import base64
import re
import urllib.parse
import urllib.request
import csv
import io
from django.http import JsonResponse, HttpResponse
from django.urls import reverse
from django.shortcuts import render, redirect, get_object_or_404
from django.db.models import Q, Sum
from django.contrib import messages
from django.core.paginator import Paginator
from .models import Voter, Tenant, Interaction, Donation, VoterLikelihood, EventParticipation, Event, EventType, InteractionType, DonationMethod, ElectionType, CampaignSettings, Volunteer
from .forms import VoterForm, InteractionForm, DonationForm, VoterLikelihoodForm, EventParticipationForm, VoterImportForm, AdvancedVoterSearchForm
import logging
from django.utils import timezone

logger = logging.getLogger(__name__)

def index(request):
    """
    Main landing page for Grassroots Campaign Manager.
    Displays a list of campaigns if the user is logged in but hasn't selected one.
    """
    tenants = Tenant.objects.all()
    selected_tenant_id = request.session.get('tenant_id')
    selected_tenant = None
    metrics = {}
    recent_interactions = []
    upcoming_events = []
    
    if selected_tenant_id:
        selected_tenant = Tenant.objects.filter(id=selected_tenant_id).first()
        if selected_tenant:
            voters = selected_tenant.voters.all()
            total_donations = Donation.objects.filter(voter__tenant=selected_tenant).aggregate(total=Sum('amount'))['total'] or 0
            
            # Get or create settings for the tenant
            campaign_settings, _ = CampaignSettings.objects.get_or_create(tenant=selected_tenant)
            donation_goal = campaign_settings.donation_goal
            
            donation_percentage = 0
            if donation_goal > 0:
                donation_percentage = float(round((total_donations / donation_goal) * 100, 1))
            
            metrics = {
                'total_registered_voters': voters.count(),
                'total_target_voters': voters.filter(is_targeted=True).count(),
                'total_supporting': voters.filter(candidate_support='supporting').count(),
                'total_target_households': voters.filter(is_targeted=True).exclude(address='').values('address').distinct().count(),
                'total_door_visits': Interaction.objects.filter(voter__tenant=selected_tenant, type__name='Door Visit').count(),
                'total_signs': voters.filter(Q(yard_sign='wants') | Q(yard_sign='has')).count(),
                'total_window_stickers': voters.filter(Q(window_sticker='wants') | Q(window_sticker='has')).count(),
                'total_donations': float(total_donations),
                'donation_goal': float(donation_goal),
                'donation_percentage': donation_percentage,
                'volunteers_count': Volunteer.objects.filter(tenant=selected_tenant).count(),
                'interactions_count': Interaction.objects.filter(voter__tenant=selected_tenant).count(),
                'events_count': Event.objects.filter(tenant=selected_tenant).count(),
            }
            
            recent_interactions = Interaction.objects.filter(voter__tenant=selected_tenant).order_by('-date')[:5]
            upcoming_events = Event.objects.filter(tenant=selected_tenant, date__gte=timezone.now().date()).order_by('date')[:5]

    context = {
        'tenants': tenants,
        'selected_tenant': selected_tenant,
        'metrics': metrics,
        'recent_interactions': recent_interactions,
        'upcoming_events': upcoming_events,
    }
    return render(request, 'core/index.html', context)

def select_campaign(request, tenant_id):
    """
    Sets the selected campaign in the session.
    """
    tenant = get_object_or_404(Tenant, id=tenant_id)
    request.session['tenant_id'] = tenant.id
    messages.success(request, f"You are now managing: {tenant.name}")
    return redirect('index')

def voter_list(request):
    """
    List and search voters. Restricted to selected tenant.
    """
    selected_tenant_id = request.session.get("tenant_id")
    if not selected_tenant_id:
        messages.warning(request, "Please select a campaign first.")
        return redirect("index")

    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    query = request.GET.get("q")
    voters = Voter.objects.filter(tenant=tenant).order_by("last_name", "first_name")

    # Filtering based on dashboard metrics
    if request.GET.get("is_targeted") == "true":
        voters = voters.filter(is_targeted=True)
    if request.GET.get("support") == "supporting":
        voters = voters.filter(candidate_support="supporting")
    if request.GET.get("has_address") == "true":
        voters = voters.exclude(address__isnull=True).exclude(address="")
    if request.GET.get("visited") == "true":
        voters = voters.filter(interactions__type__name="Door Visit").distinct()
    if request.GET.get("yard_sign") == "true":
        voters = voters.filter(Q(yard_sign="wants") | Q(yard_sign="has"))
    if request.GET.get("window_sticker") == "true":
        voters = voters.filter(Q(window_sticker="wants") | Q(window_sticker="has"))
    if request.GET.get("has_donations") == "true":
        voters = voters.filter(donations__isnull=False).distinct()

    if query:
        query = query.strip()
        search_filter = Q(first_name__icontains=query) | Q(last_name__icontains=query) | Q(voter_id__icontains=query)

        if "," in query:
            parts = [p.strip() for p in query.split(",")]
            if len(parts) >= 2:
                last_part = parts[0]
                first_part = parts[1]
                search_filter |= Q(last_name__icontains=last_part, first_name__icontains=first_part)
        elif " " in query:
            parts = query.split()
            if len(parts) >= 2:
                first_part = parts[0]
                last_part = " ".join(parts[1:])
                search_filter |= Q(first_name__icontains=first_part, last_name__icontains=last_part)

        voters = voters.filter(search_filter).order_by("last_name", "first_name")
        
    paginator = Paginator(voters, 50)
    page_number = request.GET.get('page')
    voters_page = paginator.get_page(page_number)
    
    context = {
        "voters": voters_page,
        "query": query,
        "selected_tenant": tenant
    }
    return render(request, "core/voter_list.html", context)


def voter_detail(request, voter_id):
    """
    360-degree view of a voter.
    """
    selected_tenant_id = request.session.get('tenant_id')
    if not selected_tenant_id:
        messages.warning(request, "Please select a campaign first.")
        return redirect('index')

    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    context = {
        'voter': voter,
        'selected_tenant': tenant,
        'voting_records': voter.voting_records.all().order_by('-election_date'),
        'donations': voter.donations.all().order_by('-date'),
        'interactions': voter.interactions.all().order_by('-date'),
        'event_participations': voter.event_participations.all().order_by('-event__date'),
        'likelihoods': voter.likelihoods.all(),
        'voter_form': VoterForm(instance=voter),
        'interaction_form': InteractionForm(tenant=tenant),
        'donation_form': DonationForm(tenant=tenant),
        'likelihood_form': VoterLikelihoodForm(tenant=tenant),
        'event_participation_form': EventParticipationForm(tenant=tenant),
    }
    return render(request, 'core/voter_detail.html', context)

def voter_edit(request, voter_id):
    """
    Update voter core demographics.
    """
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        # Log incoming coordinate data for debugging
        lat_raw = request.POST.get('latitude')
        lon_raw = request.POST.get('longitude')
        logger.info(f"Voter Edit POST: lat={lat_raw}, lon={lon_raw}")

        form = VoterForm(request.POST, instance=voter)
        if form.is_valid():
            # If coordinates were provided in POST, ensure they are applied to the instance
            # This handles cases where readonly or other widget settings might interfere
            voter = form.save(commit=False)
            if lat_raw:
                try:
                    voter.latitude = lat_raw
                except: pass
            if lon_raw:
                try:
                    voter.longitude = lon_raw
                except: pass
            
            voter.save()
            messages.success(request, "Voter profile updated successfully.")
        else:
            logger.warning(f"Voter Edit Form Invalid: {form.errors}")
            for field, errors in form.errors.items():
                for error in errors:
                    messages.error(request, f"Error in {field}: {error}")
    return redirect('voter_detail', voter_id=voter.id)

def add_interaction(request, voter_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        form = InteractionForm(request.POST, tenant=tenant)
        if form.is_valid():
            interaction = form.save(commit=False)
            interaction.voter = voter
            interaction.save()
            messages.success(request, "Interaction added.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter.id}) + '?active_tab=interactions')

def edit_interaction(request, interaction_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    interaction = get_object_or_404(Interaction, id=interaction_id, voter__tenant=tenant)
    
    if request.method == 'POST':
        form = InteractionForm(request.POST, instance=interaction, tenant=tenant)
        if form.is_valid():
            form.save()
            messages.success(request, "Interaction updated.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': interaction.voter.id}) + '?active_tab=interactions')

def delete_interaction(request, interaction_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    interaction = get_object_or_404(Interaction, id=interaction_id, voter__tenant=tenant)
    voter_id = interaction.voter.id
    
    if request.method == 'POST':
        interaction.delete()
        messages.success(request, "Interaction deleted.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter_id}) + '?active_tab=interactions')

def add_donation(request, voter_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        form = DonationForm(request.POST, tenant=tenant)
        if form.is_valid():
            donation = form.save(commit=False)
            donation.voter = voter
            donation.save()
            messages.success(request, "Donation recorded.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter.id}) + '?active_tab=donations')

def edit_donation(request, donation_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    donation = get_object_or_404(Donation, id=donation_id, voter__tenant=tenant)
    
    if request.method == 'POST':
        form = DonationForm(request.POST, instance=donation, tenant=tenant)
        if form.is_valid():
            form.save()
            messages.success(request, "Donation updated.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': donation.voter.id}) + '?active_tab=donations')

def delete_donation(request, donation_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    donation = get_object_or_404(Donation, id=donation_id, voter__tenant=tenant)
    voter_id = donation.voter.id
    
    if request.method == 'POST':
        donation.delete()
        messages.success(request, "Donation deleted.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter_id}) + '?active_tab=donations')

def add_likelihood(request, voter_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        form = VoterLikelihoodForm(request.POST, tenant=tenant)
        if form.is_valid():
            likelihood = form.save(commit=False)
            likelihood.voter = voter
            # Handle potential duplicate election_type
            VoterLikelihood.objects.filter(voter=voter, election_type=likelihood.election_type).delete()
            likelihood.save()
            messages.success(request, "Likelihood updated.")
    return redirect('voter_detail', voter_id=voter.id)

def edit_likelihood(request, likelihood_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    likelihood = get_object_or_404(VoterLikelihood, id=likelihood_id, voter__tenant=tenant)
    
    if request.method == 'POST':
        form = VoterLikelihoodForm(request.POST, instance=likelihood, tenant=tenant)
        if form.is_valid():
            # Check for conflict with another record of same election_type
            election_type = form.cleaned_data['election_type']
            if VoterLikelihood.objects.filter(voter=likelihood.voter, election_type=election_type).exclude(id=likelihood.id).exists():
                VoterLikelihood.objects.filter(voter=likelihood.voter, election_type=election_type).exclude(id=likelihood.id).delete()
            form.save()
            messages.success(request, "Likelihood updated.")
    return redirect('voter_detail', voter_id=likelihood.voter.id)

def delete_likelihood(request, likelihood_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    likelihood = get_object_or_404(VoterLikelihood, id=likelihood_id, voter__tenant=tenant)
    voter_id = likelihood.voter.id
    
    if request.method == 'POST':
        likelihood.delete()
        messages.success(request, "Likelihood record deleted.")
    return redirect('voter_detail', voter_id=voter_id)

def add_event_participation(request, voter_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        form = EventParticipationForm(request.POST, tenant=tenant)
        if form.is_valid():
            participation = form.save(commit=False)
            participation.voter = voter
            # Avoid duplicate participation
            if not EventParticipation.objects.filter(voter=voter, event=participation.event).exists():
                participation.save()
                messages.success(request, "Event participation added.")
            else:
                messages.warning(request, "Voter is already participating in this event.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter.id}) + '?active_tab=events')

def edit_event_participation(request, participation_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    participation = get_object_or_404(EventParticipation, id=participation_id, voter__tenant=tenant)
    
    if request.method == 'POST':
        form = EventParticipationForm(request.POST, instance=participation, tenant=tenant)
        if form.is_valid():
            event = form.cleaned_data['event']
            if EventParticipation.objects.filter(voter=participation.voter, event=event).exclude(id=participation.id).exists():
                messages.warning(request, "Voter is already participating in that event.")
            else:
                form.save()
                messages.success(request, "Event participation updated.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': participation.voter.id}) + '?active_tab=events')

def delete_event_participation(request, participation_id):
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    participation = get_object_or_404(EventParticipation, id=participation_id, voter__tenant=tenant)
    voter_id = participation.voter.id
    
    if request.method == 'POST':
        participation.delete()
        messages.success(request, "Event participation removed.")
    return redirect(reverse('voter_detail', kwargs={'voter_id': voter_id}) + '?active_tab=events')

def voter_geocode(request, voter_id):
    """
    Manually trigger geocoding for a voter, potentially using values from the request.
    """
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        street = request.POST.get('address_street', voter.address_street)
        city = request.POST.get('city', voter.city)
        state = request.POST.get('state', voter.state)
        zip_code = request.POST.get('zip_code', voter.zip_code)
        
        parts = [street, city, state, zip_code]
        full_address = ", ".join([p for p in parts if p])
        
        # Use a temporary instance to avoid saving until the user clicks "Save" in the modal
        temp_voter = Voter(
            address_street=street,
            city=city,
            state=state,
            zip_code=zip_code,
            address=full_address
        )
        success, error_msg = temp_voter.geocode_address()
        
        if success:
            return JsonResponse({
                'success': True,
                'latitude': str(temp_voter.latitude),
                'longitude': str(temp_voter.longitude),
                'address': full_address
            })
        else:
            return JsonResponse({
                'success': False,
                'error': f"Geocoding failed: {error_msg or 'No results found.'}"
            })

    return JsonResponse({'success': False, 'error': 'Invalid request method.'})

def voter_advanced_search(request):
    """
    Advanced search for voters with multiple filters.
    """
    selected_tenant_id = request.session.get("tenant_id")
    if not selected_tenant_id:
        messages.warning(request, "Please select a campaign first.")
        return redirect("index")

    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voters = Voter.objects.filter(tenant=tenant).order_by("last_name", "first_name")
    
    form = AdvancedVoterSearchForm(request.GET)
    if form.is_valid():
        data = form.cleaned_data
        if data.get('first_name'):
            voters = voters.filter(first_name__icontains=data['first_name'])
        if data.get('last_name'):
            voters = voters.filter(last_name__icontains=data['last_name'])
        if data.get('voter_id'):
            voters = voters.filter(voter_id__icontains=data['voter_id'])
        if data.get('birth_month'):
            voters = voters.filter(birthdate__month=data['birth_month'])
        if data.get('city'):
            voters = voters.filter(city__icontains=data['city'])
        if data.get('zip_code'):
            voters = voters.filter(zip_code__icontains=data['zip_code'])
        if data.get('district'):
            voters = voters.filter(district__icontains=data['district'])
        if data.get('precinct'):
            voters = voters.filter(precinct__icontains=data['precinct'])
        if data.get('phone_type'):
            voters = voters.filter(phone_type=data['phone_type'])
        if data.get('is_targeted'):
            voters = voters.filter(is_targeted=True)
        if data.get('candidate_support'):
            voters = voters.filter(candidate_support=data['candidate_support'])
        if data.get('yard_sign'):
            voters = voters.filter(yard_sign=data['yard_sign'])
        if data.get('window_sticker'):
            voters = voters.filter(window_sticker=data['window_sticker'])

    paginator = Paginator(voters, 50)
    page_number = request.GET.get('page')
    voters_page = paginator.get_page(page_number)

    context = {
        'form': form,
        'voters': voters_page,
        'selected_tenant': tenant,
    }
    return render(request, 'core/voter_advanced_search.html', context)

def export_voters_csv(request):
    """
    Exports selected or filtered voters to a CSV file.
    """
    selected_tenant_id = request.session.get("tenant_id")
    if not selected_tenant_id:
        messages.warning(request, "Please select a campaign first.")
        return redirect("index")

    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    
    if request.method != 'POST':
        return redirect('voter_advanced_search')
        
    action = request.POST.get('action')
    voters = Voter.objects.filter(tenant=tenant)
    
    if action == 'export_selected':
        voter_ids = request.POST.getlist('selected_voters')
        voters = voters.filter(id__in=voter_ids)
    else: # export_all
        # Re-apply filters from hidden inputs
        # These are passed as filter_fieldname
        filters = {}
        for key, value in request.POST.items():
            if key.startswith('filter_') and value:
                field_name = key.replace('filter_', '')
                filters[field_name] = value
        
        # We can use the AdvancedVoterSearchForm to validate and apply filters
        # but we need to pass data without the prefix
        form = AdvancedVoterSearchForm(filters)
        if form.is_valid():
            data = form.cleaned_data
            if data.get('first_name'):
                voters = voters.filter(first_name__icontains=data['first_name'])
            if data.get('last_name'):
                voters = voters.filter(last_name__icontains=data['last_name'])
            if data.get('voter_id'):
                voters = voters.filter(voter_id__icontains=data['voter_id'])
            if data.get('birth_month'):
                voters = voters.filter(birthdate__month=data['birth_month'])
            if data.get('city'):
                voters = voters.filter(city__icontains=data['city'])
            if data.get('zip_code'):
                voters = voters.filter(zip_code__icontains=data['zip_code'])
            if data.get('district'):
                voters = voters.filter(district__icontains=data['district'])
            if data.get('precinct'):
                voters = voters.filter(precinct__icontains=data['precinct'])
            if data.get('phone_type'):
                voters = voters.filter(phone_type=data['phone_type'])
            if data.get('is_targeted'):
                voters = voters.filter(is_targeted=True)
            if data.get('candidate_support'):
                voters = voters.filter(candidate_support=data['candidate_support'])
            if data.get('yard_sign'):
                voters = voters.filter(yard_sign=data['yard_sign'])
            if data.get('window_sticker'):
                voters = voters.filter(window_sticker=data['window_sticker'])

    voters = voters.order_by('last_name', 'first_name')
    
    response = HttpResponse(content_type='text/csv')
    response['Content-Disposition'] = f'attachment; filename="voters_export_{timezone.now().strftime("%Y%m%d_%H%M%S")}.csv"'
    
    writer = csv.writer(response)
    writer.writerow([
        'Voter ID', 'First Name', 'Last Name', 'Nickname', 'Birthdate', 
        'Address', 'City', 'State', 'Zip Code', 'Phone', 'Phone Type', 'Email', 
        'District', 'Precinct', 'Is Targeted', 'Support', 'Yard Sign', 'Window Sticker', 'Notes'
    ])
    
    for voter in voters:
        writer.writerow([
            voter.voter_id, voter.first_name, voter.last_name, voter.nickname, voter.birthdate,
            voter.address, voter.city, voter.state, voter.zip_code, voter.phone, voter.get_phone_type_display(), voter.email,
            voter.district, voter.precinct, 'Yes' if voter.is_targeted else 'No',
            voter.get_candidate_support_display(), voter.get_yard_sign_display(), voter.get_window_sticker_display(), voter.notes
        ])
        
    return response

def voter_delete(request, voter_id):
    """
    Delete a voter profile.
    """
    selected_tenant_id = request.session.get('tenant_id')
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    voter = get_object_or_404(Voter, id=voter_id, tenant=tenant)

    if request.method == 'POST':
        voter.delete()
        messages.success(request, "Voter profile deleted successfully.")
        return redirect('voter_list')
    
    return redirect('voter_detail', voter_id=voter.id)

def bulk_send_sms(request):
    """
    Sends bulk SMS to selected voters using Twilio API.
    """
    if request.method != 'POST':
        return redirect('voter_advanced_search')
        
    selected_tenant_id = request.session.get("tenant_id")
    if not selected_tenant_id:
        messages.warning(request, "Please select a campaign first.")
        return redirect("index")
    
    tenant = get_object_or_404(Tenant, id=selected_tenant_id)
    settings = getattr(tenant, 'settings', None)
    if not settings:
        messages.error(request, "Campaign settings not found.")
        return redirect('voter_advanced_search')
    
    account_sid = settings.twilio_account_sid
    auth_token = settings.twilio_auth_token
    from_number = settings.twilio_from_number
    
    if not account_sid or not auth_token or not from_number:
        messages.error(request, "Twilio configuration is incomplete in Campaign Settings.")
        return redirect('voter_advanced_search')
        
    voter_ids = request.POST.getlist('selected_voters')
    message_body = request.POST.get('message_body')
    client_time_str = request.POST.get('client_time')

    interaction_date = timezone.now()
    if client_time_str:
        try:
            from datetime import datetime
            interaction_date = datetime.fromisoformat(client_time_str)
            if timezone.is_naive(interaction_date):
                interaction_date = timezone.make_aware(interaction_date)
        except Exception as e:
            logger.warning(f'Failed to parse client_time {client_time_str}: {e}')
    
    if not message_body:
        messages.error(request, "Message body cannot be empty.")
        return redirect('voter_advanced_search')
        
    voters = Voter.objects.filter(tenant=tenant, id__in=voter_ids, phone_type='cell').exclude(phone='')
    
    if not voters.exists():
        messages.warning(request, "No voters with a valid cell phone number were selected.")
        return redirect('voter_advanced_search')

    success_count = 0
    fail_count = 0
    
    auth_str = f"{account_sid}:{auth_token}"
    auth_header = base64.b64encode(auth_str.encode()).decode()
    url = f"https://api.twilio.com/2010-04-01/Accounts/{account_sid}/Messages.json"
    
    # Get or create interaction type for SMS
    interaction_type, _ = InteractionType.objects.get_or_create(tenant=tenant, name="SMS Text")

    for voter in voters:
        # Format phone to E.164 (assume US +1)
        digits = re.sub(r'\D', '', str(voter.phone))
        if len(digits) == 10:
            to_number = f"+1{digits}"
        elif len(digits) == 11 and digits.startswith('1'):
            to_number = f"+{digits}"
        else:
            # Skip invalid phone numbers
            fail_count += 1
            continue
            
        data_dict = {
            'To': to_number,
            'From': from_number,
            'Body': message_body
        }
        data = urllib.parse.urlencode(data_dict).encode()
        
        req = urllib.request.Request(url, data=data, method='POST')
        req.add_header("Authorization", f"Basic {auth_header}")
        
        try:
            with urllib.request.urlopen(req, timeout=10) as response:
                if response.status in [200, 201]:
                    success_count += 1
                    # Log interaction
                    Interaction.objects.create(
                        voter=voter,
                        type=interaction_type,
                        date=interaction_date,
                        description='Mass SMS Text',
                        notes=message_body
                    )
                else:
                    fail_count += 1
        except Exception as e:
            logger.error(f"Error sending SMS to {voter.phone}: {e}")
            fail_count += 1
            
    messages.success(request, f"Bulk SMS process completed: {success_count} successful, {fail_count} failed/skipped.")
    return redirect('voter_advanced_search')