content: /*
   * Copyright (c) 2009, 2021, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.javac.file;
  
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.io.Reader;
  import java.io.Writer;
  import java.net.URI;
  import java.net.URISyntaxException;
  import java.nio.ByteBuffer;
  import java.nio.CharBuffer;
  import java.nio.charset.CharsetDecoder;
  import java.nio.file.FileSystem;
  import java.nio.file.FileSystems;
  import java.nio.file.Files;
  import java.nio.file.LinkOption;
  import java.nio.file.Path;
  import java.text.Normalizer;
  import java.util.Objects;
  
  import jdkx.lang.model.element.Modifier;
  import jdkx.lang.model.element.NestingKind;
  import jdkx.tools.FileObject;
  import jdkx.tools.JavaFileObject;
  
  import openjdk.tools.javac.file.RelativePath.RelativeFile;
  import openjdk.tools.javac.util.DefinedBy;
  import openjdk.tools.javac.util.DefinedBy.Api;
  
  
  /**
   *  Implementation of JavaFileObject using java.nio.file API.
   *
   *  <p>PathFileObjects are, for the most part, straightforward wrappers around
   *  immutable absolute Path objects. Different subtypes are used to provide
   *  specialized implementations of "inferBinaryName" and "getName" that capture
   *  additional information available at the time the object is created.
   *
   *  <p>In general, {@link JavaFileManager#isSameFile} should be used to
   *  determine whether two file objects refer to the same file on disk.
   *  PathFileObject also supports the standard {@code equals} and {@code hashCode}
   *  methods, primarily for convenience when working with collections.
   *  All of these operations delegate to the equivalent operations on the
   *  underlying Path object.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public abstract class PathFileObject implements JavaFileObject {
      private static final FileSystem defaultFileSystem = FileSystems.getDefault();
      private static final boolean isMacOS = System.getProperty("os.name", "").contains("OS X");
  
      protected final BaseFileManager fileManager;
      protected final Path path;
      private boolean hasParents;
  
      /**
       * Create a PathFileObject for a file within a directory, such that the
       * binary name can be inferred from the relationship to an enclosing directory.
       *
       * The binary name is derived from {@code relativePath}.
       * The name is derived from the composition of {@code userPackageRootDir}
       * and {@code relativePath}.
       *
       * @param fileManager the file manager creating this file object
       * @param path the absolute path referred to by this file object
       * @param userPackageRootDir the path of the directory containing the
       *          root of the package hierarchy
       * @param relativePath the path of this file relative to {@code userPackageRootDir}
       */
      static PathFileObject forDirectoryPath(BaseFileManager fileManager, Path path,
              Path userPackageRootDir, RelativePath relativePath) {
          return new DirectoryFileObject(fileManager, path, userPackageRootDir, relativePath);
      }
  
      private static class DirectoryFileObject extends PathFileObject {
          private final Path userPackageRootDir;
          private final RelativePath relativePath;
  
          private DirectoryFileObject(BaseFileManager fileManager, Path path,
                  Path userPackageRootDir, RelativePath relativePath) {
              super(fileManager, path);
              this.userPackageRootDir = Objects.requireNonNull(userPackageRootDir);
              this.relativePath = relativePath;
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public String getName() {
              return relativePath.resolveAgainst(userPackageRootDir).toString();
          }
  
          @Override
          public String inferBinaryName(Iterable<? extends Path> paths) {
              return toBinaryName(relativePath);
          }
  
          @Override
          public String toString() {
              return "DirectoryFileObject[" + userPackageRootDir + ":" + relativePath.path + "]";
          }
  
          @Override
          PathFileObject getSibling(String baseName) {
              return new DirectoryFileObject(fileManager,
                      path.resolveSibling(baseName),
                      userPackageRootDir,
                      new RelativeFile(relativePath.dirname(), baseName)
              );
          }
      }
  
      /**
       * Create a PathFileObject for a file in a file system such as a jar file,
       * such that the binary name can be inferred from its position within the
       * file system.
       *
       * The binary name is derived from {@code path}.
       * The name is derived from the composition of {@code userJarPath}
       * and {@code path}.
       *
       * @param fileManager the file manager creating this file object
       * @param path the path referred to by this file object
       * @param userJarPath the path of the jar file containing the file system.
       * @return the file object
       */
      public static PathFileObject forJarPath(BaseFileManager fileManager,
              Path path, Path userJarPath) {
          return new JarFileObject(fileManager, path, userJarPath);
      }
  
      private static class JarFileObject extends PathFileObject {
          private final Path userJarPath;
  
          private JarFileObject(BaseFileManager fileManager, Path path, Path userJarPath) {
              super(fileManager, path);
              this.userJarPath = userJarPath;
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public String getName() {
              // The use of ( ) to delimit the entry name is not ideal
              // but it does match earlier behavior
              return userJarPath + "(" + path + ")";
          }
  
          @Override
          public String inferBinaryName(Iterable<? extends Path> paths) {
              Path root = path.getFileSystem().getRootDirectories().iterator().next();
              return toBinaryName(root.relativize(path));
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public URI toUri() {
              // Work around bug JDK-8134451:
              // path.toUri() returns double-encoded URIs, that cannot be opened by URLConnection
              return createJarUri(userJarPath, path.toString());
          }
  
          @Override
          public String toString() {
              return "JarFileObject[" + userJarPath + ":" + path + "]";
          }
  
          @Override
          PathFileObject getSibling(String baseName) {
              return new JarFileObject(fileManager,
                      path.resolveSibling(baseName),
                      userJarPath
              );
          }
  
          private static URI createJarUri(Path jarFile, String entryName) {
              URI jarURI = jarFile.toUri().normalize();
              String separator = entryName.startsWith("/") ? "!" : "!/";
              try {
                  // The jar URI convention appears to be not to re-encode the jarURI
                  return new URI("jar:" + jarURI + separator + entryName);
              } catch (URISyntaxException e) {
                  throw new CannotCreateUriError(jarURI + separator + entryName, e);
              }
          }
      }
  
      /**
       * Create a PathFileObject for a file in a modular file system, such as jrt:,
       * such that the binary name can be inferred from its position within the
       * filesystem.
       *
       * The binary name is derived from {@code path}, ignoring the first two
       * elements of the name (which are "modules" and a module name).
       * The name is derived from {@code path}.
       *
       * @param fileManager the file manager creating this file object
       * @param path the path referred to by this file object
       * @return the file object
       */
      public static PathFileObject forJRTPath(BaseFileManager fileManager,
              final Path path) {
          return new JRTFileObject(fileManager, path);
      }
  
      private static class JRTFileObject extends PathFileObject {
          // private final Path javaHome;
          private JRTFileObject(BaseFileManager fileManager, Path path) {
              super(fileManager, path);
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public String getName() {
              return path.toString();
          }
  
          @Override
          public String inferBinaryName(Iterable<? extends Path> paths) {
              // use subpath to ignore the leading /modules/MODULE-NAME
              return toBinaryName(path.subpath(2, path.getNameCount()));
          }
  
          @Override
          public String toString() {
              return "JRTFileObject[" + path + "]";
          }
  
          @Override
          PathFileObject getSibling(String baseName) {
              return new JRTFileObject(fileManager,
                      path.resolveSibling(baseName)
              );
          }
      }
  
      /**
       * Create a PathFileObject for a file whose binary name must be inferred
       * from its position on a search path.
       *
       * The binary name is inferred by finding an enclosing directory in
       * the sequence of paths associated with the location given to
       * {@link JavaFileManager#inferBinaryName).
       * The name is derived from {@code userPath}.
       *
       * @param fileManager the file manager creating this file object
       * @param path the path referred to by this file object
       * @param userPath the "user-friendly" name for this path.
       */
      static PathFileObject forSimplePath(BaseFileManager fileManager,
              Path path, Path userPath) {
          return new SimpleFileObject(fileManager, path, userPath);
      }
  
      private static class SimpleFileObject extends PathFileObject {
          private final Path userPath;
          private SimpleFileObject(BaseFileManager fileManager, Path path, Path userPath) {
              super(fileManager, path);
              this.userPath = userPath;
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public String getName() {
              return userPath.toString();
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public String getShortName() {
              return userPath.getFileName().toString();
          }
  
          @Override
          public String inferBinaryName(Iterable<? extends Path> paths) {
              Path absPath = path.toAbsolutePath();
              for (Path p: paths) {
                  Path ap = p.toAbsolutePath();
                  if (absPath.startsWith(ap)) {
                      try {
                          Path rp = ap.relativize(absPath);
                          if (rp != null) // maybe null if absPath same as ap
                              return toBinaryName(rp);
                      } catch (IllegalArgumentException e) {
                          // ignore this p if cannot relativize path to p
                      }
                  }
              }
              return null;
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public Kind getKind() {
              return BaseFileManager.getKind(userPath);
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public boolean isNameCompatible(String simpleName, Kind kind) {
              return isPathNameCompatible(userPath, simpleName, kind);
          }
  
          @Override @DefinedBy(Api.COMPILER)
          public URI toUri() {
              return userPath.toUri().normalize();
          }
  
          @Override
          PathFileObject getSibling(String baseName) {
              return new SimpleFileObject(fileManager,
                      path.resolveSibling(baseName),
                      userPath.resolveSibling(baseName)
              );
          }
      }
  
      /**
       * Create a PathFileObject, for a specified path, in the context of
       * a given file manager.
       *
       * In general, this path should be an
       * {@link Path#toAbsolutePath absolute path}, if not a
       * {@link Path#toRealPath} real path.
       * It will be used as the basis of {@code equals}, {@code hashCode}
       * and {@code isSameFile} methods on this file object.
       *
       * A PathFileObject should also have a "friendly name" per the
       * specification for {@link FileObject#getName}. The friendly name
       * is provided by the various subtypes of {@code PathFileObject}.
       *
       * @param fileManager the file manager creating this file object
       * @param path the path contained in this file object.
       */
      protected PathFileObject(BaseFileManager fileManager, Path path) {
          this.fileManager = Objects.requireNonNull(fileManager);
          if (Files.isDirectory(path)) {
              throw new IllegalArgumentException("directories not supported");
          }
          this.path = path;
      }
  
      /**
       * See {@link JavacFileManager#inferBinaryName}.
       */
      abstract String inferBinaryName(Iterable<? extends Path> paths);
  
      /**
       * Return the file object for a sibling file with a given file name.
       * See {@link JavacFileManager#getFileForOutput} and
       * {@link JavacFileManager#getJavaFileForOutput}.
       */
      abstract PathFileObject getSibling(String basename);
  
      /**
       * Return the Path for this object.
       * @return the Path for this object.
       * @see StandardJavaFileManager#asPath
       */
      public Path getPath() {
          return path;
      }
  
      /**
       * The short name is used when generating raw diagnostics.
       * @return the last component of the path
       */
      public String getShortName() {
          return path.getFileName().toString();
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public Kind getKind() {
          return BaseFileManager.getKind(path);
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public boolean isNameCompatible(String simpleName, Kind kind) {
          return isPathNameCompatible(path, simpleName, kind);
      }
  
      protected boolean isPathNameCompatible(Path p, String simpleName, Kind kind) {
          Objects.requireNonNull(simpleName);
          Objects.requireNonNull(kind);
  
          if (kind == Kind.OTHER && BaseFileManager.getKind(p) != kind) {
              return false;
          }
  
          String sn = simpleName + kind.extension;
          String pn = p.getFileName().toString();
          if (pn.equals(sn)) {
              return true;
          }
  
          if (p.getFileSystem() == defaultFileSystem) {
              if (isMacOS) {
                  if (Normalizer.isNormalized(pn, Normalizer.Form.NFD)
                          && Normalizer.isNormalized(sn, Normalizer.Form.NFC)) {
                      // On Mac OS X it is quite possible to have the file name and the
                      // given simple name normalized in different ways.
                      // In that case we have to normalize file name to the
                      // Normal Form Composed (NFC).
                      String normName = Normalizer.normalize(pn, Normalizer.Form.NFC);
                      if (normName.equals(sn)) {
                          return true;
                      }
                  }
              }
  
              if (pn.equalsIgnoreCase(sn)) {
                  try {
                      // allow for Windows
                      return p.toRealPath(LinkOption.NOFOLLOW_LINKS).getFileName().toString().equals(sn);
                  } catch (IOException e) {
                  }
              }
          }
  
          return false;
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public NestingKind getNestingKind() {
          return null;
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public Modifier getAccessLevel() {
          return null;
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public URI toUri() {
          return path.toUri();
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public InputStream openInputStream() throws IOException {
          fileManager.updateLastUsedTime();
          return Files.newInputStream(path);
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public OutputStream openOutputStream() throws IOException {
          fileManager.updateLastUsedTime();
          fileManager.flushCache(this);
          ensureParentDirectoriesExist();
          return Files.newOutputStream(path);
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public Reader openReader(boolean ignoreEncodingErrors) throws IOException {
          CharsetDecoder decoder = fileManager.getDecoder(fileManager.getEncodingName(), ignoreEncodingErrors);
          return new InputStreamReader(openInputStream(), decoder);
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public CharSequence getCharContent(boolean ignoreEncodingErrors) throws IOException {
          CharBuffer cb = fileManager.getCachedContent(this);
          if (cb == null) {
              try (InputStream in = openInputStream()) {
                  ByteBuffer bb = fileManager.makeByteBuffer(in);
                  JavaFileObject prev = fileManager.log.useSource(this);
                  try {
                      cb = fileManager.decode(bb, ignoreEncodingErrors);
                  } finally {
                      fileManager.log.useSource(prev);
                  }
                  fileManager.recycleByteBuffer(bb);
                  if (!ignoreEncodingErrors) {
                      fileManager.cache(this, cb);
                  }
              }
          }
          return cb;
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public Writer openWriter() throws IOException {
          fileManager.updateLastUsedTime();
          fileManager.flushCache(this);
          ensureParentDirectoriesExist();
          return new OutputStreamWriter(Files.newOutputStream(path), fileManager.getEncodingName());
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public long getLastModified() {
          try {
              return Files.getLastModifiedTime(path).toMillis();
          } catch (IOException e) {
              return 0;
          }
      }
  
      @Override @DefinedBy(Api.COMPILER)
      public boolean delete() {
          try {
              Files.delete(path);
              return true;
          } catch (IOException e) {
              return false;
          }
      }
  
      boolean isSameFile(PathFileObject other) {
          // By construction, the "path" field should be canonical in all likely, supported scenarios.
          // (Any exceptions would involve the use of symlinks within a package hierarchy.)
          // Therefore, it is sufficient to check that the paths are .equals.
          return path.equals(other.path);
      }
  
      @Override
      public boolean equals(Object other) {
          return (other instanceof PathFileObject && path.equals(((PathFileObject) other).path));
      }
  
      @Override
      public int hashCode() {
          return path.hashCode();
      }
  
      @Override
      public String toString() {
          return getClass().getSimpleName() + "[" + path + "]";
      }
  
      private void ensureParentDirectoriesExist() throws IOException {
          if (!hasParents) {
              Path parent = path.getParent();
              if (parent != null && !Files.isDirectory(parent)) {
                  try {
                      Files.createDirectories(parent);
                  } catch (IOException e) {
                      throw new IOException("could not create parent directories", e);
                  }
              }
              hasParents = true;
          }
      }
  
      protected static String toBinaryName(RelativePath relativePath) {
          return toBinaryName(relativePath.path, "/");
      }
  
      protected static String toBinaryName(Path relativePath) {
          return toBinaryName(relativePath.toString(),
                  relativePath.getFileSystem().getSeparator());
      }
  
      private static String toBinaryName(String relativePath, String sep) {
          return removeExtension(relativePath).replace(sep, ".");
      }
  
      private static String removeExtension(String fileName) {
          int lastDot = fileName.lastIndexOf(".");
          return (lastDot == -1 ? fileName : fileName.substring(0, lastDot));
      }
  
      /**
       * Return the last component of a presumed hierarchical URI.
       * From the scheme specific part of the URI, it returns the substring
       * after the last "/" if any, or everything if no "/" is found.
       * @param fo the file object
       * @return the simple name of the file object
       */
      public static String getSimpleName(FileObject fo) {
          URI uri = fo.toUri();
          String s = uri.getSchemeSpecificPart();
          return s.substring(s.lastIndexOf("/") + 1); // safe when / not found
  
      }
  
      /** Used when URLSyntaxException is thrown unexpectedly during
       *  implementations of FileObject.toURI(). */
      public static class CannotCreateUriError extends Error {
          private static final long serialVersionUID = 9101708840997613546L;
          public CannotCreateUriError(String value, Throwable cause) {
              super(value, cause);
          }
      }
  }
  