Update MkvInfoReader, Add MkvNode extensions

MkvToolnixWrapper/MkvInfo/Reader/MkvInfoReader.cs

@@ -0,0 +1,121 @@
+using System.Runtime.CompilerServices;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public class MkvInfoReader
+{
+    public const char LineDelimiter = '\n';
+
+    private readonly ReadOnlyMemory<char> _memory;
+    private ReadOnlyMemory<char> _remainingMemory;
+
+    private readonly MkvNodeRoot _root;
+    private MkvNode _currentNode;
+
+    private int _currentPosition;
+
+    public MkvInfoReader(string mkvInfoOutput)
+    {
+        _memory = mkvInfoOutput.AsMemory();
+        _remainingMemory = _memory;
+
+        _root = new MkvNodeRoot();
+        _currentNode = _root;
+
+        _currentPosition = 0;
+    }
+
+    public MkvNodeRoot Read()
+    {
+        if (_root.Children.Count > 0)
+        {
+            return _root;
+        }
+
+        while (_currentPosition < _memory.Length)
+        {
+            var line = ReadLine();
+
+            // Skip empty lines
+            if (line.Length < 1)
+            {
+                continue;
+            }
+
+            ProcessLine(line);
+        }
+
+        return _root;
+    }
+
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private void ProcessLine(ReadOnlyMemory<char> line)
+    {
+        var lineSpan = line.Span;
+
+        // Find depth
+        int depth = lineSpan.IndexOf('+');
+
+        // Climb up the node tree
+        while (depth <= _currentNode.Depth)
+        {
+            _currentNode = _currentNode.Parent!;
+        }
+
+        // Node content
+        var content = line[(depth + 2)..];
+        var contentSpan = content.Span;
+
+        // Check for property
+        int propertyIndex = contentSpan.IndexOf(':');
+
+        MkvNode node;
+        // Property node
+        if (propertyIndex != -1)
+        {
+            var name = content[..propertyIndex];
+            var value = content[(propertyIndex + 2)..];
+
+            node = new MkvProperty(_currentNode, name, value);
+        }
+        // Generic node
+        else
+        {
+            node = new MkvNode(_currentNode, content);
+        }
+
+        _currentNode.Children.Add(node);
+
+        _currentNode = node;
+    }
+
+    /// <summary>
+    /// Read in the span till next \n or EOF while incrementing _currentPosition
+    /// </summary>
+    /// <returns></returns>
+    [MethodImpl(MethodImplOptions.AggressiveInlining)]
+    private ReadOnlyMemory<char> ReadLine()
+    {
+        var remainingSpan = _remainingMemory.Span;
+        ReadOnlyMemory<char> line;
+
+        int index = remainingSpan.IndexOf(LineDelimiter);
+
+        // Reach the end
+        if (index == -1)
+        {
+            line = _remainingMemory;
+            _currentPosition = _memory.Length;
+        }
+        else
+        {
+            line = _remainingMemory[..(index - 1)]; // -1 to skip \r
+            _currentPosition += index + 1; // Skip \n
+        }
+
+        // Move forward in the span
+        _remainingMemory = _memory[_currentPosition..];
+
+        return line;
+    }
+}

MkvToolnixWrapper/MkvInfo/Reader/MkvNode.cs

@@ -0,0 +1,80 @@
+using System.Collections;
+using System.Text;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public class MkvNode : IEnumerable<MkvNode>
+{
+    private static class KnowNodeTypes
+    {
+        public const string Head = "EBML head";
+        public const string Segment = "Segment";
+        public const string Chapter = "Chapters";
+        public const string Tag = "Tags";
+        public const string Track = "Tracks";
+        public const string Attachment = "Attachments";
+    }
+
+    public MkvNode? Parent { get; }
+    public IList<MkvNode> Children { get; }
+
+    public virtual NodeType NodeType { get; }
+    public virtual int Depth { get; }
+
+    public ReadOnlyMemory<char> Name { get; }
+
+    public MkvNode(MkvNode? parent, ReadOnlyMemory<char> name)
+    {
+        Parent = parent;
+        Name = name;
+
+        Depth = parent?.Depth + 1 ?? 0;
+
+        NodeType = parent is null ? NodeType.Root : FindNodeType();
+
+        Children = new List<MkvNode>();
+    }
+
+    private NodeType FindNodeType()
+    {
+        var span = Name.Span;
+
+        return Depth switch
+        {
+            0 when span.SequenceEqual(KnowNodeTypes.Head) => NodeType.Head,
+            0 when span.StartsWith(KnowNodeTypes.Segment) => NodeType.Segment,
+            1 when span.SequenceEqual(KnowNodeTypes.Chapter) => NodeType.Chapter,
+            1 when span.SequenceEqual(KnowNodeTypes.Tag) => NodeType.Tag,
+            1 when span.SequenceEqual(KnowNodeTypes.Track) => NodeType.Track,
+            1 when span.SequenceEqual(KnowNodeTypes.Attachment) => NodeType.Attachment,
+            1 => NodeType.Unknown,
+            _ => Parent!.NodeType
+        };
+    }
+
+    protected virtual void AppendSelf(StringBuilder builder) => builder.AppendLine($"{new string('-', Depth)}> [{NodeType}] {Name}");
+
+    public IEnumerator<MkvNode> GetEnumerator()
+    {
+        return Children.GetEnumerator();
+    }
+
+    IEnumerator IEnumerable.GetEnumerator()
+    {
+        return GetEnumerator();
+    }
+
+    public override string ToString()
+    {
+        var builder = new StringBuilder();
+
+        AppendSelf(builder);
+
+        foreach (var mkvNode in Children)
+        {
+            builder.Append(mkvNode);
+        }
+
+        return builder.ToString();
+    }
+}

MkvToolnixWrapper/MkvInfo/Reader/MkvNodeRoot.cs

@@ -0,0 +1,19 @@
+using System.Text;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public class MkvNodeRoot : MkvNode
+{
+    public override NodeType NodeType => NodeType.Root;
+    public override int Depth => -1;
+
+    public MkvNodeRoot()
+        : base(null, "Root".AsMemory())
+    {
+    }
+
+    protected override void AppendSelf(StringBuilder builder)
+    {
+
+    }
+}

MkvToolnixWrapper/MkvInfo/Reader/MkvProperty.cs

@@ -0,0 +1,64 @@
+using System.Text;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public class MkvProperty : MkvNode
+{
+    private static class KnownProperties
+    {
+        public const string TrackType = "Track type";
+        public const string TrackNumber = "Track number";
+        public const string FlagDefault = "\"Default track\" flag";
+        public const string FlagForced = "\"Forced display\" flag";
+        public const string Language = "Language";
+    }
+
+    public override NodeType NodeType => NodeType.Property;
+    public PropertyType PropertyType { get; }
+    public ReadOnlyMemory<char> Value { get; }
+
+    public MkvProperty(MkvNode? parent, ReadOnlyMemory<char> name, ReadOnlyMemory<char> value)
+        : base(parent, name)
+    {
+        Value = value;
+
+        PropertyType = FindPropertyType(name);
+    }
+
+    private static PropertyType FindPropertyType(ReadOnlyMemory<char> name)
+    {
+        var span = name.Span;
+        
+        if (span.SequenceEqual(KnownProperties.TrackType))
+        {
+            return PropertyType.TrackType;
+        }
+        
+        if (span.SequenceEqual(KnownProperties.TrackNumber))
+        {
+            return PropertyType.TrackNumber;
+        }
+
+        if (span.SequenceEqual(KnownProperties.FlagDefault))
+        {
+            return PropertyType.FlagDefault;
+        }
+
+        if (span.SequenceEqual(KnownProperties.FlagForced))
+        {
+            return PropertyType.FlagForced;
+        }
+
+        if (span.SequenceEqual(KnownProperties.Language))
+        {
+            return PropertyType.Language;
+        }
+
+        return PropertyType.Unknown;
+    }
+
+    protected override void AppendSelf(StringBuilder builder)
+    {
+        builder.AppendLine($"{new string('-', Depth)}> [{NodeType}] {Name}: {Value}");
+    }
+}

MkvToolnixWrapper/MkvInfo/Reader/NodeType.cs

@@ -0,0 +1,14 @@
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public enum NodeType
+{
+    Unknown,
+    Property,
+    Root,
+    Head,
+    Segment,
+    Track,
+    Tag,
+    Attachment,
+    Chapter
+}

MkvToolnixWrapper/MkvInfo/Reader/NodeUtils.cs

@@ -0,0 +1,107 @@
+using MkvPropEditWrapper.Shared;
+
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public static class NodeUtils
+{
+    public static IEnumerable<MkvNode> Descendants(this MkvNode root)
+    {
+        var nodes = new Stack<MkvNode>(new[] {root});
+
+        while (nodes.Any())
+        {
+            var node = nodes.Pop();
+
+            yield return node;
+
+            foreach (var newNode in node.Children)
+            {
+                nodes.Push(newNode);
+            }
+        }
+    }
+
+    /// <summary>
+    /// Generate track info from parsed output, only works on the first root node as it uses absolute depth
+    /// </summary>
+    /// <param name="root">Node root</param>
+    /// <returns>All parseable <see cref="TrackInfo"/></returns>
+    public static IEnumerable<TrackInfo> GetTrackInfos(this MkvNodeRoot root)
+    {        
+        TrackInfo? ParseTrackInfo(MkvNode track)
+        {
+            ReadOnlySpan<char> audioType = "audio";
+            ReadOnlySpan<char> subtitleType = "subtitles";
+            
+            int number = -1;
+            var trackType = TrackType.Unknown;
+            string language = "Unknown";
+            bool defaultFlag = default;
+            bool forcedFlag = default;
+
+            foreach (var child in track.Children)
+            {
+                if (child is MkvProperty property)
+                {
+                    ReadOnlySpan<char> span;
+                    
+                    switch (property.PropertyType)
+                    {
+                        case PropertyType.TrackType:
+                            span = property.Value.Span;
+
+                            if (span.SequenceEqual(audioType))
+                            {
+                                trackType = TrackType.Audio;
+                            }
+                            else if (span.SequenceEqual(subtitleType))
+                            {
+                                trackType = TrackType.Subtitles;
+                            }
+                            else
+                            {
+                                return null;
+                            }
+                            
+                            break;
+                        case PropertyType.TrackNumber:
+                            span = property.Value.Span;
+                        
+                            number = int.Parse(span[..span.IndexOf(' ')]);
+                            break;
+                        case PropertyType.Language:
+                            language = property.Value.ToString();
+                            break;
+                        case PropertyType.FlagDefault:
+                            defaultFlag = property.Value.Span[0] == '1';
+                            break;
+                        case PropertyType.FlagForced:
+                            forcedFlag = property.Value.Span[0] == '1';
+                            break;
+                    }
+                }
+            }
+            
+            return number == -1 ? null : new TrackInfo(number, trackType, language, defaultFlag, forcedFlag);
+        }
+    
+        var tracks = root.Descendants().Where(n => n is { Depth: 2, NodeType: NodeType.Track });
+
+        foreach (var track in tracks)
+        {
+            var trackInfo = ParseTrackInfo(track);
+
+            if (trackInfo is not null)
+            {
+                yield return trackInfo;
+            }
+        }
+    }
+    
+    public static (IEnumerable<TrackInfo> audio, IEnumerable<TrackInfo> subtitles) SplitByType(this IEnumerable<TrackInfo> trackInfos)
+    {
+        var lookup = trackInfos.OrderBy(t => t.Number).ToLookup(t => t.TrackType);
+
+        return (lookup[TrackType.Audio], lookup[TrackType.Subtitles]);
+    }
+}

MkvToolnixWrapper/MkvInfo/Reader/PropertyType.cs

@@ -0,0 +1,11 @@
+namespace MkvPropEditWrapper.MkvInfo.Reader;
+
+public enum PropertyType
+{
+    TrackType,
+    TrackNumber,
+    Unknown,
+    FlagDefault,
+    FlagForced,
+    Language
+}