from functools import lru_cache
from typing import Any

from pydantic import field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict


class Settings(BaseSettings):
    model_config = SettingsConfigDict(
        env_file=".env",
        env_file_encoding="utf-8",
        case_sensitive=False,
        extra="ignore",
    )

    app_name: str = "财务 AI 助手 API"
    app_version: str = "1.0.0"
    debug: bool = True
    secret_key: str = "change-me-in-production"
    allowed_origins: list[str] = ["http://localhost:3000"]

    database_url: str = "postgresql+asyncpg://s2f_user:s2f_password@localhost:5432/s2f_db"

    jwt_secret_key: str = "change-me-in-production"
    jwt_algorithm: str = "HS256"
    jwt_access_token_expire_minutes: int = 60

    openai_api_key: str = ""
    openai_model: str = "gpt-4-turbo-preview"
    zhipu_api_key: str = ""
    ai_provider: str = "zhipu"
    ai_api_key: str = ""

    upload_dir: str = "./uploads"
    max_upload_size: int = 10_485_760

    log_level: str = "INFO"

    @field_validator("allowed_origins", mode="before")
    @classmethod
    def parse_allowed_origins(cls, value: Any) -> list[str]:
        if isinstance(value, str):
            return [origin.strip() for origin in value.split(",") if origin.strip()]
        if isinstance(value, list):
            return value
        return ["http://localhost:3000"]


@lru_cache
def get_settings() -> Settings:
    return Settings()