/*
 * 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.web.bind;

import java.util.ArrayList;
import java.util.List;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.validation.Errors;
import org.springframework.validation.FieldError;
import org.springframework.validation.ObjectError;
import org.springframework.web.util.HtmlUtils;

Errors wrapper that adds automatic HTML escaping to the wrapped instance, for convenient usage in HTML views. Can be retrieved easily via RequestContext's getErrors method. 
Note that BindTag does not use this class to avoid unnecessary
creation of ObjectError instances. It just escapes the messages and values
that get copied into the respective BindStatus instance.
Author:
Juergen Hoeller
See Also:
getErrors.getErrors
BindTag
Since:
01.03.2003/**
 * Errors wrapper that adds automatic HTML escaping to the wrapped instance,
 * for convenient usage in HTML views. Can be retrieved easily via
 * RequestContext's {@code getErrors} method.
 *
 * <p>Note that BindTag does <i>not</i> use this class to avoid unnecessary
 * creation of ObjectError instances. It just escapes the messages and values
 * that get copied into the respective BindStatus instance.
 *
 * @author Juergen Hoeller
 * @since 01.03.2003
 * @see org.springframework.web.servlet.support.RequestContext#getErrors
 * @see org.springframework.web.servlet.tags.BindTag
 */
public class EscapedErrors implements Errors {

	private final Errors source;


	
Create a new EscapedErrors instance for the given source instance.
/**
	 * Create a new EscapedErrors instance for the given source instance.
	 */
	public EscapedErrors(Errors source) {
		Assert.notNull(source, "Errors source must not be null");
		this.source = source;
	}

	public Errors getSource() {
		return this.source;
	}


	@Override
	public String getObjectName() {
		return this.source.getObjectName();
	}

	@Override
	public void setNestedPath(String nestedPath) {
		this.source.setNestedPath(nestedPath);
	}

	@Override
	public String getNestedPath() {
		return this.source.getNestedPath();
	}

	@Override
	public void pushNestedPath(String subPath) {
		this.source.pushNestedPath(subPath);
	}

	@Override
	public void popNestedPath() throws IllegalStateException {
		this.source.popNestedPath();
	}


	@Override
	public void reject(String errorCode) {
		this.source.reject(errorCode);
	}

	@Override
	public void reject(String errorCode, String defaultMessage) {
		this.source.reject(errorCode, defaultMessage);
	}

	@Override
	public void reject(String errorCode, @Nullable Object[] errorArgs, @Nullable String defaultMessage) {
		this.source.reject(errorCode, errorArgs, defaultMessage);
	}

	@Override
	public void rejectValue(@Nullable String field, String errorCode) {
		this.source.rejectValue(field, errorCode);
	}

	@Override
	public void rejectValue(@Nullable String field, String errorCode, String defaultMessage) {
		this.source.rejectValue(field, errorCode, defaultMessage);
	}

	@Override
	public void rejectValue(@Nullable String field, String errorCode, @Nullable Object[] errorArgs,
			@Nullable String defaultMessage) {

		this.source.rejectValue(field, errorCode, errorArgs, defaultMessage);
	}

	@Override
	public void addAllErrors(Errors errors) {
		this.source.addAllErrors(errors);
	}


	@Override
	public boolean hasErrors() {
		return this.source.hasErrors();
	}

	@Override
	public int getErrorCount() {
		return this.source.getErrorCount();
	}

	@Override
	public List<ObjectError> getAllErrors() {
		return escapeObjectErrors(this.source.getAllErrors());
	}

	@Override
	public boolean hasGlobalErrors() {
		return this.source.hasGlobalErrors();
	}

	@Override
	public int getGlobalErrorCount() {
		return this.source.getGlobalErrorCount();
	}

	@Override
	public List<ObjectError> getGlobalErrors() {
		return escapeObjectErrors(this.source.getGlobalErrors());
	}

	@Override
	@Nullable
	public ObjectError getGlobalError() {
		return escapeObjectError(this.source.getGlobalError());
	}

	@Override
	public boolean hasFieldErrors() {
		return this.source.hasFieldErrors();
	}

	@Override
	public int getFieldErrorCount() {
		return this.source.getFieldErrorCount();
	}

	@Override
	public List<FieldError> getFieldErrors() {
		return this.source.getFieldErrors();
	}

	@Override
	@Nullable
	public FieldError getFieldError() {
		return this.source.getFieldError();
	}

	@Override
	public boolean hasFieldErrors(String field) {
		return this.source.hasFieldErrors(field);
	}

	@Override
	public int getFieldErrorCount(String field) {
		return this.source.getFieldErrorCount(field);
	}

	@Override
	public List<FieldError> getFieldErrors(String field) {
		return escapeObjectErrors(this.source.getFieldErrors(field));
	}

	@Override
	@Nullable
	public FieldError getFieldError(String field) {
		return escapeObjectError(this.source.getFieldError(field));
	}

	@Override
	@Nullable
	public Object getFieldValue(String field) {
		Object value = this.source.getFieldValue(field);
		return (value instanceof String ? HtmlUtils.htmlEscape((String) value) : value);
	}

	@Override
	@Nullable
	public Class<?> getFieldType(String field) {
		return this.source.getFieldType(field);
	}

	@SuppressWarnings("unchecked")
	@Nullable
	private <T extends ObjectError> T escapeObjectError(@Nullable T source) {
		if (source == null) {
			return null;
		}
		String defaultMessage = source.getDefaultMessage();
		if (defaultMessage != null) {
			defaultMessage = HtmlUtils.htmlEscape(defaultMessage);
		}
		if (source instanceof FieldError) {
			FieldError fieldError = (FieldError) source;
			Object value = fieldError.getRejectedValue();
			if (value instanceof String) {
				value = HtmlUtils.htmlEscape((String) value);
			}
			return (T) new FieldError(
					fieldError.getObjectName(), fieldError.getField(), value, fieldError.isBindingFailure(),
					fieldError.getCodes(), fieldError.getArguments(), defaultMessage);
		}
		else {
			return (T) new ObjectError(
					source.getObjectName(), source.getCodes(), source.getArguments(), defaultMessage);
		}
	}

	private <T extends ObjectError> List<T> escapeObjectErrors(List<T> source) {
		List<T> escaped = new ArrayList<>(source.size());
		for (T objectError : source) {
			escaped.add(escapeObjectError(objectError));
		}
		return escaped;
	}

}