"""
Explanation request UI views for complaints.
"""

from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.http import HttpResponseForbidden
from django.shortcuts import get_object_or_404, redirect, render
from django.utils import timezone
from django.utils.translation import gettext as _
from django.views.decorators.http import require_http_methods

from apps.core.services import AuditService
from apps.notifications.services import NotificationService
from apps.organizations.models import Staff

from .models import Complaint, ComplaintExplanation, ComplaintStatus
from .services.complaint_service import ComplaintService, ComplaintServiceError


@login_required
@require_http_methods(["GET", "POST"])
def request_explanation_form(request, pk):
    """
    Form to request explanations from involved staff members.

    Shows all involved staff with their managers and departments.
    All staff and managers are selected by default.
    """
    complaint = get_object_or_404(
        Complaint.objects.prefetch_related(
            "involved_staff__staff__department",
            "involved_staff__staff__report_to",
        ),
        pk=pk,
    )

    # Check permissions
    user = request.user
    can_request = (
        user.is_px_admin()
        or user.is_hospital_admin()
        or (user.is_department_manager() and complaint.department == user.department)
        or (complaint.hospital == user.hospital)
    )

    if not can_request:
        return HttpResponseForbidden(_("You don't have permission to request explanations."))

    # Check complaint is in active status
    if not complaint.is_active_status:
        messages.error(
            request,
            _(
                "Cannot request explanation for complaint with status '{}'. Complaint must be Open, In Progress, or Partially Resolved."
            ).format(complaint.get_status_display()),
        )
        return redirect("complaints:complaint_detail", pk=complaint.pk)

    # Get all involved staff with their managers
    involved_staff = complaint.involved_staff.select_related("staff", "staff__department", "staff__report_to").all()

    if not involved_staff.exists():
        messages.error(request, _("No staff members are involved in this complaint."))
        return redirect("complaints:complaint_detail", pk=complaint.pk)

    # Build list of recipients (staff + managers)
    recipients = []
    manager_ids = set()

    for staff_inv in involved_staff:
        staff = staff_inv.staff
        manager = staff.report_to

        recipient = {
            "staff_inv": staff_inv,
            "staff": staff,
            "staff_id": str(staff.id),
            "staff_name": staff.get_full_name(),
            "staff_email": staff.email or (staff.user.email if staff.user else None),
            "department": staff.department.name if staff.department else "-",
            "role": staff_inv.get_role_display(),
            "manager": manager,
            "manager_id": str(manager.id) if manager else None,
            "manager_name": manager.get_full_name() if manager else None,
            "manager_email": manager.email if manager else None,
        }
        recipients.append(recipient)

        # Track unique managers
        if manager and manager.id not in manager_ids:
            manager_ids.add(manager.id)

    if request.method == "POST":
        # Get selected staff and managers
        selected_staff_ids = request.POST.getlist("selected_staff")
        selected_manager_ids = request.POST.getlist("selected_managers")
        request_message = request.POST.get("request_message", "").strip()

        if not selected_staff_ids:
            messages.error(request, _("Please select at least one staff member."))
            return render(
                request,
                "complaints/request_explanation_form.html",
                {
                    "complaint": complaint,
                    "recipients": recipients,
                    "manager_ids": manager_ids,
                },
            )

        # Send explanation requests
        from django.contrib.sites.shortcuts import get_current_site

        site = get_current_site(request)
        results = ComplaintService.request_explanation(
            complaint,
            recipients,
            selected_staff_ids,
            selected_manager_ids,
            request_message,
            request.user,
            site.domain,
            request=request,
        )

        # Check results and show appropriate message
        if results["staff_count"] == 0 and results["manager_count"] == 0:
            if results["skipped_no_email"] > 0:
                messages.warning(
                    request,
                    _(
                        "No explanation requests were sent. {} staff member(s) do not have email addresses. Please update staff records with email addresses before sending explanation requests."
                    ).format(results["skipped_no_email"]),
                )
            else:
                messages.warning(
                    request, _("No explanation requests were sent. Please check staff email configuration.")
                )
        elif results["staff_count"] == 0 and results["manager_count"] > 0:
            messages.warning(
                request,
                _(
                    "Only manager notifications were sent ({}). Staff explanation requests could not be sent due to missing email addresses."
                ).format(results["manager_count"]),
            )
        else:
            messages.success(
                request,
                _("Explanation requests sent successfully! Staff: {}, Managers notified: {}.").format(
                    results["staff_count"], results["manager_count"]
                ),
            )
        return redirect("complaints:complaint_detail", pk=complaint.pk)

    return render(
        request,
        "complaints/request_explanation_form.html",
        {
            "complaint": complaint,
            "recipients": recipients,
            "manager_ids": manager_ids,
        },
    )