package org.whispersystems.dispatch.io;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;

public class RedisInputStream {

  private static final byte CR = 0x0D;
  private static final byte LF = 0x0A;

  private final InputStream inputStream;

  public RedisInputStream(InputStream inputStream) {
    this.inputStream = inputStream;
  }

  public String readLine() throws IOException {
    ByteArrayOutputStream boas = new ByteArrayOutputStream();

    boolean foundCr = false;

    while (true) {
      int character = inputStream.read();

      if (character == -1) {
        throw new IOException("Stream closed!");
      }

      boas.write(character);

      if      (foundCr && character == LF) break;
      else if (character == CR)            foundCr = true;
      else if (foundCr)                    foundCr = false;
    }

    byte[] data = boas.toByteArray();
    return new String(data, 0, data.length-2);
  }

  public byte[] readFully(int size) throws IOException {
    byte[] result    = new byte[size];
    int    offset    = 0;
    int    remaining = result.length;

    while (remaining > 0) {
      int read = inputStream.read(result, offset, remaining);

      if (read < 0) {
        throw new IOException("Stream closed!");
      }

      offset    += read;
      remaining -= read;
    }

    return result;
  }

  public void close() throws IOException {
    inputStream.close();
  }

}