from datetime import datetime, timedelta

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

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


CACHE_TTL = 2 * 24 * 3600


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


def recache_user_stats():
    users = User.objects.exclude(Q(id=None) | Q(id__in=settings.STATS_REQUEST_IGNORE_USER_IDS)).values("id")
    for user in users:
        new_stats = user_stats(user["id"])
        cacheloc = "userstats_{}".format(user["id"])
        caches["userstats"].delete(cacheloc)
        caches["userstats"].set(cacheloc, new_stats, CACHE_TTL)
    return new_stats


def best_uploaders_list(requests_uploader, most_requested_uploaders):
    for requests in requests_uploader:
        a = len(most_requested_uploaders)
        b = 0
        while b <= a:
            if b == a:
                adding_list_item(most_requested_uploaders, requests)
            elif requests["song__user__id"] == most_requested_uploaders[b]["id"]:
                if requests["song__user__name"] == requests["user__name"]:
                    most_requested_uploaders[b]["own_total"] = requests["total"]
                else:
                    most_requested_uploaders[b]["total"] += requests["total"]
                break
            b += 1


def adding_list_item(most_requested_list, requests):
    # adds a single item to the best_uploaders list
    most_requested_list.append(
        {"id": requests["song__user__id"], "name": requests["song__user__name"], "total": 0, "own_total": 0}
    )
    if requests["song__user__id"] == requests["user__id"]:
        most_requested_list[-1]["own_total"] = requests["total"]
    else:
        most_requested_list[-1]["total"] = requests["total"]


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

    stats["total_uploads"] = Song.objects.filter(deleted=False).exclude(user_id=None).count()

    stats["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]
    )

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

    stats["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]
    )

    stats["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_requests=Count("id", distinct=True), unique_requests=Count("song__id", distinct=True))
        .order_by("-unique_requests")[: settings.STATS_TOP_COUNT]
    )

    stats["total_unique_requests"] = (
        PlaylistSong.objects.filter(state=2)
        .exclude(Q(user_id=None) | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS))
        .aggregate(total=Count("song__id", distinct=True))
    )

    stats["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]
    )

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

    stats["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]
    )

    stats["time_requested"] = (
        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=Sum("song__duration"), avg_dur=Sum("song__duration") / Count("id"))
        .order_by("-total")[: settings.STATS_TOP_COUNT]
    )

    stats["total_time_requested"] = (
        PlaylistSong.objects.all()
        .filter(state=2)
        .exclude(Q(user_id=None) | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS))
        .aggregate(total=Sum("song__duration"))
    )

    total_time_overall = sum(x["avg_dur"] for x in list(stats["time_requested"]))
    total_average = total_time_overall / len(stats["time_requested"])
    avg_dur_min, avg_dur_sec = divmod(total_average, 60)
    total_average = "{:.0f} minutes and {:.0f} seconds".format(avg_dur_min, avg_dur_sec)

    requests_uploader = (
        PlaylistSong.objects.filter(state=2)
        .exclude(Q(user_id=None) | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS))
        .values("song__user__id", "song__user__name", "user__name", "user__id")
        .annotate(total=Count("song__user__name"))
    )

    most_requested_uploaders = []
    best_uploaders_list(list(requests_uploader), most_requested_uploaders)
    most_requested_uploaders = sorted(most_requested_uploaders, key=lambda x: x["total"], reverse=True)[
        : settings.STATS_TOP_COUNT
    ]
    for time in list(stats["time_requested"]):
        # converts total time and average time in respectively days and minutes, seconds
        time["duration"] = str(round(time["total"] / 86400, 2)) + " days"
        avg_dur_min, avg_dur_sec = divmod(time["avg_dur"], 60)
        if avg_dur_sec < 10:
            avg_dur_sec = "0" + str(avg_dur_sec)
        time["avg_dur"] = "{}:{}".format(avg_dur_min, avg_dur_sec)

    # Convert requested time to days
    time_requested = list(stats["time_requested"])
    for tr in time_requested:
        tr["duration"] = "{:5.2f} days".format(tr["total"] / 86400)

    return {
        "last_updated": last_updated,
        "total_uploads": "{0:,.0f}".format(stats["total_uploads"]),
        "total_uploads_perc": stats["total_uploads"],
        "upload_stats": list(stats["upload_stats"]),
        "total_requests": "{0:,.0f}".format(stats["total_requests"]),
        "total_requests_perc": stats["total_requests"],
        "request_stats": list(stats["request_stats"]),
        "unique_request_stats": list(stats["unique_request_stats"]),
        "total_unique_requests": "{0:,.0f}".format(stats["total_unique_requests"]["total"]),
        "most_played_songs": list(stats["most_played_songs"]),
        "most_played_artists": list(stats["most_played_artists"]),
        "most_played_songs_14_days": list(stats["most_played_songs_14_days"]),
        "time_requested": stats["time_requested"],
        "total_time_requested": str(round(float(stats["total_time_requested"]["total"]) / 86400, 2)) + " days",
        "stats_top_count": settings.STATS_TOP_COUNT,
        "most_requested_uploaders": list(most_requested_uploaders),
        "total_average": total_average,
    }


def user_stats(request):
    last_updated = datetime.now()

    total_uploads = Song.objects.filter(user__id=request, deleted=False).count()

    total_requests = PlaylistSong.objects.filter(user__id=request, state=2).count()

    unique_requests = (
        PlaylistSong.objects.filter(user__id=request, state=2, song_id__isnull=False)
        .values("song_id")
        .distinct()
        .count()
    )

    most_played_songs = (
        PlaylistSong.objects.filter(user__id=request, 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", "song__title")[: settings.STATS_TOP_COUNT]
    )

    most_played_artists = (
        PlaylistSong.objects.filter(user__id=request, state=2, song_id__isnull=False)
        .values("song__artist")
        .annotate(total=Count("song__artist"))
        .order_by("-total", "song__artist")[: settings.STATS_TOP_COUNT]
    )

    most_played_uploaders = (
        PlaylistSong.objects.filter(user__id=request, state=2)
        .exclude(Q(user_id=None) | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS))
        .values("song__user__id", "song__user__name")
        .annotate(total=Count("song__user__id"))
        .order_by("-total")[: settings.STATS_TOP_COUNT]
    )

    biggest_fans = (
        PlaylistSong.objects.filter(state=2, song_id__in=Song.objects.filter(user__id=request))
        .exclude(Q(user_id=None) | Q(user_id__in=settings.STATS_REQUEST_IGNORE_USER_IDS))
        .values("user__id", "user__name")
        .annotate(total=Count("user__id"))
        .order_by("-total")[: settings.STATS_TOP_COUNT]
    )

    most_played_uploads = (
        PlaylistSong.objects.filter(state=2, song_id__in=Song.objects.filter(user__id=request))
        .exclude(user__id=None)
        .values("song__artist", "song__title")
        .annotate(total=Count("id", filter=~Q(user__id=request)), user_total=Count("id", filter=Q(user__id=request)))
        .order_by("-total", "song__artist", "song__title")
    )

    most_played_uploaded_artists = (
        PlaylistSong.objects.filter(state=2, song_id__in=Song.objects.filter(user__id=request))
        .exclude(user__id=None)
        .values("song__artist")
        .annotate(
            total=Count("song__artist", filter=~Q(user__id=request)),
            user_total=Count("id", filter=Q(user__id=request)),
        )
        .order_by("-total", "song__artist")
    )

    most_played = list(most_played_uploads)
    total_played = {}
    total_played["uploads"] = 0
    total_played["user_uploads"] = 0
    for x in most_played:
        total_played["uploads"] += x["total"]
        total_played["user_uploads"] += x["user_total"]
    most_played_uploads_list = sorted(most_played_uploads, key=lambda x: (x["song__artist"], x["song__title"]))
    most_played_uploads_list = sorted(most_played_uploads_list, key=lambda x: x["total"], reverse=True)[
        : settings.STATS_TOP_COUNT
    ]
    most_played_uploaded_artists = sorted(list(most_played_uploaded_artists), key=lambda x: x["total"], reverse=True)[
        : settings.STATS_TOP_COUNT
    ]
    return {
        "last_updated": last_updated,
        "total_uploads": total_uploads,
        "total_requests": total_requests,
        "unique_requests": unique_requests,
        "most_played_songs": list(most_played_songs),
        "most_played_artists": list(most_played_artists),
        "most_played_uploaders": list(most_played_uploaders),
        "most_played_uploads": most_played_uploads_list,
        "most_played_uploaded_artists": most_played_uploaded_artists,
        "stats_top_count": settings.STATS_TOP_COUNT,
        "total_played_uploads": total_played["uploads"],
        "total_played_user_uploads": total_played["user_uploads"],
        "biggest_fans": list(biggest_fans),
    }