"""Tests for the notification store's per-user read-state contract.

These pin the core property that makes broadcast-to-everyone work without a
subscription model: one notification row is shared by all users, and each
user's read state is tracked independently against it.
"""
from __future__ import annotations

from app.infrastructure.perception.mock_notification_store import MockNotificationStore


def _store_with_one_notification() -> MockNotificationStore:
    store = MockNotificationStore()
    store.create(
        event_id="evt-001",
        kind="new",
        title="《电动汽车安全要求》国家标准第三版正式发布",
        impact_level="high",
        summary=None,
    )
    return store


def test_a_new_notification_is_unread_for_everyone():
    """Nobody has read it yet, so unread_count is 1 for any user."""
    store = _store_with_one_notification()
    assert store.unread_count("user-a") == 1
    assert store.unread_count("user-b") == 1


def test_mark_all_read_zeroes_the_count_for_that_user():
    """Reading clears the count for the user who read it."""
    store = _store_with_one_notification()
    marked = store.mark_all_read("user-a")
    assert marked == 1
    assert store.unread_count("user-a") == 0


def test_one_users_read_state_does_not_affect_another():
    """The whole point of read receipts over per-user fan-out: independence."""
    store = _store_with_one_notification()
    store.mark_all_read("user-a")
    assert store.unread_count("user-a") == 0
    assert store.unread_count("user-b") == 1


def test_list_for_user_reports_the_read_flag_correctly():
    """The list endpoint must reflect this user's own read state per item."""
    store = _store_with_one_notification()
    store.mark_all_read("user-a")

    items_a = store.list_for_user("user-a")
    items_b = store.list_for_user("user-b")

    assert len(items_a) == 1
    assert items_a[0]["read"] is True
    assert items_b[0]["read"] is False


def test_list_for_user_orders_newest_first():
    """Notifications appear most-recent-first regardless of creation order."""
    store = MockNotificationStore()
    store.create(event_id="evt-1", kind="new", title="first", impact_level="low", summary=None)
    store.create(event_id="evt-2", kind="new", title="second", impact_level="low", summary=None)

    items = store.list_for_user("user-a")

    assert [item["title"] for item in items] == ["second", "first"]


def test_mark_all_read_is_a_no_op_on_an_empty_feed():
    """Reading an empty feed must not raise and reports zero marked."""
    store = MockNotificationStore()
    assert store.mark_all_read("user-a") == 0


def test_mark_all_read_does_not_recount_already_read_notifications():
    """Calling mark_all_read twice must not double-count as newly marked."""
    store = _store_with_one_notification()
    first = store.mark_all_read("user-a")
    second = store.mark_all_read("user-a")
    assert first == 1
    assert second == 0