package io.github.lonamiwebs.overgram.network;

import io.github.lonamiwebs.overgram.network.connection.Connection;
import io.github.lonamiwebs.overgram.tl.TLObject;
import io.github.lonamiwebs.overgram.tl.TLRequest;
import io.github.lonamiwebs.overgram.utils.BinaryReader;
import io.github.lonamiwebs.overgram.utils.BinaryWriter;

import java.io.IOException;
import java.nio.ByteBuffer;

public class MTProtoPlainSender {
    private final Connection connection;
    private final MTProtoState state;

    public MTProtoPlainSender(final Connection connection) {
        this.connection = connection;
        this.state = new MTProtoState(null);
    }

    public <T extends TLObject> T send(final TLRequest request) throws IOException, ClassNotFoundException {
        final long msgId = state.getNewMsgId();

        final BinaryWriter writer = new BinaryWriter();
        request.serialize(writer);
        final byte[] requestBytes = writer.toBytes();
        writer.clear();

        writer.write(0L);
        writer.write(msgId);
        writer.write(requestBytes.length);
        writer.writeRaw(requestBytes);
        connection.send(writer.toBytes());

        final byte[] body = connection.recv();
        if (body[0] == (byte) 0x6c
                && body[1] == (byte) 0xfe
                && body[2] == (byte) 0xff
                && body[3] == (byte) 0xff) {
            // -404 as little endian, broken authorization
            throw new RuntimeException();
        }

        final BinaryReader reader = new BinaryReader(ByteBuffer.wrap(body));
        final long authKeyId = reader.readLong();
        assert authKeyId == 0;

        final long serverMsgId = reader.readLong();
        assert serverMsgId != 0;

        final int length = reader.readInt();
        assert length > 0;

        //noinspection unchecked
        return (T) reader.readTl();
    }
}