/*
*    Copyright (c) 2013, Will Szumski
*    Copyright (c) 2013, Doug Szumski
*
*    This file is part of Cyclismo.
*
*    Cyclismo is free software: you can redistribute it and/or modify
*    it under the terms of the GNU General Public License as published by
*    the Free Software Foundation, either version 3 of the License, or
*    (at your option) any later version.
*
*    Cyclismo is distributed in the hope that it will be useful,
*    but WITHOUT ANY WARRANTY; without even the implied warranty of
*    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*    GNU General Public License for more details.
*
*    You should have received a copy of the GNU General Public License
*    along with Cyclismo.  If not, see <http://www.gnu.org/licenses/>.
*/
package org.cowboycoders.ant.utils;


import org.cowboycoders.pid.PidParameterController;
import org.cowboycoders.pid.PidUpdateListener;

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Formatter;
import java.util.logging.Logger;


public class SimplePidLogger implements PidUpdateListener {

  private static final String DIRECTORY_NAME = "logs";
  private static final String FILE_NAME = "pidlog";
  private static final Logger LOGGER = Logger.getLogger(SimplePidLogger.class.getSimpleName());
  private static final String HEADINGS = "time/seconds;setpoint;procesValue;output;error";
  private static final String PARAMETERS = "proportionalGain %e : integralGain: %e : " +
      "DerivativeGain %e ";
  private Long timeOffset;

  private File directory;
  private File file;
  private boolean setupOk = false;
  private PidParameterController pidController;
  private boolean writeHeadings;

  public SimplePidLogger() {
    File directory = new File(DIRECTORY_NAME);
    if (!directory.exists()) {
      directory.mkdir();
    }
    file = new File(directory, FILE_NAME);
    file.delete();
    //setupOk = true;
    //write(HEADINGS);
  }


  /**
   * Creates a new output stream to write to the given filename.
   */
  protected PrintWriter newPrintWriter()
      throws IOException {
    file = new File(directory, FILE_NAME);
    return new PrintWriter(new FileWriter(file, true));
  }

  @Override
  public synchronized void onPidUpdate(double setpoint, double processValue, double output,
      double error) {
    if (!setupOk) {
      LOGGER.warning("newLog not called");
      return;
    }

    if (writeHeadings) {
      writeHeadings = false;
      writeHeadings();
    }


    if (timeOffset == null) {
      timeOffset = System.nanoTime();
    }

    double currentTimeStamp = (System.nanoTime() - timeOffset) / Math.pow(10, 9);

    StringBuilder outputText = new StringBuilder();
    outputText.append(currentTimeStamp);
    outputText.append(";");
    outputText.append(setpoint);
    outputText.append(";");
    outputText.append(processValue);
    outputText.append(";");
    outputText.append(output);
    outputText.append(";");
    outputText.append(error);
    outputText.append("\n");

    write(outputText);

  }

  public synchronized void newLog(PidParameterController pidController) {
    //we need to write headings on next update as getters could refer to stale values
    writeHeadings = true;
    this.pidController = pidController;
    setupOk = true;
  }

  private void writeHeadings() {
    StringBuilder outputText = new StringBuilder();
    outputText.append("\n");
    Formatter formatter = new Formatter(outputText);
    formatter.format(PARAMETERS, pidController.getProportionalGain(), pidController
        .getIntegralGain(), pidController.getDerivativeGain());
    outputText.append("\n");
    outputText.append(HEADINGS);
    outputText.append("\n");
    write(outputText);
  }

  private void write(CharSequence string) {
    PrintWriter writer = null;
    try {
      writer = newPrintWriter();
      writer.append(string);
      writer.flush();
    } catch (FileNotFoundException e) {
      e.printStackTrace();
    } catch (IOException e) {
      e.printStackTrace();
    } finally {
      if (writer != null) {
        writer.close();
      }
    }
  }

}