import shlex

from django.shortcuts import render, get_object_or_404, redirect
from django.contrib.postgres.search import SearchVector, TrigramSimilarity
from django.http import Http404, JsonResponse, HttpResponse
from django.contrib.admin.models import LogEntry
from django_select2.views import AutoResponseView
from django.db import connection
from django.db.models import Q

from storage.models import Item, Label

from django.contrib.auth.decorators import login_required
from rest_framework.authtoken.models import Token

def apply_smart_search(query, objects):
    general_term = []

    filters = {}

    for prop in shlex.split(query):
        if ':' not in prop:
            general_term.append(prop)
        else:
            key, value = prop.split(':', 1)
            if key in ['owner', 'taken_by']:
                filters[key + '__username'] = value
            elif hasattr(Item, key):
                filters[key + '__search'] = value
            elif key == 'ancestor':
                objects = Item.objects.get(pk=value).get_children()
            elif key == 'prop' or value:
                if key == 'prop':
                    key, _, value = value.partition(':')
                if not value:
                    filters['props__isnull'] = {key: False}
                else:
                    filters['props__contains'] = {key: value}
            else:
                # "Whatever:"
                general_term.append(prop)

    objects = objects.filter(**filters)

    if not general_term:
        return objects
    general_term = ' '.join(general_term)

    objects = objects.annotate(
        search=SearchVector('name', 'description', 'props', config='simple'),
        similarity=TrigramSimilarity('name', general_term)
    ).filter(
        Q(similarity__gte=0.15) | Q(search__contains=general_term)
    ).order_by('-similarity')
    return objects


def index(request):
    return render(request, 'results.html', {
            'results': Item.get_roots()
            })


def search(request):
    query = request.GET.get('q', '')

    results = apply_smart_search(query, Item.objects).all()

    if results and (len(results) == 1 or getattr(results[0], 'similarity', 0) == 1):
        return redirect(results[0])

    return render(request, 'results.html', {
        'query': query,
        'results': results,
        })


def item_display(request, pk):
    if not pk:
        return index(request)
    item = get_object_or_404(Item, pk=pk)

    labels = item.labels.all()
    has_one_label = len(labels) == 1

    return render(request, 'item.html', {
        'title': item.name,
        'item': item,
        'categories': item.categories.all(),
        'props': sorted(item.props.items()),
        'images': item.images.all(),
        'labels': labels,
        'has_one_label': has_one_label,
        'history': LogEntry.objects.filter(object_id=item.pk),
        'ancestors': item.get_ancestors(),
        'children': item.get_children().prefetch_related('categories'),
        })


def label_lookup(request, pk):
    try:
        label = Label.objects.get(pk=pk)
        return redirect(label.item)
    except Label.DoesNotExist:
        try:
            # look up by short id
            item = Item.objects.get(uuid__startswith=pk)
            return redirect(item)
        except Item.DoesNotExist:
            raise Http404("Very sad to say, I could not find this thing")


@login_required
def apitoken(request):
    print(Token)
    token, created = Token.objects.get_or_create(user=request.user)
    return HttpResponse(token.key, content_type='text/plain')


class ItemSelectView(AutoResponseView):
    def get(self, request, *args, **kwargs):
        self.widget = self.get_widget_or_404()
        self.term = kwargs.get('term', request.GET.get('term', ''))
        self.object_list = apply_smart_search(self.term, Item.objects)
        context = self.get_context_data()
        return JsonResponse({
            'results': [
                {
                    'text': obj.name,
                    'path': [o.name for o in obj.get_ancestors()],
                    'id': obj.pk,
                }
                for obj in context['object_list']
                ],
            'more': context['page_obj'].has_next()
        })


class PropSelectView(AutoResponseView):
    def get(self, request, *args, **kwargs):
        # self.widget = self.get_widget_or_404()
        self.term = kwargs.get('term', request.GET.get('term', ''))
        # context = self.get_context_data()
        with connection.cursor() as c:
            c.execute("""
                SELECT key, count(*) FROM
                (SELECT (each(props)).key FROM storage_item) AS stat
                WHERE key like %s
                GROUP BY key
                ORDER BY count DESC, key
                limit 10;
            """, ['%' + self.term + '%'])
            props = [e[0] for e in c.fetchall()]
        return JsonResponse({
            'results': [
                {
                    'text': p,
                    'id': p,
                }
                for p in props
                ],
        })