"""本模块定义了 NoneBot 本身运行所需的配置项。

NoneBot 使用 [`pydantic`](https://pydantic-docs.helpmanual.io/) 以及 [`python-dotenv`](https://saurabh-kumar.com/python-dotenv/) 来读取配置。

配置项需符合特殊格式或 json 序列化格式。详情见 [`pydantic Field Type`](https://pydantic-docs.helpmanual.io/usage/types/) 文档。

FrontMatter:
    sidebar_position: 1
    description: nonebot.config 模块
"""
import os
from pathlib import Path
from datetime import timedelta
from ipaddress import IPv4Address
from typing import TYPE_CHECKING, Any, Set, Dict, Tuple, Union, Mapping, Optional

from pydantic import BaseSettings, IPvAnyAddress
from pydantic.env_settings import (
    SettingsError,
    EnvSettingsSource,
    InitSettingsSource,
    SettingsSourceCallable,
    read_env_file,
    env_file_sentinel,
)

from nonebot.log import logger
from nonebot.utils import escape_tag


class CustomEnvSettings(EnvSettingsSource):
    def __call__(self, settings: BaseSettings) -> Dict[str, Any]:
        """
        Build environment variables suitable for passing to the Model.
        """
        d: Dict[str, Optional[str]] = {}

        if settings.__config__.case_sensitive:
            env_vars: Mapping[str, Optional[str]] = os.environ  # pragma: no cover
        else:
            env_vars = {k.lower(): v for k, v in os.environ.items()}

        env_file_vars: Dict[str, Optional[str]] = {}
        env_file = (
            self.env_file
            if self.env_file != env_file_sentinel
            else settings.__config__.env_file
        )
        env_file_encoding = (
            self.env_file_encoding
            if self.env_file_encoding is not None
            else settings.__config__.env_file_encoding
        )
        if env_file is not None:
            env_path = Path(env_file)
            if env_path.is_file():
                env_file_vars = read_env_file(
                    env_path,
                    encoding=env_file_encoding,
                    case_sensitive=settings.__config__.case_sensitive,
                )
                env_vars = {**env_file_vars, **env_vars}

        for field in settings.__fields__.values():
            env_val: Optional[str] = None
            for env_name in field.field_info.extra["env_names"]:
                env_val = env_vars.get(env_name)
                if env_name in env_file_vars:
                    del env_file_vars[env_name]
                if env_val is not None:
                    break

            if env_val is None:
                continue

            if field.is_complex():
                try:
                    env_val = settings.__config__.json_loads(env_val)
                except ValueError as e:  # pragma: no cover
                    raise SettingsError(
                        f'error parsing JSON for "{env_name}"'  # type: ignore
                    ) from e
            d[field.alias] = env_val

        if env_file_vars:
            for env_name, env_val in env_file_vars.items():
                if (env_val is None or len(env_val) == 0) and env_name in env_vars:
                    env_val = env_vars[env_name]
                try:
                    if env_val:
                        env_val = settings.__config__.json_loads(env_val.strip())
                except ValueError as e:
                    logger.opt(colors=True, exception=e).trace(
                        f"Error while parsing JSON for {escape_tag(env_name)}. Assumed as string."
                    )

                d[env_name] = env_val

        return d


class BaseConfig(BaseSettings):
    if TYPE_CHECKING:
        # dummy getattr for pylance checking, actually not used
        def __getattr__(self, name: str) -> Any:  # pragma: no cover
            return self.__dict__.get(name)

    class Config:
        @classmethod
        def customise_sources(
            cls,
            init_settings: InitSettingsSource,
            env_settings: EnvSettingsSource,
            file_secret_settings: SettingsSourceCallable,
        ) -> Tuple[SettingsSourceCallable, ...]:
            common_config = init_settings.init_kwargs.pop("_common_config", {})
            return (
                init_settings,
                CustomEnvSettings(
                    env_settings.env_file, env_settings.env_file_encoding
                ),
                InitSettingsSource(common_config),
                file_secret_settings,
            )


class Env(BaseConfig):
    """运行环境配置。大小写不敏感。

    将会从 `环境变量` > `.env 环境配置文件` 的优先级读取环境信息。
    """

    environment: str = "prod"
    """当前环境名。

    NoneBot 将从 `.env.{environment}` 文件中加载配置。
    """

    class Config:
        extra = "allow"
        env_file = ".env"


class Config(BaseConfig):
    """NoneBot 主要配置。大小写不敏感。

    除了 NoneBot 的配置项外，还可以自行添加配置项到 `.env.{environment}` 文件中。
    这些配置将会在 json 反序列化后一起带入 `Config` 类中。

    配置方法参考: [配置](https://v2.nonebot.dev/docs/tutorial/configuration)
    """

    _env_file: str = ".env"
    _common_config: Dict[str, Any] = {}

    # nonebot configs
    driver: str = "~fastapi"
    """NoneBot 运行所使用的 `Driver` 。继承自 {ref}`nonebot.drivers.Driver` 。

    配置格式为 `<module>[:<Driver>][+<module>[:<Mixin>]]*`。

    `~` 为 `nonebot.drivers.` 的缩写。
    """
    host: IPvAnyAddress = IPv4Address("127.0.0.1")  # type: ignore
    """NoneBot {ref}`nonebot.drivers.ReverseDriver` 服务端监听的 IP/主机名。"""
    port: int = 8080
    """NoneBot {ref}`nonebot.drivers.ReverseDriver` 服务端监听的端口。"""
    log_level: Union[int, str] = "INFO"
    """NoneBot 日志输出等级，可以为 `int` 类型等级或等级名称

    参考 [`loguru 日志等级`](https://loguru.readthedocs.io/en/stable/api/logger.html#levels)。

    :::tip 提示
    日志等级名称应为大写，如 `INFO`。
    :::

    用法:
        ```conf
        LOG_LEVEL=25
        LOG_LEVEL=INFO
        ```
    """

    # bot connection configs
    api_timeout: Optional[float] = 30.0
    """API 请求超时时间，单位: 秒。"""

    # bot runtime configs
    superusers: Set[str] = set()
    """机器人超级用户。

    用法:
        ```conf
        SUPERUSERS=["12345789"]
        ```
    """
    nickname: Set[str] = set()
    """机器人昵称。"""
    command_start: Set[str] = {"/"}
    """命令的起始标记，用于判断一条消息是不是命令。

    用法:
        ```conf
        COMMAND_START=["/", ""]
        ```
    """
    command_sep: Set[str] = {"."}
    """命令的分隔标记，用于将文本形式的命令切分为元组（实际的命令名）。

    用法:
        ```conf
        COMMAND_SEP=["."]
        ```
    """
    session_expire_timeout: timedelta = timedelta(minutes=2)
    """等待用户回复的超时时间。

    用法:
        ```conf
        SESSION_EXPIRE_TIMEOUT=120  # 单位: 秒
        SESSION_EXPIRE_TIMEOUT=[DD ][HH:MM]SS[.ffffff]
        SESSION_EXPIRE_TIMEOUT=P[DD]DT[HH]H[MM]M[SS]S  # ISO 8601
        ```
    """

    # adapter configs
    # adapter configs are defined in adapter/config.py

    # custom configs
    # custom configs can be assigned during nonebot.init
    # or from env file using json loads

    class Config:
        extra = "allow"
        env_file = ".env.prod"


__autodoc__ = {
    "CustomEnvSettings": False,
    "BaseConfig": False,
}