// 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 JetBrains.Annotations;
using Newtonsoft.Json;
using osu.Framework.Audio.Sample;
using osu.Framework.Bindables;
using osu.Framework.Graphics;
using osu.Framework.Graphics.OpenGL.Textures;
using osu.Framework.Graphics.Textures;
using osu.Framework.Logging;
using osu.Game.Audio;
using osu.Game.Database;
using osu.Game.Extensions;
using osu.Game.IO;
using osu.Game.Screens.Play.HUD;

namespace osu.Game.Skinning
{
    public abstract class Skin : IDisposable, ISkin
    {
        public readonly ILive<SkinInfo> SkinInfo;
        private readonly IStorageResourceProvider resources;

        public SkinConfiguration Configuration { get; set; }

        public IDictionary<SkinnableTarget, SkinnableInfo[]> DrawableComponentInfo => drawableComponentInfo;

        private readonly Dictionary<SkinnableTarget, SkinnableInfo[]> drawableComponentInfo = new Dictionary<SkinnableTarget, SkinnableInfo[]>();

        public abstract ISample GetSample(ISampleInfo sampleInfo);

        public Texture GetTexture(string componentName) => GetTexture(componentName, default, default);

        public abstract Texture GetTexture(string componentName, WrapMode wrapModeS, WrapMode wrapModeT);

        public abstract IBindable<TValue> GetConfig<TLookup, TValue>(TLookup lookup);

        protected Skin(SkinInfo skin, IStorageResourceProvider resources, [CanBeNull] Stream configurationStream = null)
        {
            SkinInfo = resources?.RealmAccess != null
                ? skin.ToLive(resources.RealmAccess)
                // This path should only be used in some tests.
                : skin.ToLiveUnmanaged();

            this.resources = resources;

            configurationStream ??= getConfigurationStream();

            if (configurationStream != null)
                // stream will be closed after use by LineBufferedReader.
                ParseConfigurationStream(configurationStream);
            else
                Configuration = new SkinConfiguration();

            // skininfo files may be null for default skin.
            SkinInfo.PerformRead(s =>
            {
                // we may want to move this to some kind of async operation in the future.
                foreach (SkinnableTarget skinnableTarget in Enum.GetValues(typeof(SkinnableTarget)))
                {
                    string filename = $"{skinnableTarget}.json";

                    // skininfo files may be null for default skin.
                    var fileInfo = s.Files.FirstOrDefault(f => f.Filename == filename);

                    if (fileInfo == null)
                        continue;

                    byte[] bytes = resources?.Files.Get(fileInfo.File.GetStoragePath());

                    if (bytes == null)
                        continue;

                    try
                    {
                        string jsonContent = Encoding.UTF8.GetString(bytes);
                        var deserializedContent = JsonConvert.DeserializeObject<IEnumerable<SkinnableInfo>>(jsonContent);

                        if (deserializedContent == null)
                            continue;

                        DrawableComponentInfo[skinnableTarget] = deserializedContent.ToArray();
                    }
                    catch (Exception ex)
                    {
                        Logger.Error(ex, "Failed to load skin configuration.");
                    }
                }
            });
        }

        protected virtual void ParseConfigurationStream(Stream stream)
        {
            using (LineBufferedReader reader = new LineBufferedReader(stream, true))
                Configuration = new LegacySkinDecoder().Decode(reader);
        }

        private Stream getConfigurationStream()
        {
            string path = SkinInfo.PerformRead(s => s.Files.SingleOrDefault(f => f.Filename.Equals(@"skin.ini", StringComparison.OrdinalIgnoreCase))?.File.GetStoragePath());

            if (string.IsNullOrEmpty(path))
                return null;

            return resources?.Files.GetStream(path);
        }

        /// <summary>
        /// Remove all stored customisations for the provided target.
        /// </summary>
        /// <param name="targetContainer">The target container to reset.</param>
        public void ResetDrawableTarget(ISkinnableTarget targetContainer)
        {
            DrawableComponentInfo.Remove(targetContainer.Target);
        }

        /// <summary>
        /// Update serialised information for the provided target.
        /// </summary>
        /// <param name="targetContainer">The target container to serialise to this skin.</param>
        public void UpdateDrawableTarget(ISkinnableTarget targetContainer)
        {
            DrawableComponentInfo[targetContainer.Target] = targetContainer.CreateSkinnableInfo().ToArray();
        }

        public virtual Drawable GetDrawableComponent(ISkinComponent component)
        {
            switch (component)
            {
                case SkinnableTargetComponent target:
                    if (!DrawableComponentInfo.TryGetValue(target.Target, out var skinnableInfo))
                        return null;

                    return new SkinnableTargetComponentsContainer
                    {
                        ChildrenEnumerable = skinnableInfo.Select(i => i.CreateInstance())
                    };
            }

            return null;
        }

        #region Disposal

        ~Skin()
        {
            // required to potentially clean up sample store from audio hierarchy.
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private bool isDisposed;

        protected virtual void Dispose(bool isDisposing)
        {
            if (isDisposed)
                return;

            isDisposed = true;
        }

        #endregion
    }
}