/*
 * Copyright (C) 2016-2022 ActionTech.
 * License: http://www.gnu.org/licenses/gpl.html GPL version 2 or higher.
 */

package com.actiontech.dble.services.manager.response;

import com.actiontech.dble.backend.mysql.PacketUtil;
import com.actiontech.dble.config.Fields;
import com.actiontech.dble.config.model.user.UserName;
import com.actiontech.dble.net.mysql.*;
import com.actiontech.dble.services.manager.ManagerService;
import com.actiontech.dble.statistic.stat.SqlResultSet;
import com.actiontech.dble.statistic.stat.UserStat;
import com.actiontech.dble.statistic.stat.UserStatAnalyzer;
import com.actiontech.dble.util.LongUtil;
import com.actiontech.dble.util.StringUtil;

import java.nio.ByteBuffer;
import java.util.Map;
import java.util.concurrent.ConcurrentMap;

/**
 * ShowSqlResultSet
 *
 * @author songgw
 */
public final class ShowSqlResultSet {
    private ShowSqlResultSet() {
    }

    private static final int FIELD_COUNT = 5;
    private static final ResultSetHeaderPacket HEADER = PacketUtil.getHeader(FIELD_COUNT);
    private static final FieldPacket[] FIELDS = new FieldPacket[FIELD_COUNT];
    private static final EOFPacket EOF = new EOFPacket();

    static {
        int i = 0;
        byte packetId = 0;
        HEADER.setPacketId(++packetId);

        FIELDS[i] = PacketUtil.getField("ID", Fields.FIELD_TYPE_LONGLONG);
        FIELDS[i++].setPacketId(++packetId);

        FIELDS[i] = PacketUtil.getField("USER", Fields.FIELD_TYPE_VARCHAR);
        FIELDS[i++].setPacketId(++packetId);

        FIELDS[i] = PacketUtil.getField("FREQUENCY", Fields.FIELD_TYPE_LONGLONG);
        FIELDS[i++].setPacketId(++packetId);

        FIELDS[i] = PacketUtil.getField("SQL", Fields.FIELD_TYPE_VAR_STRING);
        FIELDS[i++].setPacketId(++packetId);

        FIELDS[i] = PacketUtil.getField("RESULTSET_SIZE", Fields.FIELD_TYPE_INT24);
        FIELDS[i++].setPacketId(++packetId);

        EOF.setPacketId(++packetId);
    }

    public static void execute(ManagerService service) {
        ByteBuffer buffer = service.allocate();

        // write header
        buffer = HEADER.write(buffer, service, true);

        // write fields
        for (FieldPacket field : FIELDS) {
            buffer = field.write(buffer, service, true);
        }

        // write eof
        buffer = EOF.write(buffer, service, true);

        // write rows
        byte packetId = EOF.getPacketId();
        int i = 0;
        Map<UserName, UserStat> statMap = UserStatAnalyzer.getInstance().getUserStatMap();
        for (UserStat userStat : statMap.values()) {
            UserName user = userStat.getUser();
            ConcurrentMap<String, SqlResultSet> map = userStat.getSqlResultSizeRecorder().getSqlResultSet();
            if (map != null) {
                for (SqlResultSet sqlResultSet : map.values()) {
                    RowDataPacket row = getRow(++i, user, sqlResultSet.getSql(), sqlResultSet.getCount(), sqlResultSet.getResultSetSize(), service.getCharset().getResults());
                    row.setPacketId(++packetId);
                    buffer = row.write(buffer, service, true);
                }
            }
        }
        // write last eof
        EOFRowPacket lastEof = new EOFRowPacket();
        lastEof.setPacketId(++packetId);


        lastEof.write(buffer, service);
    }

    private static RowDataPacket getRow(int i, UserName user, String sql, int count, long resultSetSize, String charset) {
        RowDataPacket row = new RowDataPacket(FIELD_COUNT);
        row.add(LongUtil.toBytes(i));
        row.add(StringUtil.encode(user.getFullName(), charset));
        row.add(LongUtil.toBytes(count));
        row.add(StringUtil.encode(sql, charset));
        row.add(LongUtil.toBytes(resultSetSize));
        return row;
    }


}
