#  Copyright 2026 zhaoxi826
#
#  Licensed under the Apache License, Version 2.0 (the "License");
#  you may not use this file except in compliance with the License.
#  You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.

import os
import sys

from loguru import logger
from rich.logging import RichHandler
from loguru._logger import Logger

from kilostar.utils.request_context import get_request_id, get_trace_id


def _is_json_mode() -> bool:
    """根据环境变量决定是否启用 JSON 结构化日志。

    支持开关：``KILOSTAR_LOG_FORMAT=json`` 或 ``KILOSTAR_LOG_JSON=1/true``。
    """
    fmt = os.environ.get("KILOSTAR_LOG_FORMAT", "").lower()
    if fmt == "json":
        return True
    flag = os.environ.get("KILOSTAR_LOG_JSON", "").lower()
    return flag in {"1", "true", "yes", "on"}


def _ctx_patcher(record):
    """日志切面：每条日志写出前，把 contextvars 里的 request_id / trace_id 注入。

    显式 ``bind(trace_id=...)`` 的 logger 优先（业务代码可以覆盖切面值）；
    没有 bind 时回退到 contextvars，没有 contextvars 时为空串。
    """
    extra = record["extra"]
    if not extra.get("trace_id"):
        extra["trace_id"] = get_trace_id()
    if not extra.get("request_id"):
        extra["request_id"] = get_request_id()


def setup_logger() -> Logger:
    """初始化全局 loguru logger。

    - 默认（开发模式）：``RichHandler`` 彩色输出，格式 ``actor:(...) | request_id:(...) | trace_id:(...) : message``
    - JSON 模式（``KILOSTAR_LOG_FORMAT=json``）：写到 stdout，每行一条 JSON，便于 ELK/Loki 采集

    request_id / trace_id 来自 ``kilostar.utils.request_context``，由 FastAPI middleware
    或工作流入口绑定到 contextvars，本模块通过 ``patcher`` 透明注入。
    """
    logger.remove()

    log_level = os.environ.get("KILOSTAR_LOG_LEVEL", "DEBUG").upper()

    if _is_json_mode():
        logger.configure(
            extra={"actor_name": "System", "trace_id": "", "request_id": ""},
            patcher=_ctx_patcher,
        )
        logger.add(
            sys.stdout,
            serialize=True,
            level=log_level,
            enqueue=True,
        )
        return logger

    def format_record(record):
        actor = record["extra"].get("actor_name", "System")
        trace_id = record["extra"].get("trace_id", "")
        request_id = record["extra"].get("request_id", "")
        ids = []
        if request_id:
            ids.append(f"request_id:({request_id})")
        if trace_id:
            ids.append(f"trace_id:({trace_id})")
        ids_str = " | " + " | ".join(ids) if ids else ""
        return f"actor:({actor}){ids_str} : {record['message']}"

    logger.configure(
        extra={"actor_name": "System", "trace_id": "", "request_id": ""},
        patcher=_ctx_patcher,
    )

    logger.add(
        RichHandler(
            rich_tracebacks=True,
            markup=True,
            show_time=False,
            show_level=False,
            show_path=False,
        ),
        format=format_record,
        level=log_level,
        enqueue=True,
    )

    return logger


global_logger = setup_logger()


def get_logger(actor_name: str, trace_id: str = "") -> Logger:
    """获取一个绑定了 actor_name 与可选 trace_id 的 logger，便于日志按 Actor/请求归类。

    若 ``trace_id`` 留空，会回退到 ``contextvars`` 中的当前值（由 middleware 或
    工作流入口设置）。显式传值则会覆盖切面注入。
    """
    return global_logger.bind(actor_name=actor_name, trace_id=trace_id)