using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;

namespace MediaContainers.Matroska;

public class MatroskaInfo
{
	public byte[] SegmentUID { get; set; }
	public string SegmentFilename { get; set; }
	public byte[] PrevUID { get; set; }
	public string PrevFilename { get; set; }
	public byte[] NextUID { get; set; }
	public string NextFilename { get; set; }
	public byte[] SegmentFamily { get; set; }
	public List<ChapterTranslate> ChapterTranslateEntries { get; set; }
	public ulong TimestampScale { get; set; } = 1000000;
	public double Duration { get; set; }
	public DateTime? DateUTC { get; set; }
	public string Title { get; set; }
	public string MuxingApp { get; set; } = "mkvdotnet_1.0";
	public string WritingApp { get; set; } = "mkvdotnet_1.0";

	public class ChapterTranslate
	{
		public byte[] ChapterTranslateEditionUID { get; set; }
		public int ChapterTranslateCodec { get; set; }
		public byte[] ChapterTranslateID { get; set; }
	}

	public void CopyTo(MatroskaInfo info, bool shallow = false, bool copyAppName = false)
	{
		info.SegmentUID = SegmentUID;
		info.SegmentFilename = SegmentFilename;
		info.PrevUID = PrevUID;
		info.PrevFilename = PrevFilename;
		info.NextUID = NextUID;
		info.NextFilename = NextFilename;
		info.SegmentFamily = SegmentFamily;
		if (shallow) { info.ChapterTranslateEntries = ChapterTranslateEntries; }
		else
		{
			info.ChapterTranslateEntries = null;
			if (ChapterTranslateEntries != null)
			{
				info.ChapterTranslateEntries = ChapterTranslateEntries.Select(x => new ChapterTranslate()
				{
					ChapterTranslateEditionUID = x.ChapterTranslateEditionUID,
					ChapterTranslateCodec = x.ChapterTranslateCodec,
					ChapterTranslateID = x.ChapterTranslateID
				})
				.ToList();
			}
		}
		info.TimestampScale = TimestampScale;
		info.Duration = Duration;
		info.DateUTC = DateUTC;
		info.Title = Title;
		if (copyAppName)
		{
			info.MuxingApp = MuxingApp;
			info.WritingApp = WritingApp;
		}
	}

	public void ReadFrom(EBMLMasterElement element)
	{
		if (element == null) { return; }
		if (element.Definition != MatroskaSpecification.Info) { return; }
		foreach (var child in element.Children)
		{
			if (child.Definition == MatroskaSpecification.SegmentUID) { SegmentUID = (child as EBMLBinaryElement).Value.ToArray(); }
			else if (child.Definition == MatroskaSpecification.SegmentFilename) { SegmentFilename = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.PrevUID) { PrevUID = (child as EBMLBinaryElement).Value.ToArray(); }
			else if (child.Definition == MatroskaSpecification.PrevFilename) { PrevFilename = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.NextUID) { NextUID = (child as EBMLBinaryElement).Value.ToArray(); }
			else if (child.Definition == MatroskaSpecification.NextFilename) { NextFilename = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.SegmentFamily) { SegmentFamily = (child as EBMLBinaryElement).Value.ToArray(); }
			else if (child.Definition == MatroskaSpecification.TimestampScale) { TimestampScale = child.UIntValue; }
			else if (child.Definition == MatroskaSpecification.Duration) { Duration = child.DoubleValue; }
			else if (child.Definition == MatroskaSpecification.DateUTC) { DateUTC = child.DateValue; }
			else if (child.Definition == MatroskaSpecification.Title) { Title = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.MuxingApp) { MuxingApp = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.WritingApp) { WritingApp = child.StringValue; }
			else if (child.Definition == MatroskaSpecification.ChapterTranslate)
			{
				var entry = new ChapterTranslate();
				foreach (var sub in ((EBMLMasterElement)child).Children)
				{
					if (sub.Definition == MatroskaSpecification.ChapterTranslateID) { entry.ChapterTranslateID = (sub as EBMLBinaryElement).Value.ToArray(); }
					else if (sub.Definition == MatroskaSpecification.ChapterTranslateCodec) { entry.ChapterTranslateCodec = (int)sub.IntValue; }
					else if (sub.Definition == MatroskaSpecification.ChapterTranslateEditionUID) { entry.ChapterTranslateEditionUID = (sub as EBMLBinaryElement).Value.ToArray(); }
				}
				if (ChapterTranslateEntries == null) { ChapterTranslateEntries = new List<ChapterTranslate>(); }
				ChapterTranslateEntries.Add(entry);
			}
		}
	}

	public async ValueTask<EBMLWriter.RelativeOffset> Write(EBMLWriter writer, CancellationToken cancellationToken = default)
	{
		EBMLWriter.RelativeOffset durationMark = default;
		await writer.BeginMasterElement(MatroskaSpecification.Info, cancellationToken);
		if (SegmentUID != null) { await writer.WriteBinary(MatroskaSpecification.SegmentUID, SegmentUID, cancellationToken); }
		if (SegmentFilename != null) { await writer.WriteString(MatroskaSpecification.SegmentFilename, SegmentFilename, cancellationToken); }
		if (PrevUID != null) { await writer.WriteBinary(MatroskaSpecification.PrevUID, PrevUID, cancellationToken); }
		if (PrevFilename != null) { await writer.WriteString(MatroskaSpecification.PrevFilename, SegmentFilename, cancellationToken); }
		if (NextUID != null) { await writer.WriteBinary(MatroskaSpecification.NextUID, NextUID, cancellationToken); }
		if (NextFilename != null) { await writer.WriteString(MatroskaSpecification.NextFilename, NextFilename, cancellationToken); }
		if (SegmentFamily != null) { await writer.WriteBinary(MatroskaSpecification.SegmentFamily, SegmentFamily, cancellationToken); }
		if (ChapterTranslateEntries != null && ChapterTranslateEntries.Count > 0)
		{
			await writer.BeginMasterElement(MatroskaSpecification.ChapterTranslate, cancellationToken);
			for (int i = 0; i < ChapterTranslateEntries.Count; i++)
			{
				var item = ChapterTranslateEntries[i];
				if (item.ChapterTranslateID != null) { await writer.WriteBinary(MatroskaSpecification.ChapterTranslateID, item.ChapterTranslateID, cancellationToken); }
				await writer.WriteUnsignedInteger(MatroskaSpecification.ChapterTranslateCodec, (ulong)item.ChapterTranslateCodec, cancellationToken);
				await writer.WriteBinary(MatroskaSpecification.ChapterTranslateEditionUID, item.ChapterTranslateEditionUID, cancellationToken);
			}
			await writer.EndMasterElement(cancellationToken);
		}
		await writer.WriteUnsignedInteger(MatroskaSpecification.TimestampScale, TimestampScale, cancellationToken);
		if (Duration > 0)
		{
			durationMark = writer.MarkRelativeOffset(null);
			await writer.WriteFloat(MatroskaSpecification.Duration, Duration, cancellationToken);
		}
		if (DateUTC != null) { await writer.WriteDate(MatroskaSpecification.DateUTC, DateUTC.Value, cancellationToken); }
		if (Title != null) { await writer.WriteString(MatroskaSpecification.Title, Title, cancellationToken); }
		await writer.WriteString(MatroskaSpecification.MuxingApp, MuxingApp, cancellationToken);
		await writer.WriteString(MatroskaSpecification.WritingApp, WritingApp, cancellationToken);
		await writer.EndMasterElement(cancellationToken);
		return durationMark;
	}

	public EBMLMasterElement ToElement()
	{
		var info = new EBMLMasterElement(MatroskaSpecification.Info);
		if (SegmentUID != null) { info.AddChild(new EBMLBinaryElement(MatroskaSpecification.SegmentUID, SegmentUID)); }
		if (SegmentFilename != null) { info.AddChild(new EBMLStringElement(MatroskaSpecification.SegmentFilename, SegmentFilename)); }
		if (PrevUID != null) { info.AddChild(new EBMLBinaryElement(MatroskaSpecification.PrevUID, PrevUID)); }
		if (PrevFilename != null) { info.AddChild(new EBMLStringElement(MatroskaSpecification.PrevFilename, PrevFilename)); }
		if (NextUID != null) { info.AddChild(new EBMLBinaryElement(MatroskaSpecification.NextUID, NextUID)); }
		if (NextFilename != null) { info.AddChild(new EBMLStringElement(MatroskaSpecification.NextFilename, NextFilename)); }
		if (SegmentFamily != null) { info.AddChild(new EBMLBinaryElement(MatroskaSpecification.SegmentFamily, SegmentFamily)); }
		if (ChapterTranslateEntries != null && ChapterTranslateEntries.Count > 0)
		{
			var chap = new EBMLMasterElement(MatroskaSpecification.ChapterTranslate);
			foreach (var item in ChapterTranslateEntries)
			{
				if (item.ChapterTranslateID != null) { info.AddChild(new EBMLBinaryElement(MatroskaSpecification.ChapterTranslateID, item.ChapterTranslateID)); }
				info.AddChild(new EBMLUnsignedIntegerElement(MatroskaSpecification.ChapterTranslateCodec, (ulong)item.ChapterTranslateCodec));
				info.AddChild(new EBMLBinaryElement(MatroskaSpecification.ChapterTranslateEditionUID, item.ChapterTranslateEditionUID));
			}
			info.AddChild(chap);
		}
		info.AddChild(new EBMLUnsignedIntegerElement(MatroskaSpecification.TimestampScale, TimestampScale));
		if (Duration > 0) { info.AddChild(new EBMLFloatElement(MatroskaSpecification.Duration, Duration)); }
		if (DateUTC != null) { info.AddChild(new EBMLDateElement(MatroskaSpecification.DateUTC, DateUTC.Value)); }
		if (Title != null) { info.AddChild(new EBMLStringElement(MatroskaSpecification.Title, Title)); }
		info.AddChild(new EBMLStringElement(MatroskaSpecification.MuxingApp, MuxingApp));
		info.AddChild(new EBMLStringElement(MatroskaSpecification.WritingApp, WritingApp));
		return info;
	}
}