llm-chat/src/llm_chat/settings.py

from enum import StrEnum
from pathlib import Path

from pydantic import field_validator
from pydantic_settings import BaseSettings, SettingsConfigDict


class Model(StrEnum):
    """Model to use for the LLM Chat application."""

    GPT3 = "gpt-3.5-turbo"
    GPT4 = "gpt-4"
    GPT4_TURBO = "gpt-4-turbo-preview"


DEFAULT_MODEL = Model.GPT3
DEFAULT_TEMPERATURE = 0.7
DEFAULT_HISTORY_DIR = Path.home() / ".llm_chat" / "history"


class OpenAISettings(BaseSettings):
    """Settings for the LLM Chat application."""

    api_key: str = ""
    model: Model = DEFAULT_MODEL
    temperature: float = DEFAULT_TEMPERATURE
    history_dir: Path = DEFAULT_HISTORY_DIR

    model_config: SettingsConfigDict = SettingsConfigDict(  # type: ignore[misc]
        env_file=".env",
        env_file_encoding="utf-8",
        env_prefix="OPENAI_",
        frozen=True,
        use_enum_values=True,
    )

    @field_validator("history_dir")
    def history_dir_must_exist(cls, history_dir: Path) -> Path:
        """Ensure that the history directory exists."""
        if not history_dir.exists():
            history_dir.mkdir(parents=True)
        return history_dir