/*
 * Copyright (C) 2008-2017, Juick
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package com.juick.service;

import com.juick.Tag;
import com.juick.User;
import com.juick.server.helpers.TagStats;
import com.juick.util.StreamUtils;
import org.apache.commons.collections4.CollectionUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.jdbc.core.RowMapper;
import org.springframework.jdbc.core.namedparam.MapSqlParameterSource;
import org.springframework.jdbc.support.GeneratedKeyHolder;
import org.springframework.jdbc.support.KeyHolder;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Arrays;
import java.util.Collection;
import java.util.List;
import java.util.Objects;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.Stream;

/**
 * Created by aalexeev on 11/13/16.
 */
@Repository
public class TagServiceImpl extends BaseJdbcService implements TagService {

    @Transactional(readOnly = true)
    @Override
    public com.juick.Tag getTag(final int tid) {
        List<Tag> list = getJdbcTemplate().query(
                "SELECT synonym_id,name FROM tags WHERE tag_id=?",
                (rs, num) -> {
                    Tag ret = new Tag(rs.getString(2));
                    ret.TID = tid;
                    ret.SynonymID = rs.getInt(1);
                    return ret;
                },
                tid);

        return list.isEmpty() ?
                null : list.get(0);
    }

    @Transactional
    @Override
    public com.juick.Tag getTag(final String tag, final boolean autoCreate) {
        if (StringUtils.isBlank(tag))
            return null;

        List<Tag> list = getJdbcTemplate().query(
                "SELECT tag_id, synonym_id, name FROM tags WHERE name = ?",
                (rs, rowNum) -> {
                    Tag ret1 = new Tag(rs.getString(3));
                    ret1.TID = rs.getInt(1);
                    ret1.SynonymID = rs.getInt(2);
                    return ret1;
                },
                tag);

        Tag ret = list.isEmpty() ?
                null : list.get(0);

        if (ret == null && autoCreate) {
            ret = new com.juick.Tag(tag);
            ret.TID = createTag(tag);
        }

        return ret;
    }

    @Override
    public List<Tag> getTags(Stream<String> tags, final boolean autoCreate) {
        return tags.filter(StringUtils::isNotBlank).map(tag -> getTag(tag, autoCreate)).filter(Objects::nonNull).distinct()
            .collect(Collectors.toList());
    }

    @Transactional(readOnly = true)
    @Override
    public boolean getTagNoIndex(final int tagId) {
        List<Integer> list = getJdbcTemplate().queryForList(
                "SELECT noindex FROM tags WHERE tag_id=?", Integer.class, tagId);

        return !list.isEmpty() && list.get(0) == 1;
    }

    @Transactional
    @Override
    public int createTag(final String name) {
        KeyHolder holder = new GeneratedKeyHolder();
        getJdbcTemplate().update(
                con -> {
                    PreparedStatement stmt = con.prepareStatement(
                            "INSERT INTO tags(name) VALUES (?)",
                            Statement.RETURN_GENERATED_KEYS);
                    stmt.setString(1, name);
                    return stmt;
                },
                holder);

        return holder.getKey().intValue();
    }

    private class TagStatsMapper implements RowMapper<TagStats> {

        @Override
        public TagStats mapRow(ResultSet rs, int rowNum) throws SQLException {
            Tag t = new Tag(rs.getString(1));
            TagStats s = new TagStats();
            s.setTag(t);
            s.setUsageCount(rs.getInt(2));
            return s;
        }
    }

    @Transactional(readOnly = true)
    @Override
    public List<TagStats> getUserTagStats(final int uid) {
        return getJdbcTemplate().query(
                "SELECT tags.name,COUNT(messages.message_id) " +
                        "FROM (messages INNER JOIN messages_tags ON (messages.user_id=? " +
                        "AND messages.message_id=messages_tags.message_id)) " +
                        "INNER JOIN tags ON messages_tags.tag_id=tags.tag_id GROUP BY tags.tag_id ORDER BY tags.name ASC",
                new TagStatsMapper(),
                uid);
    }

    @Transactional(readOnly = true)
    @Override
    public List<String> getUserBLTags(final int uid) {
        return getJdbcTemplate().queryForList(
                "SELECT tags.name FROM tags INNER JOIN bl_tags " +
                        "ON (bl_tags.user_id = ? AND bl_tags.tag_id = tags.tag_id) ORDER BY tags.name",
                String.class, uid);
    }

    @Transactional(readOnly = true)
    @Override
    public List<String> getPopularTags() {
        return getJdbcTemplate().queryForList(
                "select name from tags where noindex=0 order by stat_messages desc limit 20", String.class);
    }

    @Transactional(readOnly = true)
    @Override
    public List<TagStats> getTagStats() {
        return getJdbcTemplate().query(
                "SELECT tags.name,COUNT(DISTINCT messages.user_id) AS cnt " +
                        "FROM (messages INNER JOIN messages_tags ON (messages.ts>TIMESTAMPADD(DAY,-3,NOW()) " +
                        "AND messages.message_id=messages_tags.message_id)) " +
                        "INNER JOIN tags ON messages_tags.tag_id=tags.tag_id " +
                        "WHERE tags.tag_id NOT IN (SELECT tag_id FROM tags_ignore) " +
                        "GROUP BY tags.tag_id ORDER BY cnt DESC LIMIT 20", new TagStatsMapper());
    }

    @Transactional
    @Override
    public List<Tag> updateTags(final int mid, final Collection<Tag> newTags) {
        List<Tag> currentTags = getMessageTags(mid).stream()
                .map(TagStats::getTag).collect(Collectors.toList());

        if (CollectionUtils.isEmpty(newTags))
            return currentTags;

        List<Integer> idsForDelete = newTags.stream()
                .filter(currentTags::contains)
                .map(tag -> tag.TID)
                .collect(Collectors.toList());
        if (newTags.size() - idsForDelete.size() >= 5) {
            return currentTags;
        }

        if (!idsForDelete.isEmpty())
            getNamedParameterJdbcTemplate().update(
                    "DELETE FROM messages_tags WHERE message_id = :mid AND tag_id in (:ids)",
                    new MapSqlParameterSource().addValue("ids", idsForDelete).addValue("mid", mid));

        newTags.stream().filter(t -> !currentTags.contains(t))
                .forEach(t -> getJdbcTemplate().update("INSERT INTO messages_tags(message_id,tag_id) VALUES (?,?)", mid, t.TID));

        List<Tag> result = getMessageTags(mid).stream()
                .map(TagStats::getTag).collect(Collectors.toList());
        jdbcTemplate.update("UPDATE messages_txt SET tags=? WHERE message_id=?", result.stream()
        .map(Tag::getName).collect(Collectors.joining(" ")), mid);
        return result;
    }

    @Override
    public List<Tag> fromString(final String txt) {
        String firstLine = txt.split("\\n", 2)[0];
        return StreamUtils.takeWhile(Arrays.stream(firstLine.split("\\ ")),
                t -> !t.equals("*") && t.startsWith("*"))
                .map(t -> getTag(t.substring(1), true))
                .collect(Collectors.toList());
    }

    @Transactional(readOnly = true)
    @Override
    public List<TagStats> getMessageTags(final int mid) {
        return getJdbcTemplate().query(
                "SELECT tags.tag_id,synonym_id,name,stat_messages FROM tags " +
                        "INNER JOIN messages_tags ON (messages_tags.message_id = ? AND messages_tags.tag_id = tags.tag_id)",
                (rs, num) -> {
                    com.juick.Tag t = new com.juick.Tag(rs.getString(3));
                    t.TID = rs.getInt(1);
                    t.SynonymID = rs.getInt(2);
                    TagStats s = new TagStats();
                    s.setTag(t);
                    s.setUsageCount(rs.getInt(4));
                    return s;
                }, mid);
    }

    @Transactional(readOnly = true)
    @Override
    public List<Integer> getMessageTagsIDs(final int mid) {
        return getJdbcTemplate().queryForList(
                "SELECT tag_id FROM messages_tags WHERE message_id = ?",
                Integer.class, mid);
    }

    @Override
    public boolean blacklistTag(User user, Tag tag) {
        int rowcount = getNamedParameterJdbcTemplate().update("DELETE FROM bl_tags WHERE tag_id = :tid AND user_id = :uid",
                new MapSqlParameterSource().addValue("tid", tag.TID).addValue("uid", user.getUid()));
        return rowcount <= 0 && getNamedParameterJdbcTemplate()
                .update("INSERT INTO bl_tags(user_id, tag_id) VALUES(:uid,:tid)",
                        new MapSqlParameterSource().addValue("tid", tag.TID)
                                .addValue("uid", user.getUid())) > 0;
    }

    @Transactional(readOnly = true)
    @Override
    public boolean isInBL(User user, Tag tag) {
        List<Integer> list = getJdbcTemplate().queryForList(
                "SELECT 1 FROM bl_tags WHERE user_id = ? AND tag_id = ?",
                Integer.class, user.getUid(), tag.TID);
        return !list.isEmpty() && list.get(0) == 1;
    }

    @Transactional(readOnly = true)
    @Override
    public boolean isSubscribed(User user, Tag tag) {
        List<Integer> list = getJdbcTemplate().queryForList(
                "SELECT 1 FROM subscr_tags WHERE suser_id = ? AND tag_id = ?",
                Integer.class, user.getUid(), tag.TID);
        return !list.isEmpty() && list.get(0) == 1;
    }

}