// 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.IO;
using System.Linq;
using System.Text;
using NUnit.Framework;
using osu.Framework.Allocation;
using osu.Framework.Audio;
using osu.Framework.Extensions;
using osu.Framework.Platform;
using osu.Framework.Screens;
using osu.Framework.Utils;
using osu.Game.Beatmaps;
using osu.Game.Online.Rooms;
using osu.Game.Rulesets;
using osu.Game.Rulesets.Mods;
using osu.Game.Rulesets.Osu;
using osu.Game.Rulesets.Osu.Mods;
using osu.Game.Screens.OnlinePlay.Components;
using osu.Game.Screens.OnlinePlay.Playlists;
using osu.Game.Tests.Visual.OnlinePlay;

namespace osu.Game.Tests.Visual.Multiplayer
{
    public class TestScenePlaylistsSongSelect : OnlinePlayTestScene
    {
        [Resolved]
        private BeatmapManager beatmapManager { get; set; }

        private BeatmapManager manager;

        private RulesetStore rulesets;

        private TestPlaylistsSongSelect songSelect;

        [BackgroundDependencyLoader]
        private void load(GameHost host, AudioManager audio)
        {
            Dependencies.Cache(rulesets = new RulesetStore(ContextFactory));
            Dependencies.Cache(manager = new BeatmapManager(LocalStorage, ContextFactory, rulesets, null, audio, Resources, host, Beatmap.Default));

            var beatmaps = new List<BeatmapInfo>();

            for (int i = 0; i < 6; i++)
            {
                int beatmapId = 10 * 10 + i;

                int length = RNG.Next(30000, 200000);
                double bpm = RNG.NextSingle(80, 200);

                beatmaps.Add(new BeatmapInfo
                {
                    Ruleset = new OsuRuleset().RulesetInfo,
                    OnlineID = beatmapId,
                    DifficultyName = $"{beatmapId} (length {TimeSpan.FromMilliseconds(length):m\\:ss}, bpm {bpm:0.#})",
                    Length = length,
                    BPM = bpm,
                    BaseDifficulty = new BeatmapDifficulty
                    {
                        OverallDifficulty = 3.5f,
                    },
                });
            }

            manager.Import(new BeatmapSetInfo
            {
                OnlineID = 10,
                Hash = new MemoryStream(Encoding.UTF8.GetBytes(Guid.NewGuid().ToString())).ComputeMD5Hash(),
                Metadata = new BeatmapMetadata
                {
                    // Create random metadata, then we can check if sorting works based on these
                    Artist = "Some Artist " + RNG.Next(0, 9),
                    Title = $"Some Song (set id 10), max bpm {beatmaps.Max(b => b.BPM):0.#})",
                    AuthorString = "Some Guy " + RNG.Next(0, 9),
                },
                Beatmaps = beatmaps,
                DateAdded = DateTimeOffset.UtcNow,
            }).Wait();
        }

        public override void SetUpSteps()
        {
            base.SetUpSteps();

            AddStep("reset", () =>
            {
                SelectedRoom.Value = new Room();
                Ruleset.Value = new OsuRuleset().RulesetInfo;
                Beatmap.SetDefault();
                SelectedMods.Value = Array.Empty<Mod>();
            });

            AddStep("create song select", () => LoadScreen(songSelect = new TestPlaylistsSongSelect(SelectedRoom.Value)));
            AddUntilStep("wait for present", () => songSelect.IsCurrentScreen());
        }

        [Test]
        public void TestItemAddedIfEmptyOnStart()
        {
            AddStep("finalise selection", () => songSelect.FinaliseSelection());
            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
        }

        [Test]
        public void TestItemAddedWhenCreateNewItemClicked()
        {
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
        }

        [Test]
        public void TestItemNotAddedIfExistingOnStart()
        {
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddStep("finalise selection", () => songSelect.FinaliseSelection());
            AddAssert("playlist has 1 item", () => SelectedRoom.Value.Playlist.Count == 1);
        }

        [Test]
        public void TestAddSameItemMultipleTimes()
        {
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddAssert("playlist has 2 items", () => SelectedRoom.Value.Playlist.Count == 2);
        }

        [Test]
        public void TestAddItemAfterRearrangement()
        {
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddStep("rearrange", () =>
            {
                var item = SelectedRoom.Value.Playlist[0];
                SelectedRoom.Value.Playlist.RemoveAt(0);
                SelectedRoom.Value.Playlist.Add(item);
            });

            AddStep("create new item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddAssert("new item has id 2", () => SelectedRoom.Value.Playlist.Last().ID == 2);
        }

        /// <summary>
        /// Tests that the same <see cref="Mod"/> instances are not shared between two playlist items.
        /// </summary>
        [Test]
        public void TestNewItemHasNewModInstances()
        {
            AddStep("set dt mod", () => SelectedMods.Value = new[] { new OsuModDoubleTime() });
            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());
            AddStep("change mod rate", () => ((OsuModDoubleTime)SelectedMods.Value[0]).SpeedChange.Value = 2);
            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());

            AddAssert("item 1 has rate 1.5", () => Precision.AlmostEquals(1.5, ((OsuModDoubleTime)SelectedRoom.Value.Playlist.First().RequiredMods[0]).SpeedChange.Value));
            AddAssert("item 2 has rate 2", () => Precision.AlmostEquals(2, ((OsuModDoubleTime)SelectedRoom.Value.Playlist.Last().RequiredMods[0]).SpeedChange.Value));
        }

        /// <summary>
        /// Tests that the global mod instances are not retained by the rooms, as global mod instances are retained and re-used by the mod select overlay.
        /// </summary>
        [Test]
        public void TestGlobalModInstancesNotRetained()
        {
            OsuModDoubleTime mod = null;

            AddStep("set dt mod and store", () =>
            {
                SelectedMods.Value = new[] { new OsuModDoubleTime() };

                // Mod select overlay replaces our mod.
                mod = (OsuModDoubleTime)SelectedMods.Value[0];
            });

            AddStep("create item", () => songSelect.BeatmapDetails.CreateNewItem());

            AddStep("change stored mod rate", () => mod.SpeedChange.Value = 2);
            AddAssert("item has rate 1.5", () => Precision.AlmostEquals(1.5, ((OsuModDoubleTime)SelectedRoom.Value.Playlist.First().RequiredMods[0]).SpeedChange.Value));
        }

        private class TestPlaylistsSongSelect : PlaylistsSongSelect
        {
            public new MatchBeatmapDetailArea BeatmapDetails => (MatchBeatmapDetailArea)base.BeatmapDetails;

            public TestPlaylistsSongSelect(Room room)
                : base(room)
            {
            }
        }
    }
}