/*
 * Copyright (c) 2017, WSO2 Inc. (http://www.wso2.org) All Rights Reserved.
 *
 * WSO2 Inc. licenses this file to you 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.
 */

package org.wso2.carbon.device.mgt.core.archival.dao.impl;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.device.mgt.core.archival.dao.*;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class ArchivalDAOImpl implements ArchivalDAO {

    private static final Log log = LogFactory.getLog(ArchivalDAOImpl.class);

    private int retentionPeriod;
    private int batchSize = ArchivalDAO.DEFAULT_BATCH_SIZE;
    private Timestamp currentTimestamp;


    public ArchivalDAOImpl(int retentionPeriod) {
        this.retentionPeriod = retentionPeriod;
    }

    public ArchivalDAOImpl(int retentionPeriod, int batchSize) {
        this.retentionPeriod = retentionPeriod;
        this.batchSize = batchSize;
        this.currentTimestamp = new Timestamp(new java.util.Date().getTime());
        if (log.isDebugEnabled()) {
            log.debug("Using batch size of " + this.batchSize + " with retention period " + this.retentionPeriod);
        }
    }

    @Override
    public List<Integer> getAllOperations() throws ArchivalDAOException {
        List<Integer> operationIds = new ArrayList<>();
        Statement stmt = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT DISTINCT OPERATION_ID FROM DM_ENROLMENT_OP_MAPPING " +
                    "WHERE CREATED_TIMESTAMP BETWEEN DATE_SUB(NOW(), INTERVAL " +
                    this.retentionPeriod + " DAY) AND NOW()";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                operationIds.add(rs.getInt("OPERATION_ID"));
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("An error occurred while getting a list operation Ids to archive", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
        }
        if (log.isDebugEnabled()) {
            log.debug(operationIds.size() + " operations found for the archival");
        }
        return operationIds;
    }

    @Override
    public List<Integer> getPendingAndInProgressOperations() throws ArchivalDAOException {
        List<Integer> operationIds = new ArrayList<>();
        Statement stmt = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT DISTINCT OPERATION_ID " +
                    " FROM DM_ENROLMENT_OP_MAPPING WHERE STATUS IN('PENDING', 'IN_PROGRESS') " +
                    " AND CREATED_TIMESTAMP BETWEEN DATE_SUB(NOW(), INTERVAL " + this.retentionPeriod +" DAY) AND NOW()";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);
            while (rs.next()) {
                operationIds.add(rs.getInt("OPERATION_ID"));
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("An error occurred while getting a list operation Ids to archive", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
        }
        if (log.isDebugEnabled()) {
            log.debug(operationIds.size() + " PENDING and IN_PROFRESS operations found for the archival");
        }
        return operationIds;
    }

    @Override
    public void copyOperationIDsForArchival(List<Integer> operationIds) throws ArchivalDAOException {
        PreparedStatement stmt = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "INSERT INTO DM_ARCHIVED_OPERATIONS(ID,CREATED_TIMESTAMP) VALUES (?,NOW())";
            stmt = conn.prepareStatement(sql);

            int count = 0;
            for (int i = 0; i < operationIds.size(); i++) {
                stmt.setInt(1, operationIds.get(i));
                stmt.addBatch();

                if (++count % this.batchSize == 0) {
                    stmt.executeBatch();
                }
            }
            stmt.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " Records copied to the temporary table.");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error while copying operation Ids for archival", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt);
        }
    }

    @Override
    public void moveOperationResponses() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_DEVICE_OPERATION_RESPONSE WHERE OPERATION_ID IN " +
                    "(SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();
            sql = "INSERT INTO DM_DEVICE_OPERATION_RESPONSE_ARCH VALUES(?, ?, ?, ?, ?,?,?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("ID"));
                stmt2.setInt(2, rs.getInt("ENROLMENT_ID"));
                stmt2.setInt(3, rs.getInt("OPERATION_ID"));
                stmt2.setInt(4, rs.getInt("EN_OP_MAP_ID"));
                stmt2.setBytes(5, rs.getBytes("OPERATION_RESPONSE"));
                stmt2.setTimestamp(6, rs.getTimestamp("RECEIVED_TIMESTAMP"));
                stmt2.setTimestamp(7, this.currentTimestamp);
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                    if (log.isDebugEnabled()) {
                        log.debug("Executing batch " + count);
                    }
                }
            }
            stmt2.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " [OPERATION_RESPONSES] Records copied to the archival table. Starting deletion");
            }
            //try the deletion now
            sql = "DELETE FROM DM_DEVICE_OPERATION_RESPONSE WHERE OPERATION_ID IN (" +
                    " SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving operations ", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void moveNotifications() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_NOTIFICATION WHERE OPERATION_ID IN (SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

//            ArchivalDestinationDAOFactory.beginTransaction();
            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();

            sql = "INSERT INTO DM_NOTIFICATION_ARCH VALUES(?, ?, ?, ?, ?, ?, ?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("NOTIFICATION_ID"));
                stmt2.setInt(2, rs.getInt("DEVICE_ID"));
                stmt2.setInt(3, rs.getInt("OPERATION_ID"));
                stmt2.setInt(4, rs.getInt("TENANT_ID"));
                stmt2.setString(5, rs.getString("STATUS"));
                stmt2.setString(6, rs.getString("DESCRIPTION"));
                stmt2.setTimestamp(7, this.currentTimestamp);
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                }
            }
            stmt2.executeBatch();
//            ArchivalDestinationDAOFactory.commitTransaction();
            if (log.isDebugEnabled()) {
                log.debug(count + " [NOTIFICATIONS] Records copied to the archival table. Starting deletion");
            }
            sql = "DELETE FROM DM_NOTIFICATION" +
                    "  WHERE OPERATION_ID IN (SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving notifications ", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void moveCommandOperations() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_COMMAND_OPERATION WHERE OPERATION_ID IN " +
                    "(SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();

            sql = "INSERT INTO DM_COMMAND_OPERATION_ARCH VALUES(?,?,?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("OPERATION_ID"));
                stmt2.setInt(2, rs.getInt("ENABLED"));
                stmt2.setTimestamp(3, this.currentTimestamp);
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                }
            }
            stmt2.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " [COMMAND_OPERATION] Records copied to the archival table. Starting deletion");
            }
            sql = "DELETE FROM DM_COMMAND_OPERATION" +
                    "  WHERE OPERATION_ID IN (SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving command operations", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void moveProfileOperations() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_PROFILE_OPERATION WHERE OPERATION_ID IN " +
                    "(SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();

            sql = "INSERT INTO DM_PROFILE_OPERATION_ARCH VALUES(?, ?, ?, ?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("OPERATION_ID"));
                stmt2.setInt(2, rs.getInt("ENABLED"));
                stmt2.setBytes(3, rs.getBytes("OPERATION_DETAILS"));
                stmt2.setTimestamp(4,this.currentTimestamp );
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                }
            }
            stmt2.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " [PROFILE_OPERATION] Records copied to the archival table. Starting deletion");
            }
            sql = "DELETE FROM DM_PROFILE_OPERATION" +
                    "  WHERE OPERATION_ID IN (SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving profile operations", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void moveEnrolmentMappings() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_ENROLMENT_OP_MAPPING WHERE OPERATION_ID IN " +
                    "(SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();

            sql = "INSERT INTO DM_ENROLMENT_OP_MAPPING_ARCH VALUES(?, ?, ?, ?, ?, ?, ?,?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("ID"));
                stmt2.setInt(2, rs.getInt("ENROLMENT_ID"));
                stmt2.setInt(3, rs.getInt("OPERATION_ID"));
                stmt2.setString(4, rs.getString("STATUS"));
                stmt2.setString(5, rs.getString("PUSH_NOTIFICATION_STATUS"));
                stmt2.setInt(6, rs.getInt("CREATED_TIMESTAMP"));
                stmt2.setInt(7, rs.getInt("UPDATED_TIMESTAMP"));
                stmt2.setTimestamp(8, this.currentTimestamp);
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                    if (log.isDebugEnabled()) {
                        log.debug("Executing batch " + count);
                    }
                }
            }
            stmt2.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " [ENROLMENT_OP_MAPPING] Records copied to the archival table. Starting deletion");
            }
            sql = "DELETE FROM DM_ENROLMENT_OP_MAPPING WHERE OPERATION_ID IN (" +
                    "SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving enrolment mappings", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void moveOperations() throws ArchivalDAOException {
        Statement stmt = null;
        PreparedStatement stmt2 = null;
        Statement stmt3 = null;
        ResultSet rs = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            String sql = "SELECT * FROM DM_OPERATION WHERE ID IN (SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt = this.createMemoryEfficientStatement(conn);
            rs = stmt.executeQuery(sql);

            Connection conn2 = ArchivalDestinationDAOFactory.getConnection();
            sql = "INSERT INTO DM_OPERATION_ARCH VALUES(?, ?, ?, ?, ?, ?)";
            stmt2 = conn2.prepareStatement(sql);

            int count = 0;
            while (rs.next()) {
                stmt2.setInt(1, rs.getInt("ID"));
                stmt2.setString(2, rs.getString("TYPE"));
                stmt2.setTimestamp(3, rs.getTimestamp("CREATED_TIMESTAMP"));
                stmt2.setTimestamp(4, rs.getTimestamp("RECEIVED_TIMESTAMP"));
                stmt2.setString(5, rs.getString("OPERATION_CODE"));
                stmt2.setTimestamp(6, this.currentTimestamp);
                stmt2.addBatch();

                if (++count % batchSize == 0) {
                    stmt2.executeBatch();
                }
            }
            stmt2.executeBatch();
            if (log.isDebugEnabled()) {
                log.debug(count + " [OPERATIONS] Records copied to the archival table. Starting deletion");
            }
            sql = "DELETE FROM DM_OPERATION WHERE ID IN (" +
                    "SELECT ID FROM DM_ARCHIVED_OPERATIONS)";
            stmt3 = conn.createStatement();
            int affected = stmt3.executeUpdate(sql);
            if (log.isDebugEnabled()) {
                log.debug(affected + " Rows deleted");
            }
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while moving operations", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt, rs);
            ArchivalDAOUtil.cleanupResources(stmt2);
            ArchivalDAOUtil.cleanupResources(stmt3);
        }
    }

    @Override
    public void truncateOperationIDsForArchival() throws ArchivalDAOException {
        PreparedStatement stmt = null;
        try {
            Connection conn = ArchivalSourceDAOFactory.getConnection();
            conn.setAutoCommit(false);
            String sql = "TRUNCATE DM_ARCHIVED_OPERATIONS";
            stmt = conn.prepareStatement(sql);
            stmt.addBatch();
            stmt.executeBatch();
            conn.commit();
        } catch (SQLException e) {
            throw new ArchivalDAOException("Error occurred while truncating operation Ids", e);
        } finally {
            ArchivalDAOUtil.cleanupResources(stmt);
        }
    }

    private Statement createMemoryEfficientStatement(Connection conn) throws ArchivalDAOException, SQLException {
        Statement stmt = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, ResultSet.CONCUR_READ_ONLY);
        stmt.setFetchSize(Integer.MIN_VALUE);
        return stmt;
    }

}
