/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.core.io;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.junit.Test;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.*;

/**
 * Unit tests that serve as regression tests for the bugs described in SPR-6888
 * and SPR-9413.
 *
 * @author Chris Beams
 * @author Sam Brannen
 */
public class ClassPathResourceTests {

	private static final String PACKAGE_PATH = "org/springframework/core/io";
	private static final String NONEXISTENT_RESOURCE_NAME = "nonexistent.xml";
	private static final String FQ_RESOURCE_PATH = PACKAGE_PATH + '/' + NONEXISTENT_RESOURCE_NAME;

	/**
	 * Absolute path version of {@link #FQ_RESOURCE_PATH}.
	 */
	private static final String FQ_RESOURCE_PATH_WITH_LEADING_SLASH = '/' + FQ_RESOURCE_PATH;

	private static final Pattern DESCRIPTION_PATTERN = Pattern.compile("^class path resource \\[(.+?)\\]$");


	@Test
	public void stringConstructorRaisesExceptionWithFullyQualifiedPath() {
		assertExceptionContainsFullyQualifiedPath(new ClassPathResource(FQ_RESOURCE_PATH));
	}

	@Test
	public void classLiteralConstructorRaisesExceptionWithFullyQualifiedPath() {
		assertExceptionContainsFullyQualifiedPath(new ClassPathResource(NONEXISTENT_RESOURCE_NAME, getClass()));
	}

	@Test
	public void classLoaderConstructorRaisesExceptionWithFullyQualifiedPath() {
		assertExceptionContainsFullyQualifiedPath(new ClassPathResource(FQ_RESOURCE_PATH, getClass().getClassLoader()));
	}

	@Test
	public void getDescriptionWithStringConstructor() {
		assertDescriptionContainsExpectedPath(new ClassPathResource(FQ_RESOURCE_PATH), FQ_RESOURCE_PATH);
	}

	@Test
	public void getDescriptionWithStringConstructorAndLeadingSlash() {
		assertDescriptionContainsExpectedPath(new ClassPathResource(FQ_RESOURCE_PATH_WITH_LEADING_SLASH),
				FQ_RESOURCE_PATH);
	}

	@Test
	public void getDescriptionWithClassLiteralConstructor() {
		assertDescriptionContainsExpectedPath(new ClassPathResource(NONEXISTENT_RESOURCE_NAME, getClass()),
				FQ_RESOURCE_PATH);
	}

	@Test
	public void getDescriptionWithClassLiteralConstructorAndLeadingSlash() {
		assertDescriptionContainsExpectedPath(
				new ClassPathResource(FQ_RESOURCE_PATH_WITH_LEADING_SLASH, getClass()), FQ_RESOURCE_PATH);
	}

	@Test
	public void getDescriptionWithClassLoaderConstructor() {
		assertDescriptionContainsExpectedPath(
				new ClassPathResource(FQ_RESOURCE_PATH, getClass().getClassLoader()), FQ_RESOURCE_PATH);
	}

	@Test
	public void getDescriptionWithClassLoaderConstructorAndLeadingSlash() {
		assertDescriptionContainsExpectedPath(
				new ClassPathResource(FQ_RESOURCE_PATH_WITH_LEADING_SLASH, getClass().getClassLoader()), FQ_RESOURCE_PATH);
	}

	@Test
	public void dropLeadingSlashForClassLoaderAccess() {
		assertEquals("test.html", new ClassPathResource("/test.html").getPath());
		assertEquals("test.html", ((ClassPathResource) new ClassPathResource("").createRelative("/test.html")).getPath());
	}

	@Test
	public void preserveLeadingSlashForClassRelativeAccess() {
		assertEquals("/test.html", new ClassPathResource("/test.html", getClass()).getPath());
		assertEquals("/test.html", ((ClassPathResource) new ClassPathResource("", getClass()).createRelative("/test.html")).getPath());
	}


	private void assertDescriptionContainsExpectedPath(ClassPathResource resource, String expectedPath) {
		Matcher matcher = DESCRIPTION_PATTERN.matcher(resource.getDescription());
		assertTrue(matcher.matches());
		assertEquals(1, matcher.groupCount());
		String match = matcher.group(1);

		assertEquals(expectedPath, match);
	}

	private void assertExceptionContainsFullyQualifiedPath(ClassPathResource resource) {
		try {
			resource.getInputStream();
			fail("FileNotFoundException expected for resource: " + resource);
		}
		catch (IOException ex) {
			assertThat(ex, instanceOf(FileNotFoundException.class));
			assertThat(ex.getMessage(), containsString(FQ_RESOURCE_PATH));
		}
	}

}
