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 Count, F, Q
from django.http import Http404, HttpResponse
from django.shortcuts import get_object_or_404, redirect
from django.urls import reverse
from django.utils import timezone
from django.utils.http import url_has_allowed_host_and_scheme
from django.views.decorators.http import require_POST
from django.views.generic import DetailView, ListView, TemplateView, UpdateView

from apps.profiles.models import SearchProfile

from .forms import ApplicationForm
from .models import Application, Employer, Feedback, JobPosting, ScoreRun
from .services.activity import ACTIVITY_FILTERS, build_activity_page
from .services.applications import (
    build_application_export,
    build_print_html,
    change_application_status,
    delete_application_dossier,
    track_application_changes,
)
from .services.cockpit import annotate_latest_profile_score, build_job_intelligence
from .services.employer_intelligence import (
    build_employer_detail,
    employer_index_queryset,
    filter_employers,
)
from .services.feedback import record_feedback
from .services.relevance import it_relevance_query
from .services.skill_demand import build_skill_demand_report


class SkillInsightsView(LoginRequiredMixin, TemplateView):
    template_name = "jobs/skill_insights.html"

    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["active_profile"] = profile
        context["report"] = (
            build_skill_demand_report(
                profile,
                category=self.request.GET.get("category", "all"),
                coverage=self.request.GET.get("coverage", "all"),
            )
            if profile
            else None
        )
        return context


class ActivityListView(LoginRequiredMixin, TemplateView):
    template_name = "activity/list.html"

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        event_type = self.request.GET.get("type", "all")
        valid_types = {value for value, _label in ACTIVITY_FILTERS}
        if event_type not in valid_types:
            event_type = "all"
        context.update(
            {
                "event_page": build_activity_page(
                    user=self.request.user,
                    event_type=event_type,
                    query=self.request.GET.get("q", ""),
                    page=self.request.GET.get("page", 1),
                ),
                "activity_filters": ACTIVITY_FILTERS,
                "current_type": event_type,
            }
        )
        return context


class EmployerListView(LoginRequiredMixin, ListView):
    model = Employer
    template_name = "employers/list.html"
    context_object_name = "employers"
    paginate_by = 40

    def get_queryset(self):
        self.profile = SearchProfile.objects.filter(user=self.request.user, is_active=True).first()
        return filter_employers(
            employer_index_queryset(user=self.request.user, profile=self.profile),
            query=self.request.GET.get("q", ""),
            channel=self.request.GET.get("channel", ""),
            active_only=self.request.GET.get("active") == "1",
        )

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        employers = list(context["employers"])
        selected_id = self.request.GET.get("selected", "")
        selected = next((item for item in employers if str(item.pk) == selected_id), None)
        if selected is None and employers:
            selected = employers[0]
        context.update(
            {
                "selected_employer": selected,
                "selected_detail": build_employer_detail(
                    employer=selected, user=self.request.user, profile=self.profile
                )
                if selected
                else None,
                "active_profile": self.profile,
                "employer_total": Employer.objects.count(),
                "employer_active_total": Employer.objects.filter(
                    jobs__status=JobPosting.Status.ACTIVE
                )
                .distinct()
                .count(),
            }
        )
        return context


class EmployerDetailView(LoginRequiredMixin, DetailView):
    model = Employer
    template_name = "employers/detail.html"
    context_object_name = "employer"

    def get_queryset(self):
        self.profile = SearchProfile.objects.filter(user=self.request.user, is_active=True).first()
        return employer_index_queryset(user=self.request.user, profile=self.profile)

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context.update(
            build_employer_detail(
                employer=self.object, user=self.request.user, profile=self.profile
            )
        )
        context["active_profile"] = self.profile
        return context


class JobListView(LoginRequiredMixin, ListView):
    model = JobPosting
    template_name = "jobs/list.html"
    context_object_name = "jobs"
    paginate_by = 20

    VALID_RECOMMENDATIONS = {
        ScoreRun.Recommendation.STRONG,
        ScoreRun.Recommendation.POSSIBLE,
        ScoreRun.Recommendation.WEAK,
        ScoreRun.Recommendation.HIDDEN,
    }
    VALID_MATCH_FILTERS = {*VALID_RECOMMENDATIONS, "radar", "all"}
    VALID_SORTS = {"match", "newest", "closing"}

    def get_queryset(self):
        queryset = JobPosting.objects.select_related("employer").annotate(
            duplicate_count=Count("duplicates", distinct=True)
        )
        profile = SearchProfile.objects.filter(user=self.request.user, is_active=True).first()
        queryset = annotate_latest_profile_score(queryset, profile)
        query = self.request.GET.get("q", "").strip()
        status = self.request.GET.get("status", "active").strip()
        workplace = self.request.GET.get("workplace", "").strip()
        channel = self.request.GET.get("channel", "").strip()
        focus = self.request.GET.get("focus", "it").strip()
        recommendation = self.request.GET.get("match", "radar").strip()
        sort = self.request.GET.get("sort", "match").strip()
        if recommendation not in self.VALID_MATCH_FILTERS:
            recommendation = "radar"
        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)
        if channel == "direct":
            queryset = queryset.filter(direct_employer=True, recruiter=False)
        elif channel == "recruiter":
            queryset = queryset.filter(recruiter=True)
        if focus != "all":
            queryset = queryset.filter(it_relevance_query())
        if profile and recommendation == "radar":
            queryset = queryset.filter(
                Q(
                    match_recommendation__in=[
                        ScoreRun.Recommendation.STRONG,
                        ScoreRun.Recommendation.POSSIBLE,
                        ScoreRun.Recommendation.WEAK,
                    ]
                )
                | Q(match_recommendation__isnull=True)
            )
        elif profile and recommendation in self.VALID_RECOMMENDATIONS:
            queryset = queryset.filter(match_recommendation=recommendation)
        if sort not in self.VALID_SORTS:
            sort = "match"
        if sort == "newest":
            return queryset.order_by("-first_seen", F("match_score").desc(nulls_last=True))
        if sort == "closing":
            return queryset.order_by(F("valid_through").asc(nulls_last=True), "-first_seen")
        return queryset.order_by(F("match_score").desc(nulls_last=True), "-first_seen")

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        active_jobs = JobPosting.objects.filter(status=JobPosting.Status.ACTIVE)
        it_jobs = active_jobs.filter(it_relevance_query())
        context.update(
            {
                "active_profile": SearchProfile.objects.filter(
                    user=self.request.user, is_active=True
                ).first(),
                "active_job_count": active_jobs.count(),
                "it_job_count": it_jobs.count(),
                "filtered_non_it_count": active_jobs.exclude(it_relevance_query()).count(),
                "current_focus": self.request.GET.get("focus", "it"),
                "current_match": (
                    self.request.GET.get("match", "radar")
                    if self.request.GET.get("match", "radar") in self.VALID_MATCH_FILTERS
                    else "radar"
                ),
                "current_sort": self.request.GET.get("sort", "match"),
                "current_channel": self.request.GET.get("channel", ""),
            }
        )
        jobs = list(context["jobs"])
        selected_id = self.request.GET.get("selected", "")
        selected_job = next((job for job in jobs if str(job.pk) == selected_id), None)
        if selected_job is None and jobs:
            selected_job = jobs[0]
        context["selected_job"] = selected_job
        if selected_job is not None:
            context["selected_intelligence"] = build_job_intelligence(
                job=selected_job,
                profile=context["active_profile"],
                user=self.request.user,
            )
        return context


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.update(
            build_job_intelligence(job=self.object, profile=profile, user=self.request.user)
        )
        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")
    if next_url and url_has_allowed_host_and_scheme(
        next_url,
        allowed_hosts={request.get_host()},
        require_https=request.is_secure(),
    ):
        return redirect(next_url)
    return redirect(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")
            .prefetch_related("timeline_events")
        )

    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
        ]
        context["status_choices"] = Application.Status.choices
        context["open_count"] = sum(
            item.status not in {Application.Status.REJECTED, Application.Status.WITHDRAWN}
            for item in applications
        )
        context["follow_up_count"] = sum(
            bool(item.follow_up_date and item.follow_up_date <= timezone.localdate())
            for item in applications
        )
        context["today"] = timezone.localdate()
        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", "job__employer")
            .prefetch_related("timeline_events")
        )

    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
@require_POST
def application_status(request, pk: int):
    application = get_object_or_404(Application, pk=pk, user=request.user)
    try:
        change_application_status(
            application=application,
            user=request.user,
            status=request.POST.get("status", ""),
        )
    except ValueError as exc:
        messages.error(request, str(exc))
    else:
        messages.success(request, "Pipelinestatus bijgewerkt.")
    return redirect("jobs:applications")


@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")