/*

 * Copyright (c) 2009, 2010, 2011, 2012, B3log Team

 *

 * Licensed under the Apache License, Version 2.0 (the "License");

 * you may not use this file except in compliance with the License.

 * You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package org.b3log.solo.util;



import java.io.IOException;

import java.net.URL;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.b3log.latke.Keys;

import org.b3log.latke.mail.MailService;

import org.b3log.latke.mail.MailService.Message;

import org.b3log.latke.mail.MailServiceFactory;

import org.b3log.latke.service.LangPropsService;

import org.b3log.latke.util.Strings;

import org.b3log.solo.SoloServletListener;

import org.b3log.solo.model.*;

import org.b3log.solo.repository.ArticleRepository;

import org.b3log.solo.repository.PageRepository;

import org.b3log.solo.repository.impl.ArticleRepositoryImpl;

import org.b3log.solo.repository.impl.PageRepositoryImpl;

import org.b3log.solo.service.PreferenceQueryService;

import org.json.JSONException;

import org.json.JSONObject;



/**

 * Comment utilities.

 *

 * @author <a href="mailto:DL88250@gmail.com">Liang Ding</a>

 * @version 1.0.0.9, Mar 28, 2012

 * @since 0.3.1

 */

public final class Comments {



    /**

     * Logger.

     */

    private static final Logger LOGGER = Logger.getLogger(Comments.class.getName());

    /**

     * Language service.

     */

    private static LangPropsService langPropsService = LangPropsService.getInstance();

    /**

     * Preference query service.

     */

    private static PreferenceQueryService preferenceQueryService = PreferenceQueryService.getInstance();

    /**

     * Article repository.

     */

    private static ArticleRepository articleRepository = ArticleRepositoryImpl.getInstance();

    /**

     * Page repository.

     */

    private static PageRepository pageRepository = PageRepositoryImpl.getInstance();

    /**

     * Mail service.

     */

    private static final MailService MAIL_SVC = MailServiceFactory.getMailService();

    /**

     * Minimum length of comment name.

     */

    private static final int MIN_COMMENT_NAME_LENGTH = 2;

    /**

     * Maximum length of comment name.

     */

    private static final int MAX_COMMENT_NAME_LENGTH = 20;

    /**

     * Minimum length of comment content.

     */

    private static final int MIN_COMMENT_CONTENT_LENGTH = 2;

    /**

     * Maximum length of comment content.

     */

    private static final int MAX_COMMENT_CONTENT_LENGTH = 500;

    /**

     * Comment mail HTML body.

     */

    public static final String COMMENT_MAIL_HTML_BODY =

                               "<p>{articleOrPage} [<a href=\"" + "{articleOrPageURL}\">"

                               + "{title}</a>]" + " received a new comment:</p>"

                               + "{commenter}: <span><a href=\"http://{commentSharpURL}\">"

                               + "{commentContent}</a></span>";



    /**

     * Gets comment sharp URL with the specified page and comment id.

     *

     * @param page the specified page

     * @param commentId the specified comment id

     * @return comment sharp URL

     * @throws JSONException json exception

     */

    public static String getCommentSharpURLForPage(final JSONObject page, final String commentId) throws JSONException {

        return page.getString(Page.PAGE_PERMALINK) + "#" + commentId;

    }



    /**

     * Gets comment sharp URL with the specified article and comment id.

     *

     * @param article the specified article

     * @param commentId the specified comment id

     * @return comment sharp URL

     * @throws JSONException json exception

     */

    public static String getCommentSharpURLForArticle(final JSONObject article, final String commentId) throws JSONException {

        final String articleLink = article.getString(Article.ARTICLE_PERMALINK);



        return articleLink + "#" + commentId;

    }



    /**

     * Checks the specified comment adding request.

     * 

     * @param requestJSONObject the specified comment adding request, for example, 

     * <pre>

     * {

     *     "type": "", // "article"/"page"

     *     "oId": "",

     *     "commentName": "",

     *     "commentEmail": "",

     *     "commentURL": "",

     *     "commentContent": "",

     * }

     * </pre>

     * @return check result, for example, 

     * <pre>

     * {

     *     "sc": boolean,

     *     "msg": "" // Exists if "sc" equals to false

     * }

     * </pre>

     */

    public static JSONObject checkAddCommentRequest(final JSONObject requestJSONObject) {

        final JSONObject ret = new JSONObject();



        try {

            ret.put(Keys.STATUS_CODE, false);

            final JSONObject preference = preferenceQueryService.getPreference();

            if (null == preference || !preference.optBoolean(Preference.COMMENTABLE)) {

                ret.put(Keys.MSG, langPropsService.get("notAllowCommentLabel"));



                return ret;

            }



            final String id = requestJSONObject.optString(Keys.OBJECT_ID);

            final String type = requestJSONObject.optString(Common.TYPE);

            if (Article.ARTICLE.equals(type)) {

                final JSONObject article = articleRepository.get(id);

                if (null == article || !article.optBoolean(Article.ARTICLE_COMMENTABLE)) {

                    ret.put(Keys.MSG, langPropsService.get("notAllowCommentLabel"));



                    return ret;

                }

            } else {

                final JSONObject page = pageRepository.get(id);

                if (null == page || !page.optBoolean(Page.PAGE_COMMENTABLE)) {

                    ret.put(Keys.MSG, langPropsService.get("notAllowCommentLabel"));



                    return ret;

                }

            }



            final String commentName = requestJSONObject.getString(Comment.COMMENT_NAME);

            if (MAX_COMMENT_NAME_LENGTH < commentName.length() || MIN_COMMENT_NAME_LENGTH > commentName.length()) {

                LOGGER.log(Level.WARNING, "Comment name is too long[{0}]", commentName);

                ret.put(Keys.MSG, langPropsService.get("nameTooLongLabel"));



                return ret;

            }



            final String commentEmail = requestJSONObject.getString(Comment.COMMENT_EMAIL).trim().toLowerCase();

            if (!Strings.isEmail(commentEmail)) {

                LOGGER.log(Level.WARNING, "Comment email is invalid[{0}]", commentEmail);

                ret.put(Keys.MSG, langPropsService.get("mailInvalidLabel"));



                return ret;

            }



            final String commentURL = requestJSONObject.optString(Comment.COMMENT_URL);

            try {

                new URL(commentURL);



                if (commentURL.contains("<") || commentURL.contains(">")) {

                    throw new IllegalArgumentException();

                }

            } catch (final Exception e) {

                LOGGER.log(Level.WARNING, "Comment URL is invalid[{0}]", commentURL);

                ret.put(Keys.MSG, langPropsService.get("urlInvalidLabel"));



                return ret;

            }



            final String commentContent = requestJSONObject.optString(Comment.COMMENT_CONTENT).

                    replaceAll("\\n", SoloServletListener.ENTER_ESC);

            if (MAX_COMMENT_CONTENT_LENGTH < commentContent.length() || MIN_COMMENT_CONTENT_LENGTH > commentContent.length()) {

                LOGGER.log(Level.WARNING, "Comment conent length is invalid[{0}]", commentContent.length());

                ret.put(Keys.MSG, langPropsService.get("commentContentCannotEmptyLabel"));



                return ret;

            }



            ret.put(Keys.STATUS_CODE, true);



            return ret;

        } catch (final Exception e) {

            LOGGER.log(Level.WARNING, "Checks add comment request[" + requestJSONObject.toString() + "] failed", e);



            ret.put(Keys.STATUS_CODE, false);

            ret.put(Keys.MSG, langPropsService.get("addFailLabel"));



            return ret;

        }

    }



    /**

     * Sends a notification mail to administrator for notifying the specified

     * article or page received the specified comment and original comment.

     *

     * @param articleOrPage the specified article or page

     * @param comment the specified comment

     * @param originalComment original comment, if not exists, set it as

     * {@code null}

     * @param preference the specified preference

     * @throws IOException io exception

     * @throws JSONException json exception

     */

    public static void sendNotificationMail(final JSONObject articleOrPage,

                                            final JSONObject comment,

                                            final JSONObject originalComment,

                                            final JSONObject preference)

            throws IOException, JSONException {

        final String commentEmail = comment.getString(Comment.COMMENT_EMAIL);

        final String commentId = comment.getString(Keys.OBJECT_ID);

        final String commentContent = comment.getString(Comment.COMMENT_CONTENT).

                replaceAll(SoloServletListener.ENTER_ESC, "<br/>");



        final String adminEmail = preference.getString(Preference.ADMIN_EMAIL);

        if (adminEmail.equalsIgnoreCase(commentEmail)) {

            LOGGER.log(Level.FINER, "Do not send comment notification mail to admin itself[{0}]", adminEmail);

            return;

        }



        if (null != originalComment && comment.has(Comment.COMMENT_ORIGINAL_COMMENT_ID)) {

            final String originalEmail = originalComment.getString(Comment.COMMENT_EMAIL);

            if (originalEmail.equalsIgnoreCase(adminEmail)) {

                LOGGER.log(Level.FINER, "Do not send comment notification mail to admin while the specified comment[{0}] is an reply",

                           commentId);

                return;

            }

        }



        final String blogTitle = preference.getString(Preference.BLOG_TITLE);

        final String blogHost = preference.getString(Preference.BLOG_HOST);

        boolean isArticle = true;

        String title = articleOrPage.optString(Article.ARTICLE_TITLE);

        if (Strings.isEmptyOrNull(title)) {

            title = articleOrPage.getString(Page.PAGE_TITLE);

            isArticle = false;

        }



        final String commentSharpURL = comment.getString(Comment.COMMENT_SHARP_URL);

        final Message message = new Message();

        message.setFrom(adminEmail);

        message.addRecipient(adminEmail);

        String mailSubject = null;

        String articleOrPageURL = null;

        String mailBody = null;

        if (isArticle) {

            mailSubject = blogTitle + ": New comment on article [" + title + "]";

            articleOrPageURL = "http://" + blogHost + articleOrPage.getString(Article.ARTICLE_PERMALINK);

            mailBody = COMMENT_MAIL_HTML_BODY.replace("{articleOrPage}", "Article");

        } else {

            mailSubject = blogTitle + ": New comment on page [" + title + "]";

            articleOrPageURL = "http://" + blogHost + articleOrPage.getString(Page.PAGE_PERMALINK);

            mailBody = COMMENT_MAIL_HTML_BODY.replace("{articleOrPage}", "Page");

        }



        message.setSubject(mailSubject);

        final String commentName = comment.getString(Comment.COMMENT_NAME);

        final String commentURL = comment.getString(Comment.COMMENT_URL);

        String commenter = null;

        if (!"http://".equals(commentURL)) {

            commenter = "<a target=\"_blank\" " + "href=\"" + commentURL + "\">" + commentName + "</a>";

        } else {

            commenter = commentName;

        }



        mailBody = mailBody.replace("{articleOrPageURL}", articleOrPageURL).

                replace("{title}", title).

                replace("{commentContent}", commentContent).

                replace("{commentSharpURL}", blogHost + commentSharpURL).

                replace("{commenter}", commenter);

        message.setHtmlBody(mailBody);



        LOGGER.log(Level.FINER,

                   "Sending a mail[mailSubject={0}, mailBody=[{1}] to admin[email={2}]",

                   new Object[]{mailSubject, mailBody, adminEmail});

        MAIL_SVC.send(message);

    }



    /**

     * Gets the {@link Comments} singleton.

     *

     * @return the singleton

     */

    public static Comments getInstance() {

        return SingletonHolder.SINGLETON;

    }



    /**

     * Private default constructor.

     */

    private Comments() {

    }



    /**

     * Singleton holder.

     *

     * @author <a href="mailto:DL88250@gmail.com">Liang Ding</a>

     * @version 1.0.0.0, Jan 12, 2011

     */

    private static final class SingletonHolder {



        /**

         * Singleton.

         */

        private static final Comments SINGLETON = new Comments();



        /**

         * Private default constructor.

         */

        private SingletonHolder() {

        }

    }

}