from django.contrib import messages
from django.contrib.auth import authenticate, login
from django.contrib.auth.decorators import login_required
from django.contrib.auth.forms import AuthenticationForm
from django.db.models import Exists, OuterRef
from django.http import JsonResponse
from django.shortcuts import render, redirect
from django.views.decorators.http import require_POST
from .models import Issue, IssueCategory, User, Vote
from .forms import CitizenRegistrationForm, IssueForm

def home(request):
    total_issues = Issue.objects.count()
    resolved_issues = Issue.objects.filter(status='resolved').count()
    active_users = User.objects.filter(is_active=True).count()
    
    # Get recently reported issues (last 3 issues)
    recent_issues = Issue.objects.all().order_by('-created_at')[:3]
    
    for issue in recent_issues:
        issue.user_has_voted = issue.has_user_voted(request.user) if request.user.is_authenticated else False

    # Get municipal departments count (assuming you have a Department model)
    # If you don't have one yet, you can use a placeholder or create the model
    municipal_departments = 5  # Placeholder - replace with actual count when you have the model
    
    context = {
        'total_issues': total_issues,
        'resolved_issues': resolved_issues,
        'active_users': active_users,
        'municipal_departments': municipal_departments,
        'recent_issues': recent_issues,
    }
    return render(request, 'core/index.html', context)


@login_required
def citizen_dashboard(request):
    if not request.user.is_citizen:
        messages.error(request, 'Access denied. Citizen role required.')
        return redirect('home')
    
    # Get only basic data for now
    all_user_issues = Issue.objects.filter(reporter=request.user)
    user_issues_display = all_user_issues.order_by('-created_at')[:5]
    resolved_count = all_user_issues.filter(status='resolved').count()
    categories = IssueCategory.objects.all()
    
    context = {
        'user_issues': user_issues_display, 
        'resolved_count': resolved_count,    
        'categories': categories,
        'issue_form': IssueForm(),
    }
    return render(request, 'core/citizen_dashboard.html', context)

@login_required
def report_issue(request):
    if not request.user.is_citizen:
        messages.error(request, 'Access denied. Citizen role required.')
        return redirect('home')
    
    if request.method == 'POST':
        form = IssueForm(request.POST, request.FILES)
        if form.is_valid():
            issue = form.save(commit=False)
            issue.reporter = request.user
            issue.save()
            messages.success(request, 'Issue reported successfully!')
            return redirect('citizen_dashboard')
        else:
            messages.error(request, 'Please correct the errors below.')
    else:
        form = IssueForm()
    
    return render(request, 'core/report_issue.html', {'form': form})

@login_required
def view_all_issues(request):
    if not request.user.is_citizen:
        messages.error(request, 'Access denied. Citizen role required.')
        return redirect('home')

    # Efficiently annotate whether the current user has voted
    user_vote_subq = Vote.objects.filter(user=request.user, issue_id=OuterRef('pk'))
    issues = (
        Issue.objects
        .select_related('category', 'reporter')
        .annotate(user_has_voted=Exists(user_vote_subq))
        .order_by('-created_at')
    )

    categories = IssueCategory.objects.all()

    # Optional filters (status/category) if you wired the dropdowns
    status = request.GET.get('status') or ''
    category_id = request.GET.get('category') or ''
    if status:
        issues = issues.filter(status=status)
    if category_id:
        issues = issues.filter(category_id=category_id)

    return render(request, 'core/view_all_issues.html', {
        'issues': issues,
        'categories': categories,
        'selected_status': status,
        'selected_category': category_id,
    })


def register(request):
    if request.method == 'POST':
        form = CitizenRegistrationForm(request.POST)
        if form.is_valid():
            user = form.save()
            messages.success(request, 'Registration successful! Please login.')
            return redirect('login')
    else:
        form = CitizenRegistrationForm()
    
    return render(request, 'core/register.html', {'form': form})

def custom_login(request):
    if request.method == 'POST':
        form = AuthenticationForm(request, data=request.POST)
        if form.is_valid():
            username = form.cleaned_data.get('username')
            password = form.cleaned_data.get('password')
            user = authenticate(username=username, password=password)
            if user is not None:
                login(request, user)
                messages.success(request, f'Welcome back, {username}!')
                return redirect('home')
            else:
                messages.error(request, 'Invalid username or password.')
        else:
            messages.error(request, 'Invalid username or password.')
    else:
        form = AuthenticationForm()
    return render(request, 'core/login.html', {'form': form})

@login_required
@require_POST
def vote_issue(request, issue_id):
    try:
        issue = Issue.objects.get(id=issue_id)
        vote, created = Vote.objects.get_or_create(user=request.user, issue=issue)
        
        if not created:
            # User already voted, so remove the vote (toggle)
            vote.delete()
            voted = False
        else:
            voted = True
        
        return JsonResponse({
            'success': True,
            'voted': voted,
            'vote_count': issue.vote_count()
        })
        
    except Issue.DoesNotExist:
        return JsonResponse({'success': False, 'error': 'Issue not found'})
    except Exception as e:
        return JsonResponse({'success': False, 'error': str(e)})