/*
 * Copyright © 2016-2018 European Support Limited
 *
 * 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.openecomp.core.utilities.file;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.nio.file.Path;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.function.Function;
import org.apache.commons.io.FilenameUtils;
import org.apache.commons.io.IOUtils;
import org.onap.sdc.tosca.services.YamlUtil;
import org.openecomp.core.utilities.json.JsonUtil;
import org.openecomp.sdc.common.zip.ZipUtils;
import org.openecomp.sdc.common.zip.exception.ZipException;

/**
 * The type File utils.
 */
public class FileUtils {

  /**
   * Allows to consume an input stream open against a resource with a given file name.
   *
   * @param fileName the file name
   * @param function logic to be applied to the input stream
   */
  public static <T> T readViaInputStream(String fileName, Function<InputStream, T> function) {

    Objects.requireNonNull(fileName);

    // the leading slash doesn't make sense and doesn't work when used with a class loader
    URL resource = FileUtils.class.getClassLoader().getResource(fileName.startsWith("/")
        ? fileName.substring(1) : fileName);
    if (resource == null) {
      throw new IllegalArgumentException("Resource not found: " + fileName);
    }

    return readViaInputStream(resource, function);
  }

  /**
   * Allows to consume an input stream open against a resource with a given URL.
   *
   * @param urlFile the url file
   * @param function logic to be applied to the input stream
   */
  public static <T> T readViaInputStream(URL urlFile, Function<InputStream, T> function) {

    Objects.requireNonNull(urlFile);
    try (InputStream is = urlFile.openStream()) {
      return function.apply(is);
    } catch (IOException exception) {
      throw new RuntimeException(exception);
    }
  }

  /**
   * Gets file input streams.
   *
   * @param fileName the file name
   * @return the file input streams
   */
  public static List<URL> getAllLocations(String fileName) {

    List<URL> urls = new LinkedList<>();
    Enumeration<URL> urlFiles;

    try {
      urlFiles = FileUtils.class.getClassLoader().getResources(fileName);
      while (urlFiles.hasMoreElements()) {
        urls.add(urlFiles.nextElement());
      }


    } catch (IOException exception) {
      throw new RuntimeException(exception);
    }

    return urls.isEmpty() ? Collections.emptyList() : Collections.unmodifiableList(urls);
  }

  /**
   * Convert to bytes byte [ ].
   *
   * @param object    the object
   * @param extension the extension
   * @return the byte [ ]
   */
  public static byte[] convertToBytes(Object object, FileExtension extension) {
    if (object != null) {
      if (extension.equals(FileExtension.YAML) || extension.equals(FileExtension.YML)) {
        return new YamlUtil().objectToYaml(object).getBytes();
      } else {
        return JsonUtil.object2Json(object).getBytes();
      }
    } else {
      return new byte[]{};
    }
  }

  /**
   * Convert to input stream input stream.
   *
   * @param object    the object
   * @param extension the extension
   * @return the input stream
   */
  public static InputStream convertToInputStream(Object object, FileExtension extension) {
    if (object != null) {

      byte[] content;

      if (extension.equals(FileExtension.YAML) || extension.equals(FileExtension.YML)) {
        content = new YamlUtil().objectToYaml(object).getBytes();
      } else {
        content = JsonUtil.object2Json(object).getBytes();

      }
      return new ByteArrayInputStream(content);
    } else {
      return null;
    }
  }

  /**
   * Load file to input stream input stream.
   *
   * @param fileName the file name
   * @return the input stream
   */
  public static InputStream loadFileToInputStream(String fileName) {
    URL urlFile = Thread.currentThread().getContextClassLoader().getResource(fileName);
    try {
      Enumeration<URL> en = Thread.currentThread().getContextClassLoader().getResources(fileName);
      while (en.hasMoreElements()) {
        urlFile = en.nextElement();
      }
    } catch (IOException | NullPointerException exception) {
      throw new RuntimeException(exception);
    }
    try {
      if (urlFile != null) {
        return urlFile.openStream();
      } else {
        throw new RuntimeException();
      }
    } catch (IOException | NullPointerException exception) {
      throw new RuntimeException(exception);
    }

  }

  /**
   * To byte array byte [ ].
   *
   * @param input the input
   * @return the byte [ ]
   */
  public static byte[] toByteArray(InputStream input) {
    if (input == null) {
      return new byte[0];
    }
    try {
      return IOUtils.toByteArray(input);
    } catch (IOException exception) {
      throw new RuntimeException(
          "error while converting input stream to byte array", exception);
    }
  }

  /**
   * Gets file without extention.
   *
   * @param fileName the file name
   * @return the file without extention
   */
  public static String getFileWithoutExtention(String fileName) {
    if (!fileName.contains(".")) {
      return fileName;
    }
    return fileName.substring(0, fileName.lastIndexOf('.'));
  }

  public static String getFileExtension(String filename) {
      return FilenameUtils.getExtension(filename);
  }

  public static String getNetworkPackageName(String filename) {
    String[] split = filename.split("\\.");
    String name = null;
    if (split.length > 1) {
      name = split[0];
    }
    return name;
  }

  /**
   * Gets file content map from zip.
   *
   * @param zipData the zip data
   * @return the file content map from zip
   * @throws ZipException when an error occurs while extracting zip files
   */
  public static FileContentHandler getFileContentMapFromZip(byte[] zipData)
      throws ZipException {
    final Map<String, byte[]> zipFileAndByteMap = ZipUtils.readZip(zipData, true);
    final FileContentHandler mapFileContent = new FileContentHandler();
    mapFileContent.setFiles(zipFileAndByteMap);
    return mapFileContent;
  }


  /**
   * The enum File extension.
   */
  public enum FileExtension {

    /**
     * Json file extension.
     */
    JSON("json"),
    /**
     * Yaml file extension.
     */
    YAML("yaml"),
    /**
     * Yml file extension.
     */
    YML("yml");

    private final String displayName;

    FileExtension(String displayName) {
      this.displayName = displayName;
    }

    /**
     * Gets display name.
     *
     * @return the display name
     */
    public String getDisplayName() {
      return displayName;
    }
  }


  /**
   * Write files and folders map to disk in the given path
   *
   * @param fileContentHandler the file content handler
   * @param dir                the dir
   * @return a map containing file names and their absolute paths
   * @throws IOException the io exception
   */
  public static Map<String, String> writeFilesFromFileContentHandler(final FileContentHandler fileContentHandler,
                                                                     final Path dir) throws IOException {
    File file;
    final File dirFile = dir.toFile();
    final Map<String, String> filePaths = new HashMap<>();
    for (final Map.Entry<String, byte[]> fileEntry : fileContentHandler.getFiles().entrySet()) {
      file = new File(dirFile, fileEntry.getKey());
      filePaths.put(fileEntry.getKey(), file.getAbsolutePath());
      final byte[] fileBytes = fileEntry.getValue();
      if (fileBytes == null) {
        if (!file.exists() && !file.mkdirs()) {
          throw new IOException("Could not create directory " + file.getAbsolutePath());
        }
        continue;
      } else {
        if (!file.getParentFile().exists() && !file.getParentFile().mkdirs()) {
          throw new IOException("Could not create parent directory for " + file.getAbsolutePath());
        }
      }

      try (final FileOutputStream fop = new FileOutputStream(file.getAbsolutePath());) {
        fop.write(fileBytes);
        fop.flush();
      }
    }

    return filePaths;
  }

  /**
   * Verify whether the provided extension is valid Yaml/Yml extension or not.
   *
   * @param fileExtension the file extension
   * @return the boolean
   */
  public static boolean isValidYamlExtension(String fileExtension){
    return fileExtension.equalsIgnoreCase(FileExtension.YML.getDisplayName()) ||
        fileExtension.equalsIgnoreCase(FileExtension.YAML.getDisplayName());
  }

}