/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.apache.struts2.junit;

import com.opensymphony.xwork2.ActionContext;
import com.opensymphony.xwork2.ActionProxy;
import com.opensymphony.xwork2.ActionProxyFactory;
import com.opensymphony.xwork2.config.Configuration;
import com.opensymphony.xwork2.interceptor.ValidationAware;
import com.opensymphony.xwork2.interceptor.annotations.After;
import com.opensymphony.xwork2.interceptor.annotations.Before;
import org.apache.commons.lang3.StringUtils;
import org.apache.struts2.ServletActionContext;
import org.apache.struts2.dispatcher.Dispatcher;
import org.apache.struts2.dispatcher.HttpParameters;
import org.apache.struts2.dispatcher.mapper.ActionMapper;
import org.apache.struts2.dispatcher.mapper.ActionMapping;
import org.apache.struts2.util.StrutsTestCaseHelper;
import org.springframework.core.io.DefaultResourceLoader;
import org.springframework.mock.web.MockHttpServletRequest;
import org.springframework.mock.web.MockHttpServletResponse;
import org.springframework.mock.web.MockHttpSession;
import org.springframework.mock.web.MockPageContext;
import org.springframework.mock.web.MockServletContext;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.UnsupportedEncodingException;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Map;

import static org.junit.Assert.assertNotNull;

public abstract class StrutsJUnit4TestCase<T> extends XWorkJUnit4TestCase {

    protected MockHttpServletResponse response;
    protected MockHttpServletRequest request;
    protected MockPageContext pageContext;
    protected MockServletContext servletContext;
    protected Map<String, String> dispatcherInitParams;
    protected Dispatcher dispatcher;

    protected DefaultResourceLoader resourceLoader = new DefaultResourceLoader();

    /**
     * gets an object from the stack after an action is executed
     */
    protected Object findValueAfterExecute(String key) {
        return ServletActionContext.getValueStack(request).findValue(key);
    }

    /**
     * gets an object from the stack after an action is executed
     *
     * @return The executed action
     */
    @SuppressWarnings("unchecked")
    protected T getAction() {
        return (T) findValueAfterExecute("action");
    }

    protected boolean containsErrors() {
        T action = this.getAction();
        if (action instanceof ValidationAware) {
            return ((ValidationAware) action).hasActionErrors();
        }
        throw new UnsupportedOperationException("Current action does not implement ValidationAware interface");
    }

    /**
     * Executes an action and returns it's output (not the result returned from
     * execute()), but the actual output that would be written to the response.
     * For this to work the configured result for the action needs to be
     * FreeMarker, or Velocity (JSPs can be used with the Embedded JSP plugin)
     */
    protected String executeAction(String uri) throws ServletException, UnsupportedEncodingException {
        request.setRequestURI(uri);
        ActionMapping mapping = getActionMapping(request);

        assertNotNull(mapping);
        Dispatcher.getInstance().serviceAction(request, response, mapping);

        if (response.getStatus() != HttpServletResponse.SC_OK)
            throw new ServletException("Error code [" + response.getStatus() + "], Error: ["
                + response.getErrorMessage() + "]");

        return response.getContentAsString();
    }

    /**
     * Creates an action proxy for a request, and sets parameters of the ActionInvocation to the passed
     * parameters. Make sure to set the request parameters in the protected "request" object before calling this method.
     */
    protected ActionProxy getActionProxy(String uri) {
        request.setRequestURI(uri);
        ActionMapping mapping = getActionMapping(request);
        String namespace = mapping.getNamespace();
        String name = mapping.getName();
        String method = mapping.getMethod();

        Configuration config = configurationManager.getConfiguration();
        ActionProxy proxy = config.getContainer().getInstance(ActionProxyFactory.class).createActionProxy(
            namespace, name, method, new HashMap<String, Object>(), true, false);

        initActionContext(proxy.getInvocation().getInvocationContext());

        // this is normally done in onSetUp(), but we are using Struts internal
        // objects (proxy and action invocation)
        // so we have to hack around so it works
        ServletActionContext.setServletContext(servletContext);
        ServletActionContext.setRequest(request);
        ServletActionContext.setResponse(response);

        ServletActionContext.getContext().put(ServletActionContext.ACTION_MAPPING, mapping);

        return proxy;
    }

    protected void initActionContext(ActionContext actionContext) {
        actionContext.withParameters(HttpParameters.create(request.getParameterMap()).build());
        initSession(actionContext);
        // set the action context to the one used by the proxy
        ActionContext.bind(actionContext);
    }

    protected void initSession(ActionContext actionContext) {
        if (actionContext.getSession() == null) {
            actionContext.withSession(new HashMap<>());
            request.setSession(new MockHttpSession(servletContext));
        }
    }

    /**
     * Finds an ActionMapping for a given request
     */
    protected ActionMapping getActionMapping(HttpServletRequest request) {
        return container.getInstance(ActionMapper.class).getMapping(request, configurationManager);
    }

    /**
     * Finds an ActionMapping for a given url
     */
    protected ActionMapping getActionMapping(String url) {
        MockHttpServletRequest req = new MockHttpServletRequest();
        req.setRequestURI(url);
        return getActionMapping(req);
    }

    /**
     * Injects dependencies on an Object using Struts internal IoC container
     */
    protected void injectStrutsDependencies(Object object) {
        container.inject(object);
    }

    protected void setupBeforeInitDispatcher() throws Exception {
    }

    protected void initServletMockObjects() {
        servletContext = new MockServletContext(resourceLoader);
        response = new MockHttpServletResponse();
        request = new MockHttpServletRequest();
        pageContext = new MockPageContext(servletContext, request, response);
    }

    public void finishExecution() {
        HttpSession session = this.request.getSession();
        Enumeration attributeNames = session.getAttributeNames();

        MockHttpServletRequest nextRequest = new MockHttpServletRequest();

        while (attributeNames.hasMoreElements()) {
            String key = (String) attributeNames.nextElement();
            Object attribute = session.getAttribute(key);
            nextRequest.getSession().setAttribute(key, attribute);
        }

        this.response = new MockHttpServletResponse();
        this.request = nextRequest;
        this.pageContext = new MockPageContext(servletContext, request, response);
    }

    /**
     * Sets up the configuration settings, XWork configuration, and
     * message resources
     */
    @Override
    @Before
    public void setUp() throws Exception {
        initServletMockObjects();
        setupBeforeInitDispatcher();
        initDispatcherParams();
        initDispatcher(dispatcherInitParams);
    }

    protected void initDispatcherParams() {
        if (StringUtils.isNotBlank(getConfigPath())) {
            dispatcherInitParams = new HashMap<>();
            dispatcherInitParams.put("config", "struts-default.xml," + getConfigPath());
        }
    }

    protected Dispatcher initDispatcher(Map<String, String> params) {
        dispatcher = StrutsTestCaseHelper.initDispatcher(servletContext, params);
        configurationManager = dispatcher.getConfigurationManager();
        configuration = configurationManager.getConfiguration();
        container = configuration.getContainer();
        container.inject(dispatcher);
        return dispatcher;
    }

    /**
     * Override this method to return a comma separated list of paths to a configuration
     * file.
     * <p>The default implementation simply returns <code>null</code>.
     *
     * @return a comma separated list of config locations
     */
    protected String getConfigPath() {
        return null;
    }

    @Override
    @After
    public void tearDown() throws Exception {
        StrutsTestCaseHelper.tearDown(dispatcher);
    }

}
