using System.Linq;

namespace MediaContainers;

public class EBMLElementDefiniton
{
	public static readonly EBMLElementDefiniton EBML = new EBMLElementDefiniton(0x1A45DFA3, EBMLElementType.Master, @"\EBML");
	public static readonly EBMLElementDefiniton EBMLVersion = new EBMLElementDefiniton(0x4286, EBMLElementType.UnsignedInteger, @"\EBML\EBMLVersion", defaultVal: "1");
	public static readonly EBMLElementDefiniton EBMLReadVersion = new EBMLElementDefiniton(0x42F7, EBMLElementType.UnsignedInteger, @"\EBML\EBMLReadVersion");
	public static readonly EBMLElementDefiniton EBMLMaxIDLength = new EBMLElementDefiniton(0x42F2, EBMLElementType.UnsignedInteger, @"\EBML\EBMLMaxIDLength", defaultVal: "4");
	public static readonly EBMLElementDefiniton EBMLMaxSizeLength = new EBMLElementDefiniton(0x42F3, EBMLElementType.UnsignedInteger, @"\EBML\EBMLMaxSizeLength", defaultVal: "8");
	public static readonly EBMLElementDefiniton DocType = new EBMLElementDefiniton(0x4282, EBMLElementType.String, @"\EBML\DocType");
	public static readonly EBMLElementDefiniton DocTypeVersion = new EBMLElementDefiniton(0x4287, EBMLElementType.UnsignedInteger, @"\EBML\DocTypeVersion");
	public static readonly EBMLElementDefiniton DocTypeReadVersion = new EBMLElementDefiniton(0x4285, EBMLElementType.UnsignedInteger, @"\EBML\DocTypeReadVersion");
	public static readonly EBMLElementDefiniton DocTypeExtension = new EBMLElementDefiniton(0x4281, EBMLElementType.Master, @"\EBML\DocTypeExtension");
	public static readonly EBMLElementDefiniton DocTypeExtensionName = new EBMLElementDefiniton(0x4283, EBMLElementType.String, @"\EBML\DocTypeExtension\DocTypeExtensionName");
	public static readonly EBMLElementDefiniton DocTypeExtensionVersion = new EBMLElementDefiniton(0x4284, EBMLElementType.UnsignedInteger, @"\EBML\DocTypeExtension\DocTypeExtensionVersion");
	public static readonly EBMLElementDefiniton Crc32 = new EBMLElementDefiniton(0xBF, EBMLElementType.Binary, "CRC-32");
	public static readonly EBMLElementDefiniton Void = new EBMLElementDefiniton(0xEC, EBMLElementType.Binary, "Void");
	public static readonly EBMLElementDefiniton Unknown = new EBMLElementDefiniton(0, EBMLElementType.Binary, "Unknown");

	private static readonly EBMLElementDefiniton[] headerElements = new EBMLElementDefiniton[]
	{
	 EBML, EBMLVersion, EBMLReadVersion, EBMLMaxIDLength, EBMLMaxSizeLength,
	 DocType, DocTypeVersion, DocTypeReadVersion, DocTypeExtension, DocTypeExtensionName, DocTypeExtensionVersion,
	};

	private static readonly EBMLElementDefiniton[] globalElements = new EBMLElementDefiniton[]
	{
	 Crc32, Void
	};

	public readonly EBMLVInt Id;
	public readonly EBMLElementType Type;
	public readonly string Name;
	public readonly string Path;
	public readonly string FullPath;
	public readonly string DefaultValue;
	public readonly bool AllowUnknownSize;
	public readonly bool IsGlobal;

	public EBMLElementDefiniton(ulong id, EBMLElementType type, string fullPath, bool allowUnknownSize = false, string defaultVal = null)
	{
		Id = EBMLVInt.CreateWithMarker(id);
		Type = type;
		FullPath = fullPath;
		var components = fullPath.Split('\\', System.StringSplitOptions.RemoveEmptyEntries);
		Name = components[^1];
		if (Name.StartsWith('+')) { Name = Name.Substring(1); }
		if (!fullPath.StartsWith('\\') && components.Length == 1) { IsGlobal = true; Path = "\\"; }
		else { Path = "\\" + string.Join("\\", components.Take(components.Length - 1)); }
		AllowUnknownSize = allowUnknownSize;
		DefaultValue = defaultVal;
	}

	public static void AddHeaderElements(EBMLReader reader)
	{
		for (int i = 0; i < headerElements.Length; i++)
		{
			reader.AddElementDefinition(headerElements[i]);
		}
	}

	public static void AddGlobalElements(EBMLReader reader)
	{
		for (int i = 0; i < globalElements.Length; i++)
		{
			reader.AddElementDefinition(globalElements[i]);
		}
	}

	public bool IsDirectChildOf(EBMLElementDefiniton parent)
	{
		return IsGlobal || Path == parent.FullPath;
	}
}