/*

 * Copyright (c) 2003, 2012, 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.FileNotFoundException;

import java.util.Iterator;

import java.io.File;

import java.io.IOException;

import java.net.MalformedURLException;

import java.net.URL;

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.LinkedHashSet;

import java.util.Map;

import java.util.Set;

import java.util.StringTokenizer;

import java.util.zip.ZipFile;

import javax.tools.JavaFileManager.Location;

import javax.tools.StandardLocation;

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

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

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

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

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

import javax.tools.JavaFileManager;

import static javax.tools.StandardLocation.*;

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

/** 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

 *  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;

    /** Collection of command-line options */

    private Options options;

    /** Handler for -Xlint options */

    private Lint lint;

    /** Access to (possibly cached) file info */

    private FSInfo fsInfo;

    /** Whether to warn about non-existent path elements */

    private boolean warn;

    // TODO: remove need for this

    private boolean inited = false; // TODO? caching bad?

    public Locations() {

        initHandlers();

    }

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

        this.log = log;

        this.options = options;

        this.lint = lint;

        this.fsInfo = fsInfo;

    }

    public Collection<File> bootClassPath() {

        return getLocation(PLATFORM_CLASS_PATH);

    }

    public boolean isDefaultBootClassPath() {

        BootClassPathLocationHandler h =

                (BootClassPathLocationHandler) getHandler(PLATFORM_CLASS_PATH);

        return h.isDefault();

    }

    boolean isDefaultBootClassPathRtJar(File file) {

        BootClassPathLocationHandler h =

                (BootClassPathLocationHandler) getHandler(PLATFORM_CLASS_PATH);

        return h.isDefaultRtJar(file);

    }

    public Collection<File> userClassPath() {

        return getLocation(CLASS_PATH);

    }

    public Collection<File> sourcePath() {

        Collection<File> p = getLocation(SOURCE_PATH);

        // TODO: this should be handled by the LocationHandler

        return p == null || p.isEmpty() ? null : p;

    }

    /**

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

     * @param path The path to be split

     * @return The elements of the path

     */

    private static Iterable<File> getPathEntries(String path) {

        return getPathEntries(path, null);

    }

    /**

     * Split a 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 path The 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 static Iterable<File> getPathEntries(String path, File emptyPathDefault) {

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

        int start = 0;

        while (start <= path.length()) {

            int sep = path.indexOf(File.pathSeparatorChar, start);

            if (sep == -1)

                sep = path.length();

            if (start < sep)

                entries.add(new File(path.substring(start, sep)));

            else if (emptyPathDefault != null)

                entries.add(emptyPathDefault);

            start = sep + 1;

        }

        return entries;

    }

    /**

     * Utility class to help evaluate a path option.

     * Duplicate entries are ignored, jar class paths can be expanded.

     */

    private class Path extends LinkedHashSet<File> {

        private static final long serialVersionUID = 0;

        private boolean expandJarClassPaths = false;

        private Set<File> canonicalValues = new HashSet<File>();

        public Path expandJarClassPaths(boolean x) {

            expandJarClassPaths = x;

            return this;

        }

        /** What to use when path element is the empty string */

        private File emptyPathDefault = null;

        public Path emptyPathDefault(File x) {

            emptyPathDefault = x;

            return this;

        }

        public Path() { super(); }

        public Path addDirectories(String dirs, boolean warn) {

            boolean prev = expandJarClassPaths;

            expandJarClassPaths = true;

            try {

                if (dirs != null)

                    for (File dir : getPathEntries(dirs))

                        addDirectory(dir, warn);

                return this;

            } finally {

                expandJarClassPaths = prev;

            }

        }

        public Path addDirectories(String dirs) {

            return addDirectories(dirs, warn);

        }

        private void addDirectory(File dir, boolean warn) {

            if (!dir.isDirectory()) {

                if (warn)

                    log.warning(Lint.LintCategory.PATH,

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

                return;

            }

            File[] files = dir.listFiles();

            if (files == null)

                return;

            for (File direntry : files) {

                if (isArchive(direntry))

                    addFile(direntry, warn);

            }

        }

        public Path addFiles(String files, boolean warn) {

            if (files != null) {

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

            }

            return this;

        }

        public Path addFiles(String files) {

            return addFiles(files, warn);

        }

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

            if (files != null) {

                for (File file: files)

                    addFile(file, warn);

            }

            return this;

        }

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

            return addFiles(files, warn);

        }

        public void addFile(File 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;

            }

            File 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 (!isArchive(file)) {

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

                     it looks like a valid zip file. */

                    try {

                        ZipFile z = new ZipFile(file);

                        z.close();

                        if (warn) {

                            log.warning(Lint.LintCategory.PATH,

                                    "unexpected.archive.file", file);

                        }

                    } catch (IOException e) {

                        // FIXME: include e.getLocalizedMessage in warning

                        if (warn) {

                            log.warning(Lint.LintCategory.PATH,

                                    "invalid.archive.file", 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))

                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(File jarFile, boolean warn) {

            try {

                for (File 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.

     * Implementations are responsible for handling the interactions between

     * the command line options for a location, and API access via setLocation.

     * @see #initHandlers

     * @see #getHandler

     */

    protected abstract class 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.

         * @see #initHandlers

         */

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

            this.location = location;

            this.options = options.length == 0 ?

                EnumSet.noneOf(Option.class):

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

        }

        // TODO: TEMPORARY, while Options still used for command line options

        void update(Options optionTable) {

            for (Option o: options) {

                String v = optionTable.get(o);

                if (v != null) {

                    handleOption(o, v);

                }

            }

        }

        /** @see JavaFileManager#handleOption. */

        abstract boolean handleOption(Option option, String value);

        /** @see JavaFileManager#getLocation. */

        abstract Collection<File> getLocation();

        /** @see JavaFileManager#setLocation. */

        abstract void setLocation(Iterable<? extends File> files) throws IOException;

    }

    /**

     * 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 LocationHandler {

        private File outputDir;

        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.

            outputDir = new File(value);

            return true;

        }

        @Override

        Collection<File> getLocation() {

            return (outputDir == null) ? null : Collections.singleton(outputDir);

        }

        @Override

        void setLocation(Iterable<? extends File> files) throws IOException {

            if (files == null) {

                outputDir = null;

            } else {

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

                if (!pathIter.hasNext())

                    throw new IllegalArgumentException("empty path for directory");

                File dir = pathIter.next();

                if (pathIter.hasNext())

                    throw new IllegalArgumentException("path too long for directory");

                if (!dir.exists())

                    throw new FileNotFoundException(dir + ": does not exist");

                else if (!dir.isDirectory())

                    throw new IOException(dir + ": not a directory");

                outputDir = dir;

            }

        }

    }

    /**

     * General purpose implementation for search path locations,

     * such as -sourcepath/SOURCE_PATH and -processorPath/ANNOTATION_PROCESS_PATH.

     * All options are treated as equivalent (i.e. aliases.)

     * The value is an ordered set of files and/or directories.

     */

    private class SimpleLocationHandler extends LocationHandler {

        protected Collection<File> searchPath;

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

            super(location, options);

        }

        @Override

        boolean handleOption(Option option, String value) {

            if (!options.contains(option))

                return false;

            searchPath = value == null ? null :

                    Collections.unmodifiableCollection(computePath(value));

            return true;

        }

        protected Path computePath(String value) {

            return new Path().addFiles(value);

        }

        @Override

        Collection<File> getLocation() {

            return searchPath;

        }

        @Override

        void setLocation(Iterable<? extends File> files) {

            Path p;

            if (files == null) {

                p = computePath(null);

            } else {

                p = new Path().addFiles(files);

            }

            searchPath = Collections.unmodifiableCollection(p);

        }

    }

    /**

     * Subtype of SimpleLocationHandler for -classpath/CLASS_PATH.

     * If no value is given, a default is provided, based on system properties

     * and other values.

     */

    private class ClassPathLocationHandler extends SimpleLocationHandler {

        ClassPathLocationHandler() {

            super(StandardLocation.CLASS_PATH,

                    Option.CLASSPATH, Option.CP);

        }

        @Override

        Collection<File> getLocation() {

            lazy();

            return searchPath;

        }

        @Override

        protected Path computePath(String value) {

            String cp = value;

            // CLASSPATH environment variable when run from `javac'.

            if (cp == null) cp = System.getProperty("env.class.path");

            // If invoked via a java VM (not the javac launcher), use the

            // platform class path

            if (cp == null && System.getProperty("application.home") == null)

                cp = System.getProperty("java.class.path");

            // Default to current working directory.

            if (cp == null) cp = ".";

            return new Path()

                .expandJarClassPaths(true)        // Only search user jars for Class-Paths

                .emptyPathDefault(new File("."))  // Empty path elt ==> current directory

                .addFiles(cp);

            }

        private void lazy() {

            if (searchPath == null)

                setLocation(null);

        }

    }

    /**

     * Custom subtype of LocationHandler for PLATFORM_CLASS_PATH.

     * Various options are supported for different components of the

     * platform class path.

     * Setting a value with setLocation overrides all existing option values.

     * Setting any option overrides any value set with setLocation, and reverts

     * to using default values for options that have not been set.