from typing import Dict, Any, List, Optional
from dataclasses import dataclass
from uuid import uuid4

# In-memory storage for countries
_countries_store: List[Dict[str, Any]] = []

@dataclass
class CountryData:
    name: str
    landmass_size: float

def validate_country_data(name: str, landmass_size: float) -> bool:
    """
    Validates the country data before creation.

    Args:
        name (str): The name of the country.
        landmass_size (float): The landmass size in square kilometers.

    Returns:
        bool: True if data is valid, False otherwise.
    """
    if not name or not isinstance(name, str) or len(name.strip()) == 0:
        return False
    if not isinstance(landmass_size, (int, float)) or landmass_size <= 0:
        return False
    
    # Check if country name already exists
    for country in _countries_store:
        if country["name"].lower() == name.lower():
            return False
    
    return True

def create_country(name: str, landmass_size: float) -> Optional[Dict[str, Any]]:
    """
    Creates a new country entry in the in-memory store.

    Args:
        name (str): The name of the country.
        landmass_size (float): The landmass size in square kilometers.

    Returns:
        Optional[Dict[str, Any]]: The created country data if successful, None if validation fails.
    """
    if not validate_country_data(name, landmass_size):
        return None
    
    country_data = {
        "id": str(uuid4()),
        "name": name.strip(),
        "landmass_size": float(landmass_size)
    }
    
    _countries_store.append(country_data)
    return country_data

def get_all_countries() -> List[Dict[str, Any]]:
    """
    Retrieves all countries from the in-memory store.

    Returns:
        List[Dict[str, Any]]: A list of all stored countries.
    """
    return _countries_store

def get_country_by_name(name: str) -> Optional[Dict[str, Any]]:
    """
    Retrieves a country by its name.

    Args:
        name (str): The name of the country to find.

    Returns:
        Optional[Dict[str, Any]]: The country data if found, None otherwise.
    """
    name = name.lower()
    for country in _countries_store:
        if country["name"].lower() == name:
            return country
    return None

def format_country_response(country: Dict[str, Any]) -> Dict[str, Any]:
    """
    Formats the country data for API response.

    Args:
        country (Dict[str, Any]): The raw country data.

    Returns:
        Dict[str, Any]: Formatted country data.
    """
    return {
        "id": country["id"],
        "name": country["name"],
        "landmass_size": country["landmass_size"],
        "landmass_size_formatted": f"{country['landmass_size']:,.2f} km²"
    }