using InnovEnergy.Lib.Protocols.DBus.Protocol.DataTypes;
using InnovEnergy.Lib.Protocols.DBus.Protocol.DataTypes.Signatures;
using static System.Text.Encoding;

namespace InnovEnergy.Lib.Protocols.DBus.WireFormat;

internal abstract class DBusWriter
{
    public abstract Int32 BytesWritten { get; }
    public abstract void WriteByte(Byte value);

    public void Align(Int32 align)
    {
        while (BytesWritten % align != 0)
            WriteNull();
    }

    private void WriteNull() => WriteByte(0);

    private void WriteBytes(IEnumerable<Byte> bytes)
    {
        foreach (var b in bytes)
            WriteByte(b);
    }

    public void AlignForComposite() => Align(8); // structs/arrays/dict elements are always 8-aligned

    public void WriteUInt16(UInt16 value)
    {
        Align(sizeof(UInt16));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteInt16(Int16 value)
    {
        Align(sizeof(Int16));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteUInt32(UInt32 value)
    {
        Align(sizeof(UInt32));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteInt32(Int32 value)
    {
        Align(sizeof(Int32));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteUInt64(UInt64 value)
    {
        Align(sizeof(UInt64));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteInt64(Int64 value)
    {
        Align(sizeof(Int64));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteDouble(Double value)
    {
        Align(sizeof(Double));
        WriteBytes(BitConverter.GetBytes(value));
    }

    public void WriteBoolean(Boolean value) => WriteUInt32(value ? 1u : 0);

    public void WriteString(String value)
    {
        var str = UTF8.GetBytes(value);
        WriteInt32(str.Length);
        WriteBytes(str);
        WriteNull();
    }

    public void WriteObjectPath(ObjectPath value) => WriteString(value.Path);

    public void WriteSignature(Signature signature)
    {
        var str = ASCII.GetBytes(signature.ToString()!);
        WriteByte((Byte) str.Length);
        WriteBytes(str);
        WriteNull();
    }

    public void WriteVariant(Variant variant)
    {
        var variantSignature = variant.Signature;
        WriteSignature(variantSignature);
        variantSignature.Write(variant.Value, this);
    }

    public override String ToString() => $"@{BytesWritten}";
}