package com.roboclub.robobuggy.main;

import Jama.Matrix;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonObject;
import purejavacomm.CommPortIdentifier;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Enumeration;
import java.util.List;

/**
 * Util - Matrix utilities and other utilities
 */
public final class Util {

    /**
     * creates the identity matrix
     *
     * @param size size of the matrix
     * @return the identity matrix
     */
    public static Matrix createIdentityMatrix(int size) {
        Matrix result = new Matrix(size, size, 0.0);
        for (int i = 0; i < size; i++) {
            result.set(i, i, 1.0);
        }
        return result;
    }

    /**
     * Evaluates to a List of the com ports(serial) which are available on the computer
     *
     * @return List<String> of available com ports
     */
    public static List<String> getAvailablePorts() {

        List<String> list = new ArrayList<String>();

        Enumeration<?> portList = CommPortIdentifier.getPortIdentifiers();

        while (portList.hasMoreElements()) {
            CommPortIdentifier portId = (CommPortIdentifier) portList.nextElement();
            if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
                list.add(portId.getName());
            }
        }

        return list;
    }

    /**
     * This is a helper function which evaluates to a Json object encoding the same
     * information as the file which was passed to this function
     *
     * @param path a string of the path to a file containing a Json object
     * @return JsonObject of the contents of the file
     * @throws UnsupportedEncodingException if the file is not JSON
     * @throws FileNotFoundException        if the file is not found
     */
    public static JsonObject readJSONFile(String path) throws UnsupportedEncodingException, FileNotFoundException {
        Gson translator = new GsonBuilder().create();
        InputStreamReader fileReader = new InputStreamReader(new FileInputStream(new File(path)), "UTF-8");
        return translator.fromJson(fileReader, JsonObject.class);

    }


    /**
     * Normalizes an an input angle in degrees to be between -180 and 180
     *
     * @param degrees input angle in degrees
     * @return normalized angle in degrees
     */
    public static double normalizeAngleDeg(double degrees) {
        //java mod keeps the sign of the dividend so lets make everything positive
        while (degrees < 0.0) {
            degrees = degrees + 360;
        }
        degrees = degrees % 360.0;
        if (degrees > 180.0) {
            degrees = degrees - 360.0;
        }
        return degrees;

    }

    /**
     * Normalizes an an input angle in degrees to be between -pi and pi
     *
     * @param radians input angle in radians
     * @return normalized angle in radians
     */
    public static double normalizeAngleRad(double radians) {
        //java mod keeps the sign of the dividend so lets make everything positive
        while (radians < 0.0) {
            radians = radians + 2 * Math.PI;
        }

        radians = radians % (2 * Math.PI);

        if (radians > Math.PI) {
            radians = radians - 2.0 * Math.PI;
        }
        return radians;

    }


}