import os
from urllib.parse import quote_plus as url_encode
from functools import lru_cache

from pydantic import BaseSettings, PostgresDsn


class Settings(BaseSettings):
    """Contains application-specific configuration values.

    Reads the values from environment variables and falls back to default values
    if the corresponding environment variable is unset.
    """

    app_name: str = os.getenv("APP_NAME", "MEDWingS")
    admin_email: str = os.getenv("ADMIN_EMAIL", "admin@example.com")

    debug_mode: bool = False
    if os.getenv("DEBUG_MODE", "false").lower() == "true":
        debug_mode = True

    _pg_hostname = os.getenv("POSTGRES_HOST", "db")
    _pg_port = os.getenv("POSTGRES_PORT", "5432")
    _pg_dbname = os.getenv("POSTGRES_DB", "medwings")
    _pg_user = url_encode(os.getenv("POSTGRES_USER", "medwings"))
    _pg_password = url_encode(os.getenv("POSTGRES_PASSWORD", "medwings"))
    pg_dsn: PostgresDsn = f"postgresql://{_pg_user}:{_pg_password}@{_pg_hostname}:{_pg_port}/{_pg_dbname}"


@lru_cache
def get_settings() -> Settings:
    """Creates the settings once and returns a cached version on subsequent requests."""

    return Settings()