"""Tests for chapter cover Celery enqueue deduplication gate."""

from unittest.mock import MagicMock, patch

from app.tasks.chapter_cover_enqueue import (
    _enqueue_dedup_key,
    try_enqueue_generate_chapter_cover,
)


def _md_with_n_inline_images(n: int) -> str:
    lines = [f"![c](asset://a{i})" for i in range(n)]
    return "\n\n".join(lines) + "\n\n正文"


def _eligible_pipeline_chapter():
    ch = MagicMock()
    ch.cover_asset_id = None
    # 章节封面：正文内 asset 插图需 >3 才入队
    ch.canonical_markdown = _md_with_n_inline_images(4)
    ch.images = []
    return ch


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_false_when_chapter_missing(mock_load, mock_redis, mock_gen_task):
    mock_load.return_value = None
    assert try_enqueue_generate_chapter_cover("missing-id", "pipeline") is False
    mock_gen_task.delay.assert_not_called()
    mock_redis.assert_not_called()


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_false_when_cover_asset_exists(
    mock_load, mock_redis, mock_gen_task
):
    ch = _eligible_pipeline_chapter()
    ch.cover_asset_id = "asset-1"
    mock_load.return_value = ch
    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is False
    mock_gen_task.delay.assert_not_called()
    mock_redis.assert_not_called()


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_false_when_redis_nx_not_acquired(
    mock_load, mock_redis, mock_gen_task
):
    mock_load.return_value = _eligible_pipeline_chapter()
    r = MagicMock()
    r.set.return_value = False
    mock_redis.return_value = r
    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is False
    mock_gen_task.delay.assert_not_called()
    r.set.assert_called_once()


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_true_when_eligible_and_nx_ok(mock_load, mock_redis, mock_gen_task):
    mock_load.return_value = _eligible_pipeline_chapter()
    r = MagicMock()
    r.set.return_value = True
    mock_redis.return_value = r
    mock_gen_task.delay = MagicMock()
    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is True
    mock_gen_task.delay.assert_called_once_with("ch-1")
    r.set.assert_called_once()


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_false_when_inline_images_not_enough(
    mock_load, mock_redis, mock_gen_task
):
    ch = _eligible_pipeline_chapter()
    ch.canonical_markdown = _md_with_n_inline_images(3)
    mock_load.return_value = ch
    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is False
    mock_gen_task.delay.assert_not_called()
    mock_redis.assert_not_called()


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_deletes_dedup_key_when_delay_fails(
    mock_load, mock_redis, mock_gen_task
):
    mock_load.return_value = _eligible_pipeline_chapter()
    r = MagicMock()
    r.set.return_value = True
    mock_redis.return_value = r
    mock_gen_task.delay = MagicMock(side_effect=RuntimeError("broker down"))
    assert try_enqueue_generate_chapter_cover("ch-1", "pipeline") is False
    mock_gen_task.delay.assert_called_once_with("ch-1")
    r.delete.assert_called_once_with(_enqueue_dedup_key("ch-1"))


@patch("app.tasks.chapter_cover_tasks.generate_chapter_cover")
@patch("app.tasks.chapter_cover_enqueue.redis.from_url")
@patch("app.tasks.chapter_cover_enqueue._load_chapter_for_enqueue_sync")
def test_try_enqueue_http_skips_empty_category(mock_load, mock_redis, mock_gen_task):
    ch = _eligible_pipeline_chapter()
    ch.category = None
    ch.status = "completed"
    mock_load.return_value = ch
    assert try_enqueue_generate_chapter_cover("ch-1", "http") is False
    mock_gen_task.delay.assert_not_called()
    mock_redis.assert_not_called()