Add helper functions for Country

helpers/country_helpers.py

@@ -0,0 +1,102 @@
+from typing import List, Optional, Dict, Union
+from sqlalchemy.orm import Session
+from sqlalchemy import func
+from models.country import Country
+from pydantic import BaseModel, constr
+
+def validate_country_code(country_code: str) -> bool:
+    """
+    Validate that country code is exactly 2 characters and contains only letters.
+    
+    Args:
+        country_code: The country code to validate
+        
+    Returns:
+        bool: True if valid, False otherwise
+    """
+    if len(country_code) != 2:
+        return False
+    return country_code.isalpha()
+
+def search_countries(db: Session, search_query: Optional[str] = None) -> List[Country]:
+    """
+    Search for countries that start with the given search query.
+    
+    Args:
+        db: Database session
+        search_query: Optional search string to filter country names
+        
+    Returns:
+        List of matching Country objects
+    """
+    query = db.query(Country)
+    
+    if search_query:
+        query = query.filter(Country.name.ilike(f'{search_query}%'))
+    
+    return query.order_by(Country.name).all()
+
+def get_country_by_code(db: Session, country_code: str) -> Optional[Country]:
+    """
+    Get a country by its unique code.
+    
+    Args:
+        db: Database session
+        country_code: Two letter country code
+        
+    Returns:
+        Country object if found, None otherwise
+    """
+    return db.query(Country).filter(Country.code == country_code.upper()).first()
+
+def create_country_safely(db: Session, name: str, code: str) -> Union[Country, Dict[str, str]]:
+    """
+    Create a new country with validation and error handling.
+    
+    Args:
+        db: Database session
+        name: Country name
+        code: Country code
+        
+    Returns:
+        Country object if created successfully, error dict otherwise
+    """
+    if not validate_country_code(code):
+        return {"error": "Invalid country code format"}
+        
+    existing_country = db.query(Country).filter(
+        func.lower(Country.name) == name.lower()
+    ).first()
+    
+    if existing_country:
+        return {"error": "Country name already exists"}
+        
+    existing_code = get_country_by_code(db, code)
+    if existing_code:
+        return {"error": "Country code already exists"}
+        
+    db_country = Country(
+        name=name,
+        code=code.upper()
+    )
+    
+    db.add(db_country)
+    db.commit()
+    db.refresh(db_country)
+    
+    return db_country
+
+def format_country_response(country: Country) -> Dict[str, str]:
+    """
+    Format a country object into a standardized response format.
+    
+    Args:
+        country: Country object to format
+        
+    Returns:
+        Dict containing formatted country data
+    """
+    return {
+        "name": country.name,
+        "code": country.code,
+    }