/*

 * 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.service;



import java.util.List;

import java.util.logging.Level;

import java.util.logging.Logger;

import org.b3log.latke.Keys;

import org.b3log.latke.repository.RepositoryException;

import org.b3log.latke.repository.Transaction;

import org.b3log.latke.service.LangPropsService;

import org.b3log.latke.service.ServiceException;

import org.b3log.latke.util.Ids;

import org.b3log.latke.util.Strings;

import org.b3log.solo.model.Comment;

import org.b3log.solo.model.Page;

import org.b3log.solo.model.Preference;

import org.b3log.solo.repository.CommentRepository;

import org.b3log.solo.repository.PageRepository;

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

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

import org.b3log.solo.util.Comments;

import org.b3log.solo.util.Permalinks;

import org.b3log.solo.util.Statistics;

import org.json.JSONException;

import org.json.JSONObject;



/**

 * Page management service.

 *

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

 * @version 1.0.0.7, Jun 8, 2012

 * @since 0.4.0

 */

public final class PageMgmtService {



    /**

     * Logger.

     */

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

    /**

     * Page repository.

     */

    private PageRepository pageRepository = PageRepositoryImpl.getInstance();

    /**

     * Comment repository.

     */

    private CommentRepository commentRepository = CommentRepositoryImpl.getInstance();

    /**

     * Statistic utilities.

     */

    private Statistics statistics = Statistics.getInstance();

    /**

     * Language service.

     */

    private LangPropsService langPropsService = LangPropsService.getInstance();

    /**

     * Permalink utilities.

     */

    private Permalinks permalinks = Permalinks.getInstance();

    /**

     * Preference query service.

     */

    private PreferenceQueryService preferenceQueryService = PreferenceQueryService.getInstance();



    /**

     * Updates a page by the specified request json object.

     *

     * @param requestJSONObject the specified request json object, for example,

     * <pre>

     * {

     *     "page": {

     *         "oId": "",

     *         "pageTitle": "",

     *         "pageContent": "",

     *         "pageOrder": int,

     *         "pageCommentCount": int,

     *         "pagePermalink": "",

     *         "pageCommentable": boolean,

     *         "pageType": "",

     *         "pageOpenTarget": ""

     *     }

     * }, see {@link Page} for more details

     * </pre>

     * @throws ServiceException service exception

     */

    public void updatePage(final JSONObject requestJSONObject) throws ServiceException {



        final Transaction transaction = pageRepository.beginTransaction();

        try {

            final JSONObject page = requestJSONObject.getJSONObject(Page.PAGE);

            final String pageId = page.getString(Keys.OBJECT_ID);

            final JSONObject oldPage = pageRepository.get(pageId);

            final JSONObject newPage = new JSONObject(page, JSONObject.getNames(page));

            newPage.put(Page.PAGE_ORDER, oldPage.getInt(Page.PAGE_ORDER));

            newPage.put(Page.PAGE_COMMENT_COUNT, oldPage.getInt(Page.PAGE_COMMENT_COUNT));

            String permalink = page.optString(Page.PAGE_PERMALINK).trim();



            final String oldPermalink = oldPage.getString(Page.PAGE_PERMALINK);

            if (!oldPermalink.equals(permalink)) {

                if (Strings.isEmptyOrNull(permalink)) {

                    permalink = "/pages/" + pageId + ".html";

                }



                if (Page.PAGE.equals(page.getString(Page.PAGE_TYPE))) {

                    if (!permalink.startsWith("/")) {

                        permalink = "/" + permalink;

                    }



                    if (Permalinks.invalidPagePermalinkFormat(permalink)) {

                        if (transaction.isActive()) {

                            transaction.rollback();

                        }



                        throw new ServiceException(langPropsService.get("invalidPermalinkFormatLabel"));

                    }



                    if (!oldPermalink.equals(permalink)

                        && permalinks.exist(permalink)) {

                        if (transaction.isActive()) {

                            transaction.rollback();

                        }



                        throw new ServiceException(langPropsService.get("duplicatedPermalinkLabel"));

                    }

                }

            }



            // TODO: SBC case

            newPage.put(Page.PAGE_PERMALINK, permalink.replaceAll(" ", "-"));



            if (!oldPage.getString(Page.PAGE_PERMALINK).equals(permalink)) {  // The permalink has been updated

                // Updates related comments' links

                processCommentsForPageUpdate(newPage);

            }



            // Editor type

            final JSONObject preference = preferenceQueryService.getPreference();

            newPage.put(Page.PAGE_EDITOR_TYPE, preference.optString(Preference.EDITOR_TYPE));



            pageRepository.update(pageId, newPage);



            transaction.commit();



            LOGGER.log(Level.FINER, "Updated a page[id={0}]", pageId);

        } catch (final Exception e) {

            LOGGER.log(Level.SEVERE, e.getMessage(), e);

            if (transaction.isActive()) {

                transaction.rollback();

            }



            throw new ServiceException(e);

        }

    }



    /**

     * Removes a page specified by the given page id.

     *

     * @param pageId the given page id

     * @throws ServiceException service exception

     */

    public void removePage(final String pageId) throws ServiceException {

        final Transaction transaction = pageRepository.beginTransaction();

        try {

            LOGGER.log(Level.FINER, "Removing a page[id={0}]", pageId);

            removePageComments(pageId);

            pageRepository.remove(pageId);



            transaction.commit();



        } catch (final Exception e) {

            if (transaction.isActive()) {

                transaction.rollback();

            }



            LOGGER.log(Level.SEVERE, "Removes a page[id=" + pageId + "] failed", e);



            throw new ServiceException(e);

        }

    }



    /**

     * Adds a page with the specified request json object.

     * 

     * @param requestJSONObject the specified request json object, for example,

     * <pre>

     * {

     *     "page": {

     *         "pageTitle": "",

     *         "pageContent": "",

     *         "pageOpenTarget": "",

     *         "pageCommentable": boolean,

     *         "pageType": "",

     *         "pagePermalink": "" // optional

     *     }

     * }, see {@link Page} for more details

     * </pre>

     * @return generated page id

     * @throws ServiceException if permalink format checks failed or persists

     * failed

     */

    public String addPage(final JSONObject requestJSONObject) throws ServiceException {

        final Transaction transaction = pageRepository.beginTransaction();

        try {

            final JSONObject page = requestJSONObject.getJSONObject(Page.PAGE);

            page.put(Page.PAGE_COMMENT_COUNT, 0);

            final int maxOrder = pageRepository.getMaxOrder();

            page.put(Page.PAGE_ORDER, maxOrder + 1);



            String permalink = page.optString(Page.PAGE_PERMALINK);

            if (Strings.isEmptyOrNull(permalink)) {

                permalink = "/pages/" + Ids.genTimeMillisId() + ".html";

            }



            if (Page.PAGE.equals(page.getString(Page.PAGE_TYPE))) {

                if (!permalink.startsWith("/")) {

                    permalink = "/" + permalink;

                }



                if (Permalinks.invalidPagePermalinkFormat(permalink)) {

                    if (transaction.isActive()) {

                        transaction.rollback();

                    }



                    throw new ServiceException(langPropsService.get("invalidPermalinkFormatLabel"));

                }



                if (permalinks.exist(permalink)) {

                    if (transaction.isActive()) {

                        transaction.rollback();

                    }



                    throw new ServiceException(langPropsService.get("duplicatedPermalinkLabel"));

                }

            }



            // TODO: SBC case

            page.put(Page.PAGE_PERMALINK, permalink.replaceAll(" ", "-"));



            // Editor type

            final JSONObject preference = preferenceQueryService.getPreference();

            page.put(Page.PAGE_EDITOR_TYPE, preference.optString(Preference.EDITOR_TYPE));



            final String ret = pageRepository.add(page);



            transaction.commit();



            return ret;

        } catch (final JSONException e) {

            LOGGER.log(Level.SEVERE, e.getMessage(), e);

            if (transaction.isActive()) {

                transaction.rollback();

            }



            throw new ServiceException(e);

        } catch (final RepositoryException e) {

            LOGGER.log(Level.SEVERE, e.getMessage(), e);

            if (transaction.isActive()) {

                transaction.rollback();

            }



            throw new ServiceException(e);

        }

    }



    /**

     * Changes the order of a page specified by the given page id with 

     * the specified direction.

     *

     * @param pageId the given page id

     * @param direction the specified direction, "up"/"down"

     * @throws ServiceException service exception

     */

    public void changeOrder(final String pageId, final String direction) throws ServiceException {



        final Transaction transaction = pageRepository.beginTransaction();

        try {

            final JSONObject srcPage = pageRepository.get(pageId);

            final int srcPageOrder = srcPage.getInt(Page.PAGE_ORDER);



            JSONObject targetPage = null;

            if ("up".equals(direction)) {

                targetPage = pageRepository.getUpper(pageId);

            } else { // Down

                targetPage = pageRepository.getUnder(pageId);

            }



            if (null == targetPage) {

                if (transaction.isActive()) {

                    transaction.rollback();

                }



                LOGGER.log(Level.WARNING, "Cant not find the target page of source page[order={0}]", srcPageOrder);

                return;

            }



            // Swaps

            srcPage.put(Page.PAGE_ORDER, targetPage.getInt(Page.PAGE_ORDER));

            targetPage.put(Page.PAGE_ORDER, srcPageOrder);



            pageRepository.update(srcPage.getString(Keys.OBJECT_ID), srcPage);

            pageRepository.update(targetPage.getString(Keys.OBJECT_ID), targetPage);



            transaction.commit();

        } catch (final Exception e) {

            if (transaction.isActive()) {

                transaction.rollback();

            }



            LOGGER.log(Level.SEVERE, "Changes page's order failed", e);



            throw new ServiceException(e);

        }

    }



    /**

     * Gets the {@link PageMgmtService} singleton.

     *

     * @return the singleton

     */

    public static PageMgmtService getInstance() {

        return SingletonHolder.SINGLETON;

    }



    /**

     * Removes page comments by the specified page id.

     *

     * <p>

     * Removes related comments, sets page/blog comment statistic count.

     * </p>

     *

     * @param pageId the specified page id

     * @throws JSONException json exception

     * @throws RepositoryException repository exception

     */

    private void removePageComments(final String pageId) throws JSONException, RepositoryException {

        final int removedCnt = commentRepository.removeComments(pageId);



        int blogCommentCount = statistics.getBlogCommentCount();

        blogCommentCount -= removedCnt;

        statistics.setBlogCommentCount(blogCommentCount);



        int publishedBlogCommentCount = statistics.getPublishedBlogCommentCount();

        publishedBlogCommentCount -= removedCnt;

        statistics.setPublishedBlogCommentCount(publishedBlogCommentCount);

    }



    /**

     * Processes comments for page update.

     * 

     * @param page the specified page to update

     * @throws Exception exception 

     */

    public void processCommentsForPageUpdate(final JSONObject page) throws Exception {

        final String pageId = page.getString(Keys.OBJECT_ID);



        final List<JSONObject> comments = commentRepository.getComments(pageId, 1, Integer.MAX_VALUE);



        for (final JSONObject comment : comments) {

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

            final String sharpURL = Comments.getCommentSharpURLForPage(page, commentId);



            comment.put(Comment.COMMENT_SHARP_URL, sharpURL);



            if (Strings.isEmptyOrNull(comment.optString(Comment.COMMENT_ORIGINAL_COMMENT_ID))) {

                comment.put(Comment.COMMENT_ORIGINAL_COMMENT_ID, "");

            }

            if (Strings.isEmptyOrNull(comment.optString(Comment.COMMENT_ORIGINAL_COMMENT_NAME))) {

                comment.put(Comment.COMMENT_ORIGINAL_COMMENT_NAME, "");

            }



            commentRepository.update(commentId, comment);

        }

    }



    /**

     * Private constructor.

     */

    private PageMgmtService() {

    }



    /**

     * Singleton holder.

     *

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

     * @version 1.0.0.0, Oct 27, 2011

     */

    private static final class SingletonHolder {



        /**

         * Singleton.

         */

        private static final PageMgmtService SINGLETON = new PageMgmtService();



        /**

         * Private default constructor.

         */

        private SingletonHolder() {

        }

    }

}