ZXSpectrum48K/Core/Io/TzxBlocks.cs

using System;
using System.Collections.Generic;

namespace Core.Io
{
    // The base class all future TZX blocks will inherit from
    public abstract class TzxBlock
    {
        public abstract int BlockId { get; }
    }

    // ID 0x10: Standard Speed Data Block
    public class StandardSpeedBlock : TzxBlock
    {
        public override int BlockId => 0x10;

        // How long to pause the tape in milliseconds after this block loads
        public ushort PauseAfterMs { get; set; }

        public ushort DataLength { get; set; }

        // The actual tape bytes
        public byte[] Data { get; set; } = Array.Empty<byte>();
    }

    // ID 0x32: Archive Info Block (Metadata)
    public class ArchiveInfoBlock : TzxBlock
    {
        public override int BlockId => 0x32;

        // Key: Text ID (e.g., 0 = Full Title, 1 = Software House, 2 = Publisher, 4 = Year)
        // Value: The actual text string
        public Dictionary<byte, string> Metadata { get; set; } = new Dictionary<byte, string>();
    }

    // ID 0x11: Turbo Speed Data Block
    public class TurboSpeedBlock : TzxBlock
    {
        public override int BlockId => 0x11;

        public ushort PilotPulseLength { get; set; }
        public ushort SyncFirstPulseLength { get; set; }
        public ushort SyncSecondPulseLength { get; set; }
        public ushort ZeroBitPulseLength { get; set; }
        public ushort OneBitPulseLength { get; set; }
        public ushort PilotToneLength { get; set; }
        public byte UsedBitsInLastByte { get; set; }
        public ushort PauseAfterMs { get; set; }

        // This is a 24-bit integer in the file, so we store it in a standard 32-bit int
        public int DataLength { get; set; }

        public byte[] Data { get; set; } = Array.Empty<byte>();
        // ID 0x30: Text Description
        public class TextDescriptionBlock : TzxBlock
        {
            public override int BlockId => 0x30;
            public string Description { get; set; } = string.Empty;
        }

        // ID 0x20: Pause / Stop the Tape
        public class PauseBlock : TzxBlock
        {
            public override int BlockId => 0x20;
            public ushort PauseDurationMs { get; set; } // 0 means "Stop the tape"
        }

        // ID 0x21: Group Start (Used to group blocks in UI tape browsers)
        public class GroupStartBlock : TzxBlock
        {
            public override int BlockId => 0x21;
            public string GroupName { get; set; } = string.Empty;
        }

        // ID 0x22: Group End
        public class GroupEndBlock : TzxBlock
        {
            public override int BlockId => 0x22;
        }

        // ID 0x12: Pure Tone Block
        public class PureToneBlock : TzxBlock
        {
            public override int BlockId => 0x12;
            public ushort PulseLength { get; set; }
            public ushort PulseCount { get; set; }
        }
        // ID 0x13: Pulse Sequence Block
        public class PulseSequenceBlock : TzxBlock
        {
            public override int BlockId => 0x13;

            // Number of pulses (1 to 255)
            public int PulseCount { get; set; }

            // The exact T-State lengths of each pulse
            public ushort[] Pulses { get; set; } = Array.Empty<ushort>();
        }
        // ID 0x14: Pure Data Block
        public class PureDataBlock : TzxBlock
        {
            public override int BlockId => 0x14;

            public ushort ZeroBitPulseLength { get; set; }
            public ushort OneBitPulseLength { get; set; }
            public byte UsedBitsInLastByte { get; set; }
            public ushort PauseAfterMs { get; set; }

            // The return of the 24-bit integer!
            public int DataLength { get; set; }

            public byte[] Data { get; set; } = Array.Empty<byte>();
        }
    }
}