/*-
    * #%L
    * io.earcam.instrumental.module.osgi
    * %%
    * Copyright (C) 2018 earcam
    * %%
    * SPDX-License-Identifier: (BSD-3-Clause OR EPL-1.0 OR Apache-2.0 OR MIT)
    * 
    * You <b>must</b> choose to accept, in full - any individual or combination of 
   * the following licenses:
   * <ul>
   * 	<li><a href="https://opensource.org/licenses/BSD-3-Clause">BSD-3-Clause</a></li>
   * 	<li><a href="https://www.eclipse.org/legal/epl-v10.html">EPL-1.0</a></li>
   * 	<li><a href="https://www.apache.org/licenses/LICENSE-2.0">Apache-2.0</a></li>
   * 	<li><a href="https://opensource.org/licenses/MIT">MIT</a></li>
   * </ul>
   * #L%
   */
  package io.earcam.instrumental.module.osgi.parser;
  
  import org.antlr.v4.runtime.ParserRuleContext;
  import org.hamcrest.Description;
  import org.hamcrest.TypeSafeMatcher;
  
  public class ParserValidityMatcher extends TypeSafeMatcher<ParserRuleContext> {
  
  	private boolean shouldSucceed;
  
  
  	private ParserValidityMatcher(boolean shouldSucceed)
  	{
  		this.shouldSucceed = shouldSucceed;
  	}
  
  
  	public static ParserValidityMatcher valid()
  	{
  		return new ParserValidityMatcher(true);
  	}
  
  
  	public static ParserValidityMatcher invalid()
  	{
  		return new ParserValidityMatcher(false);
  	}
  
  
  	@Override
  	public void describeTo(Description description)
  	{
  		if(shouldSucceed) {
  			description.appendText("expected success");
  		} else {
  			description.appendText("expected failure");
  		}
  	}
  
  
  	@Override
  	protected void describeMismatchSafely(ParserRuleContext context, Description mismatchDescription)
  	{
  		super.describeMismatchSafely(context, mismatchDescription);
  		mismatchDescription.appendValue(context.exception);
  		// TODO invoke the TestRig to get a good description of failure....
  	}
  
  
  	@Override
  	protected boolean matchesSafely(ParserRuleContext context)
  	{
  		return (context.exception == null) == shouldSucceed;
  	}
  
  }