package goodjava.rpc;

import java.io.InputStream;
import java.io.OutputStream;
import java.io.IOException;
import java.io.EOFException;
import java.net.Socket;
import java.nio.charset.StandardCharsets;
import java.util.List;
import goodjava.parser.ParseException;
import goodjava.json.JsonParser;
import goodjava.json.JsonToString;


public class RpcCon {
	final Socket socket;
	final InputStream in;
	final OutputStream out;
	InputStream inBinary = null;
	long lenBinary = -1;
	boolean readSome = false;

	RpcCon(Socket socket)
		throws RpcError
	{
		try {
			this.socket = socket;
			this.in = socket.getInputStream();
			this.out = socket.getOutputStream();
		} catch(IOException e) {
			close();
			throw new RpcError(e);
		}
	}

	public void close()
		throws RpcError
	{
		try {
			socket.close();
		} catch(IOException e) {
			throw new RpcError(e);
		}
	}

	public boolean isClosed() {
		return socket.isClosed();
	}

	void write(InputStream in,long lenIn,List list)
		throws RpcError
	{
		if( in != null )
			list.add(0,lenIn);
		String json = JsonToString.toString(list);
		byte[] aJson = json.getBytes(StandardCharsets.UTF_8);
		int len = aJson.length;
		byte[] a = new byte[4+len];
        a[0] = (byte)(len >>> 24);
        a[1] = (byte)(len >>> 16);
        a[2] = (byte)(len >>>  8);
        a[3] = (byte)(len >>>  0);
		System.arraycopy(aJson,0,a,4,len);
		try {
			out.write(a);
			if( in != null ) {
				a = new byte[8192];
				long total = 0;
				int n;
				while( (n=in.read(a)) != -1 ) {
					out.write(a,0,n);
					total += n;
				}
				if( total != lenIn ) {
					close();
					throw new RpcError("InputStream wrong length "+total+" when should be "+lenIn);
				}
			}
		} catch(IOException e) {
			close();
			throw new RpcError(e);
		}
	}

	List readJson()
		throws RpcError
	{
		try {
			if( inBinary != null ) {
				inBinary.close();
				inBinary = null;
				lenBinary = -1;
			}
			readSome = false;
			byte[] a = new byte[4];
			readAll(a);
			int len = 0;
			for( byte b : a ) {
				len <<= 8;
				len |= b&0xFF;
			}
			a = new byte[len];
			readAll(a);
			String json = new String(a,StandardCharsets.UTF_8);
			List list = (List)JsonParser.parse(json);
			if( list.get(0) instanceof Long ) {
				lenBinary = (Long)list.remove(0);
				inBinary = new FixedLengthInputStream(in,lenBinary);
			}
			return list;
		} catch(IOException e) {
			close();
			throw new RpcError(e);
		} catch(ParseException e) {
			close();
			throw new RpcError(e);
		}
	}

	private void readAll(final byte[] a) throws IOException {
		int total = 0;
		int n;
		while( total < a.length ){
			n = in.read( a, total, a.length-total );
			if( n == -1 )
				throw new EOFException();
			readSome = true;
			total += n;
		}
	}

}