/*

 * Copyright (c) 2006, 2018, 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 javax.tools;

import java.io.File;

import java.io.IOException;

import java.nio.file.Path;

import java.util.Arrays;

import java.util.Collection;

import java.util.Iterator;

/**

 * File manager based on {@linkplain File java.io.File} and {@linkplain Path java.nio.file.Path}.

 *

 * A common way to obtain an instance of this class is using

 * {@linkplain JavaCompiler#getStandardFileManager getStandardFileManager}, for example:

 *

 * <pre>

 *   JavaCompiler compiler = ToolProvider.getSystemJavaCompiler();

 *   {@code DiagnosticCollector<JavaFileObject>} diagnostics =

 *       new {@code DiagnosticCollector<JavaFileObject>()};

 *   StandardJavaFileManager fm = compiler.getStandardFileManager(diagnostics, null, null);

 * </pre>

 *

 * This file manager creates file objects representing regular

 * {@linkplain File files},

 * {@linkplain java.util.zip.ZipEntry zip file entries}, or entries in

 * similar file system based containers.  Any file object returned

 * from a file manager implementing this interface must observe the

 * following behavior:

 *

 * <ul>

 *   <li>

 *     File names need not be canonical.

 *   </li>

 *   <li>

 *     For file objects representing regular files

 *     <ul>

 *       <li>

 *         the method <code>{@linkplain FileObject#delete()}</code>

 *         is equivalent to <code>{@linkplain File#delete()}</code>,

 *       </li>

 *       <li>

 *         the method <code>{@linkplain FileObject#getLastModified()}</code>

 *         is equivalent to <code>{@linkplain File#lastModified()}</code>,

 *       </li>

 *       <li>

 *         the methods <code>{@linkplain FileObject#getCharContent(boolean)}</code>,

 *         <code>{@linkplain FileObject#openInputStream()}</code>, and

 *         <code>{@linkplain FileObject#openReader(boolean)}</code>

 *         must succeed if the following would succeed (ignoring

 *         encoding issues):

 *         <blockquote>

 *           <pre>new {@linkplain java.io.FileInputStream#FileInputStream(File) FileInputStream}(new {@linkplain File#File(java.net.URI) File}({@linkplain FileObject fileObject}.{@linkplain FileObject#toUri() toUri}()))</pre>

 *         </blockquote>

 *       </li>

 *       <li>

 *         and the methods

 *         <code>{@linkplain FileObject#openOutputStream()}</code>, and

 *         <code>{@linkplain FileObject#openWriter()}</code> must

 *         succeed if the following would succeed (ignoring encoding

 *         issues):

 *         <blockquote>

 *           <pre>new {@linkplain java.io.FileOutputStream#FileOutputStream(File) FileOutputStream}(new {@linkplain File#File(java.net.URI) File}({@linkplain FileObject fileObject}.{@linkplain FileObject#toUri() toUri}()))</pre>

 *         </blockquote>

 *       </li>

 *     </ul>

 *   </li>

 *   <li>

 *     The {@linkplain java.net.URI URI} returned from

 *     <code>{@linkplain FileObject#toUri()}</code>

 *     <ul>

 *       <li>

 *         must be {@linkplain java.net.URI#isAbsolute() absolute} (have a schema), and

 *       </li>

 *       <li>

 *         must have a {@linkplain java.net.URI#normalize() normalized}

 *         {@linkplain java.net.URI#getPath() path component} which

 *         can be resolved without any process-specific context such

 *         as the current directory (file names must be absolute).

 *       </li>

 *     </ul>

 *   </li>

 * </ul>

 *

 * According to these rules, the following URIs, for example, are

 * allowed:

 * <ul>

 *   <li>

 *     <code>file:///C:/Documents%20and%20Settings/UncleBob/BobsApp/Test.java</code>

 *   </li>

 *   <li>

 *     <code>jar:///C:/Documents%20and%20Settings/UncleBob/lib/vendorA.jar!/com/vendora/LibraryClass.class</code>

 *   </li>

 * </ul>

 * Whereas these are not (reason in parentheses):

 * <ul>

 *   <li>

 *     <code>file:BobsApp/Test.java</code> (the file name is relative

 *     and depend on the current directory)

 *   </li>

 *   <li>

 *     <code>jar:lib/vendorA.jar!/com/vendora/LibraryClass.class</code>

 *     (the first half of the path depends on the current directory,

 *     whereas the component after ! is legal)

 *   </li>

 *   <li>

 *     <code>Test.java</code> (this URI depends on the current

 *     directory and does not have a schema)

 *   </li>

 *   <li>

 *     <code>jar:///C:/Documents%20and%20Settings/UncleBob/BobsApp/../lib/vendorA.jar!com/vendora/LibraryClass.class</code>

 *     (the path is not normalized)

 *   </li>

 * </ul>

 *

 * <p>All implementations of this interface must support Path objects representing

 * files in the {@linkplain java.nio.file.FileSystems#getDefault() default file system.}

 * It is recommended that implementations should support Path objects from any filesystem.</p>

 *

 *

 * @apiNote

 * Some methods on this interface take a {@code Collection<? extends Path>}

 * instead of {@code Iterable<? extends Path>}.

 * This is to prevent the possibility of accidentally calling the method

 * with a single {@code Path} as such an argument, because although

 * {@code Path} implements {@code Iterable<Path>}, it would almost never be

 * correct to call these methods with a single {@code Path} and have it be treated as

 * an {@code Iterable} of its components.

 *

 *

 * @author Peter von der Ahé

 * @since 1.6

 */

public interface StandardJavaFileManager extends JavaFileManager {

    /**

     * Compares two file objects and return true if they represent the

     * same canonical file, zip file entry, or entry in any file

     * system based container.

     *

     * @param a a file object

     * @param b a file object

     * @return true if the given file objects represent the same

     * canonical file, zip file entry or path; false otherwise

     *

     * @throws IllegalArgumentException if either of the arguments

     * were created with another file manager implementation

     */

    @Override

    boolean isSameFile(FileObject a, FileObject b);

    /**

     * Returns file objects representing the given files.

     *

     * @param files a list of files

     * @return a list of file objects

     * @throws IllegalArgumentException if the list of files includes

     * a directory

     */

    Iterable<? extends JavaFileObject> getJavaFileObjectsFromFiles(

        Iterable<? extends File> files);

    /**

     * Returns file objects representing the given paths.

     *

     * @implSpec

     * The default implementation converts each path to a file and calls

     * {@link #getJavaFileObjectsFromFiles getJavaObjectsFromFiles}.

     * IllegalArgumentException will be thrown if any of the paths

     * cannot be converted to a file.

     *

     * @param paths a list of paths

     * @return a list of file objects

     * @throws IllegalArgumentException if the list of paths includes

     * a directory or if this file manager does not support any of the

     * given paths.

     *

     * @since 9

     */

    default Iterable<? extends JavaFileObject> getJavaFileObjectsFromPaths(

            Iterable<? extends Path> paths) {

        return getJavaFileObjectsFromFiles(asFiles(paths));

    }

    /**

     * Returns file objects representing the given files.

     * Convenience method equivalent to:

     *

     * <pre>

     *     getJavaFileObjectsFromFiles({@linkplain java.util.Arrays#asList Arrays.asList}(files))

     * </pre>

     *

     * @param files an array of files

     * @return a list of file objects

     * @throws IllegalArgumentException if the array of files includes

     * a directory

     * @throws NullPointerException if the given array contains null

     * elements

     */

    Iterable<? extends JavaFileObject> getJavaFileObjects(File... files);

    /**

     * Returns file objects representing the given paths.

     * Convenience method equivalent to:

     *

     * <pre>

     *     getJavaFileObjectsFromPaths({@linkplain java.util.Arrays#asList Arrays.asList}(paths))

     * </pre>

     *

     * @param paths an array of paths

     * @return a list of file objects

     * @throws IllegalArgumentException if the array of files includes

     * a directory

     * @throws NullPointerException if the given array contains null

     * elements

     *

     * @since 9

     */

    default Iterable<? extends JavaFileObject> getJavaFileObjects(Path... paths) {

        return getJavaFileObjectsFromPaths(Arrays.asList(paths));

    }

    /**

     * Returns file objects representing the given file names.

     *

     * @param names a list of file names

     * @return a list of file objects

     * @throws IllegalArgumentException if the list of file names

     * includes a directory

     */

    Iterable<? extends JavaFileObject> getJavaFileObjectsFromStrings(

        Iterable<String> names);

    /**

     * Returns file objects representing the given file names.

     * Convenience method equivalent to:

     *

     * <pre>

     *     getJavaFileObjectsFromStrings({@linkplain java.util.Arrays#asList Arrays.asList}(names))

     * </pre>

     *

     * @param names a list of file names

     * @return a list of file objects

     * @throws IllegalArgumentException if the array of file names

     * includes a directory

     * @throws NullPointerException if the given array contains null

     * elements

     */

    Iterable<? extends JavaFileObject> getJavaFileObjects(String... names);

    /**

     * Associates the given search path with the given location.  Any

     * previous value will be discarded.

     *

     * If the location is a module-oriented or output location, any module-specific

     * associations set up by {@linkplain #setLocationForModule setLocationForModule}

     * will be cancelled.

     *

     * @param location a location

     * @param files a list of files, if {@code null} use the default

     * search path for this location

     * @see #getLocation

     * @throws IllegalArgumentException if {@code location} is an output

     * location and {@code files} does not contain exactly one element

     * @throws IOException if {@code location} is an output location and

     * does not represent an existing directory

     */

    void setLocation(Location location, Iterable<? extends File> files)

        throws IOException;

    /**

     * Associates the given search path with the given location.

     * Any previous value will be discarded.

     *

     * If the location is a module-oriented or output location, any module-specific

     * associations set up by {@linkplain #setLocationForModule setLocationForModule}

     * will be cancelled.

     *

     * @implSpec

     * The default implementation converts each path to a file and calls

     * {@link #getJavaFileObjectsFromFiles getJavaObjectsFromFiles}.

     * {@linkplain IllegalArgumentException IllegalArgumentException}

     * will be thrown if any of the paths cannot be converted to a file.

     *

     * @param location a location

     * @param paths a list of paths, if {@code null} use the default

     * search path for this location

     * @see #getLocation

     * @throws IllegalArgumentException if {@code location} is an output

     * location and {@code paths} does not contain exactly one element

     * or if this file manager does not support any of the given paths

     * @throws IOException if {@code location} is an output location and

     * {@code paths} does not represent an existing directory

     *

     * @since 9

     */

    default void setLocationFromPaths(Location location, Collection<? extends Path> paths)

            throws IOException {

        setLocation(location, asFiles(paths));

    }

    /**

     * Associates the given search path with the given module and location,

     * which must be a module-oriented or output location.

     * Any previous value will be discarded.

     * This overrides any default association derived from the search path

     * associated with the location itself.

     *

     * All such module-specific associations will be cancelled if a

     * new search path is associated with the location by calling

     * {@linkplain #setLocation setLocation } or

     * {@linkplain #setLocationFromPaths setLocationFromPaths}.

     *

     * @throws IllegalStateException if the location is not a module-oriented

     *  or output location.

     * @throws UnsupportedOperationException if this operation is not supported by

     *  this file manager.

     * @throws IOException if {@code location} is an output location and

     * {@code paths} does not represent an existing directory

     *

     * @param location the location

     * @param moduleName the name of the module

     * @param paths the search path to associate with the location and module.

     *

     * @see setLocation

     * @see setLocationFromPaths

     *

     * @since 9

     */

    default void setLocationForModule(Location location, String moduleName,

            Collection<? extends Path> paths) throws IOException {

        throw new UnsupportedOperationException();

    }

    /**

     * Returns the search path associated with the given location.

     *

     * @param location a location

     * @return a list of files or {@code null} if this location has no

     * associated search path

     * @throws IllegalStateException if any element of the search path

     * cannot be converted to a {@linkplain File}, or if the search path

     * cannot be represented as a simple series of files.

     *

     * @see #setLocation

     * @see Path#toFile

     */

    Iterable<? extends File> getLocation(Location location);

    /**

     * Returns the search path associated with the given location.

     *

     * @implSpec

     * The default implementation calls {@link #getLocation getLocation}

     * and then returns an {@code Iterable} formed by calling {@code toPath()}

     * on each {@code File} returned from {@code getLocation}.

     *

     * @param location a location

     * @return a list of paths or {@code null} if this location has no

     * associated search path

     * @throws IllegalStateException if the search path cannot be represented

     * as a simple series of paths.

     *

     * @see #setLocationFromPaths

     * @since 9

     */

    default Iterable<? extends Path> getLocationAsPaths(Location location) {

        return asPaths(getLocation(location));

    }

    /**

     * Returns the path, if any, underlying this file object (optional operation).

     * File objects derived from a {@link java.nio.file.FileSystem FileSystem},

     * including the default file system, typically have a corresponding underlying

     * {@link java.nio.file.Path Path} object. In such cases, this method may be

     * used to access that object.

     *

     * @implSpec

     * The default implementation throws {@link UnsupportedOperationException}

     * for all files.

     *

     * @param file a file object

     * @return a path representing the same underlying file system artifact

     * @throws IllegalArgumentException if the file object does not have an underlying path

     * @throws UnsupportedOperationException if the operation is not supported by this file manager

     *

     * @since 9

     */

    default Path asPath(FileObject file) {

        throw new UnsupportedOperationException();

    }

    /**

     * Factory to create {@code Path} objects from strings.

     *

     * @since 9

     */

    interface PathFactory {

        /**

         * Converts a path string, or a sequence of strings that when joined form a path string, to a Path.

         *

         * @param first  the path string or initial part of the path string

         * @param more   additional strings to be joined to form the path string

         * @return       the resulting {@code Path}

         */

        Path getPath(String first, String... more);

    }

     /**

      * Specify a factory that can be used to generate a path from a string, or series of strings.

      *

      * If this method is not called, a factory whose {@code getPath} method is

      * equivalent to calling

      * {@link java.nio.file.Paths#get(String, String...) java.nio.file.Paths.get(first, more)}

      * will be used.

      *

      * @implSpec

      * The default implementation of this method ignores the factory that is provided.

      *

      * @param f  the factory

      *

      * @since 9

      */

    default void setPathFactory(PathFactory f) { }

    private static Iterable<Path> asPaths(final Iterable<? extends File> files) {

        return () -> new Iterator<Path>() {

            Iterator<? extends File> iter = files.iterator();

            @Override

            public boolean hasNext() {

                return iter.hasNext();

            }

            @Override

            public Path next() {

                return iter.next().toPath();

            }

        };

    }

    private static Iterable<File> asFiles(final Iterable<? extends Path> paths) {

        return () -> new Iterator<File>() {

            Iterator<? extends Path> iter = paths.iterator();

            @Override

            public boolean hasNext() {

                return iter.hasNext();

            }

            @Override

            public File next() {

                Path p = iter.next();

                try {

                    return p.toFile();

                } catch (UnsupportedOperationException e) {

                    throw new IllegalArgumentException(p.toString(), e);

                }

            }

        };

    }

}