// Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
// Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE

using System.Collections.Generic;
using osu.Framework.Allocation;
using osu.Framework.Extensions.Color4Extensions;
using OpenTK;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Graphics.Shapes;
using osu.Framework.Graphics.Sprites;
using osu.Game.Beatmaps;
using osu.Game.Beatmaps.Drawables;
using osu.Game.Graphics;
using osu.Game.Graphics.Sprites;
using OpenTK.Graphics;
using osu.Framework.Input;
using osu.Game.Graphics.UserInterface;
using osu.Framework.Logging;
using osu.Game.Online.API.Requests;
using osu.Framework.Configuration;
using osu.Framework.Audio.Track;

namespace osu.Game.Overlays.Direct
{
    public abstract class DirectPanel : Container
    {
        public readonly BeatmapSetInfo SetInfo;

        protected Box BlackBackground;

        private const double hover_transition_time = 400;

        private Container content;

        private ProgressBar progressBar;
        private BeatmapManager beatmaps;
        private BeatmapSetOverlay beatmapSetOverlay;

        public Track Preview => PlayButton.Preview;
        public Bindable<bool> PreviewPlaying => PlayButton.Playing;
        protected abstract PlayButton PlayButton { get; }
        protected abstract Box PreviewBar { get; }

        protected override Container<Drawable> Content => content;

        protected DirectPanel(BeatmapSetInfo setInfo)
        {
            SetInfo = setInfo;
        }

        private readonly EdgeEffectParameters edgeEffectNormal = new EdgeEffectParameters
        {
            Type = EdgeEffectType.Shadow,
            Offset = new Vector2(0f, 1f),
            Radius = 2f,
            Colour = Color4.Black.Opacity(0.25f),
        };

        private readonly EdgeEffectParameters edgeEffectHovered = new EdgeEffectParameters
        {
            Type = EdgeEffectType.Shadow,
            Offset = new Vector2(0f, 5f),
            Radius = 10f,
            Colour = Color4.Black.Opacity(0.3f),
        };


        [BackgroundDependencyLoader(permitNulls: true)]
        private void load(BeatmapManager beatmaps, OsuColour colours, BeatmapSetOverlay beatmapSetOverlay)
        {
            this.beatmaps = beatmaps;
            this.beatmapSetOverlay = beatmapSetOverlay;

            AddInternal(content = new Container
            {
                RelativeSizeAxes = Axes.Both,
                Masking = true,
                EdgeEffect = edgeEffectNormal,
                Children = new[]
                {
                    // temporary blackness until the actual background loads.
                    BlackBackground = new Box
                    {
                        RelativeSizeAxes = Axes.Both,
                        Colour = Color4.Black,
                    },
                    CreateBackground(),
                    progressBar = new ProgressBar
                    {
                        Anchor = Anchor.BottomLeft,
                        Origin = Anchor.BottomLeft,
                        Height = 0,
                        Alpha = 0,
                        BackgroundColour = Color4.Black.Opacity(0.7f),
                        FillColour = colours.Blue,
                        Depth = -1,
                    },
                }
            });

            var downloadRequest = beatmaps.GetExistingDownload(SetInfo);

            if (downloadRequest != null)
                attachDownload(downloadRequest);

            beatmaps.BeatmapDownloadBegan += attachDownload;
        }

        protected override void Dispose(bool isDisposing)
        {
            base.Dispose(isDisposing);
            beatmaps.BeatmapDownloadBegan -= attachDownload;
        }

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

            if (PreviewPlaying && Preview != null && Preview.IsLoaded)
            {
                PreviewBar.Width = (float)(Preview.CurrentTime / Preview.Length);
            }
        }

        protected override bool OnHover(InputState state)
        {
            content.TweenEdgeEffectTo(edgeEffectHovered, hover_transition_time, Easing.OutQuint);
            content.MoveToY(-4, hover_transition_time, Easing.OutQuint);
            PlayButton.FadeIn(120, Easing.InOutQuint);

            return base.OnHover(state);
        }

        protected override void OnHoverLost(InputState state)
        {
            content.TweenEdgeEffectTo(edgeEffectNormal, hover_transition_time, Easing.OutQuint);
            content.MoveToY(0, hover_transition_time, Easing.OutQuint);
            if (!PreviewPlaying)
                PlayButton.FadeOut(120, Easing.InOutQuint);

            base.OnHoverLost(state);
        }

        protected override bool OnClick(InputState state)
        {
            ShowInformation();
            PreviewPlaying.Value = false;
            return true;
        }

        protected void ShowInformation() => beatmapSetOverlay?.ShowBeatmapSet(SetInfo);

        protected void StartDownload()
        {
            if (beatmaps.GetExistingDownload(SetInfo) != null)
            {
                // we already have an active download running.
                content.MoveToX(-5, 50, Easing.OutSine).Then()
                       .MoveToX(5, 100, Easing.InOutSine).Then()
                       .MoveToX(-5, 100, Easing.InOutSine).Then()
                       .MoveToX(0, 50, Easing.InSine).Then();

                return;
            }

            beatmaps.Download(SetInfo);
        }

        private void attachDownload(DownloadBeatmapSetRequest request)
        {
            if (request.BeatmapSet.OnlineBeatmapSetID != SetInfo.OnlineBeatmapSetID)
                return;

            progressBar.FadeIn(400, Easing.OutQuint);
            progressBar.ResizeHeightTo(4, 400, Easing.OutQuint);

            progressBar.Current.Value = 0;

            request.Failure += e =>
            {
                progressBar.Current.Value = 0;
                progressBar.FadeOut(500);
                Logger.Error(e, "Failed to get beatmap download information");
            };

            request.DownloadProgressed += progress => progressBar.Current.Value = progress;

            request.Success += data =>
            {
                progressBar.Current.Value = 1;
                progressBar.FadeOut(500);
            };
        }

        protected override void LoadComplete()
        {
            base.LoadComplete();
            this.FadeInFromZero(200, Easing.Out);

            PreviewPlaying.ValueChanged += newValue => PlayButton.FadeTo(newValue || IsHovered ? 1 : 0, 120, Easing.InOutQuint);
            PreviewPlaying.ValueChanged += newValue => PreviewBar.FadeTo(newValue ? 1 : 0, 120, Easing.InOutQuint);
        }

        protected List<DifficultyIcon> GetDifficultyIcons()
        {
            var icons = new List<DifficultyIcon>();

            foreach (var b in SetInfo.Beatmaps)
                icons.Add(new DifficultyIcon(b));

            return icons;
        }

        protected Drawable CreateBackground() => new DelayedLoadWrapper(
            new BeatmapSetCover(SetInfo)
            {
                Anchor = Anchor.Centre,
                Origin = Anchor.Centre,
                RelativeSizeAxes = Axes.Both,
                FillMode = FillMode.Fill,
                OnLoadComplete = d =>
                {
                    d.FadeInFromZero(400, Easing.Out);
                    BlackBackground.Delay(400).FadeOut();
                },
            }, 300)
        {
            RelativeSizeAxes = Axes.Both,
        };

        public class Statistic : FillFlowContainer
        {
            private readonly SpriteText text;

            private int value;

            public int Value
            {
                get { return value; }
                set
                {
                    this.value = value;
                    text.Text = Value.ToString(@"N0");
                }
            }

            public Statistic(FontAwesome icon, int value = 0)
            {
                Anchor = Anchor.TopRight;
                Origin = Anchor.TopRight;
                AutoSizeAxes = Axes.Both;
                Direction = FillDirection.Horizontal;
                Spacing = new Vector2(5f, 0f);

                Children = new Drawable[]
                {
                    text = new OsuSpriteText
                    {
                        Font = @"Exo2.0-SemiBoldItalic",
                    },
                    new SpriteIcon
                    {
                        Icon = icon,
                        Shadow = true,
                        Size = new Vector2(14),
                        Margin = new MarginPadding { Top = 1 },
                    },
                };

                Value = value;
            }
        }
    }
}