"""Validation utilities for the barber booking system."""

import re
from typing import Tuple, Dict, Optional

def validate_email(email: str) -> bool:
    """Validate email format."""
    pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
    return bool(re.match(pattern, email))

def validate_phone(phone: str) -> bool:
    """Validate phone number format."""
    pattern = r'^\+?[1-9]\d{1,14}$'
    return bool(re.match(pattern, phone))

def validate_name(name: str) -> bool:
    """Validate customer name."""
    words = name.strip().split()
    return len(words) >= 1 and all(len(word) >= 2 for word in words)

def format_phone(phone: str) -> str:
    """Format phone number to international format."""
    if not phone.startswith('+'):
        return f"+{phone.lstrip('0')}"
    return phone

def validate_booking_info(current_node: str, booking_info: Dict) -> Tuple[bool, str]:
    """Validate required booking information for the current node."""
    if current_node == "ShowTopSlots" and not booking_info.get("name"):
        return False, "I need your name first. What's your name?"
    elif current_node == "CollectEmail" and not booking_info.get("service"):
        return False, "Please select a service first."
    elif current_node == "CollectPhone" and not booking_info.get("email"):
        return False, "I need your email for the confirmation. What's your email address?"
    elif current_node == "Confirmation" and not booking_info.get("phone"):
        return False, "What's your phone number for appointment reminders?"
    return True, ""

def get_closest_service(query: str) -> Optional[str]:
    """Find the closest matching service based on the user's input."""
    query = query.lower().strip()
    
    # Direct matches
    if query in ["haircut", "beard trim", "full service"]:
        return query
        
    # Handle variations and partial matches
    if any(word in query for word in ["hair", "cut", "haircut"]):
        return "haircut"
    elif any(word in query for word in ["beard", "trim", "beardtrim"]):
        return "beard trim"
    elif any(word in query for word in ["full", "complete", "both", "all"]):
        return "full service"
            
    return None