package io.netty.handler.codec.smtp;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.DecoderException;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.util.CharsetUtil;
import io.netty.util.internal.UnstableApi;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
@UnstableApi
public final class SmtpResponseDecoder extends LineBasedFrameDecoder {
private List<CharSequence> details;
public SmtpResponseDecoder(int maxLineLength) {
super(maxLineLength);
}
@Override
protected SmtpResponse decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception {
ByteBuf frame = (ByteBuf) super.decode(ctx, buffer);
if (frame == null) {
return null;
}
try {
final int readable = frame.readableBytes();
final int readerIndex = frame.readerIndex();
if (readable < 3) {
throw newDecoderException(buffer, readerIndex, readable);
}
final int code = parseCode(frame);
final int separator = frame.readByte();
final CharSequence detail = frame.isReadable() ? frame.toString(CharsetUtil.US_ASCII) : null;
List<CharSequence> details = this.details;
switch (separator) {
case ' ':
this.details = null;
if (details != null) {
if (detail != null) {
details.add(detail);
}
} else {
if (detail == null) {
details = Collections.emptyList();
} else {
details = Collections.singletonList(detail);
}
}
return new DefaultSmtpResponse(code, details);
case '-':
if (detail != null) {
if (details == null) {
this.details = details = new ArrayList<CharSequence>(4);
}
details.add(detail);
}
break;
default:
throw newDecoderException(buffer, readerIndex, readable);
}
} finally {
frame.release();
}
return null;
}
private static DecoderException newDecoderException(ByteBuf buffer, int readerIndex, int readable) {
return new DecoderException(
"Received invalid line: '" + buffer.toString(readerIndex, readable, CharsetUtil.US_ASCII) + '\'');
}
private static int parseCode(ByteBuf buffer) {
final int first = parseNumber(buffer.readByte()) * 100;
final int second = parseNumber(buffer.readByte()) * 10;
final int third = parseNumber(buffer.readByte());
return first + second + third;
}
private static int parseNumber(byte b) {
return Character.digit((char) b, 10);
}
}