import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Scanner;

public class VoteMsgTextCoder implements VoteMsgCoder {
  /*
   * Wire Format "VOTEPROTO" <"v" | "i"> [<RESPFLAG>] <CANDIDATE> [<VOTECNT>]
   * Charset is fixed by the wire format.
   */

  // Manifest constants for encoding
  public static final String MAGIC = "Voting";
  public static final String VOTESTR = "v";
  public static final String INQSTR = "i";
  public static final String RESPONSESTR = "R";

  public static final String CHARSETNAME = "US-ASCII";
  public static final String DELIMSTR = " ";
  public static final int MAX_WIRE_LENGTH = 2000;

  public byte[] toWire(VoteMsg msg) throws IOException {
    String msgString = MAGIC + DELIMSTR + (msg.isInquiry() ? INQSTR : VOTESTR)
        + DELIMSTR + (msg.isResponse() ? RESPONSESTR + DELIMSTR : "")
        + Integer.toString(msg.getCandidateID()) + DELIMSTR
        + Long.toString(msg.getVoteCount());
    byte data[] = msgString.getBytes(CHARSETNAME);
    return data;
  }

  public VoteMsg fromWire(byte[] message) throws IOException {
    ByteArrayInputStream msgStream = new ByteArrayInputStream(message);
    Scanner s = new Scanner(new InputStreamReader(msgStream, CHARSETNAME));
    boolean isInquiry;
    boolean isResponse;
    int candidateID;
    long voteCount;
    String token;

    try {
      token = s.next();
      if (!token.equals(MAGIC)) {
        throw new IOException("Bad magic string: " + token);
      }
      token = s.next();
      if (token.equals(VOTESTR)) {
        isInquiry = false;
      } else if (!token.equals(INQSTR)) {
        throw new IOException("Bad vote/inq indicator: " + token);
      } else {
        isInquiry = true;
      }

      token = s.next();
      if (token.equals(RESPONSESTR)) {
        isResponse = true;
        token = s.next();
      } else {
        isResponse = false;
      }
      // Current token is candidateID
      // Note: isResponse now valid
      candidateID = Integer.parseInt(token);
      if (isResponse) {
        token = s.next();
        voteCount = Long.parseLong(token);
      } else {
        voteCount = 0;
      }
    } catch (IOException ioe) {
      throw new IOException("Parse error...");
    }
    return new VoteMsg(isResponse, isInquiry, candidateID, voteCount);
  }
}