using System;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.Linq;
using Jellyfin.Data.Enums;
using Jellyfin.Server.ServerSetupApp;
using MediaBrowser.Controller.Entities;
using MediaBrowser.Controller.Library;
using MediaBrowser.Controller.Trickplay;
using MediaBrowser.Model.IO;
using Microsoft.Extensions.Logging;

namespace Jellyfin.Server.Migrations.Routines;

/// <summary>
/// Migration to move trickplay files to the new directory.
/// </summary>
#pragma warning disable CS0618 // Type or member is obsolete
[JellyfinMigration("2025-04-20T23:00:00", nameof(MoveTrickplayFiles), RunMigrationOnSetup = true)]
public class MoveTrickplayFiles : IMigrationRoutine
#pragma warning restore CS0618 // Type or member is obsolete
{
    private readonly ITrickplayManager _trickplayManager;
    private readonly IFileSystem _fileSystem;
    private readonly ILibraryManager _libraryManager;
    private readonly IStartupLogger _logger;

    /// <summary>
    /// Initializes a new instance of the <see cref="MoveTrickplayFiles"/> class.
    /// </summary>
    /// <param name="trickplayManager">Instance of the <see cref="ITrickplayManager"/> interface.</param>
    /// <param name="fileSystem">Instance of the <see cref="IFileSystem"/> interface.</param>
    /// <param name="libraryManager">Instance of the <see cref="ILibraryManager"/> interface.</param>
    /// <param name="logger">The logger.</param>
    public MoveTrickplayFiles(
        ITrickplayManager trickplayManager,
        IFileSystem fileSystem,
        ILibraryManager libraryManager,
        IStartupLogger<MoveTrickplayFiles> logger)
    {
        _trickplayManager = trickplayManager;
        _fileSystem = fileSystem;
        _libraryManager = libraryManager;
        _logger = logger;
    }

    /// <inheritdoc />
    public void Perform()
    {
        const int Limit = 5000;
        int itemCount = 0, offset = 0, previousCount;

        var sw = Stopwatch.StartNew();
        var trickplayQuery = new InternalItemsQuery
        {
            MediaTypes = [MediaType.Video],
            SourceTypes = [SourceType.Library],
            IsVirtualItem = false,
            IsFolder = false
        };

        do
        {
            var trickplayInfos = _trickplayManager.GetTrickplayItemsAsync(Limit, offset).GetAwaiter().GetResult();
            trickplayQuery.ItemIds = trickplayInfos.Select(i => i.ItemId).Distinct().ToArray();
            var items = _libraryManager.GetItemList(trickplayQuery);
            foreach (var trickplayInfo in trickplayInfos)
            {
                var item = items.OfType<Video>().FirstOrDefault(i => i.Id.Equals(trickplayInfo.ItemId));
                if (item is null)
                {
                    continue;
                }

                var moved = false;
                var oldPath = GetOldTrickplayDirectory(item, trickplayInfo.Width);
                var newPath = _trickplayManager.GetTrickplayDirectory(item, trickplayInfo.TileWidth, trickplayInfo.TileHeight, trickplayInfo.Width, false);
                if (_fileSystem.DirectoryExists(oldPath))
                {
                    _fileSystem.MoveDirectory(oldPath, newPath);
                    moved = true;
                }

                oldPath = GetNewOldTrickplayDirectory(item, trickplayInfo.TileWidth, trickplayInfo.TileHeight, trickplayInfo.Width, false);
                if (_fileSystem.DirectoryExists(oldPath))
                {
                    _fileSystem.MoveDirectory(oldPath, newPath);
                    moved = true;
                }

                if (moved)
                {
                    itemCount++;
                }
            }

            offset += Limit;
            previousCount = trickplayInfos.Count;

            _logger.LogInformation("Checked: {Checked} - Moved: {Count} - Time: {Time}", offset, itemCount, sw.Elapsed);
        } while (previousCount == Limit);

        _logger.LogInformation("Moved {Count} items in {Time}", itemCount, sw.Elapsed);
    }

    private string GetOldTrickplayDirectory(BaseItem item, int? width = null)
    {
        var path = Path.Combine(item.GetInternalMetadataPath(), "trickplay");

        return width.HasValue ? Path.Combine(path, width.Value.ToString(CultureInfo.InvariantCulture)) : path;
    }

    private string GetNewOldTrickplayDirectory(BaseItem item, int tileWidth, int tileHeight, int width, bool saveWithMedia = false)
    {
        var path = saveWithMedia
            ? Path.Combine(item.ContainingFolderPath, Path.ChangeExtension(item.Path, ".trickplay"))
            : Path.Combine(item.GetInternalMetadataPath(), "trickplay");

        var subdirectory = string.Format(
            CultureInfo.InvariantCulture,
            "{0} - {1}x{2}",
            width.ToString(CultureInfo.InvariantCulture),
            tileWidth.ToString(CultureInfo.InvariantCulture),
            tileHeight.ToString(CultureInfo.InvariantCulture));

        return Path.Combine(path, subdirectory);
    }
}