/*
Copyright (c) 2008, Centre for Educational Technology, Tallinn University
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

package ee.tlu.htk.waramu.fire;

import ee.tlu.htk.waramu.base.BaseType;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 *
 * @author vahur
 */
public class S2QLParser extends ParserBase {

    private List<BaseType> sampleObjects;
    Pattern kwpat = Pattern.compile("<keyword>(.*?)</keyword>");
    Pattern lpat = Pattern.compile("<language>(.*?)</language>");
    Pattern minpat = Pattern.compile("<minAge>(.*?)</minAge>");
    Pattern maxpat = Pattern.compile("<maxAge>(.*?)</maxAge>");

    public S2QLParser(List<BaseType> samples) {
        this.sampleObjects = samples;
    }

    /* QUERY 1
     *
    <?xml version="1.0" encoding="UTF-8"?>
    <s2ql xmlns="http://fire.eun.org/xsd/s2ql-2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <language>en</language>
    <language>et</language>
    <keyword>key1 key2</keyword>
    <ageRange>
    <minAge>1</minAge>
    <maxAge>4</maxAge>
    </ageRange>
    </s2ql>
     *
     * QUERY 2
     *
    <?xml version="1.0" encoding="UTF-8"?>
    <s2ql xmlns="http://fire.eun.org/xsd/s2ql-2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <language>en</language>
    <language>et</language>
    <keyword>test</keyword>
    <keyword> kala</keyword>
    </s2ql>
     *
     * QUERY 3
     *
    <?xml version="1.0" encoding="UTF-8"?>
    <s2ql xmlns="http://fire.eun.org/xsd/s2ql-2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <language>en</language>
    <language>et</language>
    <keyword>key1</keyword>
    <keyword>key2</keyword>
    <ageRange>
    <minAge>1</minAge>
    <maxAge>4</maxAge>
    </ageRange>
    </s2ql>
     */
    @Override
    public String[] parse(String query) {
        /*
         * eg. minAge -> fieldName -> columnName
         *                                          -> tableName
         * */

        List<String> res = new ArrayList<String>();

        for (BaseType obj : sampleObjects) {
            List<String> joined = new ArrayList<String>();
            String q = "SELECT INTERNAL_ID FROM <CATALOG_NAME> ";
            String joins = "";
            String wheres = " WHERE 1=1 ";
            HashMap mapp = obj.getQLMapping("s2ql");

            if (query.contains("keyword")) {
                // Keywords
                HashMap hm = (HashMap) mapp.get("keyword");
                if (hm == null) {
                    // this object doesn't have required field mapping. skip this object.
                    continue;
                }
                Matcher kwmat = kwpat.matcher(query);
                String tablename = (String) hm.get("tableName");
                String column = (String) hm.get("column");
                while (kwmat.find()) {
                    if (!joined.contains(tablename)) {
                        joins += " JOIN " + tablename + " USING (INTERNAL_ID) ";
                        joined.add(tablename);
                    }
                    wheres += " AND " + column + " LIKE '%" + kwmat.group(1).trim() + "%' ";
                }
            }

            if (query.contains("language")) {
                // language
                HashMap hm = (HashMap) mapp.get("language");
                if (hm == null) {
                    continue;
                }
                Matcher lmat = lpat.matcher(query);
                String tablename = (String) hm.get("tableName");
                String column = (String) hm.get("column");
                while (lmat.find()) {
                    if (!joined.contains(tablename)) {
                        joins += " JOIN " + tablename + " USING (INTERNAL_ID) ";
                        joined.add(tablename);
                    }
                    wheres += " AND " + column + " = '"+lmat.group(1).trim() + "'";
                }
            }
            
            if ( query.contains("ageRange")) {
                // age range
                // min
                HashMap hm = (HashMap) mapp.get("minAge");
                if ( hm == null) {
                    continue;
                }
                Matcher minmat = minpat.matcher(query);
                String tablename = (String) hm.get("tableName");
                String column = (String) hm.get("column");
                while ( minmat.find()) {
                    if (!joined.contains(tablename)) {
                        joins += " JOIN " + tablename + " USING (INTERNAL_ID) ";
                        joined.add(tablename);
                    }
                    wheres += " AND "+column+ " > " + minmat.group(1).trim()+" ";
                }
                
                // max
                hm = (HashMap) mapp.get("maxAge");
                if ( hm == null) {
                    continue;
                }
                Matcher maxmat = maxpat.matcher(query);
                tablename = (String) hm.get("tableName");
                column = (String) hm.get("column");
                while ( maxmat.find()) {
                    if (!joined.contains(tablename)) {
                        joins += " JOIN " + tablename + " USING (INTERNAL_ID) ";
                        joined.add(tablename);
                    }
                    wheres += " AND "+column+ " < " + maxmat.group(1).trim()+" ";
                }
            }

            q = q + joins + wheres;

            res.add(q);
        }
        return res.toArray(new String[]{});
    }
}