"""
Observations views - Public and internal views for observation management.

Public views (no login required):
- observation_create_public: Submit new observation
- observation_submitted: Success page with tracking code
- observation_track: Track observation by code

Internal views (login required):
- observation_list: List all observations with filters
- observation_detail: View observation details
- observation_triage: Triage observation
- observation_change_status: Change observation status
- observation_add_note: Add internal note
- observation_convert_to_action: Convert to PX Action
- category_list: Manage categories
- category_create/edit/delete: Category CRUD
"""

import logging

from django.contrib import messages
from django.contrib.auth.decorators import login_required, permission_required
from django.core.paginator import Paginator
from django.db.models import Q
from django.http import JsonResponse
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.accounts.models import User
from apps.organizations.models import Department

from .forms import (
    ConvertToActionForm,
    ObservationCategoryForm,
    ObservationInternalForm,
    ObservationNoteForm,
    ObservationPublicForm,
    ObservationStatusForm,
    ObservationTrackForm,
    ObservationTriageForm,
)
from .models import (
    Observation,
    ObservationAttachment,
    ObservationCategory,
    ObservationNote,
    ObservationStatus,
    ObservationStatusLog,
)
from .services import ObservationService

logger = logging.getLogger(__name__)


# =============================================================================
# PUBLIC VIEWS (No Login Required)
# =============================================================================


def observation_create_public(request):
    """
    Public view for submitting observations.

    No login required - anonymous submissions allowed.
    """
    if request.method == "POST":
        form = ObservationPublicForm(request.POST, request.FILES)

        if form.is_valid():
            try:
                # Get client info
                client_ip = get_client_ip(request)
                user_agent = request.META.get("HTTP_USER_AGENT", "")

                # Handle file uploads
                attachments = request.FILES.getlist("attachments")

                # Create observation using service
                observation = ObservationService.create_observation(
                    description=form.cleaned_data["description"],
                    severity=form.cleaned_data["severity"],
                    category=form.cleaned_data.get("category"),
                    title=form.cleaned_data.get("title", ""),
                    location_text=form.cleaned_data.get("location_text", ""),
                    incident_datetime=form.cleaned_data.get("incident_datetime"),
                    reporter_staff_id=form.cleaned_data.get("reporter_staff_id", ""),
                    reporter_name=form.cleaned_data.get("reporter_name", ""),
                    reporter_phone=form.cleaned_data.get("reporter_phone", ""),
                    reporter_email=form.cleaned_data.get("reporter_email", ""),
                    client_ip=client_ip,
                    user_agent=user_agent,
                    attachments=attachments,
                )

                return redirect("observations:observation_submitted", tracking_code=observation.tracking_code)

            except Exception as e:
                logger.error(f"Error creating observation: {e}")
                messages.error(request, "An error occurred while submitting your observation. Please try again.")
    else:
        form = ObservationPublicForm()

    context = {
        "form": form,
        "categories": ObservationCategory.objects.filter(is_active=True).order_by("sort_order"),
    }

    return render(request, "observations/public_new.html", context)


def observation_submitted(request, tracking_code):
    """
    Success page after observation submission.

    Shows tracking code for future reference.
    """
    observation = get_object_or_404(Observation, tracking_code=tracking_code)

    context = {
        "observation": observation,
        "tracking_code": tracking_code,
    }

    return render(request, "observations/public_success.html", context)


def observation_track(request):
    """
    Public view to track observation status by tracking code.

    Shows minimal status information only (no internal notes).
    """
    observation = None
    error_message = None
    tracking_code = request.GET.get("tracking_code", "").strip()

    if request.method == "POST":
        tracking_code = request.POST.get("tracking_code", "").strip()
        if not tracking_code:
            error_message = _("Please enter a tracking code.")
        else:
            try:
                observation = (
                    Observation.objects.select_related("category", "hospital")
                    .prefetch_related("status_logs", "notes")
                    .get(tracking_code__iexact=tracking_code)
                )
            except Observation.DoesNotExist:
                error_message = _("No observation found with this tracking code. Please check and try again.")
    elif tracking_code:
        try:
            observation = (
                Observation.objects.select_related("category", "hospital")
                .prefetch_related("status_logs", "notes")
                .get(tracking_code__iexact=tracking_code)
            )
        except Observation.DoesNotExist:
            error_message = _("No observation found with this tracking code. Please check and try again.")

    public_timeline = []
    if observation:
        for log in observation.status_logs.all().order_by("-created_at"):
            public_timeline.append(
                {
                    "type": "status_change",
                    "title": _("Status Updated"),
                    "comment": log.comment,
                    "created_at": log.created_at,
                    "from_status": log.from_status,
                    "to_status": log.to_status,
                }
            )
        for note in observation.notes.filter(is_internal=False).order_by("-created_at"):
            public_timeline.append(
                {
                    "type": "note",
                    "title": _("Update Received"),
                    "comment": note.note,
                    "created_at": note.created_at,
                }
            )
        public_timeline.sort(key=lambda x: x["created_at"], reverse=True)

    context = {
        "observation": observation,
        "public_timeline": public_timeline,
        "error_message": error_message,
        "tracking_code": tracking_code,
    }

    return render(request, "observations/public_track.html", context)


# =============================================================================
# INTERNAL VIEWS (Login Required)
# =============================================================================


@login_required
@require_http_methods(["GET", "POST"])
def observation_create(request):
    """
    Internal view for authenticated staff to create observations.
    """
    if request.method == "POST":
        form = ObservationInternalForm(request.POST, request.FILES, request=request)

        if form.is_valid():
            try:
                client_ip = get_client_ip(request)
                user_agent = request.META.get("HTTP_USER_AGENT", "")
                user = request.user
                attachments = request.FILES.getlist("attachments")

                observation = ObservationService.create_observation(
                    description=form.cleaned_data["description"],
                    severity=form.cleaned_data["severity"],
                    category=form.cleaned_data.get("category"),
                    title=form.cleaned_data.get("title", ""),
                    location_text=form.cleaned_data.get("location_text", ""),
                    incident_datetime=form.cleaned_data.get("incident_datetime"),
                    reporter_staff_id=user.employee_id or "",
                    reporter_name=user.get_full_name(),
                    reporter_phone="",
                    reporter_email=user.email,
                    client_ip=client_ip,
                    user_agent=user_agent,
                    attachments=attachments,
                )

                observation.source = "staff_portal"
                assigned_dept = form.cleaned_data.get("assigned_department")
                assigned_user = form.cleaned_data.get("assigned_to")
                if assigned_dept:
                    observation.assigned_department = assigned_dept
                if assigned_user:
                    observation.assigned_to = assigned_user
                    observation.status = ObservationStatus.ASSIGNED
                    ObservationStatusLog.objects.create(
                        observation=observation,
                        from_status=ObservationStatus.NEW,
                        to_status=ObservationStatus.ASSIGNED,
                        comment="Auto-assigned during creation",
                    )
                observation.save()

                messages.success(request, f"Observation {observation.tracking_code} created successfully.")
                return redirect("observations:observation_detail", pk=observation.id)

            except Exception as e:
                logger.error(f"Error creating observation: {e}")
                messages.error(request, "An error occurred while creating the observation. Please try again.")
    else:
        form = ObservationInternalForm(request=request)

    context = {
        "form": form,
    }

    return render(request, "observations/observation_create.html", context)


@login_required
def observation_list(request):
    """
    Internal view for listing observations with filters.

    Features:
    - Server-side pagination
    - Advanced filters (status, severity, category, department, etc.)
    - Search by tracking code, description
    - RBAC filtering
    """
    # Base queryset with optimizations
    queryset = Observation.objects.select_related(
        "category", "assigned_department", "assigned_to", "triaged_by", "resolved_by", "closed_by"
    )

    # Apply RBAC filters
    user = request.user
    # Get selected hospital for PX Admins (from middleware)
    selected_hospital = getattr(request, "tenant_hospital", None)

    if user.is_px_admin():
        # PX Admins see all, but filter by selected hospital if set
        if selected_hospital:
            queryset = queryset.filter(
                Q(assigned_department__hospital=selected_hospital) | Q(assigned_department__isnull=True)
            )
    elif user.is_hospital_admin() and user.hospital:
        queryset = queryset.filter(Q(assigned_department__hospital=user.hospital) | Q(assigned_department__isnull=True))
    elif user.is_department_manager() and user.department:
        queryset = queryset.filter(assigned_department=user.department)
    elif user.hospital:
        queryset = queryset.filter(Q(assigned_department__hospital=user.hospital) | Q(assigned_department__isnull=True))

    # Apply filters from request
    status_filter = request.GET.get("status")
    if status_filter:
        queryset = queryset.filter(status=status_filter)

    severity_filter = request.GET.get("severity")
    if severity_filter:
        queryset = queryset.filter(severity=severity_filter)

    category_filter = request.GET.get("category")
    if category_filter:
        queryset = queryset.filter(category_id=category_filter)

    department_filter = request.GET.get("assigned_department")
    if department_filter:
        queryset = queryset.filter(assigned_department_id=department_filter)

    assigned_to_filter = request.GET.get("assigned_to")
    if assigned_to_filter:
        queryset = queryset.filter(assigned_to_id=assigned_to_filter)

    is_anonymous_filter = request.GET.get("is_anonymous")
    if is_anonymous_filter == "yes":
        queryset = queryset.filter(reporter_staff_id="", reporter_name="")
    elif is_anonymous_filter == "no":
        queryset = queryset.exclude(reporter_staff_id="", reporter_name="")

    # Search
    search_query = request.GET.get("search")
    if search_query:
        queryset = queryset.filter(
            Q(tracking_code__icontains=search_query)
            | Q(title__icontains=search_query)
            | Q(description__icontains=search_query)
            | Q(reporter_name__icontains=search_query)
            | Q(reporter_staff_id__icontains=search_query)
            | Q(location_text__icontains=search_query)
        )

    # Date range filters
    date_from = request.GET.get("date_from")
    if date_from:
        queryset = queryset.filter(created_at__date__gte=date_from)

    date_to = request.GET.get("date_to")
    if date_to:
        queryset = queryset.filter(created_at__date__lte=date_to)

    # Ordering
    order_by = request.GET.get("order_by", "-created_at")
    queryset = queryset.order_by(order_by)

    # Pagination
    page_size = int(request.GET.get("page_size", 25))
    paginator = Paginator(queryset, page_size)
    page_number = request.GET.get("page", 1)
    page_obj = paginator.get_page(page_number)

    # Get filter options
    departments = Department.objects.filter(status="active")
    if not user.is_px_admin() and user.hospital:
        departments = departments.filter(hospital=user.hospital)

    assignable_users = User.objects.filter(is_active=True)
    if not user.is_px_admin() and user.hospital:
        assignable_users = assignable_users.filter(hospital=user.hospital)

    categories = ObservationCategory.objects.filter(is_active=True)

    # Statistics
    stats = ObservationService.get_statistics()

    context = {
        "page_obj": page_obj,
        "observations": page_obj.object_list,
        "stats": stats,
        "departments": departments,
        "assignable_users": assignable_users,
        "categories": categories,
        "status_choices": ObservationStatus.choices,
        "filters": request.GET,
    }

    return render(request, "observations/observation_list.html", context)


@login_required
def observation_detail(request, pk):
    """
    Internal view for observation details.

    Features:
    - Full observation details
    - Timeline (status logs + notes)
    - Attachments
    - Linked PX Action
    - Workflow actions
    """
    observation = get_object_or_404(
        Observation.objects.select_related(
            "category", "assigned_department", "assigned_to", "triaged_by", "resolved_by", "closed_by"
        ).prefetch_related("attachments", "notes__created_by", "status_logs__changed_by"),
        pk=pk,
    )

    # Check access
    user = request.user
    if not user.is_px_admin():
        if user.is_hospital_admin() and observation.assigned_department:
            if observation.assigned_department.hospital != user.hospital:
                messages.error(request, "You don't have permission to view this observation.")
                return redirect("observations:observation_list")
        elif user.is_department_manager() and observation.assigned_department:
            if observation.assigned_department != user.department:
                messages.error(request, "You don't have permission to view this observation.")
                return redirect("observations:observation_list")

    # Get timeline (combine status logs and notes)
    status_logs = list(observation.status_logs.all())
    notes = list(observation.notes.all())

    timeline = []
    for log in status_logs:
        timeline.append(
            {
                "type": "status_change",
                "created_at": log.created_at,
                "item": log,
            }
        )
    for note in notes:
        timeline.append(
            {
                "type": "note",
                "created_at": note.created_at,
                "item": note,
            }
        )
    timeline.sort(key=lambda x: x["created_at"], reverse=True)

    # Get attachments
    attachments = observation.attachments.all()

    # Get linked PX Action if exists
    px_action = None
    if observation.action_id:
        from apps.px_action_center.models import PXAction

        try:
            px_action = PXAction.objects.get(id=observation.action_id)
        except PXAction.DoesNotExist:
            pass

    # Get assignable users and departments
    departments = Department.objects.filter(status="active")
    assignable_users = User.objects.filter(is_active=True)
    if user.hospital:
        departments = departments.filter(hospital=user.hospital)
        assignable_users = assignable_users.filter(hospital=user.hospital)

    # Forms
    triage_form = ObservationTriageForm(
        initial={
            "assigned_department": observation.assigned_department,
            "assigned_to": observation.assigned_to,
            "status": observation.status,
        },
        hospital=user.hospital,
    )
    status_form = ObservationStatusForm(initial={"status": observation.status})
    note_form = ObservationNoteForm()

    from apps.rca.models import RootCauseAnalysis as RCA
    from django.contrib.contenttypes.models import ContentType as CT

    observation_ct = CT.objects.get_for_model(Observation)
    linked_rcas = RCA.objects.filter(
        content_type=observation_ct, object_id=observation.pk, is_deleted=False
    ).select_related("assigned_to", "created_by")

    context = {
        "observation": observation,
        "timeline": timeline,
        "attachments": attachments,
        "px_action": px_action,
        "departments": departments,
        "assignable_users": assignable_users,
        "triage_form": triage_form,
        "status_form": status_form,
        "note_form": note_form,
        "status_choices": ObservationStatus.choices,
        "can_triage": user.has_perm("observations.triage_observation") or user.is_px_admin(),
        "can_convert": user.is_px_admin() or user.is_hospital_admin(),
        "linked_rcas": linked_rcas,
    }

    return render(request, "observations/observation_detail.html", context)


@login_required
@require_http_methods(["POST"])
def observation_triage(request, pk):
    """
    Triage an observation - assign department/owner and update status.
    """
    observation = get_object_or_404(Observation, pk=pk)

    # Check permission
    user = request.user
    if not (user.has_perm("observations.triage_observation") or user.is_px_admin()):
        messages.error(request, "You don't have permission to triage observations.")
        return redirect("observations:observation_detail", pk=pk)

    form = ObservationTriageForm(request.POST, hospital=user.hospital)

    if form.is_valid():
        try:
            ObservationService.triage_observation(
                observation=observation,
                triaged_by=user,
                assigned_department=form.cleaned_data.get("assigned_department"),
                assigned_to=form.cleaned_data.get("assigned_to"),
                new_status=form.cleaned_data.get("status"),
                note=form.cleaned_data.get("note", ""),
            )
            messages.success(request, "Observation triaged successfully.")
        except Exception as e:
            logger.error(f"Error triaging observation: {e}")
            messages.error(request, f"Error triaging observation: {str(e)}")
    else:
        messages.error(request, "Invalid form data.")

    return redirect("observations:observation_detail", pk=pk)


@login_required
@require_http_methods(["POST"])
def observation_change_status(request, pk):
    """
    Change observation status.
    """
    observation = get_object_or_404(Observation, pk=pk)

    # Check permission
    user = request.user
    if not (user.has_perm("observations.triage_observation") or user.is_px_admin()):
        messages.error(request, "You don't have permission to change observation status.")
        return redirect("observations:observation_detail", pk=pk)

    form = ObservationStatusForm(request.POST)

    if form.is_valid():
        try:
            ObservationService.change_status(
                observation=observation,
                new_status=form.cleaned_data["status"],
                changed_by=user,
                comment=form.cleaned_data.get("comment", ""),
            )
            messages.success(request, f"Status changed to {form.cleaned_data['status']}.")
        except Exception as e:
            logger.error(f"Error changing status: {e}")
            messages.error(request, f"Error changing status: {str(e)}")
    else:
        messages.error(request, "Invalid form data.")

    return redirect("observations:observation_detail", pk=pk)


@login_required
@require_http_methods(["POST"])
def observation_add_note(request, pk):
    """
    Add internal note to observation.
    """
    observation = get_object_or_404(Observation, pk=pk)

    form = ObservationNoteForm(request.POST)

    if form.is_valid():
        try:
            ObservationService.add_note(
                observation=observation,
                note=form.cleaned_data["note"],
                created_by=request.user,
                is_internal=form.cleaned_data.get("is_internal", True),
            )
            messages.success(request, "Note added successfully.")
        except Exception as e:
            logger.error(f"Error adding note: {e}")
            messages.error(request, f"Error adding note: {str(e)}")
    else:
        messages.error(request, "Please enter a note.")

    return redirect("observations:observation_detail", pk=pk)


@login_required
@require_http_methods(["GET", "POST"])
def observation_convert_to_action(request, pk):
    """
    Convert observation to PX Action.
    """
    observation = get_object_or_404(Observation, pk=pk)

    # Check permission
    user = request.user
    if not (user.is_px_admin() or user.is_hospital_admin()):
        messages.error(request, "You don't have permission to convert observations to actions.")
        return redirect("observations:observation_detail", pk=pk)

    # Check if already converted
    if observation.action_id:
        messages.warning(request, "This observation has already been converted to an action.")
        return redirect("observations:observation_detail", pk=pk)

    if request.method == "POST":
        form = ConvertToActionForm(request.POST)

        if form.is_valid():
            try:
                action = ObservationService.convert_to_action(
                    observation=observation,
                    created_by=user,
                    title=form.cleaned_data["title"],
                    description=form.cleaned_data["description"],
                    category=form.cleaned_data["category"],
                    priority=form.cleaned_data["priority"],
                    assigned_department=form.cleaned_data.get("assigned_department"),
                    assigned_to=form.cleaned_data.get("assigned_to"),
                )
                messages.success(request, f"Observation converted to action successfully.")
                return redirect("observations:observation_detail", pk=pk)
            except Exception as e:
                logger.error(f"Error converting to action: {e}")
                messages.error(request, f"Error converting to action: {str(e)}")
    else:
        # Pre-populate form
        initial = {
            "title": f"Observation {observation.tracking_code}",
            "description": observation.description,
            "priority": observation.severity,
            "assigned_department": observation.assigned_department,
            "assigned_to": observation.assigned_to,
        }
        if observation.title:
            initial["title"] += f" - {observation.title}"
        elif observation.category:
            initial["title"] += f" - {observation.category.name_en}"

        form = ConvertToActionForm(initial=initial)

    context = {
        "observation": observation,
        "form": form,
    }

    return render(request, "observations/convert_to_action.html", context)


# =============================================================================
# CATEGORY MANAGEMENT VIEWS
# =============================================================================


@login_required
@permission_required("observations.manage_categories", raise_exception=True)
def category_list(request):
    """
    List observation categories.
    """
    categories = ObservationCategory.objects.all().order_by("sort_order", "name_en")

    context = {
        "categories": categories,
    }

    return render(request, "observations/category_list.html", context)


@login_required
@permission_required("observations.manage_categories", raise_exception=True)
@require_http_methods(["GET", "POST"])
def category_create(request):
    """
    Create new observation category.
    """
    if request.method == "POST":
        form = ObservationCategoryForm(request.POST)
        if form.is_valid():
            form.save()
            messages.success(request, "Category created successfully.")
            return redirect("observations:category_list")
    else:
        form = ObservationCategoryForm()

    context = {
        "form": form,
        "title": "Create Category",
    }

    return render(request, "observations/category_form.html", context)


@login_required
@permission_required("observations.manage_categories", raise_exception=True)
@require_http_methods(["GET", "POST"])
def category_edit(request, pk):
    """
    Edit observation category.
    """
    category = get_object_or_404(ObservationCategory, pk=pk)

    if request.method == "POST":
        form = ObservationCategoryForm(request.POST, instance=category)
        if form.is_valid():
            form.save()
            messages.success(request, "Category updated successfully.")
            return redirect("observations:category_list")
    else:
        form = ObservationCategoryForm(instance=category)

    context = {
        "form": form,
        "category": category,
        "title": "Edit Category",
    }

    return render(request, "observations/category_form.html", context)


@login_required
@permission_required("observations.manage_categories", raise_exception=True)
@require_http_methods(["POST"])
def category_delete(request, pk):
    """
    Delete observation category.
    """
    category = get_object_or_404(ObservationCategory, pk=pk)

    # Check if category is in use
    if category.observations.exists():
        messages.error(request, "Cannot delete category that is in use.")
        return redirect("observations:category_list")

    category.delete()
    messages.success(request, "Category deleted successfully.")
    return redirect("observations:category_list")


# =============================================================================
# AJAX/API HELPERS
# =============================================================================


@login_required
def get_users_by_department(request):
    """
    Get users for a department (AJAX).
    """
    department_id = request.GET.get("department_id")
    if not department_id:
        return JsonResponse({"users": []})

    users = User.objects.filter(is_active=True, department_id=department_id).values(
        "id", "first_name", "last_name", "email"
    )

    return JsonResponse(
        {
            "users": [
                {
                    "id": str(u["id"]),
                    "name": f"{u['first_name']} {u['last_name']}",
                    "email": u["email"],
                }
                for u in users
            ]
        }
    )


# =============================================================================
# UTILITY FUNCTIONS
# =============================================================================


def get_client_ip(request):
    """
    Get client IP address from request.
    """
    x_forwarded_for = request.META.get("HTTP_X_FORWARDED_FOR")
    if x_forwarded_for:
        ip = x_forwarded_for.split(",")[0].strip()
    else:
        ip = request.META.get("REMOTE_ADDR")
    return ip