/*
 * 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.freemarker.generator;

import static org.assertj.core.api.Assertions.assertThatExceptionOfType;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.FileVisitResult;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.attribute.BasicFileAttributes;
import java.util.*;

import org.apache.maven.execution.MavenSession;
import org.apache.maven.project.MavenProject;
import org.junit.Assert;
import org.testng.annotations.BeforeClass;
import org.testng.annotations.BeforeMethod;
import org.testng.annotations.Test;

import freemarker.cache.FileTemplateLoader;
import freemarker.template.Configuration;
import mockit.Expectations;
import mockit.Mocked;

public class GeneratingFileVisitorTest extends Assert {

  private static File testDir = new File("src/test/data/generating-file-visitor");
  private static File dataDir = new File(testDir, "data");
  private static File templateDir = new File(testDir, "template");
  private static File outputDir = new File("target/test-output/generating-file-visitor");
  private static Map<String, OutputGeneratorPropertiesProvider> builders = new HashMap<>();
  private Configuration config;
  private Properties pomProperties = new Properties();
  
  @BeforeClass
  public static void beforeClass() throws IOException {
  	 builders.put(".json", JsonPropertiesProvider.create(dataDir,templateDir,outputDir));
    // Clean output dir before each run.
    File outputDir = new File("target/test-output/generating-file-visitor");
    if (outputDir.exists()) {
      // Recursively delete output from previous run.
      Files.walk(outputDir.toPath())
       .sorted(Comparator.reverseOrder())
       .map(Path::toFile)
       .forEach(File::delete);
    }
  }

  @BeforeMethod
  public void before() throws IOException {
    if (!testDir.isDirectory()) {
      throw new RuntimeException("Can't find required test data directory. "
          + "If running test outside of maven, make sure working directory is the project directory. "
          + "Looking for: " + testDir);
    }

    config = new Configuration(Configuration.VERSION_2_3_23);
    config.setDefaultEncoding("UTF-8");
    config.setTemplateLoader(new FileTemplateLoader(templateDir));
    pomProperties.put("pomVar", "pom value");
  }
  
  @Test
  public void functionalHappyPathTestNoDataModel(
      @Mocked MavenSession session, 
      @Mocked MavenProject project,
      @Mocked File mockFile,
      @Mocked BasicFileAttributes attrs) throws IOException {
    List<MavenProject> projects = new ArrayList<>();
    projects.add(project);
    new Expectations(session, project, mockFile) {{
      session.getCurrentProject(); result = project;
      session.getAllProjects(); result = projects;
      project.getProperties(); result = pomProperties;
      attrs.isRegularFile(); result = true;
      project.getFile(); result = mockFile;
      mockFile.lastModified(); result = 10;
    }};
    
    File file = new File(dataDir, "mydir/success-test-2.txt.json");
    GeneratingFileVisitor gfv = GeneratingFileVisitor.create(config, session, builders);
    assertEquals(FileVisitResult.CONTINUE, gfv.visitFile(file.toPath(), attrs));
    
    File outputFile = new File(outputDir, "mydir/success-test-2.txt");
    assertTrue(outputFile.isFile());
    List<String> lines = Files.readAllLines(outputFile.toPath(), StandardCharsets.UTF_8);
    assertEquals(1, lines.size());
    assertEquals("This is a test freemarker template. Test pom data: 'pom value'.", lines.get(0));
  }

  @Test
  public void functionalHappyPathTest(
      @Mocked MavenSession session,
      @Mocked MavenProject project,
      @Mocked File mockFile,
      @Mocked BasicFileAttributes attrs) throws IOException {
    List<MavenProject> projects = new ArrayList<>();
    projects.add(project);
    new Expectations(session, project, mockFile) {{
      session.getCurrentProject(); result = project;
      session.getAllProjects(); result = projects;
      project.getProperties(); result = pomProperties;
      attrs.isRegularFile(); result = true;
      project.getFile(); result = mockFile;
      mockFile.lastModified(); result = 10;
    }};

    File file = new File(dataDir, "mydir/success-test.txt.json");
    GeneratingFileVisitor gfv = GeneratingFileVisitor.create(config, session, builders);
    assertEquals(FileVisitResult.CONTINUE, gfv.visitFile(file.toPath(), attrs));

    File outputFile = new File(outputDir, "mydir/success-test.txt");
    assertTrue(outputFile.isFile());
    List<String> lines = Files.readAllLines(outputFile.toPath(), StandardCharsets.UTF_8);
    assertEquals(1, lines.size());
    assertEquals("This is a test freemarker template. Test json data: 'test value'. Test pom data: 'pom value'.", lines.get(0));
  }

  @Test
  public void visitFile_badExtensionTest(
      @Mocked MavenSession session,
      @Mocked MavenProject project,
      @Mocked File mockFile,
      @Mocked BasicFileAttributes attrs) throws IOException {
    List<MavenProject> projects = new ArrayList<>();
    projects.add(project);
    new Expectations(session, project, mockFile) {{
      attrs.isRegularFile(); result = true;
      session.getAllProjects(); result = projects;
      project.getFile(); result = mockFile;
      mockFile.lastModified(); result = 10;
    }};
    // Test file without .json suffix.
    File file = new File(dataDir, "mydir/bad-extension-test.txt");
    GeneratingFileVisitor gfv = GeneratingFileVisitor.create(config, session, builders);
    assertThatExceptionOfType(RuntimeException.class).isThrownBy(() -> {
      gfv.visitFile(file.toPath(), attrs);
    }).withMessage("Unknown file extension: " + file.toPath());
  }

  @Test 
  public void visitFile_notRegularFileTest(@Mocked MavenSession session,
                                           @Mocked MavenProject project,
                                           @Mocked BasicFileAttributes attrs,
                                           @Mocked File mockFile
                                           ) {
    List<MavenProject> projects = new ArrayList<>();
    projects.add(project);
    new Expectations(session, project, mockFile) {{
      attrs.isRegularFile(); result = false;
      session.getAllProjects(); result = projects;
      project.getFile(); result = mockFile;
      mockFile.lastModified(); result = 10;
    }};
    // FYI: if you change above result to true, test will fail trying to read the 'mydir' directory
    // as a json file.
    File dir = new File(dataDir, "mydir");
    GeneratingFileVisitor gfv = GeneratingFileVisitor.create(config, session, builders);
    assertEquals(FileVisitResult.CONTINUE, gfv.visitFile(dir.toPath(), attrs));
  }
}