/*
 * Copyright OpenSearch Contributors
 * SPDX-License-Identifier: Apache-2.0
 */

package org.opensearch.dataprepper.expression.util;

import org.antlr.v4.runtime.tree.ParseTree;
import org.hamcrest.Description;
import org.hamcrest.DiagnosingMatcher;
import org.junit.jupiter.api.Test;
import org.opensearch.dataprepper.expression.antlr.DataPrepperExpressionParser;

import static org.hamcrest.CoreMatchers.is;
import static org.hamcrest.MatcherAssert.assertThat;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.spy;
import static org.mockito.Mockito.verify;
import static org.opensearch.dataprepper.expression.util.ContextMatcher.hasContext;

public class ContextMatcherTest {

    @Test
    void testMatchesParseTree() {
        final ContextMatcher matcher = new ContextMatcher(ParseTree.class);
        assertThat(matcher.matches(mock(ParseTree.class)), is(true));
    }

    @Test
    void testNotMatchesObject() {
        final ContextMatcher matcher = new ContextMatcher(ParseTree.class);
        assertThat(matcher.matches(new Object()), is(false));

        final Description description = mock(Description.class);

        doReturn(description)
                .when(description).appendText(anyString());

        matcher.describeTo(description);

        verify(description).appendDescriptionOf(any());
    }

    @Test
    void testMatchesChildren() {
        // mock will fail because mockito cannot identify matcher on doReturn().when().matcher()
        final DiagnosingMatcher<? extends ParseTree> childMatcher = spy(DiagnosingMatcher.class);

        final ContextMatcher matcher = new ContextMatcher(ParseTree.class, childMatcher);

        final ParseTree parseTree = mock(ParseTree.class);
        doReturn(1)
                .doReturn(0)
                .when(parseTree)
                .getChildCount();
        doReturn(parseTree).when(parseTree).getChild(eq(0));

        doReturn(true).when(childMatcher).matches(parseTree);

        assertThat(matcher.matches(parseTree), is(true));
    }

    @Test
    void testStaticConstructor() {
        final DiagnosingMatcher<ParseTree> matcher = hasContext(ParseTree.class);
        assertThat(matcher.matches(mock(ParseTree.class)), is(true));
    }

    @Test
    void testGivenAntlrGeneratedClassNameShortClassString() {
        final String shortClassName = ContextMatcher.shortClassString(mock(DataPrepperExpressionParser.ExpressionContext.class));
        assertThat(shortClassName, is("ExpressionContext"));
    }

    @Test
    void testGivenStringClassNameShortClassString() {
        final String shortClassName = ContextMatcher.shortClassString("");
        assertThat(shortClassName, is("class java.lang.String"));
    }
}