import logging
import os
from pathlib import Path
from typing import Optional

from pydantic_settings import BaseSettings, SettingsConfigDict


logger = logging.getLogger(__name__)


class Settings(BaseSettings):
    PROJECT_NAME: str = "File Upload Download API"
    API_V1_STR: str = "/api/v1"

    # Base directory for storage - can be overridden by environment variable
    STORAGE_BASE_DIR: str = os.environ.get("STORAGE_BASE_DIR", "./storage")

    # File storage directory - derived from base dir but can be overridden
    FILE_STORAGE_DIR: Optional[str] = os.environ.get("FILE_STORAGE_DIR")

    # Database directory - derived from base dir but can be overridden
    DB_DIR: Optional[str] = os.environ.get("DB_DIR")

    # Database URL - derived from DB_DIR but can be overridden
    SQLALCHEMY_DATABASE_URL: Optional[str] = os.environ.get("SQLALCHEMY_DATABASE_URL")

    # Configure max file size (10MB by default)
    MAX_FILE_SIZE: int = int(
        os.environ.get("MAX_FILE_SIZE", 10 * 1024 * 1024)
    )  # 10MB in bytes

    model_config = SettingsConfigDict(case_sensitive=True, env_file=".env")


# Create settings instance
settings = Settings()

# Resolve directory paths if not explicitly set via environment variables
if not settings.FILE_STORAGE_DIR:
    settings.FILE_STORAGE_DIR = os.path.join(settings.STORAGE_BASE_DIR, "files")

if not settings.DB_DIR:
    settings.DB_DIR = os.path.join(settings.STORAGE_BASE_DIR, "db")

if not settings.SQLALCHEMY_DATABASE_URL:
    db_path = os.path.join(settings.DB_DIR, "db.sqlite")
    settings.SQLALCHEMY_DATABASE_URL = f"sqlite:///{db_path}"

# Convert string paths to Path objects for easier manipulation
storage_base_path = Path(settings.STORAGE_BASE_DIR)
db_path = Path(settings.DB_DIR)
file_storage_path = Path(settings.FILE_STORAGE_DIR)

# Try to create directories with better error handling
try:
    # Ensure base storage directory exists
    storage_base_path.mkdir(parents=True, exist_ok=True)
    logger.info(f"Base storage directory: {storage_base_path}")

    # Ensure DB directory exists
    db_path.mkdir(parents=True, exist_ok=True)
    logger.info(f"Database directory: {db_path}")

    # Ensure file storage directory exists
    file_storage_path.mkdir(parents=True, exist_ok=True)
    logger.info(f"File storage directory: {file_storage_path}")
except PermissionError as e:
    logger.warning(
        f"Permission denied when creating directories: {e}. "
        f"The application may need to be run with appropriate permissions or "
        f"you should pre-create these directories with correct permissions."
    )
    # We'll continue running, as the application might be able to function
    # if the directories already exist with correct permissions
except Exception as e:
    logger.error(f"Error creating storage directories: {e}")
    # We'll still continue running in case the application can operate
    # without direct file access (e.g., if using external storage)