intents.submit_buy(BuyIntent(
        intent_id="buy-none", trading_date=DAY,
        symbol="000660", portfolio_id="PF-1",
    ))
    assert d.status == "rejected"
    assert d.reason == "no_idle_slot"


def test_prefers_idle_over_closed():
    repo = InMemorySlotRepository()
    svc = SlotService(repo)
    intents = IntentService(svc, repo, InMemoryIntentStore())
    svc.preallocate_daily_slots(DAY, 2)
    slots = repo.list_slots(DAY)
    _cycle_to_closed(svc, slots[0].slot_id)  # one closed (entry_count=1)

    d = intents.submit_buy(BuyIntent(
        intent_id="buy-prefer-idle", trading_date=DAY,
        symbol="000660", portfolio_id="PF-1",
    ))
    assert d.status == "admitted"
    chosen = repo.fetch_slot(d.slot_id)
    # the fresh idle slot (entry_count 0→1) is preferred over the closed one
    assert chosen.entry_count == 1