"""
该模块用于常用配置文件的加载
多配置文件编写原则:
1. 尽量不要冲突: 一个键不要多次出现
2. 分工明确: 每个配置文件给一个或一类服务提供配置
3. 扁平化编写: 配置文件尽量扁平化,不要出现过多的嵌套
4. 注意冲突时的优先级: 项目目录下的配置文件优先级高于config目录下的配置文件
5. 请不要将需要动态加载的内容写入配置文件,你应该使用其他储存方式
"""

import os
import json
import copy
import toml
import yaml

from typing import Any

from liteyuki.log import logger

_SUPPORTED_CONFIG_FORMATS = (".yaml", ".yml", ".json", ".toml")


def flat_config(config: dict[str, Any]) -> dict[str, Any]:
    """
    扁平化配置文件

    {a:{b:{c:1}}} -> {"a.b.c": 1}
    Args:
        config: 配置项目

    Returns:
        扁平化后的配置文件,但也包含原有的键值对
    """
    new_config = copy.deepcopy(config)
    for key, value in config.items():
        if isinstance(value, dict):
            for k, v in flat_config(value).items():
                new_config[f"{key}.{k}"] = v
    return new_config


def load_from_yaml(file_: str) -> dict[str, Any]:
    """
    Load config from yaml file

    """
    logger.debug(f"Loading YAML config from {file_}")
    config = yaml.safe_load(open(file_, "r", encoding="utf-8"))
    return flat_config(config if config is not None else {})


def load_from_json(file_: str) -> dict[str, Any]:
    """
    Load config from json file
    """
    logger.debug(f"Loading JSON config from {file_}")
    config = json.load(open(file_, "r", encoding="utf-8"))
    return flat_config(config if config is not None else {})


def load_from_toml(file_: str) -> dict[str, Any]:
    """
    Load config from toml file
    """
    logger.debug(f"Loading TOML config from {file_}")
    config = toml.load(open(file_, "r", encoding="utf-8"))
    return flat_config(config if config is not None else {})


def load_from_files(*files: str, no_warning: bool = False) -> dict[str, Any]:
    """
    从指定文件加载配置项,会自动识别文件格式
    默认执行扁平化选项
    """
    config = {}
    for file in files:
        if os.path.exists(file):
            if file.endswith((".yaml", "yml")):
                config.update(load_from_yaml(file))
            elif file.endswith(".json"):
                config.update(load_from_json(file))
            elif file.endswith(".toml"):
                config.update(load_from_toml(file))
            else:
                if not no_warning:
                    logger.warning(f"Unsupported config file format: {file}")
        else:
            if not no_warning:
                logger.warning(f"Config file not found: {file}")
    return config


def load_configs_from_dirs(
    *directories: str, no_waring: bool = False
) -> dict[str, Any]:
    """
    从目录下加载配置文件,不递归
    按照读取文件的优先级反向覆盖
    默认执行扁平化选项
    """
    config = {}
    for directory in directories:
        if not os.path.exists(directory):
            if not no_waring:
                logger.warning(f"Directory not found: {directory}")
            continue
        for file in os.listdir(directory):
            if file.endswith(_SUPPORTED_CONFIG_FORMATS):
                config.update(
                    load_from_files(os.path.join(directory, file), no_warning=no_waring)
                )
    return config


def load_config_in_default(no_waring: bool = False) -> dict[str, Any]:
    """
    从一个标准的轻雪项目加载配置文件
    项目目录下的config.*和config目录下的所有配置文件
    项目目录下的配置文件优先
    Args:
        no_waring: 是否关闭警告
    """
    config = load_configs_from_dirs("config", no_waring=no_waring)
    config.update(
        load_from_files(
            "config.yaml",
            "config.toml",
            "config.json",
            "config.yml",
            no_warning=no_waring,
        )
    )
    return config

# new config loader
class Loader:
    def __init__(self):
        self.config = {}

    def load_from_yaml(self, fp: str) -> "Loader":
        """从yaml文件加载配置
        Args:
            fp
        """
        with open(fp, 'r') as file:
            self.config.update(yaml.safe_load(file))
        return self

    def load_from_toml(self, fp: str) -> "Loader":
        """从toml文件加载配置"""
        with open(fp, 'r') as file:
            self.config.update(toml.load(file))
        return self

    def load_from_json(self, fp: str) -> "Loader":
        """从json文件加载配置"""
        with open(fp, 'r') as file:
            self.config.update(json.load(file))
        return self

    def load_from_env(self, prefix: str = "") -> "Loader":
        """从环境变量加载配置"""
        for key, value in os.environ.items():
            if key.startswith(prefix):
                self.config[key[len(prefix):]] = value
        return self

    def merge(self, loader: "Loader") -> "Loader":
        """合并两个Loader键值对树"""
        self.config.update(loader.config)
        return self

    def get(self, key: str, default: Any = None) -> Any:
        """获取配置值"""
        return self.config.get(key, default)

    def __repr__(self) -> str:
        return f"Loader(config={self.config})"