from django.contrib import messages
from django.db.models import Count, Q
from django.shortcuts import get_object_or_404, redirect, render

from .forms import ReplyForm, TicketForm, TicketTriageForm
from .models import Ticket


def _ticket_stats():
    return {
        "total": Ticket.objects.count(),
        "open": Ticket.objects.exclude(status=Ticket.Status.RESOLVED).count(),
        "triage": Ticket.objects.filter(status=Ticket.Status.TRIAGE).count(),
        "resolved": Ticket.objects.filter(status=Ticket.Status.RESOLVED).count(),
    }


def home(request):
    """Render the branded support center landing page and quick ticket intake."""
    if request.method == "POST":
        ticket_form = TicketForm(request.POST)
        if ticket_form.is_valid():
            ticket = ticket_form.save()
            messages.success(request, "Ticket submitted. Your support thread is ready.")
            return redirect("ticket_success", public_id=ticket.public_id)
    else:
        ticket_form = TicketForm()

    status_counts = dict(
        Ticket.objects.values_list("status").annotate(total=Count("id"))
    )
    recent_tickets = Ticket.objects.select_related("assigned_to")[:5]

    context = {
        "project_name": "RelayDesk",
        "page_description": "A lightweight support center for ticket submission, triage, threaded replies, and status tracking.",
        "ticket_form": ticket_form,
        "stats": _ticket_stats(),
        "status_choices": Ticket.Status.choices,
        "status_counts": status_counts,
        "recent_tickets": recent_tickets,
    }
    return render(request, "core/index.html", context)


def ticket_create(request):
    if request.method == "POST":
        form = TicketForm(request.POST)
        if form.is_valid():
            ticket = form.save()
            messages.success(request, "Ticket submitted. We created a trackable support thread for you.")
            return redirect("ticket_success", public_id=ticket.public_id)
    else:
        form = TicketForm()

    return render(
        request,
        "core/ticket_form.html",
        {
            "form": form,
            "project_name": "RelayDesk",
            "page_description": "Submit a support ticket with category, priority, and details.",
        },
    )


def ticket_success(request, public_id):
    ticket = get_object_or_404(Ticket.objects.select_related("assigned_to"), public_id=public_id)
    return render(
        request,
        "core/ticket_success.html",
        {
            "ticket": ticket,
            "project_name": "RelayDesk",
            "page_description": f"Confirmation for support ticket {ticket.ticket_number}.",
        },
    )


def ticket_list(request):
    tickets = Ticket.objects.select_related("assigned_to").annotate(reply_count=Count("replies"))
    query = request.GET.get("q", "").strip()
    status = request.GET.get("status", "").strip()
    priority = request.GET.get("priority", "").strip()
    category = request.GET.get("category", "").strip()

    if query:
        tickets = tickets.filter(
            Q(subject__icontains=query)
            | Q(description__icontains=query)
            | Q(requester_name__icontains=query)
            | Q(requester_email__icontains=query)
        )
    if status in Ticket.Status.values:
        tickets = tickets.filter(status=status)
    if priority in Ticket.Priority.values:
        tickets = tickets.filter(priority=priority)
    if category in Ticket.Category.values:
        tickets = tickets.filter(category=category)

    context = {
        "project_name": "RelayDesk",
        "page_description": "Search, filter, and triage support tickets.",
        "tickets": tickets,
        "stats": _ticket_stats(),
        "query": query,
        "selected_status": status,
        "selected_priority": priority,
        "selected_category": category,
        "status_choices": Ticket.Status.choices,
        "priority_choices": Ticket.Priority.choices,
        "category_choices": Ticket.Category.choices,
    }
    return render(request, "core/ticket_list.html", context)


def ticket_detail(request, public_id):
    ticket = get_object_or_404(
        Ticket.objects.select_related("assigned_to").prefetch_related("replies"),
        public_id=public_id,
    )
    reply_form = ReplyForm(
        initial={
            "author_name": request.user.get_full_name() or request.user.get_username() if request.user.is_authenticated else "",
            "author_email": request.user.email if request.user.is_authenticated else "",
        }
    )
    triage_form = TicketTriageForm(instance=ticket)

    if request.method == "POST" and "reply_submit" in request.POST:
        reply_form = ReplyForm(request.POST)
        if reply_form.is_valid():
            reply = reply_form.save(commit=False)
            reply.ticket = ticket
            if request.user.is_authenticated:
                reply.author_user = request.user
                reply.is_staff_reply = request.user.is_staff
                if not reply.author_name:
                    reply.author_name = request.user.get_full_name() or request.user.get_username()
                if not reply.author_email:
                    reply.author_email = request.user.email
            reply.save()
            messages.success(request, "Reply added to the ticket thread.")
            return redirect("ticket_detail", public_id=ticket.public_id)

    if request.method == "POST" and "triage_submit" in request.POST and request.user.is_staff:
        triage_form = TicketTriageForm(request.POST, instance=ticket)
        if triage_form.is_valid():
            triage_form.save()
            messages.success(request, "Ticket triage fields updated.")
            return redirect("ticket_detail", public_id=ticket.public_id)

    context = {
        "project_name": "RelayDesk",
        "page_description": f"Ticket thread and status for {ticket.ticket_number}.",
        "ticket": ticket,
        "reply_form": reply_form,
        "triage_form": triage_form,
    }
    return render(request, "core/ticket_detail.html", context)