/*

 * Copyright (c) 2012, 2015, 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.sjavac;

import java.io.File;

import java.io.IOException;

import java.nio.file.FileSystem;

import java.nio.file.FileVisitResult;

import java.nio.file.Files;

import java.nio.file.Path;

import java.nio.file.PathMatcher;

import java.nio.file.SimpleFileVisitor;

import java.nio.file.attribute.BasicFileAttributes;

import java.util.Set;

import java.util.Collections;

import java.util.List;

import java.util.ArrayList;

import java.util.Map;

import java.util.regex.PatternSyntaxException;

/** A Source object maintains information about a source file.

 * For example which package it belongs to and kind of source it is.

 * The class also knows how to find source files (scanRoot) given include/exclude

 * patterns and a root.

 *

 *  <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 Source implements Comparable<Source> {

    // The package the source belongs to.

   private Package pkg;

    // Name of this source file, relative its source root.

    // For example: java/lang/Object.java

    // Or if the source file is inside a module:

    // jdk.base/java/lang/Object.java

    private String name;

    // What kind of file is this.

    private String suffix;

    // When this source file was last_modified

    private long lastModified;

    // The source File.

    private File file;

    // If the source is generated.

    private boolean isGenerated;

    // If the source is only linked to, not compiled.

    private boolean linkedOnly;

    @Override

    public boolean equals(Object o) {

        return (o instanceof Source) && name.equals(((Source)o).name);

    }

    @Override

    public int compareTo(Source o) {

        return name.compareTo(o.name);

    }

    @Override

    public int hashCode() {

        return name.hashCode();

    }

    public Source(Module m, String n, File f) {

        name = n;

        int dp = n.lastIndexOf(".");

        if (dp != -1) {

            suffix = n.substring(dp);

        } else {

            suffix = "";

        }

        file = f;

        lastModified = f.lastModified();

        linkedOnly = false;

    }

    public Source(Package p, String n, long lm) {

        pkg = p;

        name = n;

        int dp = n.lastIndexOf(".");

        if (dp != -1) {

            suffix = n.substring(dp);

        } else {

            suffix = "";

        }

        file = null;

        lastModified = lm;

        linkedOnly = false;

        int ls = n.lastIndexOf('/');

    }

    public String name() { return name; }

    public String suffix() { return suffix; }

    public Package pkg() { return pkg; }

    public File   file() { return file; }

    public long lastModified() {

        return lastModified;

    }

    public void setPackage(Package p) {

        pkg = p;

    }

    public void markAsGenerated() {

        isGenerated = true;

    }

    public boolean isGenerated() {

        return isGenerated;

    }

    public void markAsLinkedOnly() {

        linkedOnly = true;

    }

    public boolean isLinkedOnly() {

        return linkedOnly;

    }

    private void save(StringBuilder b) {

        String CL = linkedOnly?"L":"C";

        String GS = isGenerated?"G":"S";

        b.append(GS+" "+CL+" "+name+" "+file.lastModified()+"\n");

    }

    // Parse a line that looks like this:

    // S C /code/alfa/A.java 1357631228000

    static public Source load(Package lastPackage, String l, boolean isGenerated) {

        int sp = l.indexOf(' ',4);

        if (sp == -1) return null;

        String name = l.substring(4,sp);

        long last_modified = Long.parseLong(l.substring(sp+1));

        boolean isLinkedOnly = false;

        if (l.charAt(2) == 'L') {

            isLinkedOnly = true;

        } else if (l.charAt(2) == 'C') {

            isLinkedOnly = false;

        } else return null;

        Source s = new Source(lastPackage, name, last_modified);

        s.file = new File(name);

        if (isGenerated) s.markAsGenerated();

        if (isLinkedOnly) s.markAsLinkedOnly();

        return s;

    }

    public static void saveSources(Map<String,Source> sources, StringBuilder b) {

        List<String> sorted_sources = new ArrayList<>();

        for (String key : sources.keySet()) {

            sorted_sources.add(key);

        }

        Collections.sort(sorted_sources);

        for (String key : sorted_sources) {

            Source s = sources.get(key);

            s.save(b);

        }

    }

    /**

     * Recurse into the directory root and find all files matchine the excl/incl/exclfiles/inclfiles rules.

     * Detects the existence of module-info.java files and presumes that the directory it resides in

     * is the name of the current module.

     */

    static public void scanRoot(File root,

                                Set<String> suffixes,

                                List<String> excludes,

                                List<String> includes,

                                Map<String,Source> foundFiles,

                                Map<String,Module> foundModules,

                                final Module currentModule,

                                boolean permitSourcesWithoutPackage,

                                boolean inGensrc,

                                boolean inLinksrc)

                                        throws IOException, ProblemException {

        if (root == null)

            return;

        FileSystem fs = root.toPath().getFileSystem();

        if (includes.isEmpty()) {

            includes = Collections.singletonList("**");

        }

        List<PathMatcher> includeMatchers = createPathMatchers(fs, includes);

        List<PathMatcher> excludeMatchers = createPathMatchers(fs, excludes);

        Files.walkFileTree(root.toPath(), new SimpleFileVisitor<Path>() {

            @Override

            public FileVisitResult visitFile(Path file, BasicFileAttributes attrs) throws IOException {

                Path relToRoot = root.toPath().relativize(file);

                if (includeMatchers.stream().anyMatch(im -> im.matches(relToRoot))

                        && excludeMatchers.stream().noneMatch(em -> em.matches(relToRoot))

                        && suffixes.contains(Util.fileSuffix(file))) {

                    // TODO: Test this.

                    Source existing = foundFiles.get(file);

                    if (existing != null) {

                        throw new IOException("You have already added the file "+file+" from "+existing.file().getPath());

                    }

                    existing = currentModule.lookupSource(file.toString());

                    if (existing != null) {

                            // Oups, the source is already added, could be ok, could be not, lets check.

                            if (inLinksrc) {

                                // So we are collecting sources for linking only.

                                if (existing.isLinkedOnly()) {

                                    // Ouch, this one is also for linking only. Bad.

                                    throw new IOException("You have already added the link only file " + file + " from " + existing.file().getPath());

                                }

                                // Ok, the existing source is to be compiled. Thus this link only is redundant

                                // since all compiled are also linked to. Continue to the next source.

                                // But we need to add the source, so that it will be visible to linking,

                                // if not the multi core compile will fail because a JavaCompiler cannot

                                // find the necessary dependencies for its part of the source.

                                foundFiles.put(file.toString(), existing);

                            } else {

                                // We are looking for sources to compile, if we find an existing to be compiled

                                // source with the same name, it is an internal error, since we must

                                // find the sources to be compiled before we find the sources to be linked to.

                                throw new IOException("Internal error: Double add of file " + file + " from " + existing.file().getPath());

                            }

                    } else {

                        //////////////////////////////////////////////////////////////

                        // Add source

                        Source s = new Source(currentModule, file.toString(), file.toFile());

                        if (inGensrc) {

                            s.markAsGenerated();

                        }

                        if (inLinksrc) {

                            s.markAsLinkedOnly();

                        }

                        String pkg = packageOfJavaFile(root.toPath(), file);

                        pkg = currentModule.name() + ":" + pkg;

                        foundFiles.put(file.toString(), s);

                        currentModule.addSource(pkg, s);

                        //////////////////////////////////////////////////////////////

                    }

                }

                return FileVisitResult.CONTINUE;

            }

        });

    }

    private static List<PathMatcher> createPathMatchers(FileSystem fs, List<String> patterns) {

        List<PathMatcher> matchers = new ArrayList<>();

        for (String pattern : patterns) {

            try {

                matchers.add(fs.getPathMatcher("glob:" + pattern));

            } catch (PatternSyntaxException e) {

                Log.error("Invalid pattern: " + pattern);

                throw e;

            }

        }

        return matchers;

    }

    private static String packageOfJavaFile(Path sourceRoot, Path javaFile) {

        Path javaFileDir = javaFile.getParent();

        Path packageDir = sourceRoot.relativize(javaFileDir);

        List<String> separateDirs = new ArrayList<>();

        for (Path pathElement : packageDir) {

            separateDirs.add(pathElement.getFileName().toString());

        }

        return String.join(".", separateDirs);

    }

    @Override

    public String toString() {

        return String.format("%s[pkg: %s, name: %s, suffix: %s, file: %s, isGenerated: %b, linkedOnly: %b]",

                             getClass().getSimpleName(),

                             pkg,

                             name,

                             suffix,

                             file,

                             isGenerated,

                             linkedOnly);

    }

}