"""
log/logger.py
统一日志配置：

- 控制台输出（强制 UTF-8，修复 Windows 控制台中文乱码）
- logs/app.log     全量日志（按大小轮转）
- logs/error.log   仅 WARNING 及以上
- logs/upload.log  上传/解析/入库链路（routers.template、services.*）
- 接管 uvicorn 的 access/error 日志，统一落盘

幂等：重复调用只配置一次。
"""

from __future__ import annotations

import logging
import sys
from logging.handlers import RotatingFileHandler
from pathlib import Path

_CONFIGURED = False

_FORMAT = "%(asctime)s | %(levelname)-7s | %(name)s | %(message)s"
_DATEFMT = "%Y-%m-%d %H:%M:%S"

# 上传/解析/入库链路相关的 logger 前缀（额外汇总到 upload.log）
_UPLOAD_PREFIXES = (
    "routers.template",
    "services.file_parse_client",
    "services.section_extractor",
    "services.declaration_service",
    "services.llm_client",
)

# 交由 root 统一处理的第三方/框架 logger
_DELEGATED_LOGGERS = ("uvicorn", "uvicorn.error", "uvicorn.access")


class _PrefixFilter(logging.Filter):
    def __init__(self, prefixes: tuple[str, ...]) -> None:
        super().__init__()
        self.prefixes = prefixes

    def filter(self, record: logging.LogRecord) -> bool:
        name = str(record.name or "")
        return any(name == p or name.startswith(p + ".") for p in self.prefixes)


def _force_utf8_stream(stream):
    """让控制台以 UTF-8 输出，避免 Windows GBK 控制台中文乱码。"""
    reconfigure = getattr(stream, "reconfigure", None)
    if callable(reconfigure):
        try:
            reconfigure(encoding="utf-8", errors="replace")
        except (ValueError, OSError):
            pass
    return stream


def configure_logging(
    *,
    log_dir: str | Path | None = None,
    level: str | int | None = None,
    to_console: bool | None = None,
    max_bytes: int | None = None,
    backup_count: int | None = None,
) -> Path:
    """配置全局日志。返回 app.log 路径。"""
    global _CONFIGURED

    # 延迟导入，避免与 config 形成循环依赖问题
    from config import settings

    log_dir = log_dir if log_dir is not None else settings.LOG_DIR
    level = level if level is not None else settings.LOG_LEVEL
    to_console = to_console if to_console is not None else settings.LOG_TO_CONSOLE
    max_bytes = max_bytes if max_bytes is not None else settings.LOG_MAX_BYTES
    backup_count = backup_count if backup_count is not None else settings.LOG_BACKUP_COUNT

    if isinstance(level, str):
        level = getattr(logging, level.strip().upper(), logging.INFO)

    target_dir = Path(log_dir).resolve()
    target_dir.mkdir(parents=True, exist_ok=True)
    app_log_path = target_dir / "app.log"

    if _CONFIGURED:
        return app_log_path

    formatter = logging.Formatter(_FORMAT, datefmt=_DATEFMT)

    def _rotating(name: str, *, backups: int | None = None) -> RotatingFileHandler:
        h = RotatingFileHandler(
            target_dir / name,
            maxBytes=max_bytes,
            backupCount=backups if backups is not None else backup_count,
            encoding="utf-8",
        )
        h.setFormatter(formatter)
        return h

    # 全量日志
    app_handler = _rotating("app.log")
    app_handler.setLevel(level)

    # 错误日志（WARNING+）
    error_handler = _rotating("error.log")
    error_handler.setLevel(logging.WARNING)

    # 上传/解析链路日志
    upload_handler = _rotating("upload.log", backups=max(backup_count, 10))
    upload_handler.setLevel(level)
    upload_handler.addFilter(_PrefixFilter(_UPLOAD_PREFIXES))

    handlers: list[logging.Handler] = [app_handler, error_handler, upload_handler]

    if to_console:
        console_handler = logging.StreamHandler(_force_utf8_stream(sys.stdout))
        console_handler.setLevel(level)
        console_handler.setFormatter(formatter)
        handlers.append(console_handler)

    root = logging.getLogger()
    root.setLevel(level)
    root.handlers.clear()
    for h in handlers:
        root.addHandler(h)

    # 让 uvicorn 的日志走 root 统一落盘
    for name in _DELEGATED_LOGGERS:
        lg = logging.getLogger(name)
        lg.handlers.clear()
        lg.propagate = True
        lg.setLevel(level)

    _CONFIGURED = True
    logging.getLogger(__name__).info("日志系统已初始化 | dir=%s | level=%s", target_dir, logging.getLevelName(level))
    return app_log_path


def get_logger(name: str) -> logging.Logger:
    return logging.getLogger(name)