/*
 * Copyright 2002-2018 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
 *
 *      https://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.mock.web;

import java.util.Collections;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.servlet.FilterConfig;
import javax.servlet.ServletContext;

import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

/**
 * Mock implementation of the {@link javax.servlet.FilterConfig} interface.
 *
 * <p>Used for testing the web framework; also useful for testing
 * custom {@link javax.servlet.Filter} implementations.
 *
 * @author Juergen Hoeller
 * @since 1.0.2
 * @see MockFilterChain
 * @see PassThroughFilterChain
 */
public class MockFilterConfig implements FilterConfig {

	private final ServletContext servletContext;

	private final String filterName;

	private final Map<String, String> initParameters = new LinkedHashMap<>();


	/**
	 * Create a new MockFilterConfig with a default {@link MockServletContext}.
	 */
	public MockFilterConfig() {
		this(null, "");
	}

	/**
	 * Create a new MockFilterConfig with a default {@link MockServletContext}.
	 * @param filterName the name of the filter
	 */
	public MockFilterConfig(String filterName) {
		this(null, filterName);
	}

	/**
	 * Create a new MockFilterConfig.
	 * @param servletContext the ServletContext that the servlet runs in
	 */
	public MockFilterConfig(@Nullable ServletContext servletContext) {
		this(servletContext, "");
	}

	/**
	 * Create a new MockFilterConfig.
	 * @param servletContext the ServletContext that the servlet runs in
	 * @param filterName the name of the filter
	 */
	public MockFilterConfig(@Nullable ServletContext servletContext, String filterName) {
		this.servletContext = (servletContext != null ? servletContext : new MockServletContext());
		this.filterName = filterName;
	}


	@Override
	public String getFilterName() {
		return this.filterName;
	}

	@Override
	public ServletContext getServletContext() {
		return this.servletContext;
	}

	public void addInitParameter(String name, String value) {
		Assert.notNull(name, "Parameter name must not be null");
		this.initParameters.put(name, value);
	}

	@Override
	public String getInitParameter(String name) {
		Assert.notNull(name, "Parameter name must not be null");
		return this.initParameters.get(name);
	}

	@Override
	public Enumeration<String> getInitParameterNames() {
		return Collections.enumeration(this.initParameters.keySet());
	}

}
