/*
 * #%L
 * BroadleafCommerce Common Libraries
 * %%
 * Copyright (C) 2009 - 2013 Broadleaf Commerce
 * %%
 * 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.
 * #L%
 */
package org.broadleafcommerce.common.util.sql.importsql;

import org.broadleafcommerce.common.logging.SupportLogManager;
import org.broadleafcommerce.common.logging.SupportLogger;
import org.hibernate.tool.hbm2ddl.SingleLineSqlCommandExtractor;

import java.io.Reader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * This is a utility class that is only meant to be used for testing the BLC demo on Oracle. In our current
 * import sql files, there are a number of value declarations that are incompatible with Oracle. This
 * custom extractor takes care of transforming those values into something Oracle understands.
 *
 * @author Jeff Fischer
 */
public class DemoOracleSingleLineSqlCommandExtractor extends SingleLineSqlCommandExtractor {

    private static final SupportLogger LOGGER = SupportLogManager.getLogger("UserOverride", DemoOracleSingleLineSqlCommandExtractor.class);

    private static final String BOOLEANTRUEMATCH = "(?i)(true)";
    private static final String BOOLEANFALSEMATCH = "(?i)(false)";
    private static final String TIMESTAMPMATCH = "(?<!\\{ts\\s)('\\d{4}-\\d{2}-\\d{2}\\s\\d{2}:\\d{2}:\\d{2}')";
    public static final String TRUE = "1";
    public static final String FALSE = "0";

    protected boolean alreadyRun = false;

    @Override
    public String[] extractCommands(Reader reader) {
        if (!alreadyRun) {
            alreadyRun = true;
            LOGGER.support("Converting hibernate.hbm2ddl.import_files sql statements for compatibility with Oracle");
        }

        String[] statements = super.extractCommands(reader);
        handleBooleans(statements);

        //remove Oracle incompatible - multi-row inserts
        List<String> stringList = new ArrayList<String>(Arrays.asList(statements)); //Arrays.asList is immutable
        int j=0;
        for (String statement : statements) {
            if (statement.matches(".*[)]\\s*[,].*")) {
                int pos = statement.toUpperCase().indexOf("VALUES ") + "VALUES ".length();
                String prefix = statement.substring(0, pos);
                stringList.remove(j);
                String values = statement.substring(pos, statement.length());
                String[] tokens = values.split("[)]\\s*[,]\\s*[(]");
                String[] newStatements = new String[tokens.length];
                for (int i=0; i<tokens.length; i++) {
                    String suffix = tokens[i];
                    if (!suffix.startsWith("(")) {
                        suffix = "(" + suffix;
                    }
                    if (!suffix.endsWith(")")) {
                        suffix += ")";
                    }
                    newStatements[i] = prefix + suffix;
                }
                stringList.addAll(j, Arrays.asList(newStatements));
                j += tokens.length;
            } else {
                j++;
            }
        }

        //Address raw string dates, if any, for Oracle
        Pattern pattern = Pattern.compile(TIMESTAMPMATCH);
        statements = stringList.toArray(new String[stringList.size()]);
        for (int x=0; x<statements.length; x++) {
            Matcher matcher = pattern.matcher(statements[x]);
            while (matcher.find()) {
                String date = matcher.group(1);
                String temp = statements[x].substring(0, statements[x].indexOf(date)) + "{ts " + date + "}" +
                        statements[x].substring(statements[x].indexOf(date) + date.length(), statements[x].length());
                statements[x] = temp;
            }
        }

        return statements;
    }

    protected void handleBooleans(String[] statements) {
        for (int j=0; j<statements.length; j++) {
            //try start matches
            statements[j] = statements[j].replaceAll(BOOLEANTRUEMATCH + "\\s*[,]", TRUE + ",");
            statements[j] = statements[j].replaceAll(BOOLEANFALSEMATCH + "\\s*[,]", FALSE + ",");

            //try middle matches
            statements[j] = statements[j].replaceAll("[,]\\s*" + BOOLEANTRUEMATCH + "\\s*[,]", "," + TRUE + ",");
            statements[j] = statements[j].replaceAll("[,]\\s*" + BOOLEANFALSEMATCH + "\\s*[,]", "," + FALSE + ",");

            //try end matches
            statements[j] = statements[j].replaceAll("[,]\\s*" + BOOLEANTRUEMATCH, "," + TRUE);
            statements[j] = statements[j].replaceAll("[,]\\s*" + BOOLEANFALSEMATCH, "," + FALSE);

            //try matches for updates
            statements[j] = statements[j].replaceAll("[=]\\s*" + BOOLEANTRUEMATCH, "=" + TRUE);
            statements[j] = statements[j].replaceAll("[=]\\s*" + BOOLEANFALSEMATCH, "=" + FALSE);
        }
    }

}