from django.shortcuts import render, get_object_or_404, redirect
from django.contrib import messages
from django.core.paginator import Paginator
from django.core.exceptions import ValidationError
from django.db.models import Q
import phonenumbers
from .models import Customer, Address
from .forms import CustomerForm


def normalize_query_phone(q):
    """Normalize phone number for search"""
    try:
        parsed = phonenumbers.parse(q, "BY")
        if phonenumbers.is_valid_number(parsed):
            return phonenumbers.format_number(parsed, phonenumbers.PhoneNumberFormat.E164)
        return q
    except:
        return q


def customer_list(request):
    """Список всех клиентов"""
    query = request.GET.get('q')
    customers = Customer.objects.all()

    if query:
        # Try to normalize the phone number for searching
        phone_normalized = normalize_query_phone(query)
        customers = customers.filter(
            Q(name__icontains=query) |
            Q(email__icontains=query) |
            Q(phone__icontains=phone_normalized)
        )

    customers = customers.order_by('-created_at')
    
    # Пагинация
    paginator = Paginator(customers, 25)  # 25 клиентов на страницу
    page_number = request.GET.get('page')
    page_obj = paginator.get_page(page_number)
    
    context = {
        'page_obj': page_obj,
        'query': query,
    }
    return render(request, 'customers/customer_list.html', context)


def customer_detail(request, pk):
    """Детали клиента"""
    customer = get_object_or_404(Customer, pk=pk)
    addresses = customer.addresses.all()
    
    context = {
        'customer': customer,
        'addresses': addresses,
    }
    return render(request, 'customers/customer_detail.html', context)


def customer_create(request):
    """Создание нового клиента"""
    if request.method == 'POST':
        form = CustomerForm(request.POST)
        if form.is_valid():
            customer = form.save()
            messages.success(request, f'Клиент {customer.full_name} успешно создан.')
            return redirect('customers:customer-detail', pk=customer.pk)
    else:
        form = CustomerForm()

    return render(request, 'customers/customer_form.html', {'form': form, 'is_creating': True})


def customer_update(request, pk):
    """Редактирование клиента"""
    customer = get_object_or_404(Customer, pk=pk)

    if request.method == 'POST':
        form = CustomerForm(request.POST, instance=customer)
        if form.is_valid():
            form.save()
            messages.success(request, f'Клиент {customer.full_name} успешно обновлён.')
            return redirect('customers:customer-detail', pk=customer.pk)
    else:
        form = CustomerForm(instance=customer)

    return render(request, 'customers/customer_form.html', {'form': form, 'is_creating': False})


def customer_delete(request, pk):
    """Удаление клиента"""
    customer = get_object_or_404(Customer, pk=pk)
    
    if request.method == 'POST':
        customer_name = customer.full_name
        customer.delete()
        messages.success(request, f'Клиент {customer_name} успешно удален.')
        return redirect('customers:customer-list')
    
    context = {
        'customer': customer
    }
    return render(request, 'customers/customer_confirm_delete.html', context)