/*
 * Hibernate Validator, declare and validate application constraints
 *
 * License: Apache License, Version 2.0
 * See the license.txt file in the root directory or <http://www.apache.org/licenses/LICENSE-2.0>.
 */
package org.hibernate.validator.constraintvalidators;

import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.validation.ConstraintValidator;
import javax.validation.ConstraintValidatorContext;

import org.hibernate.validator.constraints.URL;
import org.hibernate.validator.internal.util.DomainNameUtil;

Validate that the character sequence (e.g. string) is a valid URL using a regular expression.
Author:
Hardy Ferentschik
Since:
5.2/**
 * Validate that the character sequence (e.g. string) is a valid URL using a regular expression.
 *
 * @author Hardy Ferentschik
 *
 * @since 5.2
 */
public class RegexpURLValidator implements ConstraintValidator<URL, CharSequence> {

	// see http://stackoverflow.com/questions/161738/what-is-the-best-regular-expression-to-check-if-a-string-is-a-valid-url
	private static final Pattern URL_REGEX = Pattern
			.compile(
					"(?i)^([a-z](?:[-a-z0-9\\+\\.])*)" + // protocol
					":(?:\\/\\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:])*@)?" + // auth
					"((?:\\[(?:(?:(?:[0-9a-f]{1,4}:){6}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|::(?:[0-9a-f]{1,4}:){5}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){4}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:[0-9a-f]{1,4}:[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){3}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,2}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:){2}(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,3}[0-9a-f]{1,4})?::[0-9a-f]{1,4}:(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,4}[0-9a-f]{1,4})?::(?:[0-9a-f]{1,4}:[0-9a-f]{1,4}|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3})|(?:(?:[0-9a-f]{1,4}:){0,5}[0-9a-f]{1,4})?::[0-9a-f]{1,4}|(?:(?:[0-9a-f]{1,4}:){0,6}[0-9a-f]{1,4})?::)|v[0-9a-f]+[-a-z0-9\\._~!\\$&'\\(\\)\\*\\+,;=:]+)\\]|(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])(?:\\.(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])){3}|(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=@])*))" + // host/ip
					"(?::([0-9]*))?" + // port
					"(?:\\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@]))*)*|\\/(?:(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@]))+)(?:\\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@]))*)*)?|(?:(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@]))+)(?:\\/(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@]))*)*|(?!(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@])))(?:\\?(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@])|[\\x{E000}-\\x{F8FF}\\x{F0000}-\\x{FFFFD}|\\x{100000}-\\x{10FFFD}\\/\\?])*)?(?:\\#(?:(?:%[0-9a-f][0-9a-f]|[-a-z0-9\\._~\\x{A0}-\\x{D7FF}\\x{F900}-\\x{FDCF}\\x{FDF0}-\\x{FFEF}\\x{10000}-\\x{1FFFD}\\x{20000}-\\x{2FFFD}\\x{30000}-\\x{3FFFD}\\x{40000}-\\x{4FFFD}\\x{50000}-\\x{5FFFD}\\x{60000}-\\x{6FFFD}\\x{70000}-\\x{7FFFD}\\x{80000}-\\x{8FFFD}\\x{90000}-\\x{9FFFD}\\x{A0000}-\\x{AFFFD}\\x{B0000}-\\x{BFFFD}\\x{C0000}-\\x{CFFFD}\\x{D0000}-\\x{DFFFD}\\x{E1000}-\\x{EFFFD}!\\$&'\\(\\)\\*\\+,;=:@])|[\\/\\?])*)?$"
			);

	private String protocol;
	private String host;
	private int port;

	@Override
	public void initialize(URL url) {
		this.protocol = url.protocol();
		this.host = url.host();
		this.port = url.port();
	}

	@Override
	public boolean isValid(CharSequence value, ConstraintValidatorContext constraintValidatorContext) {
		if ( value == null || value.length() == 0 ) {
			return true;
		}

		ValueHolder values = parseUrl( value.toString() );
		if ( values == null ) {
			return false;
		}

		if ( !DomainNameUtil.isValidDomainAddress( values.getHost() ) ) {
			return false;
		}

		if ( protocol != null && protocol.length() > 0 && !protocol.equals( values.getProtocol() ) ) {
			return false;
		}

		if ( host != null && host.length() > 0 && !host.equals( values.getHost() ) ) {
			return false;
		}

		if ( port != -1 && values.getPort() != port ) {
			return false;
		}

		return true;
	}

	private ValueHolder parseUrl(String stringUrl) {
		ValueHolder valueHolder = null;

		Matcher regexpMatcher = URL_REGEX.matcher( stringUrl );
		if ( regexpMatcher.matches() ) {
			String protocol = regexpMatcher.group( 1 );
			String host = regexpMatcher.group( 2 );

			int port = -1;
			String portMatch = regexpMatcher.group( 3 );
			if ( portMatch != null ) {
				port = Integer.parseInt( portMatch );
			}
			valueHolder = new ValueHolder( protocol, host, port );
		}

		return valueHolder;
	}

	private static class ValueHolder {
		private final String protocol;
		private final String host;
		private final int port;

		public ValueHolder(String protocol, String host, int port) {
			this.protocol = protocol;
			this.host = host;
			this.port = port;
		}

		public String getHost() {
			return host;
		}

		public String getProtocol() {
			return protocol;
		}

		public int getPort() {
			return port;
		}
	}
}