from functools import lru_cache
from typing import Optional

from pydantic_settings import BaseSettings, SettingsConfigDict


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

    # Application
    app_name: str = "PromptCR-Lab"
    debug: bool = False

    # Database (psycopg2 preferred; fall back to psycopg3 if not built)
    database_url: str = "postgresql+psycopg://postgres:postgres@localhost:5432/promptcr"

    # Model API keys (loaded from environment, never hardcoded)
    deepseek_api_key: Optional[str] = None
    deepseek_base_url: str = "https://api.deepseek.com/v1"
    deepseek_model: str = "deepseek-chat"

    kimi_api_key: Optional[str] = None
    kimi_base_url: str = "https://api.moonshot.cn/v1"
    kimi_model: str = "moonshot-v1-8k"

    qwen_api_key: Optional[str] = None
    qwen_base_url: str = "https://dashscope.aliyuncs.com/compatible-mode/v1"
    qwen_model: str = "qwen-turbo"

    # Defaults
    default_model_concurrency: int = 5
    default_max_retries: int = 3


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