// 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.

#nullable disable

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using osu.Framework.Allocation;
using osu.Framework.Input.Bindings;
using osu.Framework.Input.Events;
using osu.Game.Beatmaps;
using osu.Game.Configuration;
using osu.Game.Input.Bindings;
using osu.Game.Rulesets.Mods;
using osu.Game.Scoring;
using osu.Game.Screens.Play.PlayerSettings;
using osu.Game.Screens.Ranking;
using osu.Game.Screens.Select.Leaderboards;
using osu.Game.Users;

namespace osu.Game.Screens.Play
{
    [Cached]
    public partial class ReplayPlayer : Player, IKeyBindingHandler<GlobalAction>
    {
        public const double BASE_SEEK_AMOUNT = 1000;

        private readonly Func<IBeatmap, IReadOnlyList<Mod>, Score> createScore;

        private PlaybackSettings playbackSettings;

        [Cached(typeof(IGameplayLeaderboardProvider))]
        private readonly SoloGameplayLeaderboardProvider leaderboardProvider = new SoloGameplayLeaderboardProvider();

        protected override UserActivity InitialActivity => new UserActivity.WatchingReplay(Score.ScoreInfo);

        private bool isAutoplayPlayback => GameplayState.Mods.OfType<ModAutoplay>().Any();

        private double? lastFrameTime;

        protected override bool CheckModsAllowFailure()
        {
            // autoplay should be able to fail if the beatmap is not humanly beatable
            if (isAutoplayPlayback)
                return base.CheckModsAllowFailure();

            // non-autoplay replays should be able to fail, but only after they've exhausted their frames.
            // note that the rank isn't checked here - that's because it is generally unreliable.
            // stable replays, as well as lazer replays recorded prior to https://github.com/ppy/osu/pull/28058,
            // do not even *contain* the user's rank.
            // not to mention possible gameplay mechanics changes that could make a replay fail sooner than it really should.
            if (GameplayClockContainer.CurrentTime >= lastFrameTime)
                return base.CheckModsAllowFailure();

            return false;
        }

        public ReplayPlayer(Score score, PlayerConfiguration configuration = null)
            : this((_, _) => score, configuration)
        {
        }

        public ReplayPlayer(Func<IBeatmap, IReadOnlyList<Mod>, Score> createScore, PlayerConfiguration configuration = null)
            : base(configuration)
        {
            this.createScore = createScore;
            Configuration.ShowLeaderboard = true;
        }

        /// <summary>
        /// Add a settings group to the HUD overlay. Intended to be used by rulesets to add replay-specific settings.
        /// </summary>
        /// <param name="settings">The settings group to be shown.</param>
        public void AddSettings(PlayerSettingsGroup settings) => Schedule(() =>
        {
            settings.Expanded.Value = false;
            HUDOverlay.PlayerSettingsOverlay.Add(settings);
        });

        [BackgroundDependencyLoader]
        private void load(OsuConfigManager config)
        {
            if (!LoadedBeatmapSuccessfully)
                return;

            AddInternal(leaderboardProvider);

            playbackSettings = new PlaybackSettings
            {
                Depth = float.MaxValue,
                Expanded = { BindTarget = config.GetBindable<bool>(OsuSetting.ReplayPlaybackControlsExpanded) }
            };

            if (GameplayClockContainer is MasterGameplayClockContainer master)
                playbackSettings.UserPlaybackRate.BindTo(master.UserPlaybackRate);

            HUDOverlay.PlayerSettingsOverlay.AddAtStart(playbackSettings);
        }

        protected override void PrepareReplay()
        {
            DrawableRuleset?.SetReplayScore(Score);
            lastFrameTime = Score.Replay.Frames.LastOrDefault()?.Time;
        }

        protected override Score CreateScore(IBeatmap beatmap) => createScore(beatmap, Mods.Value);

        // Don't re-import replay scores as they're already present in the database.
        protected override Task ImportScore(Score score) => Task.CompletedTask;

        protected override ResultsScreen CreateResults(ScoreInfo score) => new SoloResultsScreen(score)
        {
            // Only show the relevant button otherwise things look silly.
            AllowWatchingReplay = !isAutoplayPlayback,
            AllowRetry = isAutoplayPlayback,
        };

        public bool OnPressed(KeyBindingPressEvent<GlobalAction> e)
        {
            switch (e.Action)
            {
                case GlobalAction.StepReplayBackward:
                    StepFrame(-1);
                    return true;

                case GlobalAction.StepReplayForward:
                    StepFrame(1);
                    return true;

                case GlobalAction.SeekReplayBackward:
                    SeekInDirection(-5 * (float)playbackSettings.UserPlaybackRate.Value);
                    return true;

                case GlobalAction.SeekReplayForward:
                    SeekInDirection(5 * (float)playbackSettings.UserPlaybackRate.Value);
                    return true;

                case GlobalAction.TogglePauseReplay:
                    if (GameplayClockContainer.IsPaused.Value)
                        GameplayClockContainer.Start();
                    else
                        GameplayClockContainer.Stop();
                    return true;
            }

            return false;
        }

        public void StepFrame(int direction)
        {
            GameplayClockContainer.Stop();

            var frames = GameplayState.Score.Replay.Frames;

            if (frames.Count == 0)
                return;

            GameplayClockContainer.Seek(direction < 0
                ? (frames.LastOrDefault(f => f.Time < GameplayClockContainer.CurrentTime) ?? frames.First()).Time
                : (frames.FirstOrDefault(f => f.Time > GameplayClockContainer.CurrentTime) ?? frames.Last()).Time
            );
        }

        public void SeekInDirection(float amount)
        {
            double target = Math.Clamp(GameplayClockContainer.CurrentTime + amount * BASE_SEEK_AMOUNT, 0, GameplayState.Beatmap.GetLastObjectTime());

            Seek(target);
        }

        public void OnReleased(KeyBindingReleaseEvent<GlobalAction> e)
        {
        }
    }
}
