// 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.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using osu.Framework.Allocation;
using osu.Framework.Bindables;
using osu.Game.Beatmaps;
using osu.Game.Extensions;
using osu.Game.Online.API;
using osu.Game.Online.API.Requests;
using osu.Game.Online.Solo;
using osu.Game.Rulesets;
using osu.Game.Scoring;
using osu.Game.Screens.Ranking.Statistics;

namespace osu.Game.Screens.Ranking
{
    public partial class SoloResultsScreen : ResultsScreen
    {
        /// <summary>
        /// Whether the user's personal statistics should be shown on the extended statistics panel
        /// after clicking the score panel associated with the <see cref="ResultsScreen.Score"/> being presented.
        /// </summary>
        public bool ShowUserStatistics { get; init; }

        private GetScoresRequest? getScoreRequest;

        [Resolved]
        private RulesetStore rulesets { get; set; } = null!;

        private IBindable<SoloStatisticsUpdate?> latestUpdate = null!;
        private readonly Bindable<SoloStatisticsUpdate?> statisticsUpdate = new Bindable<SoloStatisticsUpdate?>();

        public SoloResultsScreen(ScoreInfo score, bool allowRetry)
            : base(score, allowRetry)
        {
        }

        [BackgroundDependencyLoader]
        private void load(SoloStatisticsWatcher? soloStatisticsWatcher)
        {
            if (ShowUserStatistics && soloStatisticsWatcher != null)
            {
                Debug.Assert(Score != null);

                latestUpdate = soloStatisticsWatcher.LatestUpdate.GetBoundCopy();
                latestUpdate.BindValueChanged(update =>
                {
                    if (update.NewValue?.Score.MatchesOnlineID(Score) == true)
                        statisticsUpdate.Value = update.NewValue;
                });
            }
        }

        protected override StatisticsPanel CreateStatisticsPanel()
        {
            Debug.Assert(Score != null);

            if (ShowUserStatistics)
            {
                return new SoloStatisticsPanel(Score)
                {
                    StatisticsUpdate = { BindTarget = statisticsUpdate }
                };
            }

            return base.CreateStatisticsPanel();
        }

        protected override APIRequest? FetchScores(Action<IEnumerable<ScoreInfo>>? scoresCallback)
        {
            Debug.Assert(Score != null);

            if (Score.BeatmapInfo!.OnlineID <= 0 || Score.BeatmapInfo.Status <= BeatmapOnlineStatus.Pending)
                return null;

            getScoreRequest = new GetScoresRequest(Score.BeatmapInfo, Score.Ruleset);
            getScoreRequest.Success += r => scoresCallback?.Invoke(r.Scores.Where(s => !s.MatchesOnlineID(Score)).Select(s => s.ToScoreInfo(rulesets, Beatmap.Value.BeatmapInfo)));
            return getScoreRequest;
        }

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

            getScoreRequest?.Cancel();
        }
    }
}