"""
Cache environment variables management.

This module handles reading sensitive cache configuration from environment variables,
ensuring sensitive data never gets stored in TOML files or KV storage.
"""

import logging
from typing import Optional
from urllib.parse import urlparse

logger = logging.getLogger(__name__)


def get_redis_url_from_env() -> Optional[str]:
    """
    Get Redis URL from environment variables.

    Priority order:
    1. REDIS_URL
    2. REDIS_HOST + REDIS_PORT + REDIS_DB
    3. Default: None

    Returns:
        Redis URL or None if not configured
    """
    # Environment-based configuration disabled: always return None
    return None


def get_redis_password_from_env() -> Optional[str]:
    """
    Get Redis password from environment variables.

    Returns:
        Redis password or None if not configured
    """
    return None


def get_redis_namespace_from_env() -> Optional[str]:
    """
    Get Redis namespace from environment variables.

    Returns:
        Redis namespace or None if not configured
    """
    return None


def validate_redis_url(url: str) -> bool:
    """
    Validate Redis URL format.

    Args:
        url: Redis URL to validate

    Returns:
        True if valid, False otherwise
    """
    try:
        parsed = urlparse(url)
        return parsed.scheme in ('redis', 'rediss') and parsed.netloc
    except Exception:
        return False


def get_sensitive_redis_config() -> dict:
    """
    Get all sensitive Redis configuration from environment variables.

    Returns:
        Dictionary containing sensitive configuration
    """
    config = {}
    return config


def get_cache_type_from_env() -> str:
    """
    Get cache type from environment variables.

    Returns:
        Cache type ('memory' or 'redis'), defaults to 'memory'
    """
    return "memory"
