from datetime import datetime, timedelta
from zoneinfo import ZoneInfo

from django.core.exceptions import ObjectDoesNotExist
from django.db.models import Count, F, Prefetch, Sum
from django.db.models.functions import TruncDate
from django.http import (
    HttpRequest,
    HttpResponse,
    HttpResponseBadRequest,
    HttpResponseRedirect,
)
from django.shortcuts import redirect, render
from django.urls import reverse
from django.utils import timezone

from common.time import format_duration
from common.utils import safe_division

from .forms import (
    DeviceForm,
    EditionForm,
    GameForm,
    PlatformForm,
    PurchaseForm,
    SessionForm,
)
from .models import Edition, Game, Platform, Purchase, Session


def model_counts(request):
    return {
        "game_available": Game.objects.count() != 0,
        "edition_available": Edition.objects.count() != 0,
        "platform_available": Platform.objects.count() != 0,
        "purchase_available": Purchase.objects.count() != 0,
        "session_count": Session.objects.count(),
    }


def stats_dropdown_year_range(request):
    result = {"stats_dropdown_year_range": range(timezone.now().year, 1999, -1)}
    return result


def add_session(request, purchase_id=None):
    context = {}
    initial = {"timestamp_start": timezone.now()}

    last = Session.objects.last()
    if last != None:
        initial["purchase"] = last.purchase

    if request.method == "POST":
        form = SessionForm(request.POST or None, initial=initial)
        if form.is_valid():
            form.save()
            return redirect("list_sessions")
    else:
        if purchase_id:
            purchase = Purchase.objects.get(id=purchase_id)
            form = SessionForm(
                initial={
                    **initial,
                    "purchase": purchase,
                }
            )
        else:
            form = SessionForm(initial=initial)

    context["title"] = "Add New Session"
    context["form"] = form
    return render(request, "add_session.html", context)


def update_session(request, session_id=None):
    session = Session.objects.get(id=session_id)
    session.finish_now()
    session.save()
    return redirect("list_sessions")


def use_custom_redirect(
    func: Callable[..., HttpResponse]
) -> Callable[..., HttpResponse]:
    """
    Will redirect to "return_path" session variable if set.
    """

    def wrapper(request: HttpRequest, *args: Any, **kwargs: Any) -> HttpResponse:
        response = func(request, *args, **kwargs)
        if isinstance(response, HttpResponseRedirect) and (
            next_url := request.session.get("return_path")
        ):
            return HttpResponseRedirect(next_url)
        return response

    return wrapper


@use_custom_redirect
def edit_session(request, session_id=None):
    context = {}
    session = Session.objects.get(id=session_id)
    form = SessionForm(request.POST or None, instance=session)
    if form.is_valid():
        form.save()
        return redirect("list_sessions")
    context["title"] = "Edit Session"
    context["form"] = form
    return render(request, "add_session.html", context)


@use_custom_redirect
def edit_purchase(request, purchase_id=None):
    context = {}
    purchase = Purchase.objects.get(id=purchase_id)
    form = PurchaseForm(request.POST or None, instance=purchase)
    if form.is_valid():
        form.save()
        return redirect("list_sessions")
    context["title"] = "Edit Purchase"
    context["form"] = form
    context["script_name"] = "add_purchase.js"
    return render(request, "add_purchase.html", context)


@use_custom_redirect
def edit_game(request, game_id=None):
    context = {}
    purchase = Game.objects.get(id=game_id)
    form = GameForm(request.POST or None, instance=purchase)
    if form.is_valid():
        form.save()
        return redirect("list_sessions")
    context["title"] = "Edit Game"
    context["form"] = form
    return render(request, "add.html", context)


def view_game(request, game_id=None):
    game = Game.objects.get(id=game_id)
    nongame_related_purchases_prefetch = Prefetch(
        "related_purchases",
        queryset=Purchase.objects.exclude(type=Purchase.GAME),
        to_attr="nongame_related_purchases",
    )
    game_purchases_prefetch = Prefetch(
        "purchase_set",
        queryset=Purchase.objects.filter(type=Purchase.GAME).prefetch_related(
            nongame_related_purchases_prefetch
        ),
        to_attr="game_purchases",
    )
    editions = (
        Edition.objects.filter(game=game)
        .prefetch_related(game_purchases_prefetch)
        .order_by("year_released")
    )

    sessions = Session.objects.filter(purchase__edition__game=game)
    session_count = sessions.count()

    playrange_start = sessions.earliest().timestamp_start.strftime("%b %Y")
    playrange_end = sessions.latest().timestamp_start.strftime("%b %Y")

    playrange = (
        playrange_start
        if playrange_start == playrange_end
        else f"{playrange_start} — {playrange_end}"
    )
    total_hours = float(format_duration(sessions.total_duration_unformatted(), "%2.1H"))

    context = {
        "edition_count": editions.count(),
        "editions": editions,
        "game": game,
        "playrange": playrange,
        "purchase_count": Purchase.objects.filter(edition__game=game).count(),
        "session_average": round(total_hours / int(session_count), 1),
        "session_count": session_count,
        "sessions_with_notes_count": sessions.exclude(note="").count(),
        "sessions": sessions.order_by("-timestamp_start"),
        "title": f"Game Overview - {game.name}",
        "hours_sum": total_hours,
    }

    request.session["return_path"] = request.path
    return render(request, "view_game.html", context)


@use_custom_redirect
def edit_platform(request, platform_id=None):
    context = {}
    purchase = Platform.objects.get(id=platform_id)
    form = PlatformForm(request.POST or None, instance=purchase)
    if form.is_valid():
        form.save()
        return redirect("list_sessions")
    context["title"] = "Edit Platform"
    context["form"] = form
    return render(request, "add.html", context)


@use_custom_redirect
def edit_edition(request, edition_id=None):
    context = {}
    edition = Edition.objects.get(id=edition_id)
    form = EditionForm(request.POST or None, instance=edition)
    if form.is_valid():
        form.save()
        return redirect("list_sessions")
    context["title"] = "Edit Edition"
    context["form"] = form
    return render(request, "add.html", context)


def related_purchase_by_edition(request):
    edition_id = request.GET.get("edition")
    if not edition_id:
        return HttpResponseBadRequest("Invalid edition_id")
    form = PurchaseForm()
    form.fields["related_purchase"].queryset = Purchase.objects.filter(
        edition_id=edition_id, type=Purchase.GAME
    ).order_by("edition__sort_name")
    return render(request, "partials/related_purchase_field.html", {"form": form})


@use_custom_redirect
def start_game_session(request, game_id: int):
    last_session = Session.objects.filter(purchase__edition__game_id=game_id).latest()
    session = SessionForm(
        {
            "purchase": last_session.purchase.id,
            "timestamp_start": timezone.now(),
            "device": last_session.device,
        }
    )
    session.save()
    return redirect("list_sessions")


def start_session_same_as_last(request, last_session_id: int):
    last_session = Session.objects.get(id=last_session_id)
    session = SessionForm(
        {
            "purchase": last_session.purchase.id,
            "timestamp_start": timezone.now(),
            "device": last_session.device,
        }
    )
    session.save()
    return redirect("list_sessions")


def list_sessions(
    request,
    filter="",
    purchase_id="",
    platform_id="",
    game_id="",
    edition_id="",
    ownership_type: str = "",
):
    context = {}
    context["title"] = "Sessions"

    if filter == "purchase":
        dataset = Session.objects.filter(purchase=purchase_id)
        context["purchase"] = Purchase.objects.get(id=purchase_id)
    elif filter == "platform":
        dataset = Session.objects.filter(purchase__platform=platform_id)
        context["platform"] = Platform.objects.get(id=platform_id)
    elif filter == "edition":
        dataset = Session.objects.filter(purchase__edition=edition_id)
        context["edition"] = Edition.objects.get(id=edition_id)
    elif filter == "game":
        dataset = Session.objects.filter(purchase__edition__game=game_id)
        context["game"] = Game.objects.get(id=game_id)
    elif filter == "ownership_type":
        dataset = Session.objects.filter(purchase__ownership_type=ownership_type)
        context["ownership_type"] = dict(Purchase.OWNERSHIP_TYPES)[ownership_type]
    elif filter == "recent":
        dataset = Session.objects.filter(
            timestamp_start__gte=datetime.now() - timedelta(days=30)
        )
        context["title"] = "Last 30 days"
    else:
        # by default, sort from newest to oldest
        dataset = Session.objects.order_by("-timestamp_start")

    for session in dataset:
        if session.timestamp_end == None and session.duration_manual == timedelta(
            seconds=0
        ):
            session.timestamp_end = timezone.now()
            session.unfinished = True

    context["total_duration"] = dataset.total_duration_formatted()
    context["dataset"] = dataset
    try:
        context["last"] = Session.objects.latest()
    except ObjectDoesNotExist:
        context["last"] = None

    return render(request, "list_sessions.html", context)


def stats(request, year: int = 0):
    selected_year = request.GET.get("year")
    if selected_year:
        return HttpResponseRedirect(reverse("stats_by_year", args=[selected_year]))
    if year == 0:
        year = timezone.now().year
    this_year_sessions = Session.objects.filter(timestamp_start__year=year)
    selected_currency = "CZK"
    unique_days = (
        this_year_sessions.annotate(date=TruncDate("timestamp_start"))
        .values("date")
        .distinct()
        .aggregate(dates=Count("date"))
    )
    this_year_played_purchases = Purchase.objects.filter(
        session__in=this_year_sessions
    ).distinct()

    this_year_purchases = Purchase.objects.filter(date_purchased__year=year)
    this_year_purchases_with_currency = this_year_purchases.filter(
        price_currency__exact=selected_currency
    )
    this_year_purchases_without_refunded = this_year_purchases_with_currency.filter(
        date_refunded=None
    )
    this_year_purchases_refunded = this_year_purchases_with_currency.refunded()

    this_year_purchases_unfinished = this_year_purchases_without_refunded.filter(
        date_finished__isnull=True
    ).filter(
        type=Purchase.GAME
    )  # do not count DLC etc.

    this_year_purchases_unfinished_percent = int(
        safe_division(
            this_year_purchases_unfinished.count(), this_year_purchases_refunded.count()
        )
        * 100
    )

    purchases_finished_this_year = Purchase.objects.filter(date_finished__year=year)
    purchases_finished_this_year_released_this_year = (
        purchases_finished_this_year.filter(edition__year_released=year).order_by(
            "date_finished"
        )
    )
    purchased_this_year_finished_this_year = (
        this_year_purchases_without_refunded.intersection(
            purchases_finished_this_year
        ).order_by("date_finished")
    )

    this_year_spendings = this_year_purchases_without_refunded.aggregate(
        total_spent=Sum(F("price"))
    )
    total_spent = this_year_spendings["total_spent"] or 0

    games_with_playtime = (
        Game.objects.filter(edition__purchase__session__in=this_year_sessions)
        .annotate(
            total_playtime=Sum(
                F("edition__purchase__session__duration_calculated")
                + F("edition__purchase__session__duration_manual")
            )
        )
        .values("id", "name", "total_playtime")
    )
    top_10_games_by_playtime = games_with_playtime.order_by("-total_playtime")[:10]
    for game in top_10_games_by_playtime:
        game["formatted_playtime"] = format_duration(game["total_playtime"], "%2.0H")

    total_playtime_per_platform = (
        this_year_sessions.values("purchase__platform__name")
        .annotate(total_playtime=Sum(F("duration_calculated") + F("duration_manual")))
        .annotate(platform_name=F("purchase__platform__name"))
        .values("platform_name", "total_playtime")
        .order_by("-total_playtime")
    )
    for item in total_playtime_per_platform:
        item["formatted_playtime"] = format_duration(item["total_playtime"], "%2.0H")

    backlog_decrease_count = (
        Purchase.objects.filter(date_purchased__year__lt=year)
        .intersection(purchases_finished_this_year)
        .count()
    )

    context = {
        "total_hours": format_duration(
            this_year_sessions.total_duration_unformatted(), "%2.0H"
        ),
        "total_games": this_year_played_purchases.count(),
        "total_2023_games": this_year_played_purchases.filter(
            edition__year_released=year
        ).count(),
        "top_10_games_by_playtime": top_10_games_by_playtime,
        "year": year,
        "total_playtime_per_platform": total_playtime_per_platform,
        "total_spent": total_spent,
        "total_spent_currency": selected_currency,
        "all_purchased_this_year": this_year_purchases_without_refunded,
        "spent_per_game": int(
            safe_division(total_spent, this_year_purchases_without_refunded.count())
        ),
        "all_finished_this_year": purchases_finished_this_year.order_by(
            "date_finished"
        ),
        "this_year_finished_this_year": purchases_finished_this_year_released_this_year.order_by(
            "date_finished"
        ),
        "purchased_this_year_finished_this_year": purchased_this_year_finished_this_year.order_by(
            "date_finished"
        ),
        "total_sessions": this_year_sessions.count(),
        "unique_days": unique_days["dates"],
        "unique_days_percent": int(unique_days["dates"] / 365 * 100),
        "purchased_unfinished": this_year_purchases_unfinished,
        "unfinished_purchases_percent": this_year_purchases_unfinished_percent,
        "refunded_percent": int(
            safe_division(
                this_year_purchases_refunded.count(),
                this_year_purchases_with_currency.count(),
            )
            * 100
        ),
        "all_purchased_refunded_this_year": this_year_purchases_refunded,
        "all_purchased_this_year": this_year_purchases_with_currency.order_by(
            "date_purchased"
        ),
        "backlog_decrease_count": backlog_decrease_count,
    }

    request.session["return_path"] = request.path
    return render(request, "stats.html", context)


def add_purchase(request, edition_id=None):
    context = {}
    initial = {"date_purchased": timezone.now()}

    if request.method == "POST":
        form = PurchaseForm(request.POST or None, initial=initial)
        if form.is_valid():
            purchase = form.save()
            if "submit_and_redirect" in request.POST:
                return HttpResponseRedirect(
                    reverse(
                        "add_session_for_purchase", kwargs={"purchase_id": purchase.id}
                    )
                )
            else:
                return redirect("index")
    else:
        if edition_id:
            edition = Edition.objects.get(id=edition_id)
            form = PurchaseForm(
                initial={
                    **initial,
                    "edition": edition,
                    "platform": edition.platform,
                }
            )
        else:
            form = PurchaseForm(initial=initial)

    context["form"] = form
    context["title"] = "Add New Purchase"
    context["script_name"] = "add_purchase.js"
    return render(request, "add_purchase.html", context)


def add_game(request):
    context = {}
    form = GameForm(request.POST or None)
    if form.is_valid():
        game = form.save()
        if "submit_and_redirect" in request.POST:
            return HttpResponseRedirect(
                reverse("add_edition_for_game", kwargs={"game_id": game.id})
            )
        else:
            return redirect("index")

    context["form"] = form
    context["title"] = "Add New Game"
    context["script_name"] = "add_game.js"
    return render(request, "add_game.html", context)


def add_edition(request, game_id=None):
    context = {}
    if request.method == "POST":
        form = EditionForm(request.POST or None)
        if form.is_valid():
            edition = form.save()
            if "submit_and_redirect" in request.POST:
                return HttpResponseRedirect(
                    reverse(
                        "add_purchase_for_edition", kwargs={"edition_id": edition.id}
                    )
                )
            else:
                return redirect("index")
    else:
        if game_id:
            game = Game.objects.get(id=game_id)
            form = EditionForm(
                initial={
                    "game": game,
                    "name": game.name,
                    "sort_name": game.sort_name,
                    "year_released": game.year_released,
                }
            )
        else:
            form = EditionForm()

    context["form"] = form
    context["title"] = "Add New Edition"
    context["script_name"] = "add_edition.js"
    return render(request, "add_edition.html", context)


def add_platform(request):
    context = {}
    form = PlatformForm(request.POST or None)
    if form.is_valid():
        form.save()
        return redirect("index")

    context["form"] = form
    context["title"] = "Add New Platform"
    return render(request, "add.html", context)