Add helper functions for Country

helpers/country_helpers.py

@@ -0,0 +1,98 @@
+from typing import List, Optional, Dict, Union
+from sqlalchemy.orm import Session
+from sqlalchemy.exc import IntegrityError
+import re
+from models.country import Country
+from schemas.country import CountryCreate, CountryUpdate
+
+def validate_country_code(code: str) -> bool:
+    """
+    Validate country code format (2 letter ISO code).
+    
+    Args:
+        code: Two letter country code to validate
+        
+    Returns:
+        bool: True if code format is valid, False otherwise
+    """
+    return bool(re.match(r'^[A-Z]{2}$', code))
+
+def get_country_by_code(db: Session, code: str) -> Optional[Country]:
+    """
+    Get a country by its code.
+    
+    Args:
+        db: Database session
+        code: Country code to search for
+        
+    Returns:
+        Country object if found, None otherwise
+    """
+    return db.query(Country).filter(Country.code == code.upper()).first()
+
+def format_country_response(country: Country) -> Dict:
+    """
+    Format country data for API response.
+    
+    Args:
+        country: Country object to format
+        
+    Returns:
+        Dict containing formatted country data
+    """
+    return {
+        "name": country.name,
+        "code": country.code,
+        "currency": country.currency,
+        "capital": country.capital,
+        "region": country.region
+    }
+
+def create_country_safely(db: Session, country_data: CountryCreate) -> Union[Country, Dict[str, str]]:
+    """
+    Create a new country with validation and error handling.
+    
+    Args:
+        db: Database session
+        country_data: Country data for creation
+        
+    Returns:
+        Country object if created successfully, error dict otherwise
+    """
+    if not validate_country_code(country_data.code):
+        return {"error": "Invalid country code format"}
+    
+    existing_country = get_country_by_code(db, country_data.code)
+    if existing_country:
+        return {"error": "Country code already exists"}
+    
+    try:
+        db_country = Country(
+            name=country_data.name,
+            code=country_data.code.upper(),
+            currency=country_data.currency,
+            capital=country_data.capital,
+            region=country_data.region
+        )
+        
+        db.add(db_country)
+        db.commit()
+        db.refresh(db_country)
+        return db_country
+        
+    except IntegrityError:
+        db.rollback()
+        return {"error": "Country name already exists"}
+
+def get_countries_by_region(db: Session, region: str) -> List[Country]:
+    """
+    Get all countries in a specific region.
+    
+    Args:
+        db: Database session
+        region: Region to filter by
+        
+    Returns:
+        List of Country objects in the specified region
+    """
+    return db.query(Country).filter(Country.region == region).all()