/*
 * Copyright (C) 2008-2019, 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.model.User;
import org.apache.commons.lang3.StringUtils;
import org.springframework.stereotype.Repository;
import org.springframework.transaction.annotation.Transactional;

import javax.inject.Inject;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

/**
 * Created by aalexeev on 11/18/16.
 */

@Repository
@Transactional(readOnly = true)
public class SphinxSearchService extends BaseJdbcService implements SearchService {
    private static final int DEFAULT_MAX_RESULT = 20;

    private int maxResult = DEFAULT_MAX_RESULT;

    @Inject
    UserService userService;

    boolean isOneWord(String searchString) {
        return searchString.split("[^\\S\\+]+").length == 1;
    }

    String sortHint() {
        return "extended:@weight desc, @id desc";
    }

    String keywordBoost(String searchString) {
        return isOneWord(searchString) ? String.format("%s^3", searchString) : searchString;
    }

    @Override
    public List<Integer> searchInAllMessages(User visitor, final String searchString, final int page) {
        if (StringUtils.isBlank(searchString))
            return Collections.emptyList();

        Map<String, String> sphinxQuery = new HashMap<>();
        sphinxQuery.put("limit", String.valueOf(maxResult));
        sphinxQuery.put("mode", "any");
        sphinxQuery.put("sort", sortHint());
        String usersFilter = userService.getUserBLUsers(visitor.getUid()).stream().map(u -> String.valueOf(u.getUid())).collect(Collectors.joining(","));
        sphinxQuery.put("!filter", "user_id," + usersFilter);
        if (isOneWord(searchString)) {
            sphinxQuery.put("ranker", "bm25");
        }
        if (page > 0) {
            sphinxQuery.put("offset", String.valueOf(page * maxResult));
        }

        return getJdbcTemplate().queryForList(
                String.format("SELECT id FROM search WHERE query = '%s;%s'", keywordBoost(searchString),
                        sphinxQuery.entrySet().stream().map(Object::toString)
                                .collect(Collectors.joining(";"))), Integer.class);
    }

    @Override
    public List<Integer> searchByStringAndUser(User visitor, final String searchString, final int userId, int page) {
        if (StringUtils.isBlank(searchString))
            return Collections.emptyList();

        Map<String, String> sphinxQuery = new HashMap<>();
        sphinxQuery.put("limit", String.valueOf(maxResult));
        sphinxQuery.put("mode", "any");
        sphinxQuery.put("sort", sortHint());
        if (page > 0) {
            sphinxQuery.put("offset", String.valueOf(page * maxResult));
        }
        return getJdbcTemplate().queryForList(
                String.format("SELECT id FROM search WHERE query = '%s;%s;filter=user_id,%d'", searchString,
                        sphinxQuery.entrySet().stream().map(Object::toString)
                                .collect(Collectors.joining(";")), userId), Integer.class);
    }

    @Override
    public void setMaxResult(int maxResult) {
        if (maxResult <= 0)
            throw new IllegalArgumentException("maxResult value (" + maxResult + ") must be greater then 0");

        this.maxResult = maxResult;
    }
}