/*
 * Copyright 2002-2019 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.web.reactive.result.view.freemarker;

import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Arrays;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import freemarker.template.Configuration;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import reactor.core.publisher.Mono;

import org.springframework.context.support.GenericApplicationContext;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.FileSystemResource;
import org.springframework.http.MediaType;
import org.springframework.mock.http.server.reactive.test.MockServerHttpRequest;
import org.springframework.mock.web.test.server.MockServerWebExchange;
import org.springframework.tests.sample.beans.TestBean;
import org.springframework.ui.ExtendedModelMap;
import org.springframework.ui.ModelMap;
import org.springframework.util.FileCopyUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.reactive.result.view.BindStatus;
import org.springframework.web.reactive.result.view.DummyMacroRequestContext;
import org.springframework.web.reactive.result.view.RequestContext;
import org.springframework.web.server.ServerWebExchange;

import static java.util.Collections.singletonMap;
import static java.util.stream.Collectors.toList;
import static org.assertj.core.api.Assertions.assertThat;

/**
 * @author Darren Davison
 * @author Juergen Hoeller
 * @author Issam El-atif
 * @author Sam Brannen
 * @since 5.2
 */
public class FreeMarkerMacroTests {

	private static final String TEMPLATE_FILE = "test-macro.ftl";

	private final MockServerWebExchange exchange = MockServerWebExchange.from(MockServerHttpRequest.get("/path"));

	private final GenericApplicationContext applicationContext = new GenericApplicationContext();

	private Configuration freeMarkerConfig;

	@BeforeEach
	public void setUp() throws Exception {
		this.applicationContext.refresh();

		FreeMarkerConfigurer configurer = new FreeMarkerConfigurer();
		configurer.setTemplateLoaderPaths("classpath:/", "file://" + System.getProperty("java.io.tmpdir"));
		this.freeMarkerConfig = configurer.createConfiguration();
	}

	@Test
	public void springMacroRequestContextIsAutomaticallyExposedAsModelAttribute() throws Exception {
		storeTemplateInTempDir("<@spring.bind \"testBean.name\"/>\nHi ${spring.status.value}");

		FreeMarkerView view = new FreeMarkerView() {

			@Override
			protected Mono<Void> renderInternal(Map<String, Object> renderAttributes,
					MediaType contentType, ServerWebExchange exchange) {

				Object value = renderAttributes.get(SPRING_MACRO_REQUEST_CONTEXT_ATTRIBUTE);
				assertThat(value).isInstanceOf(RequestContext.class);
				BindStatus status = ((RequestContext) value).getBindStatus("testBean.name");
				assertThat(status.getExpression()).isEqualTo("name");
				assertThat(status.getValue()).isEqualTo("Dilbert");

				return super.renderInternal(renderAttributes, contentType, exchange);
			}
		};

		view.setApplicationContext(this.applicationContext);
		view.setBeanName("myView");
		view.setUrl("tmp.ftl");
		view.setConfiguration(this.freeMarkerConfig);

		view.render(singletonMap("testBean", new TestBean("Dilbert", 99)), null, this.exchange).subscribe();

		assertThat(getOutput()).containsExactly("Hi Dilbert");
	}

	@Test
	public void name() throws Exception {
		assertThat(getMacroOutput("NAME")).containsExactly("Darren");
	}

	@Test
	public void age() throws Exception {
		assertThat(getMacroOutput("AGE")).containsExactly("99");
	}

	@Test
	public void message() throws Exception {
		assertThat(getMacroOutput("MESSAGE")).containsExactly("Howdy Mundo");
	}

	@Test
	public void defaultMessage() throws Exception {
		assertThat(getMacroOutput("DEFAULTMESSAGE")).containsExactly("hi planet");
	}

	@Test
	public void messageArgs() throws Exception {
		assertThat(getMacroOutput("MESSAGEARGS")).containsExactly("Howdy[World]");
	}

	@Test
	public void messageArgsWithDefaultMessage() throws Exception {
		assertThat(getMacroOutput("MESSAGEARGSWITHDEFAULTMESSAGE")).containsExactly("Hi");
	}

	@Test
	public void url() throws Exception {
		assertThat(getMacroOutput("URL")).containsExactly("/springtest/aftercontext.html");
	}

	@Test
	public void urlParams() throws Exception {
		assertThat(getMacroOutput("URLPARAMS")).containsExactly(
				"/springtest/aftercontext/bar?spam=bucket");
	}

	@Test
	public void formInput() throws Exception {
		assertThat(getMacroOutput("FORM1")).containsExactly(
				"<input type=\"text\" id=\"name\" name=\"name\" value=\"Darren\" >");
	}

	@Test
	public void formInputWithCss() throws Exception {
		assertThat(getMacroOutput("FORM2")).containsExactly(
				"<input type=\"text\" id=\"name\" name=\"name\" value=\"Darren\" class=\"myCssClass\" >");
	}

	@Test
	public void formTextarea() throws Exception {
		assertThat(getMacroOutput("FORM3")).containsExactly(
				"<textarea id=\"name\" name=\"name\" >Darren</textarea>");
	}

	@Test
	public void formTextareaWithCustomRowsAndColumns() throws Exception {
		assertThat(getMacroOutput("FORM4")).containsExactly(
				"<textarea id=\"name\" name=\"name\" rows=10 cols=30>Darren</textarea>");
	}

	@Test
	public void formSingleSelectFromMap() throws Exception {
		assertThat(getMacroOutput("FORM5")).containsExactly(
				"<select id=\"name\" name=\"name\" >", //
				"<option value=\"Rob&amp;Harrop\">Rob Harrop</option>", //
				"<option value=\"John\">John Doe</option>", //
				"<option value=\"Fred\">Fred Bloggs</option>", //
				"<option value=\"Darren\" selected=\"selected\">Darren Davison</option>", //
				"</select>");
	}

	@Test
	public void formSingleSelectFromList() throws Exception {
		assertThat(getMacroOutput("FORM14")).containsExactly(
				"<select id=\"name\" name=\"name\" >", //
				"<option value=\"Rob Harrop\">Rob Harrop</option>", //
				"<option value=\"Darren Davison\">Darren Davison</option>", //
				"<option value=\"John Doe\">John Doe</option>", //
				"<option value=\"Fred Bloggs\">Fred Bloggs</option>", //
				"</select>");
	}

	@Test
	public void formMultiSelect() throws Exception {
		assertThat(getMacroOutput("FORM6")).containsExactly(
				"<select multiple=\"multiple\" id=\"spouses\" name=\"spouses\" >", //
				"<option value=\"Rob&amp;Harrop\">Rob Harrop</option>", //
				"<option value=\"John\">John Doe</option>", //
				"<option value=\"Fred\" selected=\"selected\">Fred Bloggs</option>", //
				"<option value=\"Darren\">Darren Davison</option>", //
				"</select>");
	}

	@Test
	public void formRadioButtons() throws Exception {
		assertThat(getMacroOutput("FORM7")).containsExactly(
				"<input type=\"radio\" id=\"name0\" name=\"name\" value=\"Rob&amp;Harrop\" >", //
				"<label for=\"name0\">Rob Harrop</label>", //
				"<input type=\"radio\" id=\"name1\" name=\"name\" value=\"John\" >", //
				"<label for=\"name1\">John Doe</label>", //
				"<input type=\"radio\" id=\"name2\" name=\"name\" value=\"Fred\" >", //
				"<label for=\"name2\">Fred Bloggs</label>", //
				"<input type=\"radio\" id=\"name3\" name=\"name\" value=\"Darren\" checked=\"checked\" >", //
				"<label for=\"name3\">Darren Davison</label>");
	}

	@Test
	public void formCheckboxForStringProperty() throws Exception {
		assertThat(getMacroOutput("FORM15")).containsExactly(
				"<input type=\"hidden\" name=\"_name\" value=\"on\"/>",
				"<input type=\"checkbox\" id=\"name\" name=\"name\" />");
	}

	@Test
	public void formCheckboxForBooleanProperty() throws Exception {
		assertThat(getMacroOutput("FORM16")).containsExactly(
				"<input type=\"hidden\" name=\"_jedi\" value=\"on\"/>",
				"<input type=\"checkbox\" id=\"jedi\" name=\"jedi\" checked=\"checked\" />");
	}

	@Test
	public void formCheckboxForNestedPath() throws Exception {
		assertThat(getMacroOutput("FORM18")).containsExactly(
				"<input type=\"hidden\" name=\"_spouses[0].jedi\" value=\"on\"/>",
				"<input type=\"checkbox\" id=\"spouses0.jedi\" name=\"spouses[0].jedi\" checked=\"checked\" />");
	}

	@Test
	public void formCheckboxForStringArray() throws Exception {
		assertThat(getMacroOutput("FORM8")).containsExactly(
				"<input type=\"checkbox\" id=\"stringArray0\" name=\"stringArray\" value=\"Rob&amp;Harrop\" >", //
				"<label for=\"stringArray0\">Rob Harrop</label>", //
				"<input type=\"checkbox\" id=\"stringArray1\" name=\"stringArray\" value=\"John\" checked=\"checked\" >", //
				"<label for=\"stringArray1\">John Doe</label>", //
				"<input type=\"checkbox\" id=\"stringArray2\" name=\"stringArray\" value=\"Fred\" checked=\"checked\" >", //
				"<label for=\"stringArray2\">Fred Bloggs</label>", //
				"<input type=\"checkbox\" id=\"stringArray3\" name=\"stringArray\" value=\"Darren\" >", //
				"<label for=\"stringArray3\">Darren Davison</label>", //
				"<input type=\"hidden\" name=\"_stringArray\" value=\"on\"/>");
	}

	@Test
	public void formPasswordInput() throws Exception {
		assertThat(getMacroOutput("FORM9")).containsExactly(
				"<input type=\"password\" id=\"name\" name=\"name\" value=\"\" >");
	}

	@Test
	public void formHiddenInput() throws Exception {
		assertThat(getMacroOutput("FORM10")).containsExactly(
				"<input type=\"hidden\" id=\"name\" name=\"name\" value=\"Darren\" >");
	}

	@Test
	public void formInputText() throws Exception {
		assertThat(getMacroOutput("FORM11")).containsExactly(
				"<input type=\"text\" id=\"name\" name=\"name\" value=\"Darren\" >");
	}

	@Test
	public void formInputHidden() throws Exception {
		assertThat(getMacroOutput("FORM12")).containsExactly(
				"<input type=\"hidden\" id=\"name\" name=\"name\" value=\"Darren\" >");
	}

	@Test
	public void formInputPassword() throws Exception {
		assertThat(getMacroOutput("FORM13")).containsExactly(
				"<input type=\"password\" id=\"name\" name=\"name\" value=\"\" >");
	}

	@Test
	public void forInputWithNestedPath() throws Exception {
		assertThat(getMacroOutput("FORM17")).containsExactly(
				"<input type=\"text\" id=\"spouses0.name\" name=\"spouses[0].name\" value=\"Fred\" >");
	}

	private List<String> getMacroOutput(String name) throws Exception {
		String macro = fetchMacro(name);
		assertThat(macro).isNotNull();
		storeTemplateInTempDir(macro);

		Map<String, String> msgMap = new HashMap<>();
		msgMap.put("hello", "Howdy");
		msgMap.put("world", "Mundo");

		TestBean darren = new TestBean("Darren", 99);
		TestBean fred = new TestBean("Fred");
		fred.setJedi(true);
		darren.setSpouse(fred);
		darren.setJedi(true);
		darren.setStringArray(new String[] { "John", "Fred" });

		Map<String, String> names = new HashMap<>();
		names.put("Darren", "Darren Davison");
		names.put("John", "John Doe");
		names.put("Fred", "Fred Bloggs");
		names.put("Rob&Harrop", "Rob Harrop");

		ModelMap model = new ExtendedModelMap();
		DummyMacroRequestContext rc = new DummyMacroRequestContext(this.exchange, model,
				this.applicationContext);
		rc.setMessageMap(msgMap);
		rc.setContextPath("/springtest");

		model.put("command", darren);
		model.put(FreeMarkerView.SPRING_MACRO_REQUEST_CONTEXT_ATTRIBUTE, rc);
		model.put("msgArgs", new Object[] { "World" });
		model.put("nameOptionMap", names);
		model.put("options", names.values());

		FreeMarkerView view = new FreeMarkerView();
		view.setApplicationContext(this.applicationContext);
		view.setBeanName("myView");
		view.setUrl("tmp.ftl");
		view.setExposeSpringMacroHelpers(false);
		view.setConfiguration(freeMarkerConfig);

		view.render(model, null, this.exchange).subscribe();

		return getOutput();
	}

	private String fetchMacro(String name) throws Exception {
		ClassPathResource resource = new ClassPathResource(TEMPLATE_FILE, getClass());
		assertThat(resource.exists()).isTrue();
		String all = FileCopyUtils.copyToString(new InputStreamReader(resource.getInputStream()));
		all = all.replace("\r\n", "\n");
		String[] macros = StringUtils.delimitedListToStringArray(all, "\n\n");
		for (String macro : macros) {
			if (macro.startsWith(name)) {
				return macro.substring(macro.indexOf("\n")).trim();
			}
		}
		return null;
	}

	private void storeTemplateInTempDir(String macro) throws IOException {
		FileSystemResource resource = new FileSystemResource(System.getProperty("java.io.tmpdir") + "/tmp.ftl");
		FileCopyUtils.copy("<#import \"spring.ftl\" as spring />\n" + macro, new FileWriter(resource.getPath()));
	}

	private List<String> getOutput() {
		String output = this.exchange.getResponse().getBodyAsString().block();
		String[] lines = output.replace("\r\n", "\n").replaceAll(" +"," ").split("\n");
		return Arrays.stream(lines).map(String::trim).filter(line -> !line.isEmpty()).collect(toList());
	}

}
