"""VideoQueue 生产者扫描的单测。

目前只覆盖一个点：生产者列目录之后、读 mtime 之前，DiskGuard 可能刚好把文件清掉
（两个后台线程的正常竞态）。线上表现为 `生产者扫描异常: [Errno 2] No such file or
directory`，代价是**整轮扫描中断**——排在后面的新素材本轮全都登记不上，要等下一轮。
"""
import os

import pytest

from fam_edge import video_queue as vq_mod
from fam_edge.video_queue import VideoQueue


class _FakeDB:
    """只实现生产者路径上用到的方法。"""
    def __init__(self):
        self.registered = []
        self.activities = []

    def get_video_by_filename(self, fn):
        return None

    def ensure_video(self, fn, path, camera_name=None):
        self.registered.append(fn)
        return len(self.registered)

    def set_video_file_status(self, vid, valid, err, meta=None):
        pass

    def record_activity(self, service, action, detail=''):
        self.activities.append((service, action))


@pytest.fixture
def queue_with_two_files(tmp_path, monkeypatch):
    monkeypatch.setattr(vq_mod, 'load_config', lambda: {
        'gdrive_sync': {'local_dir': str(tmp_path), 'camera_name': '客厅'},
        'video_processing': {'file_validate': True, 'stable_window_sec': 60},
    })
    (tmp_path / "a_被删掉的.mp4").write_bytes(b"x")
    (tmp_path / "b_正常的.mp4").write_bytes(b"y")
    db = _FakeDB()
    q = VideoQueue(db)
    monkeypatch.setattr(q, '_enqueue', lambda vid: None)
    monkeypatch.setattr(vq_mod, 'validate_video', lambda p: (True, '', {'fps': 25}))
    return q, db


def test_produce_skips_file_deleted_mid_scan_and_keeps_going(queue_with_two_files, monkeypatch):
    """被删掉的那个跳过，后面的照常登记——不能整轮中断。"""
    q, db = queue_with_two_files
    real_getmtime = os.path.getmtime

    def fake_getmtime(path):
        if 'a_被删掉的' in path:
            raise FileNotFoundError(2, 'No such file or directory', path)
        return real_getmtime(path) - 3600      # 早于稳定窗口，视为写入完成
    monkeypatch.setattr(vq_mod.os.path, 'getmtime', fake_getmtime)

    q._produce_once()                          # 不抛异常

    assert db.registered == ["b_正常的.mp4"]   # 被删的跳过，后面的没受影响


def test_produce_still_skips_files_being_written(queue_with_two_files, monkeypatch):
    """mtime 太新（rclone 还在写）仍然要跳过，别把半成品入队。"""
    q, db = queue_with_two_files
    monkeypatch.setattr(vq_mod.os.path, 'getmtime', lambda p: __import__('time').time())

    q._produce_once()

    assert db.registered == []