package jalview.testutils;

import java.util.List;
import java.util.Objects;
import static java.util.Objects.requireNonNullElse;

import org.hamcrest.Description;
import org.hamcrest.TypeSafeMatcher;

import jalview.datamodel.Annotation;

public class AnnotationsMatcher extends TypeSafeMatcher<Annotation[]>
{
  final List<Annotation> annotations;

  public AnnotationsMatcher(List<Annotation> annotations)
  {
    this.annotations = annotations;
  }

  @Override
  public boolean matchesSafely(Annotation[] items)
  {
    if (annotations.size() != items.length)
      return false;
    for (int i = 0; i < annotations.size(); i++)
    {
      var actual = items[i];
      var expected = annotations.get(i);
      if (!annotationsEqual(actual, expected))
        return false;
    }
    return true;
  }

  static boolean annotationsEqual(Annotation a, Annotation b)
  {
    if (a == null && b == null)
      return true;
    if ((a == null) != (b == null)) // if one is null but the other is not
      return false;
    return a.secondaryStructure == b.secondaryStructure && a.value == b.value
        && Objects.equals(a.colour, b.colour)
        && Objects
            .equals(requireNonNullElse(a.displayCharacter, ""),
                requireNonNullElse(b.displayCharacter, ""))
        && Objects
            .equals(requireNonNullElse(a.description, ""),
                requireNonNullElse(b.description, ""));
  }

  @Override
  public void describeTo(Description description)
  {
    description.appendText("annotations ").appendValue(annotations);
  }

  @Override
  public void describeMismatchSafely(Annotation[] items,
      Description description)
  {
    if (annotations.size() != items.length)
    {
      description.appendText("but had length ").appendValue(items.length);
      return;
    }
    boolean first = true;
    for (int i = 0; i < annotations.size(); i++)
    {
      var actual = items[i];
      var expected = annotations.get(i);
      if (!annotationsEqual(actual, expected))
      {
        description
            .appendText(first ? "but " : ", ")
            .appendText("element [" + i + "] was ")
            .appendValue(items[i]);
        first = false;
      }
    }
  }
}