/*

 * Copyright (c) 2003, 2016, 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 com.sun.tools.javac.file;

import java.io.Closeable;

import java.io.File;

import java.io.FileNotFoundException;

import java.io.IOException;

import java.io.UncheckedIOException;

import java.net.URI;

import java.net.URL;

import java.net.URLClassLoader;

import java.nio.file.DirectoryIteratorException;

import java.nio.file.DirectoryStream;

import java.nio.file.FileSystem;

import java.nio.file.FileSystemNotFoundException;

import java.nio.file.FileSystems;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.Paths;

import java.nio.file.ProviderNotFoundException;

import java.nio.file.spi.FileSystemProvider;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.Collections;

import java.util.EnumMap;

import java.util.EnumSet;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.LinkedHashMap;

import java.util.LinkedHashSet;

import java.util.List;

import java.util.Map;

import java.util.Objects;

import java.util.NoSuchElementException;

import java.util.Set;

import java.util.regex.Matcher;

import java.util.regex.Pattern;

import java.util.stream.Collectors;

import java.util.stream.Stream;

import java.util.zip.ZipFile;

import javax.lang.model.SourceVersion;

import javax.tools.JavaFileManager;

import javax.tools.JavaFileManager.Location;

import javax.tools.StandardJavaFileManager;

import javax.tools.StandardJavaFileManager.PathFactory;

import javax.tools.StandardLocation;

import com.sun.tools.javac.code.Lint;

import com.sun.tools.javac.main.Option;

import com.sun.tools.javac.resources.CompilerProperties.Errors;

import com.sun.tools.javac.resources.CompilerProperties.Warnings;

import com.sun.tools.javac.util.DefinedBy;

import com.sun.tools.javac.util.DefinedBy.Api;

import com.sun.tools.javac.util.ListBuffer;

import com.sun.tools.javac.util.Log;

import com.sun.tools.javac.util.Pair;

import com.sun.tools.javac.util.StringUtils;

import static javax.tools.StandardLocation.PLATFORM_CLASS_PATH;

import static com.sun.tools.javac.main.Option.BOOT_CLASS_PATH;

import static com.sun.tools.javac.main.Option.DJAVA_ENDORSED_DIRS;

import static com.sun.tools.javac.main.Option.DJAVA_EXT_DIRS;

import static com.sun.tools.javac.main.Option.ENDORSEDDIRS;

import static com.sun.tools.javac.main.Option.EXTDIRS;

import static com.sun.tools.javac.main.Option.XBOOTCLASSPATH;

import static com.sun.tools.javac.main.Option.XBOOTCLASSPATH_APPEND;

import static com.sun.tools.javac.main.Option.XBOOTCLASSPATH_PREPEND;

/**

 * This class converts command line arguments, environment variables and system properties (in

 * File.pathSeparator-separated String form) into a boot class path, user class path, and source

 * path (in {@code Collection<String>} form).

 *

 * <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 class Locations {

    /**

     * The log to use for warning output

     */

    private Log log;

    /**

     * Access to (possibly cached) file info

     */

    private FSInfo fsInfo;

    /**

     * Whether to warn about non-existent path elements

     */

    private boolean warn;

    private ModuleNameReader moduleNameReader;

    private PathFactory pathFactory = Paths::get;

    static final Path javaHome = FileSystems.getDefault().getPath(System.getProperty("java.home"));

    static final Path thisSystemModules = javaHome.resolve("lib").resolve("modules");

    Map<Path, FileSystem> fileSystems = new LinkedHashMap<>();

    List<Closeable> closeables = new ArrayList<>();

    Locations() {

        initHandlers();

    }

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

        return pathFactory.getPath(first, more);

    }

    public void close() throws IOException {

        ListBuffer<IOException> list = new ListBuffer<>();

        closeables.forEach(closeable -> {

            try {

                closeable.close();

            } catch (IOException ex) {

                list.add(ex);

            }

        });

        if (list.nonEmpty()) {

            IOException ex = new IOException();

            for (IOException e: list)

                ex.addSuppressed(e);

            throw ex;

        }

    }

    // could replace Lint by "boolean warn"

    void update(Log log, Lint lint, FSInfo fsInfo) {

        this.log = log;

        warn = lint.isEnabled(Lint.LintCategory.PATH);

        this.fsInfo = fsInfo;

    }

    void setPathFactory(PathFactory f) {

        pathFactory = f;

    }

    boolean isDefaultBootClassPath() {

        BootClassPathLocationHandler h

                = (BootClassPathLocationHandler) getHandler(PLATFORM_CLASS_PATH);

        return h.isDefault();

    }

    /**

     * Split a search path into its elements. Empty path elements will be ignored.

     *

     * @param searchPath The search path to be split

     * @return The elements of the path

     */

    private Iterable<Path> getPathEntries(String searchPath) {

        return getPathEntries(searchPath, null);

    }

    /**

     * Split a search path into its elements. If emptyPathDefault is not null, all empty elements in the

     * path, including empty elements at either end of the path, will be replaced with the value of

     * emptyPathDefault.

     *

     * @param searchPath The search path to be split

     * @param emptyPathDefault The value to substitute for empty path elements, or null, to ignore

     * empty path elements

     * @return The elements of the path

     */

    private Iterable<Path> getPathEntries(String searchPath, Path emptyPathDefault) {

        ListBuffer<Path> entries = new ListBuffer<>();

        for (String s: searchPath.split(Pattern.quote(File.pathSeparator), -1)) {

            if (s.isEmpty()) {

                if (emptyPathDefault != null) {

                    entries.add(emptyPathDefault);

                }

            } else {

                entries.add(getPath(s));

            }

        }

        return entries;

    }

    /**

     * Utility class to help evaluate a path option. Duplicate entries are ignored, jar class paths

     * can be expanded.

     */

    private class SearchPath extends LinkedHashSet<Path> {

        private static final long serialVersionUID = 0;

        private boolean expandJarClassPaths = false;

        private final Set<Path> canonicalValues = new HashSet<>();

        public SearchPath expandJarClassPaths(boolean x) {

            expandJarClassPaths = x;

            return this;

        }

        /**

         * What to use when path element is the empty string

         */

        private Path emptyPathDefault = null;

        public SearchPath emptyPathDefault(Path x) {

            emptyPathDefault = x;

            return this;

        }

        public SearchPath addDirectories(String dirs, boolean warn) {

            boolean prev = expandJarClassPaths;

            expandJarClassPaths = true;

            try {

                if (dirs != null) {

                    for (Path dir : getPathEntries(dirs)) {

                        addDirectory(dir, warn);

                    }

                }

                return this;

            } finally {

                expandJarClassPaths = prev;

            }

        }

        public SearchPath addDirectories(String dirs) {

            return addDirectories(dirs, warn);

        }

        private void addDirectory(Path dir, boolean warn) {

            if (!Files.isDirectory(dir)) {

                if (warn) {

                    log.warning(Lint.LintCategory.PATH,

                            "dir.path.element.not.found", dir);

                }

                return;

            }

            try (Stream<Path> s = Files.list(dir)) {

                s.filter(dirEntry -> isArchive(dirEntry))

                        .forEach(dirEntry -> addFile(dirEntry, warn));

            } catch (IOException ignore) {

            }

        }

        public SearchPath addFiles(String files, boolean warn) {

            if (files != null) {

                addFiles(getPathEntries(files, emptyPathDefault), warn);

            }

            return this;

        }

        public SearchPath addFiles(String files) {

            return addFiles(files, warn);

        }

        public SearchPath addFiles(Iterable<? extends Path> files, boolean warn) {

            if (files != null) {

                for (Path file : files) {

                    addFile(file, warn);

                }

            }

            return this;

        }

        public SearchPath addFiles(Iterable<? extends Path> files) {

            return addFiles(files, warn);

        }

        public void addFile(Path file, boolean warn) {

            if (contains(file)) {

                // discard duplicates

                return;

            }

            if (!fsInfo.exists(file)) {

                /* No such file or directory exists */

                if (warn) {

                    log.warning(Lint.LintCategory.PATH,

                            "path.element.not.found", file);

                }

                super.add(file);

                return;

            }

            Path canonFile = fsInfo.getCanonicalFile(file);

            if (canonicalValues.contains(canonFile)) {

                /* Discard duplicates and avoid infinite recursion */

                return;

            }

            if (fsInfo.isFile(file)) {

                /* File is an ordinary file. */

                if (   !file.getFileName().toString().endsWith(".jmod")

                    && !file.endsWith("modules")) {

                    if (!isArchive(file)) {

                        /* Not a recognized extension; open it to see if

                         it looks like a valid zip file. */

                        try {

                            FileSystems.newFileSystem(file, null).close();

                            if (warn) {

                                log.warning(Lint.LintCategory.PATH,

                                        "unexpected.archive.file", file);

                            }

                        } catch (IOException | ProviderNotFoundException e) {

                            // FIXME: include e.getLocalizedMessage in warning

                            if (warn) {

                                log.warning(Lint.LintCategory.PATH,

                                        "invalid.archive.file", file);

                            }

                            return;

                        }

                    } else {

                        if (fsInfo.getJarFSProvider() == null) {

                            log.error(Errors.NoZipfsForArchive(file));

                            return ;

                        }

                    }

                }

            }

            /* Now what we have left is either a directory or a file name

             conforming to archive naming convention */

            super.add(file);

            canonicalValues.add(canonFile);

            if (expandJarClassPaths && fsInfo.isFile(file) && !file.endsWith("modules")) {

                addJarClassPath(file, warn);

            }

        }

        // Adds referenced classpath elements from a jar's Class-Path

        // Manifest entry.  In some future release, we may want to

        // update this code to recognize URLs rather than simple

        // filenames, but if we do, we should redo all path-related code.

        private void addJarClassPath(Path jarFile, boolean warn) {

            try {

                for (Path f : fsInfo.getJarClassPath(jarFile)) {

                    addFile(f, warn);

                }

            } catch (IOException e) {

                log.error("error.reading.file", jarFile, JavacFileManager.getMessage(e));

            }

        }

    }

    /**

     * Base class for handling support for the representation of Locations.

     *

     * Locations are (by design) opaque handles that can easily be implemented

     * by enums like StandardLocation. Within JavacFileManager, each Location

     * has an associated LocationHandler, which provides much of the appropriate

     * functionality for the corresponding Location.

     *

     * @see #initHandlers

     * @see #getHandler

     */

    protected abstract class LocationHandler {

        /**

         * @see JavaFileManager#handleOption

         */

        abstract boolean handleOption(Option option, String value);

        /**

         * @see StandardJavaFileManager#hasLocation

         */

        boolean isSet() {

            return (getPaths() != null);

        }

        /**

         * @see StandardJavaFileManager#getLocation

         */

        abstract Collection<Path> getPaths();

        /**

         * @see StandardJavaFileManager#setLocation

         */

        abstract void setPaths(Iterable<? extends Path> files) throws IOException;

        /**

         * @see JavaFileManager#getModuleLocation(Location, String)

         */

        Location getModuleLocation(String moduleName) throws IOException {

            return null;

        }

        /**

         * @see JavaFileManager#getModuleLocation(Location, JavaFileObject, String)

         */

        Location getModuleLocation(Path dir) {

            return null;

        }

        /**

         * @see JavaFileManager#inferModuleName

         */

        String inferModuleName() {

            return null;

        }

        /**

         * @see JavaFileManager#listModuleLocations

         */

        Iterable<Set<Location>> listModuleLocations() throws IOException {

            return null;

        }

    }

    /**

     * A LocationHandler for a given Location, and associated set of options.

     */

    private abstract class BasicLocationHandler extends LocationHandler {

        final Location location;

        final Set<Option> options;

        /**

         * Create a handler. The location and options provide a way to map from a location or an

         * option to the corresponding handler.

         *

         * @param location the location for which this is the handler

         * @param options the options affecting this location

         * @see #initHandlers

         */

        protected BasicLocationHandler(Location location, Option... options) {

            this.location = location;

            this.options = options.length == 0

                    ? EnumSet.noneOf(Option.class)

                    : EnumSet.copyOf(Arrays.asList(options));

        }

    }

    /**

     * General purpose implementation for output locations, such as -d/CLASS_OUTPUT and

     * -s/SOURCE_OUTPUT. All options are treated as equivalent (i.e. aliases.)

     * The value is a single file, possibly null.

     */

    private class OutputLocationHandler extends BasicLocationHandler {

        private Path outputDir;

        private Map<String, Location> moduleLocations;

        OutputLocationHandler(Location location, Option... options) {

            super(location, options);

        }

        @Override

        boolean handleOption(Option option, String value) {

            if (!options.contains(option)) {

                return false;

            }

            // TODO: could/should validate outputDir exists and is a directory

            // need to decide how best to report issue for benefit of

            // direct API call on JavaFileManager.handleOption(specifies IAE)

            // vs. command line decoding.