/*
 *
 * MariaDB Client for Java
 *
 * Copyright (c) 2012-2014 Monty Program Ab.
 * Copyright (c) 2015-2020 MariaDB Corporation Ab.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along
 * with this library; if not, write to Monty Program Ab info@montyprogram.com.
 *
 * This particular MariaDB Client for Java file is work
 * derived from a Drizzle-JDBC. Drizzle-JDBC file which is covered by subject to
 * the following copyright and notice provisions:
 *
 * Copyright (c) 2009-2011, Marcus Eriksson
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 * Redistributions of source code must retain the above copyright notice, this list
 * of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice, this
 * list of conditions and the following disclaimer in the documentation and/or
 * other materials provided with the distribution.
 *
 * Neither the name of the driver nor the names of its contributors may not be
 * used to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS  AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 */

package org.mariadb.jdbc.internal.protocol;

import java.sql.SQLException;
import java.util.*;
import java.util.concurrent.locks.ReentrantLock;
import org.mariadb.jdbc.HostAddress;
import org.mariadb.jdbc.UrlParser;
import org.mariadb.jdbc.internal.failover.FailoverProxy;
import org.mariadb.jdbc.internal.failover.impl.MastersSlavesListener;
import org.mariadb.jdbc.internal.failover.tools.SearchFilter;
import org.mariadb.jdbc.internal.io.LruTraceCache;
import org.mariadb.jdbc.internal.util.pool.GlobalStateInfo;

public class MastersSlavesProtocol extends MasterProtocol {

  protected boolean masterConnection = false;
  private boolean mustBeMasterConnection = false;

  public MastersSlavesProtocol(
      final UrlParser url,
      final GlobalStateInfo globalInfo,
      final ReentrantLock lock,
      LruTraceCache traceCache) {
    super(url, globalInfo, lock, traceCache);
  }

  /**
   * loop until found the failed connection.
   *
   * @param listener current failover
   * @param globalInfo server global variables information
   * @param addresses list of HostAddress to loop
   * @param searchFilter search parameter
   * @throws SQLException if not found
   */
  public static void loop(
      MastersSlavesListener listener,
      final GlobalStateInfo globalInfo,
      final List<HostAddress> addresses,
      SearchFilter searchFilter)
      throws SQLException {

    MastersSlavesProtocol protocol;
    ArrayDeque<HostAddress> loopAddresses = new ArrayDeque<>(addresses);
    if (loopAddresses.isEmpty()) {
      resetHostList(listener, loopAddresses);
    }

    int maxConnectionTry = listener.getRetriesAllDown();
    SQLException lastQueryException = null;
    boolean firstLoop = true;
    while (!loopAddresses.isEmpty() || (!searchFilter.isFailoverLoop() && maxConnectionTry > 0)) {
      protocol = getNewProtocol(listener.getProxy(), globalInfo, listener.getUrlParser());

      if (listener.isExplicitClosed()
          || (!listener.isSecondaryHostFailReconnect() && !listener.isMasterHostFailReconnect())) {
        return;
      }
      maxConnectionTry--;
      try {
        HostAddress host = loopAddresses.pollFirst();
        if (host == null) {
          loopAddresses.addAll(listener.getUrlParser().getHostAddresses());
          host = loopAddresses.pollFirst();
        }

        protocol.setHostAddress(host);

        protocol.connect();
        if (listener.isExplicitClosed()) {
          protocol.close();
          return;
        }

        listener.removeFromBlacklist(protocol.getHostAddress());

        if (listener.isMasterHostFailReconnect() && protocol.isMasterConnection()) {
          if (foundMaster(listener, protocol, searchFilter)) {
            return;
          }
        } else if (listener.isSecondaryHostFailReconnect() && !protocol.isMasterConnection()) {
          if (foundSecondary(listener, protocol, searchFilter)) {
            return;
          }
        } else {
          protocol.close();
        }

      } catch (SQLException e) {
        lastQueryException = e;
        listener.addToBlacklist(protocol.getHostAddress());
      }

      if (!listener.isMasterHostFailReconnect() && !listener.isSecondaryHostFailReconnect()) {
        return;
      }

      // in case master not found but slave is , and allowing master down
      if (loopAddresses.isEmpty()
          && (listener.isMasterHostFailReconnect()
              && listener.urlParser.getOptions().allowMasterDownConnection
              && !listener.isSecondaryHostFailReconnect())) {
        return;
      }

      // on connection and all slaves have been tested, use master if on
      if (loopAddresses.isEmpty()
          && searchFilter.isInitialConnection()
          && !listener.isMasterHostFailReconnect()) {
        return;
      }

      // if server has try to connect to all host, and there is remaining master or slave that fail
      // add all servers back to continue looping until maxConnectionTry is reached
      if (loopAddresses.isEmpty() && !searchFilter.isFailoverLoop() && maxConnectionTry > 0) {
        resetHostList(listener, loopAddresses);

        if (firstLoop) {
          firstLoop = false;
        } else {
          try {
            // wait 250ms before looping through all connection another time
            Thread.sleep(250);
          } catch (InterruptedException interrupted) {
            // interrupted, continue
          }
        }
      }
    }

    if (listener.isMasterHostFailReconnect() || listener.isSecondaryHostFailReconnect()) {
      String error = "No active connection found for replica";
      if (listener.isMasterHostFailReconnect()) {
        error = "No active connection found for master";
      }
      if (lastQueryException != null) {
        throw new SQLException(
            error + " : " + lastQueryException.getMessage(),
            lastQueryException.getSQLState(),
            lastQueryException.getErrorCode(),
            lastQueryException);
      }
      throw new SQLException(error);
    }
  }

  /**
   * Reinitialize loopAddresses with all servers in randomize order.
   *
   * @param listener current listener
   * @param loopAddresses the list to reinitialize
   */
  private static void resetHostList(
      MastersSlavesListener listener, Deque<HostAddress> loopAddresses) {
    // if all servers have been connected without result
    // add back all servers
    List<HostAddress> servers = new ArrayList<>();
    servers.addAll(listener.getUrlParser().getHostAddresses());
    Collections.shuffle(servers);

    // remove current connected hosts to avoid reconnect them
    servers.removeAll(listener.connectedHosts());

    loopAddresses.clear();
    loopAddresses.addAll(servers);
  }

  protected static boolean foundMaster(
      MastersSlavesListener listener, MastersSlavesProtocol protocol, SearchFilter searchFilter) {
    protocol.setMustBeMasterConnection(true);
    if (listener.isMasterHostFailReconnect()) {
      listener.foundActiveMaster(protocol);
    } else {
      protocol.close();
    }

    if (!listener.isSecondaryHostFailReconnect()) {
      return true;
    } else {
      return listener.isExplicitClosed()
          || searchFilter.isFineIfFoundOnlyMaster()
          || !listener.isSecondaryHostFailReconnect();
    }
  }

  protected static boolean foundSecondary(
      MastersSlavesListener listener, MastersSlavesProtocol protocol, SearchFilter searchFilter)
      throws SQLException {
    protocol.setMustBeMasterConnection(false);
    if (listener.isSecondaryHostFailReconnect()) {
      listener.foundActiveSecondary(protocol);
    } else {
      protocol.close();
    }

    if (!listener.isMasterHostFailReconnect()) {
      return true;
    } else {
      return listener.isExplicitClosed()
          || searchFilter.isFineIfFoundOnlySlave()
          || !listener.isMasterHostFailReconnect();
    }
  }

  /**
   * Get new instance of MastersSlavesProtocol.
   *
   * @param proxy proxy
   * @param urlParser connection string Object.
   * @return a new MastersSlavesProtocol instance
   */
  private static MastersSlavesProtocol getNewProtocol(
      FailoverProxy proxy, final GlobalStateInfo globalInfo, UrlParser urlParser) {
    MastersSlavesProtocol newProtocol =
        new MastersSlavesProtocol(urlParser, globalInfo, proxy.lock, proxy.traceCache);
    newProtocol.setProxy(proxy);
    return newProtocol;
  }

  public boolean mustBeMasterConnection() {
    return mustBeMasterConnection;
  }

  public void setMustBeMasterConnection(boolean mustBeMasterConnection) {
    this.mustBeMasterConnection = mustBeMasterConnection;
  }
}
