// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using System;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Game.Beatmaps;
using osu.Game.Database;
using osu.Game.Models;
using osu.Game.Online.API;
using osu.Game.Online.Leaderboards;
using osu.Game.Rulesets;
using osu.Game.Scoring;
using Realms;

namespace osu.Game.Screens.Select.Carousel
{
    public class TopLocalRank : UpdateableRank
    {
        private readonly BeatmapInfo beatmapInfo;

        [Resolved]
        private IBindable<RulesetInfo> ruleset { get; set; }

        [Resolved]
        private RealmContextFactory realmFactory { get; set; }

        [Resolved]
        private IAPIProvider api { get; set; }

        private IDisposable scoreSubscription;

        private bool rankUpdatePending;

        public TopLocalRank(BeatmapInfo beatmapInfo)
            : base(null)
        {
            this.beatmapInfo = beatmapInfo;
        }

        protected override void LoadComplete()
        {
            base.LoadComplete();

            ruleset.BindValueChanged(_ =>
            {
                rankUpdatePending = true;
                // Required since presence is changed via IsPresent override
                Invalidate(Invalidation.Presence);

                scoreSubscription?.Dispose();
                scoreSubscription = realmFactory.Context.All<ScoreInfo>()
                                                .Filter($"{nameof(ScoreInfo.User)}.{nameof(RealmUser.OnlineID)} == $0"
                                                        + $"&& {nameof(ScoreInfo.BeatmapInfo)}.{nameof(BeatmapInfo.ID)} == $1"
                                                        + $"&& {nameof(ScoreInfo.Ruleset)}.{nameof(RulesetInfo.ShortName)} == $2"
                                                        + $"&& {nameof(ScoreInfo.DeletePending)} == false", api.LocalUser.Value.Id, beatmapInfo.ID, ruleset.Value.ShortName)
                                                .OrderByDescending(s => s.TotalScore)
                                                .QueryAsyncWithNotifications((items, changes, ___) =>
                                                {
                                                    if (changes == null)
                                                        rankUpdatePending = false;

                                                    Rank = items.FirstOrDefault()?.Rank;
                                                });
            }, true);
        }

        // We're present if a rank is set, or if there is a pending rank update (IsPresent = true is required for the scheduler to run).
        public override bool IsPresent => base.IsPresent && (Rank != null || rankUpdatePending);

        protected override void Dispose(bool isDisposing)
        {
            base.Dispose(isDisposing);

            scoreSubscription?.Dispose();
        }
    }
}