import os
from pathlib import Path
import yaml
from pydantic import BaseModel, computed_field, Field
from dotenv import load_dotenv

# 加载环境变量
load_dotenv()


class DatabaseConfig(BaseModel):
    driver: str = "mysql+pymysql"
    host: str
    port: int = 3306
    name: str
    username: str
    password: str
    params: str = "characterEncoding=utf8&serverTimezone=Asia/Shanghai&allowMultiQueries=true&rewriteBatchedStatements=true"

    @computed_field
    @property
    def url(self) -> str:
        """生成数据库连接 URL"""
        return f"{self.driver}://{self.username}:{self.password}@{self.host}:{self.port}/{self.name}?{self.params}"


class ServerConfig(BaseModel):
    port: int
    context_path: str = "/"


class AppConfig(BaseModel):
    name: str = "wms_main"
    max_file_size: int = 100 * 1024 * 1024  # 100MB
    max_request_size: int = 1000 * 1024 * 1024  # 1000MB


class Settings(BaseModel):
    """全局配置模型"""
    app: AppConfig
    server: ServerConfig
    database: DatabaseConfig
    env: str = Field(default="development")  # 当前环境名称

    @classmethod
    def from_env(cls):
        """从环境变量加载配置"""
        env_name = os.getenv("ENV", "development")

        # 获取项目根目录
        base_dir = Path(__file__).resolve().parent.parent

        # 加载基础配置
        base_path = base_dir / "config" / "base.yaml"
        base_data = {}
        if base_path.exists():
            with open(base_path, "r") as f:
                base_data = yaml.safe_load(f) or {}

        # 加载环境特定配置
        env_path = base_dir / "config" / f"{env_name}.yaml"
        env_data = {}
        if env_path.exists():
            with open(env_path, "r") as f:
                env_data = yaml.safe_load(f) or {}

        # 深度合并配置
        def deep_merge(base: dict, update: dict) -> dict:
            """递归合并两个字典"""
            for key, value in update.items():
                if isinstance(value, dict) and key in base and isinstance(base[key], dict):
                    base[key] = deep_merge(base[key], value)
                else:
                    base[key] = value
            return base

        # 合并配置
        merged_config = deep_merge(base_data, env_data)
        merged_config["env"] = env_name  # 添加环境名称

        return cls(**merged_config)


# 创建全局配置对象
settings = Settings.from_env()