"""日志持久化(LOG_FILE)测试:setup_logging 启用滚动文件后日志必须落盘。

背景: 此前应用日志只进 stdout(docker json-file 收集,不可控) + Admin 内存
日志页(环形缓冲 2000 条,进程重启清零),没有任何应用层持久化 —— 排查
「昨晚采集为什么失败」这类问题时无据可查。本测试守护:
  1. 传 log_file → root logger 挂 RotatingFileHandler,日志写入文件
  2. 幂等:重复调用不重复挂 handler
  3. log_file 为空 → 不挂文件 handler(保持旧行为)
  4. 目录不存在 → 自动创建
  5. 文件打开失败(如路径是已存在的目录) → 只降级不炸,stdout/内存日志仍在

范式: 直接操作 root logger + tmp_path;fixture 保存/恢复 root 状态,
并关闭新增 handler 的文件句柄(Windows 上句柄不关会锁住 tmp 目录)。
"""
from __future__ import annotations

import logging
from logging.handlers import RotatingFileHandler

import pytest

from src.core.log_buffer import MemoryLogHandler, setup_logging


@pytest.fixture(autouse=True)
def _restore_root_logger():
    """保存/恢复 root logger;关闭测试期间新挂 handler 的句柄。"""
    root = logging.getLogger()
    saved_handlers = list(root.handlers)
    saved_level = root.level
    yield
    for h in root.handlers:
        if h not in saved_handlers and hasattr(h, "close"):
            try:
                h.close()
            except Exception:
                pass
    root.handlers[:] = saved_handlers
    root.setLevel(saved_level)


def _file_handlers():
    return [h for h in logging.getLogger().handlers if isinstance(h, RotatingFileHandler)]


def _memory_handlers():
    return [h for h in logging.getLogger().handlers if isinstance(h, MemoryLogHandler)]


class TestFileHandlerAttached:
    def test_attaches_rotating_file_handler(self, tmp_path):
        log_file = tmp_path / "app.log"

        setup_logging("INFO", str(log_file))

        fhs = _file_handlers()
        assert len(fhs) == 1
        assert fhs[0].baseFilename == str(log_file)
        # 内存日志页照常工作,两者并存
        assert len(_memory_handlers()) == 1
        # 滚动参数与文档口径一致: 单文件 10MB × 5 份
        assert fhs[0].maxBytes == 10 * 1024 * 1024
        assert fhs[0].backupCount == 5

    def test_log_written_to_file(self, tmp_path):
        log_file = tmp_path / "app.log"
        setup_logging("INFO", str(log_file))

        logging.getLogger("persist-test").info("hello-persist-12345")

        content = log_file.read_text(encoding="utf-8")
        assert "hello-persist-12345" in content
        assert "persist-test" in content          # logger 名可追溯
        assert "INFO" in content                   # 级别在行首可过滤


class TestIdempotent:
    def test_repeated_call_does_not_duplicate_handlers(self, tmp_path):
        log_file = tmp_path / "app.log"

        setup_logging("INFO", str(log_file))
        setup_logging("INFO", str(log_file))
        setup_logging("INFO", str(log_file))

        assert len(_file_handlers()) == 1
        assert len(_memory_handlers()) == 1

    def test_same_file_via_relative_and_absolute_path_counts_as_one(self, tmp_path, monkeypatch):
        """相对/绝对路径指向同一文件时不得重复挂(幂等按 abspath 判重)。"""
        monkeypatch.chdir(tmp_path)

        setup_logging("INFO", "app.log")
        setup_logging("INFO", str(tmp_path / "app.log"))

        assert len(_file_handlers()) == 1


class TestDisabled:
    def test_empty_log_file_keeps_old_behavior(self):
        setup_logging("INFO", "")

        assert _file_handlers() == []
        assert len(_memory_handlers()) == 1


class TestAutoMkdir:
    def test_creates_missing_directories(self, tmp_path):
        log_file = tmp_path / "deep" / "nested" / "app.log"

        setup_logging("INFO", str(log_file))

        assert len(_file_handlers()) == 1
        assert log_file.parent.is_dir()


class TestGracefulDegradation:
    def test_unopenable_path_degrades_without_raising(self, tmp_path):
        """路径是已存在的目录 → 打开必然失败;只降级,不炸启动。"""
        dir_as_file = tmp_path / "occupied"
        dir_as_file.mkdir()

        # 不应抛异常(文件日志是可观测性基础设施,失败只 warning)
        setup_logging("INFO", str(dir_as_file))

        assert _file_handlers() == []
        # 降级后 stdout/内存日志路径仍在
        assert len(_memory_handlers()) == 1