/*
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 *
 * Copyright (c) 2012 Oracle and/or its affiliates. All rights reserved.
 *
 * The contents of this file are subject to the terms of either the GNU
 * General Public License Version 2 only ("GPL") or the Common Development
 * and Distribution License("CDDL") (collectively, the "License").  You
 * may not use this file except in compliance with the License.  You can
 * obtain a copy of the License at
 * http://glassfish.java.net/public/CDDL+GPL_1_1.html
 * or packager/legal/LICENSE.txt.  See the License for the specific
 * language governing permissions and limitations under the License.
 *
 * When distributing the software, include this License Header Notice in each
 * file and include the License file at packager/legal/LICENSE.txt.
 *
 * GPL Classpath Exception:
 * Oracle designates this particular file as subject to the "Classpath"
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 * file that accompanied this code.
 *
 * Modifications:
 * If applicable, add the following below the License Header, with the fields
 * enclosed by brackets [] replaced by your own identifying information:
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 */
package org.glassfish.jersey.server.internal.scanning;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.NoSuchElementException;
import java.util.Stack;

import org.glassfish.jersey.internal.util.Tokenizer;
import org.glassfish.jersey.server.ResourceFinder;

/**
 * A scanner that recursively scans directories and jar files.
 * Files or jar entries are reported to a {@link ResourceProcessor}.
 *
 * @author Paul Sandoz
 */
public class FilesScanner implements ResourceFinder {

    private ResourceFinderStack resourceFinderStack = new ResourceFinderStack();

    private final File[] files;
    private final boolean recursive;

    /**
     * Scan from a set of packages.
     *
     * @param fileNames an array of package names.
     * @param recursive flag indicating whether sub-directories of any directories in the list of
     *                  files should be included in the scanning ({@code true}) or not ({@code false}).
     */
    public FilesScanner(final String[] fileNames, boolean recursive) {
        this.recursive = recursive;
        this.files = new File[Tokenizer.tokenize(fileNames, Tokenizer.COMMON_DELIMITERS).length];
        for (int i = 0; i < files.length; i++) {
            files[i] = new File(fileNames[i]);
        }

        for (final File f : files) {
            processFile(f);
        }
    }

    private void processFile(final File f) {
        if (f.getName().endsWith(".jar") || f.getName().endsWith(".zip")) {
            try {
                resourceFinderStack.push(new JarFileScanner(new FileInputStream(f), "", true));
            } catch (IOException e) {
                // logging might be sufficient in this case
                throw new ResourceFinderException(e);
            }

        } else {
            resourceFinderStack.push(new ResourceFinder() {

                Stack<File> files = new Stack<File>() {{
                    if (f.isDirectory()) {
                        final File[] subDirFiles = f.listFiles();
                        if (subDirFiles != null) {
                            for (File file : subDirFiles) {
                                push(file);
                            }
                        }
                    } else {
                        push(f);
                    }
                }};

                private File current;
                private File next;

                @Override
                public boolean hasNext() {
                    while (next == null && !files.empty()) {
                        next = files.pop();

                        if (next.isDirectory()) {
                            if (recursive) {
                                processFile(next);
                            }
                            next = null;
                        } else if(next.getName().endsWith(".jar") || next.getName().endsWith(".zip")) {
                            processFile(next);
                            next = null;
                        }
                    }

                    return next != null;
                }

                @Override
                public String next() {
                    if (next != null || hasNext()) {
                        current = next;
                        next = null;
                        return current.getName();
                    }
                    throw new NoSuchElementException();
                }

                @Override
                public void remove() {
                    throw new UnsupportedOperationException();
                }

                @Override
                public InputStream open() {
                    try {
                        return new FileInputStream(current);
                    } catch (FileNotFoundException e) {
                        throw new ResourceFinderException(e);
                    }
                }

                @Override
                public void reset() {
                }
            });
        }
    }

    @Override
    public boolean hasNext() {
        return resourceFinderStack.hasNext();
    }

    @Override
    public String next() {
        return resourceFinderStack.next();
    }

    @Override
    public void remove() {
        resourceFinderStack.remove();
    }

    @Override
    public InputStream open() {
        return resourceFinderStack.open();
    }

    @Override
    public void reset() {
        this.resourceFinderStack = new ResourceFinderStack();

        for (File f : files) {
            processFile(f);
        }
    }
}
