from datetime import datetime, timedelta

from django.core.cache import caches
from django.conf import settings
from django.db.models import Count, Q
from django.shortcuts import render
from django.utils import timezone

from queues.models import PlaylistSong
from songs.models import Song


def recache_stats():
    new_stats = compute_stats()
    caches['default'].delete('stats')
    caches['default'].set('stats', new_stats, 7200)
    return new_stats


def compute_stats():
    # We want to grab the time now, because otherwise we would be reporting a minute too late
    last_updated = datetime.now()

    total_uploads = Song.objects.filter(deleted=False).exclude(
        user_id=None).count()

    upload_stats = Song.objects.filter(deleted=False).exclude(
        user_id=None).values(
            'user__id', 'user__name').annotate(total=Count('id')).order_by(
                '-total', 'user__name')[:settings.STATS_TOP_COUNT]

    total_requests = PlaylistSong.objects.filter(state=2).exclude(
        Q(user_id=None)
        | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS)).count()

    request_stats = PlaylistSong.objects.filter(state=2).exclude(
        Q(user_id=None)
        | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS)).values(
            'user__id', 'user__name').annotate(total=Count('id')).order_by(
                '-total', 'user__name')[:settings.STATS_TOP_COUNT]

    unique_request_stats = PlaylistSong.objects.filter(state=2).exclude(
        Q(user_id=None)
        | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS)).values(
            'user__id', 'user__name').annotate(
                total=Count('song_id', distinct=True),
                ratio=Count('song_id', distinct=True) / Count('id') *
                100).order_by('-total')[:settings.STATS_TOP_COUNT]

    most_played_songs = PlaylistSong.objects.filter(state=2).exclude(
        Q(user_id=None)
        | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS)).values(
            'song__artist',
            'song__title').annotate(total=Count('id')).order_by(
                '-total', 'song__artist')[:settings.STATS_TOP_COUNT]

    most_played_songs_14_days = PlaylistSong.objects.filter(
        state=2, played_at__gte=timezone.now() -
        timedelta(days=14)).exclude(user_id=None).values(
            'song__artist',
            'song__title').annotate(total=Count('id')).order_by(
                '-total', 'song__artist')[:settings.STATS_TOP_COUNT]

    return {
        'last_updated': last_updated,
        'total_uploads': total_uploads,
        'upload_stats': list(upload_stats),
        'total_requests': total_requests,
        'request_stats': list(request_stats),
        'unique_request_stats': list(unique_request_stats),
        'most_played_songs': list(most_played_songs),
        'most_played_songs_14_days': list(most_played_songs_14_days),
        'stats_top_count': settings.STATS_TOP_COUNT,
    }