/*

 * Copyright 1998-2003 Sun Microsystems, Inc.  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.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package com.sun.tools.doclets.internal.toolkit.util;

import com.sun.tools.doclets.internal.toolkit.*;

import com.sun.javadoc.*;

import java.util.Map;

import java.util.HashMap;

import java.io.*;

import java.net.*;

/**

 * Process and manage "-link" and "-linkoffline" to external packages. The

 * options "-link" and "-linkoffline" both depend on the fact that Javadoc now

 * generates "package-list"(lists all the packages which are getting

 * documented) file in the current or the destination directory, while

 * generating the documentation.

 *

 * This code is not part of an API.

 * It is implementation that is subject to change.

 * Do not use it as an API

 *

 * @author Atul M Dambalkar

 * @author Robert Field

 */

public class Extern {

    /**

     * Map package names onto Extern Item objects.

     * Lazily initialized.

     */

    /**

     * The global configuration information for this run.

     */

    private final Configuration configuration;

    /**

     * True if we are using -linkoffline and false if -link is used instead.

     */

    private boolean linkoffline = false;

    /**

     * Stores the info for one external doc set

     */

    private class Item {

        /**

         * Package name, found in the "package-list" file in the {@link path}.

         */

        final String packageName;

        /**

         * The URL or the directory path at which the package documentation will be

         * avaliable.

         */

        final String path;

        /**

         * If given path is directory path then true else if it is a URL then false.

         */

        final boolean relative;

        /**

         * Constructor to build a Extern Item object and map it with the package name.

         * If the same package name is found in the map, then the first mapped

         * Item object or offline location will be retained.

         *

         * @param packagename Package name found in the "package-list" file.

         * @param path        URL or Directory path from where the "package-list"

         * file is picked.

         * @param relative    True if path is URL, false if directory path.

         */

        Item(String packageName, String path, boolean relative) {

            this.packageName = packageName;

            this.path = path;

            this.relative = relative;

            if (packageToItemMap == null) {

            }

            if (!packageToItemMap.containsKey(packageName)) { // save the previous

                packageToItemMap.put(packageName, this);        // mapped location

            }

        }

        /**

         * String representation of "this" with packagename and the path.

         */

        public String toString() {

            return packageName + (relative? " -> " : " => ") + path;

        }

    }

    public Extern(Configuration configuration) {

        this.configuration = configuration;

    }

    /**

     * Determine if a doc item is externally documented.

     *

     * @param doc A ProgramElementDoc.

     */

    public boolean isExternal(ProgramElementDoc doc) {

        if (packageToItemMap == null) {

            return false;

        }

        return packageToItemMap.get(doc.containingPackage().name()) != null;

    }

    /**

     * Convert a link to be an external link if appropriate.

     *

     * @param pkgName The package name.

     * @param relativepath    The relative path.

     * @param link    The link to convert.

     * @return if external return converted link else return null

     */

    public String getExternalLink(String pkgName,

                                  String relativepath, String link) {

        Item fnd = findPackageItem(pkgName);

        if (fnd != null) {

            String externlink = fnd.path + link;

            if (fnd.relative) {  // it's a relative path.

                return relativepath + externlink;

            } else {

                return externlink;

            }

        }

        return null;

    }

    /**

     * Build the extern package list from given URL or the directory path.

     * Flag error if the "-link" or "-linkoffline" option is already used.

     *

     * @param url        URL or Directory path.

     * @param pkglisturl This can be another URL for "package-list" or ordinary

     *                   file.

     * @param reporter   The <code>DocErrorReporter</code> used to report errors.

     * @param linkoffline True if -linkoffline isused and false if -link is used.

     */

    public boolean url(String url, String pkglisturl,

                              DocErrorReporter reporter, boolean linkoffline) {

        this.linkoffline = linkoffline;

        String errMsg = composeExternPackageList(url, pkglisturl);

        if (errMsg != null) {

            reporter.printWarning(errMsg);

            return false;

        } else {

            return true;

        }

    }

    /**

     * Get the Extern Item object associated with this package name.

     *

     * @param pkgname Package name.

     */

    private Item findPackageItem(String pkgName) {

        if (packageToItemMap == null) {

            return null;

        }

    }

    /**

     * Adjusts the end file separator if it is missing from the URL or the

     * directory path and depending upon the URL or file path, fetch or

     * read the "package-list" file.

     *

     * @param urlOrDirPath        URL or the directory path.

     * @param pkgListUrlOrDirPath URL or directory path for the "package-list" file or the "package-list"

     * file itself.

     */

    private String composeExternPackageList(String urlOrDirPath, String pkgListUrlOrDirPath) {

        urlOrDirPath = adjustEndFileSeparator(urlOrDirPath);

        pkgListUrlOrDirPath = adjustEndFileSeparator(pkgListUrlOrDirPath);

        return isUrl(pkgListUrlOrDirPath) ?

            fetchURLComposeExternPackageList(urlOrDirPath, pkgListUrlOrDirPath) :

            readFileComposeExternPackageList(urlOrDirPath, pkgListUrlOrDirPath);

    }

    /**

     * If the URL or Directory path is missing end file separator, add that.

     */

    private String adjustEndFileSeparator(String url) {

        String filesep = "/";

        if (!url.endsWith(filesep)) {

            url += filesep;

        }

        return url;

    }

    /**

     * Fetch the URL and read the "package-list" file.

     *

     * @param urlpath        Path to the packages.

     * @param pkglisturlpath URL or the path to the "package-list" file.

     */

    private String fetchURLComposeExternPackageList(String urlpath,

                                                   String pkglisturlpath) {

        String link = pkglisturlpath + "package-list";

        try {

            readPackageList((new URL(link)).openStream(), urlpath, false);

        } catch (MalformedURLException exc) {

            return configuration.getText("doclet.MalformedURL", link);

        } catch (IOException exc) {

            return configuration.getText("doclet.URL_error", link);

        }

        return null;

    }

    /**

     * Read the "package-list" file which is available locally.

     *

     * @param path URL or directory path to the packages.

     * @param pkgListPath Path to the local "package-list" file.

     */

    private String readFileComposeExternPackageList(String path,

                                                   String pkgListPath) {

        String link = pkgListPath + "package-list";

        if (! ((new File(pkgListPath)).isAbsolute() || linkoffline)){

            link = configuration.destDirName + link;

        }

        try {

            File file = new File(link);

            if (file.exists() && file.canRead()) {

                readPackageList(new FileInputStream(file), path,

                    ! ((new File(path)).isAbsolute() || isUrl(path)));

            } else {

                return configuration.getText("doclet.File_error", link);

            }

        } catch (FileNotFoundException exc) {

            return configuration.getText("doclet.File_error", link);

        } catch (IOException exc) {

            return configuration.getText("doclet.File_error", link);

        }

        return null;

    }

    /**

     * Read the file "package-list" and for each package name found, create

     * Extern object and associate it with the package name in the map.

     *

     * @param input    InputStream from the "package-list" file.

     * @param path     URL or the directory path to the packages.

     * @param relative Is path relative?

     */

    private void readPackageList(InputStream input, String path,

                                boolean relative)

                         throws IOException {

        BufferedReader in = new BufferedReader(new InputStreamReader(input));

        StringBuffer strbuf = new StringBuffer();

        try {

            int c;

            while ((c = in.read()) >= 0) {

                char ch = (char)c;

                if (ch == '\n' || ch == '\r') {

                    if (strbuf.length() > 0) {

                        String packname = strbuf.toString();

                        String packpath = path +

                                      packname.replace('.', '/') + '/';

                        new Item(packname, packpath, relative);

                        strbuf.setLength(0);

                    }

                } else {

                    strbuf.append(ch);

                }

            }

        } finally {

            input.close();

        }

    }

    public boolean isUrl (String urlCandidate) {

        try {

            new URL(urlCandidate);

            //No exception was thrown, so this must really be a URL.

            return true;

        } catch (MalformedURLException e) {

            //Since exception is thrown, this must be a directory path.

            return false;

        }

    }

}