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package csip.utils;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;

/**
 * Timed check pointing.
 *
 * @author od
 */
public class CheckPointing {

  static final String ROW = "[%1$tH:%1$tM:%1$tS.%1$tL] %2$5d ms (total: %3$5d ms) - %4$s\n";

  List<CP> cps = new ArrayList<>();

  static class CP {

    Date time;
    String msg;


    CP(Date time, String msg) {
      this.time = time;
      this.msg = msg;
    }
  }


  public String check(String msg) {
    CP cp = new CP(new Date(), msg);
    cps.add(cp);
    return fmt(cp, cps.size() - 1);
  }


  @Override
  public String toString() {
    StringBuilder s = new StringBuilder();
    for (int i = 0; i < cps.size(); i++) {
      s.append(fmt(cps.get(i), i));
    }
    return s.toString();
  }


  private String fmt(CP cp, int i) {
    long diff = (i > 0) ? (cp.time.getTime() - cps.get(i - 1).time.getTime()) : 0;
    long abs = (i > 0) ? (cp.time.getTime() - cps.get(0).time.getTime()) : 0;
    return String.format(ROW, cp.time, diff, abs, cp.msg);
  }

}