from __future__ import annotations

from django.contrib import messages
from django.contrib.auth.decorators import login_required
from django.contrib.auth.mixins import LoginRequiredMixin
from django.db.models import CharField, DecimalField, OuterRef, Q, Subquery
from django.http import Http404, HttpResponse
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse
from django.views.decorators.http import require_POST
from django.views.generic import DetailView, ListView, UpdateView

from apps.profiles.models import SearchProfile

from .forms import ApplicationForm
from .models import Application, Feedback, JobPosting, ScoreRun
from .services.applications import (
    build_application_export,
    build_print_html,
    delete_application_dossier,
    track_application_changes,
)
from .services.feedback import record_feedback


class JobListView(LoginRequiredMixin, ListView):
    model = JobPosting
    template_name = "jobs/list.html"
    context_object_name = "jobs"
    paginate_by = 30

    def get_queryset(self):
        queryset = JobPosting.objects.select_related("employer").all()
        profile = SearchProfile.objects.filter(user=self.request.user, is_active=True).first()
        if profile:
            latest_score = ScoreRun.objects.filter(job=OuterRef("pk"), profile=profile).order_by(
                "-created_at"
            )
            queryset = queryset.annotate(
                match_score=Subquery(
                    latest_score.values("score")[:1],
                    output_field=DecimalField(max_digits=5, decimal_places=2),
                ),
                match_confidence=Subquery(
                    latest_score.values("confidence")[:1],
                    output_field=DecimalField(max_digits=4, decimal_places=3),
                ),
                match_recommendation=Subquery(
                    latest_score.values("recommendation")[:1], output_field=CharField()
                ),
            )
        query = self.request.GET.get("q", "").strip()
        status = self.request.GET.get("status", "active").strip()
        workplace = self.request.GET.get("workplace", "").strip()
        if query:
            queryset = queryset.filter(
                Q(original_title__icontains=query)
                | Q(employer__name__icontains=query)
                | Q(description_text__icontains=query)
                | Q(raw_location__icontains=query)
            )
        if status:
            queryset = queryset.filter(status=status)
        if workplace:
            queryset = queryset.filter(workplace_type=workplace)
        return queryset.order_by("-first_seen")


class JobDetailView(LoginRequiredMixin, DetailView):
    model = JobPosting
    template_name = "jobs/detail.html"
    context_object_name = "job"

    def get_queryset(self):
        return JobPosting.objects.select_related("employer", "duplicate_of").prefetch_related(
            "source_aliases__source", "provenance", "versions", "feedback"
        )

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        profile = SearchProfile.objects.filter(user=self.request.user, is_active=True).first()
        context["score"] = (
            ScoreRun.objects.filter(job=self.object, profile=profile)
            .order_by("-created_at")
            .first()
            if profile
            else None
        )
        context["application"] = Application.objects.filter(
            user=self.request.user, job=self.object
        ).first()
        context["latest_feedback"] = Feedback.objects.filter(
            user=self.request.user, job=self.object
        ).first()
        return context


@login_required
def job_feedback(request, pk):
    job = get_object_or_404(JobPosting, pk=pk)
    if request.method != "POST":
        return redirect("jobs:detail", pk=pk)
    action = request.POST.get("action", "")
    valid_actions = {choice for choice, _ in Feedback.Action.choices}
    if action not in valid_actions:
        messages.error(request, "Ongeldige actie.")
        return redirect("jobs:detail", pk=pk)
    record_feedback(
        user=request.user,
        job=job,
        action=action,
        reason=request.POST.get("reason", ""),
    )
    messages.success(request, "Actie opgeslagen.")
    next_url = request.POST.get("next")
    return redirect(next_url or reverse("jobs:detail", kwargs={"pk": pk}))


class ApplicationListView(LoginRequiredMixin, ListView):
    model = Application
    template_name = "applications/list.html"
    context_object_name = "applications"

    def get_queryset(self):
        return Application.objects.filter(user=self.request.user).select_related(
            "job", "job__employer"
        )

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        applications = list(context["applications"])
        context["applications"] = applications
        context["pipeline_columns"] = [
            {
                "status": status,
                "label": label,
                "applications": [item for item in applications if item.status == status],
            }
            for status, label in Application.Status.choices
        ]
        return context


class ApplicationUpdateView(LoginRequiredMixin, UpdateView):
    model = Application
    form_class = ApplicationForm
    template_name = "applications/edit.html"

    def get_queryset(self):
        return Application.objects.filter(user=self.request.user).select_related("job")

    def form_valid(self, form):
        previous = (
            Application.objects.filter(pk=self.object.pk)
            .values("status", "notes", "contact_name", "contact_email")
            .get()
        )
        response = super().form_valid(form)
        track_application_changes(
            application=self.object,
            user=self.request.user,
            previous=previous,
            current={
                "status": self.object.status,
                "notes": self.object.notes,
                "contact_name": self.object.contact_name,
                "contact_email": self.object.contact_email,
            },
        )
        return response

    def get_success_url(self):
        messages.success(self.request, "Sollicitatiedossier opgeslagen.")
        return reverse("jobs:applications")


@login_required
def application_export(request, pk: int):
    application = get_object_or_404(
        Application.objects.filter(user=request.user).select_related("job"), pk=pk
    )
    zip_payload, filename = build_application_export(application)
    response = HttpResponse(zip_payload, content_type="application/zip")
    response["Content-Disposition"] = f'attachment; filename="{filename}"'
    return response


@login_required
def application_print(request, pk: int):
    application = get_object_or_404(
        Application.objects.filter(user=request.user).select_related("job"), pk=pk
    )
    return HttpResponse(build_print_html(application), content_type="text/html; charset=utf-8")


@login_required
@require_POST
def application_delete(request, pk: int):
    if Application.objects.filter(pk=pk).exclude(user=request.user).exists():
        raise Http404
    deleted = delete_application_dossier(application_id=pk, user=request.user)
    if deleted:
        messages.success(request, "Sollicitatiedossier verwijderd.")
    else:
        messages.info(request, "Geen dossier verwijderd.")
    return redirect("jobs:applications")