"""task_enqueue 单测 — 队列限流 + 安全入队逻辑 (#2098)."""

from __future__ import annotations

from unittest.mock import MagicMock, patch

import pytest
from app.core.task_enqueue import (
    GLOBAL_PENDING_LIMIT,
    USER_PENDING_LIMIT,
    GlobalQueueFull,
    UserPendingLimitExceeded,
    check_queue_limits,
    safe_enqueue_generation_task,
)


class MockRepository:
    def __init__(self, global_count: int = 0, user_count: int = 0):
        self._global = global_count
        self._user = user_count
        self.update_called = 0

    def count_pending_total(self) -> int:
        return self._global

    def count_pending_by_user(self, user_id: str) -> int:
        return self._user

    def update(self, task):
        self.update_called += 1


def make_mock_task(task_id: str = "task-1"):
    task = MagicMock()
    task.id = task_id
    task.status = "pending"
    task.mark_failed = MagicMock()
    return task


class TestCheckQueueLimits:
    def test_below_limits_passes(self):
        repo = MockRepository(global_count=5, user_count=1)
        check_queue_limits("user-1", repo)

    def test_global_at_limit_raises(self):
        repo = MockRepository(global_count=GLOBAL_PENDING_LIMIT, user_count=1)
        with pytest.raises(GlobalQueueFull) as exc_info:
            check_queue_limits("user-1", repo)
        assert exc_info.value.pending_count == GLOBAL_PENDING_LIMIT
        assert exc_info.value.limit == GLOBAL_PENDING_LIMIT

    def test_global_over_limit_raises(self):
        repo = MockRepository(global_count=GLOBAL_PENDING_LIMIT + 1, user_count=1)
        with pytest.raises(GlobalQueueFull):
            check_queue_limits("user-1", repo)

    def test_user_at_limit_no_longer_raises(self):
        repo = MockRepository(global_count=5, user_count=USER_PENDING_LIMIT)
        check_queue_limits("user-1", repo)

    def test_user_over_limit_no_longer_raises(self):
        repo = MockRepository(global_count=5, user_count=USER_PENDING_LIMIT + 100)
        check_queue_limits("user-1", repo)

    def test_empty_user_id_skips_user_check(self):
        repo = MockRepository(global_count=5, user_count=999)
        check_queue_limits("", repo)

    def test_custom_global_limit_still_honored(self):
        repo = MockRepository(global_count=15, user_count=999)
        with pytest.raises(GlobalQueueFull):
            check_queue_limits("u1", repo, user_pending_limit=999, global_pending_limit=10)
        check_queue_limits("u1", repo, user_pending_limit=999, global_pending_limit=20)


class TestSafeEnqueueGenerationTask:
    @patch("app.core.task_enqueue.celery_app")
    def test_success_path(self, mock_celery):
        repo = MockRepository(global_count=1, user_count=1)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is True
        mock_celery.send_task.assert_called_once_with("worker.generate_video", args=[task.id])
        task.mark_failed.assert_not_called()

    @patch("app.core.task_enqueue.celery_app")
    def test_no_user_id_skips_user_check(self, mock_celery):
        repo = MockRepository(global_count=1, user_count=999)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="")
        assert result is True

    @patch("app.core.task_enqueue.celery_app")
    def test_precheck_global_over_marks_failed(self, mock_celery):
        repo = MockRepository(global_count=GLOBAL_PENDING_LIMIT + 1, user_count=0)
        task = make_mock_task()
        with pytest.raises(GlobalQueueFull):
            safe_enqueue_generation_task(task, repo, user_id="user-1")
        task.mark_failed.assert_called_once()
        mock_celery.send_task.assert_not_called()
        assert repo.update_called == 1

    @patch("app.core.task_enqueue.celery_app")
    def test_precheck_user_over_still_enqueues(self, mock_celery, caplog):
        import logging

        caplog.set_level(logging.WARNING)
        repo = MockRepository(global_count=5, user_count=USER_PENDING_LIMIT + 100)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is True
        mock_celery.send_task.assert_called_once()
        task.mark_failed.assert_not_called()
        assert any("超过软上限" in r.message for r in caplog.records)

    @patch("app.core.task_enqueue.celery_app")
    def test_celery_send_false_returns_false(self, mock_celery):
        repo = MockRepository(global_count=1, user_count=1)
        task = make_mock_task()
        mock_celery.send_task.side_effect = Exception("celery down")
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is False
        task.mark_failed.assert_called_once()
        assert "入队失败" in task.mark_failed.call_args[0][0]

    @patch("app.core.task_enqueue.celery_app")
    def test_celery_send_failure_update_also_fails(self, mock_celery):
        repo = MockRepository(global_count=1, user_count=1)
        repo.update = MagicMock(side_effect=Exception("db down"))
        task = make_mock_task()
        mock_celery.send_task.side_effect = Exception("celery down")
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is False

    @patch("app.core.task_enqueue.celery_app")
    def test_postcheck_global_over_rollback(self, mock_celery):
        call_count = [0]

        def count_pending_total_side_effect():
            call_count[0] += 1
            if call_count[0] == 1:
                return GLOBAL_PENDING_LIMIT
            return GLOBAL_PENDING_LIMIT + 1

        repo = MockRepository(global_count=GLOBAL_PENDING_LIMIT, user_count=0)
        repo.count_pending_total = MagicMock(side_effect=count_pending_total_side_effect)
        task = make_mock_task()
        with pytest.raises(GlobalQueueFull):
            safe_enqueue_generation_task(task, repo, user_id="user-1")
        task.mark_failed.assert_called_once()
        assert "入队后" in task.mark_failed.call_args[0][0]
        mock_celery.send_task.assert_called_once()

    @patch("app.core.task_enqueue.celery_app")
    def test_postcheck_user_over_does_not_rollback(self, mock_celery, caplog):
        import logging

        caplog.set_level(logging.WARNING)
        repo = MockRepository(global_count=5, user_count=USER_PENDING_LIMIT)
        call_count = [0]

        def count_by_user_side_effect(user_id):
            call_count[0] += 1
            if call_count[0] <= 1:
                return USER_PENDING_LIMIT
            return USER_PENDING_LIMIT + 1

        repo.count_pending_by_user = MagicMock(side_effect=count_by_user_side_effect)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is True
        mock_celery.send_task.assert_called_once()
        task.mark_failed.assert_not_called()
        assert any("超软上限(入队后)" in r.message for r in caplog.records)

    @patch("app.core.task_enqueue.celery_app")
    def test_log_task_status_enabled(self, mock_celery):
        repo = MockRepository(global_count=1, user_count=1)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="user-1", log_task_status=True)
        assert result is True

    @patch("app.core.task_enqueue.celery_app")
    def test_custom_global_limit_in_enqueue(self, mock_celery):
        repo = MockRepository(global_count=15, user_count=999)
        task = make_mock_task()
        result = safe_enqueue_generation_task(task, repo, user_id="user-1")
        assert result is True
        task2 = make_mock_task("task-2")
        mock_celery.reset_mock()
        with pytest.raises(GlobalQueueFull):
            safe_enqueue_generation_task(task2, repo, user_id="user-1", user_pending_limit=999, global_pending_limit=10)


class TestExceptionClasses:
    def test_user_pending_limit_message(self):
        exc = UserPendingLimitExceeded("u1", 5, 3)
        assert "u1" in str(exc)
        assert "5" in str(exc)
        assert "3" in str(exc)

    def test_global_queue_full_message(self):
        exc = GlobalQueueFull(25, 20)
        assert "25" in str(exc)
        assert "20" in str(exc)

    def test_user_pending_limit_constant(self):
        assert USER_PENDING_LIMIT == 20