/*
    * 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.eclipse.aether.internal.impl;
  
  import javax.inject.Named;
  import javax.inject.Singleton;
  
  import java.io.*;
  import java.nio.ByteBuffer;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.nio.file.StandardCopyOption;
  
  import org.eclipse.aether.spi.io.FileProcessor;
  import org.eclipse.aether.util.FileUtils;
  
  /**
   * A utility class helping with file-based operations.
   */
  @Singleton
  @Named
  public class DefaultFileProcessor implements FileProcessor {
  
      /**
       * Thread-safe variant of {@link File#mkdirs()}. Creates the directory named by the given abstract pathname,
       * including any necessary but nonexistent parent directories. Note that if this operation fails it may have
       * succeeded in creating some of the necessary parent directories.
       *
       * @param directory The directory to create, may be {@code null}.
       * @return {@code true} if and only if the directory was created, along with all necessary parent directories;
       * {@code false} otherwise
       */
      @Override
      public boolean mkdirs(File directory) {
          if (directory == null) {
              return false;
          }
  
          if (directory.exists()) {
              return false;
          }
          if (directory.mkdir()) {
              return true;
          }
  
          File canonDir;
          try {
              canonDir = directory.getCanonicalFile();
          } catch (IOException e) {
              throw new UncheckedIOException(e);
          }
  
          File parentDir = canonDir.getParentFile();
          return (parentDir != null && (mkdirs(parentDir) || parentDir.exists()) && canonDir.mkdir());
      }
  
      @Override
      public void write(File target, String data) throws IOException {
          FileUtils.writeFile(target.toPath(), p -> Files.write(p, data.getBytes(StandardCharsets.UTF_8)));
      }
  
      @Override
      public void write(File target, InputStream source) throws IOException {
          FileUtils.writeFile(target.toPath(), p -> Files.copy(source, p, StandardCopyOption.REPLACE_EXISTING));
      }
  
      @Override
      public void copy(File source, File target) throws IOException {
          copy(source, target, null);
      }
  
      @Override
      public long copy(File source, File target, ProgressListener listener) throws IOException {
          try (InputStream in = new BufferedInputStream(Files.newInputStream(source.toPath()));
                  FileUtils.CollocatedTempFile tempTarget = FileUtils.newTempFile(target.toPath());
                  OutputStream out = new BufferedOutputStream(Files.newOutputStream(tempTarget.getPath()))) {
              long result = copy(out, in, listener);
              tempTarget.move();
              return result;
          }
      }
  
      private long copy(OutputStream os, InputStream is, ProgressListener listener) throws IOException {
         long total = 0L;
         byte[] buffer = new byte[1024 * 32];
         while (true) {
             int bytes = is.read(buffer);
             if (bytes < 0) {
                 break;
             }
 
             os.write(buffer, 0, bytes);
 
             total += bytes;
 
             if (listener != null && bytes > 0) {
                 try {
                     listener.progressed(ByteBuffer.wrap(buffer, 0, bytes));
                 } catch (Exception e) {
                     // too bad
                 }
             }
         }
 
         return total;
     }
 
     @Override
     public void move(File source, File target) throws IOException {
         if (!source.renameTo(target)) {
             copy(source, target);
 
             target.setLastModified(source.lastModified());
 
             source.delete();
         }
     }
 
     @Override
     public String readChecksum(final File checksumFile) throws IOException {
         // for now do exactly same as happened before, but FileProcessor is a component and can be replaced
         String checksum = "";
         try (BufferedReader br = new BufferedReader(
                 new InputStreamReader(Files.newInputStream(checksumFile.toPath()), StandardCharsets.UTF_8), 512)) {
             while (true) {
                 String line = br.readLine();
                 if (line == null) {
                     break;
                 }
                 line = line.trim();
                 if (!line.isEmpty()) {
                     checksum = line;
                     break;
                 }
             }
         }
 
         if (checksum.matches(".+= [0-9A-Fa-f]+")) {
             int lastSpacePos = checksum.lastIndexOf(' ');
             checksum = checksum.substring(lastSpacePos + 1);
         } else {
             int spacePos = checksum.indexOf(' ');
 
             if (spacePos != -1) {
                 checksum = checksum.substring(0, spacePos);
             }
         }
 
         return checksum;
     }
 
     @Override
     public void writeChecksum(final File checksumFile, final String checksum) throws IOException {
         // for now do exactly same as happened before, but FileProcessor is a component and can be replaced
         write(checksumFile, checksum);
     }
 }