package org.djunits.unit;
   
   import static org.junit.Assert.assertEquals;
   import static org.junit.Assert.assertTrue;
   
   import java.util.Locale;
   
   import org.djunits.locale.DefaultLocale;
   import org.djunits.unit.unitsystem.UnitSystem;
  import org.junit.Before;
  import org.junit.Test;
  
  /**
   * <p>
   * Copyright (c) 2013-2020 Delft University of Technology, PO Box 5, 2600 AA, Delft, the Netherlands. All rights reserved. <br>
   * BSD-style license. See <a href="https://djunits.org/docs/license.html">DJUNITS License</a>.
   * <p>
   * @author <a href="https://tudelft.nl/pknoppers">Peter Knoppers</a>
   */
  public class AngleUnitTest extends AbstractLinearUnitTest<AngleUnit>
  {
      /**
       * Set the locale to "en" so we know what texts should be retrieved from the resources.
       */
      @Before
      public final void setup()
      {
          DefaultLocale.setLocale(new Locale("en"));
      }
  
      /**
       * Verify one length conversion factor to standard unit and the localization of the name and abbreviation.
       * @param au Unit to check
       * @param expectedValue Double; expected value of one 'unit to check' in SI units
       * @param precision Double; precision of verification
       * @param expectedName String; expected name in the resources
       * @param expectedAbbreviation String; expected abbreviation in the resources
       */
      protected final void checkUnitValueNameAndAbbreviation(final AngleUnit au, final double expectedValue,
              final double precision, final String expectedName, final String expectedAbbreviation)
      {
          assertEquals("rad", AngleUnit.SI.getQuantity().getSiDimensions().toString(true, false));
          assertEquals(String.format("one %s is about %f reference unit", au.getId(), expectedValue), expectedValue,
                  au.getScale().toStandardUnit(1.0), precision);
          assertEquals(String.format("Name of %s is %s", au.getId(), expectedName), expectedName, au.getName());
          assertEquals(String.format("Abbreviation of %s is %s", au.getId(), expectedAbbreviation), expectedAbbreviation,
                  au.getDefaultDisplayAbbreviation());
      }
  
      /**
       * Verify conversion factors, English names and abbreviations.
       */
      @Test
      public final void conversions()
      {
          checkUnitValueNameAndAbbreviation(AngleUnit.DEGREE, 2 * Math.PI / 360, 0.000001, "degree", "\u00b0");
          checkUnitValueNameAndAbbreviation(AngleUnit.ARCMINUTE, 2 * Math.PI / 360 / 60, 0.0001, "arcminute", "\'");
          checkUnitValueNameAndAbbreviation(AngleUnit.GRAD, 2 * Math.PI / 400, 0.00001, "gradian", "grad");
          // TODO Check two conversions between non-standard Angle units
          assertEquals("one GRAD is about 54 ARCMINUTE", 54, getMultiplicationFactorTo(AngleUnit.GRAD, AngleUnit.ARCMINUTE), 0.5);
          assertEquals("one ARCMINUTE is about 0.0185 GRAD", 0.0185,
                  getMultiplicationFactorTo(AngleUnit.ARCMINUTE, AngleUnit.GRAD), 0.0001);
          // Check conversion factor to standard unit for all remaining time units
          checkUnitValueNameAndAbbreviation(AngleUnit.CENTESIMAL_ARCMINUTE, 0.00015708, 0.0000001, "centesimal arcminute", "c\'");
          checkUnitValueNameAndAbbreviation(AngleUnit.CENTESIMAL_ARCSECOND, 1.57079e-6, 0.1, "centesimal arcsecond", "c\"");
          checkUnitValueNameAndAbbreviation(AngleUnit.PERCENT, 0.0099996667, 0.0001, "percent", "%");
      }
  
      /**
       * Verify that we can create our own angle unit.
       */
      @Test
      public final void createAngleUnit()
      {
          AngleUnit myAPU = AngleUnit.RADIAN.deriveLinear(0.19634954085, "pt", "point", UnitSystem.OTHER);
          assertTrue("Can create a new AngleUnit", null != myAPU);
          checkUnitValueNameAndAbbreviation(myAPU, 0.19634954085, 0.0000001, "point", "pt");
          AngleUnit.BASE.unregister(myAPU);
      }
  
  }