/*
 * Copyright (c) 2015, 2021, Oracle and/or its affiliates.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 2.0, as published by the
 * Free Software Foundation.
 *
 * This program is also distributed with certain software (including but not
 * limited to OpenSSL) that is licensed under separate terms, as designated in a
 * particular file or component or in included license documentation. The
 * authors of MySQL hereby grant you an additional permission to link the
 * program and your derivative works with the separately licensed software that
 * they have included with MySQL.
 *
 * Without limiting anything contained in the foregoing, this file, which is
 * part of MySQL Connector/J, is also subject to the Universal FOSS Exception,
 * version 1.0, a copy of which can be found at
 * http://oss.oracle.com/licenses/universal-foss-exception.
 *
 * 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 General Public License, version 2.0,
 * for more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
 */

package com.mysql.cj.protocol.a;

import java.util.HashMap;
import java.util.Map;
import java.util.TimeZone;

import com.mysql.cj.CharsetSettings;
import com.mysql.cj.ServerVersion;
import com.mysql.cj.conf.PropertyKey;
import com.mysql.cj.conf.PropertySet;
import com.mysql.cj.conf.RuntimeProperty;
import com.mysql.cj.exceptions.ExceptionFactory;
import com.mysql.cj.exceptions.WrongArgumentException;
import com.mysql.cj.protocol.ServerCapabilities;
import com.mysql.cj.protocol.ServerSession;
import com.mysql.cj.protocol.ServerSessionStateController;
import com.mysql.cj.util.TimeUtil;

public class NativeServerSession implements ServerSession {

    public static final int SERVER_STATUS_IN_TRANS = 1;
    public static final int SERVER_STATUS_AUTOCOMMIT = 2; // Server in auto_commit mode
    public static final int SERVER_MORE_RESULTS_EXISTS = 8; // Multi query - next query exists
    public static final int SERVER_QUERY_NO_GOOD_INDEX_USED = 16;
    public static final int SERVER_QUERY_NO_INDEX_USED = 32;
    public static final int SERVER_STATUS_CURSOR_EXISTS = 64;
    public static final int SERVER_STATUS_LAST_ROW_SENT = 128; // The server status for 'last-row-sent'
    public static final int SERVER_QUERY_WAS_SLOW = 2048;

    public static final int CLIENT_LONG_PASSWORD = 0x00000001; /* new more secure passwords */
    public static final int CLIENT_FOUND_ROWS = 0x00000002;
    public static final int CLIENT_LONG_FLAG = 0x00000004; /* Get all column flags */
    public static final int CLIENT_CONNECT_WITH_DB = 0x00000008;
    public static final int CLIENT_COMPRESS = 0x00000020; /* Can use compression protocol */
    public static final int CLIENT_LOCAL_FILES = 0x00000080; /* Can use LOAD DATA LOCAL */
    public static final int CLIENT_PROTOCOL_41 = 0x00000200; // for > 4.1.1
    public static final int CLIENT_INTERACTIVE = 0x00000400;
    public static final int CLIENT_SSL = 0x00000800;
    public static final int CLIENT_TRANSACTIONS = 0x00002000; // Client knows about transactions
    public static final int CLIENT_RESERVED = 0x00004000; // for 4.1.0 only
    public static final int CLIENT_SECURE_CONNECTION = 0x00008000;
    public static final int CLIENT_MULTI_STATEMENTS = 0x00010000; // Enable/disable multiquery support
    public static final int CLIENT_MULTI_RESULTS = 0x00020000; // Enable/disable multi-results
    public static final int CLIENT_PS_MULTI_RESULTS = 0x00040000; // Enable/disable multi-results for server prepared statements
    public static final int CLIENT_PLUGIN_AUTH = 0x00080000;
    public static final int CLIENT_CONNECT_ATTRS = 0x00100000;
    public static final int CLIENT_PLUGIN_AUTH_LENENC_CLIENT_DATA = 0x00200000;
    public static final int CLIENT_CAN_HANDLE_EXPIRED_PASSWORD = 0x00400000;
    public static final int CLIENT_SESSION_TRACK = 0x00800000;
    public static final int CLIENT_DEPRECATE_EOF = 0x01000000;
    public static final int CLIENT_QUERY_ATTRIBUTES = 0x08000000;

    private PropertySet propertySet;
    private NativeCapabilities capabilities;
    private int oldStatusFlags = 0;
    private int statusFlags = 0;
    private long clientParam = 0;
    private NativeServerSessionStateController serverSessionStateController;

    /** The map of server variables that we retrieve at connection init. */
    private Map<String, String> serverVariables = new HashMap<>();

    private CharsetSettings charsetSettings;

    /** Are we in autoCommit mode? */
    private boolean autoCommit = true;

    /** The timezone of the server */
    private TimeZone sessionTimeZone = null;

    private TimeZone defaultTimeZone = TimeZone.getDefault();

    private RuntimeProperty<Boolean> cacheDefaultTimeZone = null;

    public NativeServerSession(PropertySet propertySet) {
        this.propertySet = propertySet;
        this.cacheDefaultTimeZone = this.propertySet.getBooleanProperty(PropertyKey.cacheDefaultTimeZone);
        this.serverSessionStateController = new NativeServerSessionStateController();
    }

    @Override
    public NativeCapabilities getCapabilities() {
        return this.capabilities;
    }

    @Override
    public void setCapabilities(ServerCapabilities capabilities) {
        this.capabilities = (NativeCapabilities) capabilities;
    }

    @Override
    public int getStatusFlags() {
        return this.statusFlags;
    }

    @Override
    public void setStatusFlags(int statusFlags) {
        setStatusFlags(statusFlags, false);
    }

    @Override
    public void setStatusFlags(int statusFlags, boolean saveOldStatus) {
        if (saveOldStatus) {
            this.oldStatusFlags = this.statusFlags;
        }
        this.statusFlags = statusFlags;
    }

    @Override
    public int getOldStatusFlags() {
        return this.oldStatusFlags;
    }

    @Override
    public void setOldStatusFlags(int oldStatusFlags) {
        this.oldStatusFlags = oldStatusFlags;
    }

    @Override
    public int getTransactionState() {
        if ((this.oldStatusFlags & SERVER_STATUS_IN_TRANS) == 0) {
            if ((this.statusFlags & SERVER_STATUS_IN_TRANS) == 0) {
                return TRANSACTION_NOT_STARTED;
            }
            return TRANSACTION_STARTED;
        }
        if ((this.statusFlags & SERVER_STATUS_IN_TRANS) == 0) {
            return TRANSACTION_COMPLETED;
        }
        return TRANSACTION_IN_PROGRESS;
    }

    @Override
    public boolean inTransactionOnServer() {
        return (this.statusFlags & SERVER_STATUS_IN_TRANS) != 0;
    }

    @Override
    public boolean cursorExists() {
        return (this.statusFlags & SERVER_STATUS_CURSOR_EXISTS) != 0;
    }

    @Override
    public boolean isAutocommit() {
        return (this.statusFlags & SERVER_STATUS_AUTOCOMMIT) != 0;
    }

    @Override
    public boolean hasMoreResults() {
        return (this.statusFlags & SERVER_MORE_RESULTS_EXISTS) != 0;
    }

    @Override
    public boolean noGoodIndexUsed() {
        return (this.statusFlags & SERVER_QUERY_NO_GOOD_INDEX_USED) != 0;
    }

    @Override
    public boolean noIndexUsed() {
        return (this.statusFlags & SERVER_QUERY_NO_INDEX_USED) != 0;
    }

    @Override
    public boolean queryWasSlow() {
        return (this.statusFlags & SERVER_QUERY_WAS_SLOW) != 0;
    }

    @Override
    public boolean isLastRowSent() {
        return (this.statusFlags & SERVER_STATUS_LAST_ROW_SENT) != 0;
    }

    @Override
    public long getClientParam() {
        return this.clientParam;
    }

    @Override
    public void setClientParam(long clientParam) {
        this.clientParam = clientParam;
    }

    @Override
    public boolean hasLongColumnInfo() {
        return (this.clientParam & CLIENT_LONG_FLAG) != 0;
    }

    @Override
    public boolean useMultiResults() {
        return (this.clientParam & CLIENT_MULTI_RESULTS) != 0 || (this.clientParam & CLIENT_PS_MULTI_RESULTS) != 0;
    }

    @Override
    public boolean isEOFDeprecated() {
        return (this.clientParam & CLIENT_DEPRECATE_EOF) != 0;
    }

    @Override
    public boolean supportsQueryAttributes() {
        return (this.clientParam & CLIENT_QUERY_ATTRIBUTES) != 0;
    }

    @Override
    public Map<String, String> getServerVariables() {
        return this.serverVariables;
    }

    @Override
    public String getServerVariable(String name) {
        return this.serverVariables.get(name);
    }

    @Override
    public int getServerVariable(String variableName, int fallbackValue) {
        try {
            return Integer.valueOf(getServerVariable(variableName));
        } catch (NumberFormatException nfe) {
            //getLog().logWarn(
            //        Messages.getString("Connection.BadValueInServerVariables", new Object[] { variableName, getServerVariable(variableName), fallbackValue }));
        }
        return fallbackValue;
    }

    @Override
    public void setServerVariables(Map<String, String> serverVariables) {
        this.serverVariables = serverVariables;
    }

    public final ServerVersion getServerVersion() {
        return this.capabilities.getServerVersion();
    }

    @Override
    public boolean isVersion(ServerVersion version) {
        return this.getServerVersion().equals(version);
    }

    /**
     * Should SET AUTOCOMMIT be sent to server if we are going to set autoCommitFlag in driver
     * 
     * @param autoCommitFlag
     *            autocommit status we are going to set in driver
     * @param elideSetAutoCommitsFlag
     *            'elideSetAutoCommits' property value
     * @return true if SET AUTOCOMMIT to be sent
     */
    public boolean isSetNeededForAutoCommitMode(boolean autoCommitFlag, boolean elideSetAutoCommitsFlag) {
        if (elideSetAutoCommitsFlag) {
            boolean autoCommitModeOnServer = isAutocommit();

            if (autoCommitModeOnServer && !autoCommitFlag) {
                // When trying to set autoCommit == false and SERVER_STATUS_AUTOCOMMIT = true we need to check
                // SERVER_STATUS_IN_TRANS flag, because SERVER_STATUS_AUTOCOMMIT isn't always correct.
                // If a transaction is in progress on the server, then we must be already in autoCommit == false
                // therefore return the opposite of transaction status
                return !inTransactionOnServer();
            }

            return autoCommitModeOnServer != autoCommitFlag;
        }

        return true;
    }

    public void preserveOldTransactionState() {
        this.statusFlags |= this.oldStatusFlags & SERVER_STATUS_IN_TRANS;
    }

    @Override
    public boolean isLowerCaseTableNames() {
        String lowerCaseTables = this.serverVariables.get("lower_case_table_names");
        return "on".equalsIgnoreCase(lowerCaseTables) || "1".equalsIgnoreCase(lowerCaseTables) || "2".equalsIgnoreCase(lowerCaseTables);
    }

    @Override
    public boolean storesLowerCaseTableNames() {
        String lowerCaseTables = this.serverVariables.get("lower_case_table_names");
        return "1".equalsIgnoreCase(lowerCaseTables) || "on".equalsIgnoreCase(lowerCaseTables);
    }

    public boolean isQueryCacheEnabled() {
        return "ON".equalsIgnoreCase(this.serverVariables.get("query_cache_type")) && !"0".equalsIgnoreCase(this.serverVariables.get("query_cache_size"));
    }

    /**
     * Is the server in a sql_mode that does not allow us to use \\ to escape things?
     * 
     * @return Returns the noBackslashEscapes.
     */
    public boolean isNoBackslashEscapesSet() {
        String sqlModeAsString = this.serverVariables.get("sql_mode");
        return sqlModeAsString != null && sqlModeAsString.indexOf("NO_BACKSLASH_ESCAPES") != -1;
    }

    public boolean useAnsiQuotedIdentifiers() {
        String sqlModeAsString = this.serverVariables.get("sql_mode");
        return sqlModeAsString != null && sqlModeAsString.indexOf("ANSI_QUOTES") != -1;
    }

    @Override
    public boolean isServerTruncatesFracSecs() {
        String sqlModeAsString = this.serverVariables.get("sql_mode");
        return sqlModeAsString != null && sqlModeAsString.indexOf("TIME_TRUNCATE_FRACTIONAL") != -1;
    }

    public boolean isAutoCommit() {
        return this.autoCommit;
    }

    public void setAutoCommit(boolean autoCommit) {
        this.autoCommit = autoCommit;
    }

    public TimeZone getSessionTimeZone() {
        if (this.sessionTimeZone == null) {
            String configuredTimeZoneOnServer = getServerVariable("time_zone");
            if ("SYSTEM".equalsIgnoreCase(configuredTimeZoneOnServer)) {
                configuredTimeZoneOnServer = getServerVariable("system_time_zone");
            }
            if (configuredTimeZoneOnServer != null) {
                try {
                    this.sessionTimeZone = TimeZone.getTimeZone(TimeUtil.getCanonicalTimeZone(configuredTimeZoneOnServer, null));
                } catch (IllegalArgumentException iae) {
                    throw ExceptionFactory.createException(WrongArgumentException.class, iae.getMessage());
                }
            }
        }

        return this.sessionTimeZone;
    }

    public void setSessionTimeZone(TimeZone sessionTimeZone) {
        this.sessionTimeZone = sessionTimeZone;
    }

    public TimeZone getDefaultTimeZone() {
        if (this.cacheDefaultTimeZone.getValue()) {
            return this.defaultTimeZone;
        }
        return TimeZone.getDefault();
    }

    @Override
    public ServerSessionStateController getServerSessionStateController() {
        return this.serverSessionStateController;
    }

    @Override
    public CharsetSettings getCharsetSettings() {
        return this.charsetSettings;
    }

    @Override
    public void setCharsetSettings(CharsetSettings charsetSettings) {
        this.charsetSettings = charsetSettings;
    }
}
