/*
 *   Copyright (c) 2015, 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.dao.impl;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.device.mgt.common.app.mgt.Application;
import org.wso2.carbon.device.mgt.core.dao.ApplicationDAO;
import org.wso2.carbon.device.mgt.core.dao.DeviceManagementDAOException;
import org.wso2.carbon.device.mgt.core.dao.DeviceManagementDAOFactory;
import org.wso2.carbon.device.mgt.core.dao.util.DeviceManagementDAOUtil;


import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.io.ObjectInputStream;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;
import java.util.Properties;

public abstract class AbstractApplicationDAOImpl implements ApplicationDAO {

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

    @Override
    public int addApplication(Application application, int tenantId) throws DeviceManagementDAOException {
        Connection conn;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        ByteArrayOutputStream bao = null;
        ObjectOutputStream oos = null;
        int applicationId = -1;
        try {
            conn = this.getConnection();
            stmt = conn.prepareStatement("INSERT INTO DM_APPLICATION (NAME, PLATFORM, CATEGORY, " +
                    "VERSION, TYPE, LOCATION_URL, IMAGE_URL, TENANT_ID, APP_PROPERTIES, APP_IDENTIFIER, MEMORY_USAGE, IS_ACTIVE) " +
                    "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");

            stmt.setString(1, application.getName());
            stmt.setString(2, application.getPlatform());
            stmt.setString(3, application.getCategory());
            stmt.setString(4, application.getVersion());
            stmt.setString(5, application.getType());
            stmt.setString(6, application.getLocationUrl());
            stmt.setString(7, application.getImageUrl());
            stmt.setInt(8, tenantId);

            bao = new ByteArrayOutputStream();
            oos = new ObjectOutputStream(bao);
            oos.writeObject(application.getAppProperties());
            stmt.setBytes(9, bao.toByteArray());

            stmt.setString(10, application.getApplicationIdentifier());
            stmt.setInt(11, application.getMemoryUsage());
            stmt.setBoolean(12, application.isActive());
            stmt.execute();

            rs = stmt.getGeneratedKeys();
            if (rs.next()) {
                applicationId = rs.getInt(1);
            }
            return applicationId;
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("Error occurred while adding application '" +
                    application.getName() + "'", e);
        } catch (IOException e) {
            throw new DeviceManagementDAOException("Error occurred while serializing application properties object", e);
        } finally {
            if (bao != null) {
                try {
                    bao.close();
                } catch (IOException e) {
                    log.error("Error occurred while closing ByteArrayOutputStream", e);
                }
            }
            if (oos != null) {
                try {
                    oos.close();
                } catch (IOException e) {
                    log.error("Error occurred while closing ObjectOutputStream", e);
                }
            }
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
    }

    @Override
    public List<Integer> removeApplications(List<Application> apps, int tenantId) throws DeviceManagementDAOException {
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        List<Integer> applicationIds = new ArrayList<>();
        try {
            conn = this.getConnection();
            conn.setAutoCommit(false);
            stmt = conn.prepareStatement("DELETE DM_APPLICATION WHERE APP_IDENTIFIER = ? AND TENANT_ID = ?",
                    new String[]{"id"});

            for (Application app : apps) {
                stmt.setString(1, app.getApplicationIdentifier());
                stmt.setInt(2, tenantId);
                stmt.addBatch();
            }
            stmt.executeBatch();
            rs = stmt.getGeneratedKeys();
            if (rs.next()) {
                applicationIds.add(rs.getInt(1));
            }
            return applicationIds;
        } catch (SQLException e) {
            try {
                if (conn != null) {
                    conn.rollback();
                }
            } catch (SQLException e1) {
                log.error("Error occurred while roll-backing the transaction", e);
            }
            throw new DeviceManagementDAOException("Error occurred while removing bulk application list", e);
        } finally {
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
    }

    @Override
    public Application getApplication(String identifier, int tenantId) throws DeviceManagementDAOException {
        Connection conn;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        Application application = null;
        try {
            conn = this.getConnection();
            stmt = conn.prepareStatement("SELECT ID, NAME, APP_IDENTIFIER, PLATFORM, CATEGORY, VERSION, TYPE, " +
                    "LOCATION_URL, IMAGE_URL, APP_PROPERTIES, MEMORY_USAGE, IS_ACTIVE, TENANT_ID FROM " +
                    "DM_APPLICATION WHERE APP_IDENTIFIER = ? AND TENANT_ID = ?");
            stmt.setString(1, identifier);
            stmt.setInt(2, tenantId);
            rs = stmt.executeQuery();

            if (rs.next()) {
                application = this.loadApplication(rs);
            }
            return application;
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("Error occurred while retrieving application application '" +
                    identifier + "'", e);
        } finally {
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
    }

    @Override
    public Application getApplication(String identifier, String version, int tenantId)
            throws DeviceManagementDAOException {
        Connection conn;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        Application application = null;
        try {
            conn = this.getConnection();
            stmt = conn.prepareStatement("SELECT ID, NAME, APP_IDENTIFIER, PLATFORM, CATEGORY, VERSION, TYPE, " +
                    "LOCATION_URL, IMAGE_URL, APP_PROPERTIES, MEMORY_USAGE, IS_ACTIVE, TENANT_ID FROM " +
                    "DM_APPLICATION WHERE APP_IDENTIFIER = ? AND VERSION = ?  AND TENANT_ID = ?");
            stmt.setString(1, identifier);
            stmt.setString(2, version);
            stmt.setInt(3, tenantId);
            rs = stmt.executeQuery();

            if (rs.next()) {
                application = this.loadApplication(rs);
            }
            return application;
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("Error occurred while retrieving application application '" +
                    identifier + "' and version '" + version + "'.", e);
        } finally {
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
    }

    @Override
    public Application getApplication(String identifier, String version, int deviceId,  int enrolmentId,  int tenantId)
            throws DeviceManagementDAOException {
        Connection conn;
        PreparedStatement stmt = null;
        ResultSet rs = null;
        Application application = null;
        try {
            conn = this.getConnection();
            stmt = conn.prepareStatement("SELECT ID,  NAME, APP_IDENTIFIER, PLATFORM, CATEGORY, VERSION, TYPE, " +
                    "LOCATION_URL, IMAGE_URL, appmap.APP_PROPERTIES, appmap.MEMORY_USAGE, appmap.IS_ACTIVE, TENANT_ID " +
                    "FROM DM_APPLICATION app INNER JOIN (SELECT  APPLICATION_ID, APP_PROPERTIES, MEMORY_USAGE, " +
                    "IS_ACTIVE FROM DM_DEVICE_APPLICATION_MAPPING WHERE  DEVICE_ID = ? AND ENROLMENT_ID = ?) appmap " +
                    "WHERE app.APP_IDENTIFIER = ? AND app.VERSION = ? AND  " +
                    "appmap.APPLICATION_ID = app.id  AND TENANT_ID = ?");
            stmt.setInt(1, deviceId);
            stmt.setInt(2, enrolmentId);
            stmt.setString(3, identifier);
            stmt.setString(4, version);
            stmt.setInt(5, tenantId);
            rs = stmt.executeQuery();

            if (rs.next()) {
                application = this.loadApplication(rs);
            }
            return application;
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("Error occurred while retrieving application application '" +
                    identifier + "' and version '" + version + "'.", e);
        } finally {
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
    }

    private Connection getConnection() throws SQLException {
        return DeviceManagementDAOFactory.getConnection();
    }

    @Override
    public List<Application> getInstalledApplications(int deviceId, int enrolmentId) throws DeviceManagementDAOException {
        Connection conn;
        PreparedStatement stmt = null;
        List<Application> applications = new ArrayList<>();
        Application application;
        ResultSet rs = null;
        try {
            conn = this.getConnection();
            stmt = conn.prepareStatement("Select ID, NAME, APP_IDENTIFIER, PLATFORM, CATEGORY, VERSION, TYPE, " +
                    "LOCATION_URL, IMAGE_URL, APPMAP.APP_PROPERTIES, APPMAP.MEMORY_USAGE, APPMAP.IS_ACTIVE, " +
                    "TENANT_ID From DM_APPLICATION app INNER JOIN " +
                    "(Select APPLICATION_ID,  APP_PROPERTIES, MEMORY_USAGE, IS_ACTIVE" +
                    " From DM_DEVICE_APPLICATION_MAPPING WHERE  DEVICE_ID=? AND ENROLMENT_ID = ?) APPMAP " +
                    "ON " +
                    "app.ID = APPMAP.APPLICATION_ID ");

            stmt.setInt(1, deviceId);
            stmt.setInt(2, enrolmentId);
            rs = stmt.executeQuery();

            while (rs.next()) {
                application = loadApplication(rs);
                applications.add(application);
            }
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("SQL Error occurred while retrieving the list of Applications " +
                    "installed in device id '" + deviceId, e);
        } finally {
            DeviceManagementDAOUtil.cleanupResources(stmt, rs);
        }
        return applications;
    }

    private Application loadApplication(ResultSet rs) throws DeviceManagementDAOException {
        ByteArrayInputStream bais;
        ObjectInputStream ois;
        Properties properties;

        Application application = new Application();
        try {
            application.setId(rs.getInt("ID"));
            application.setName(rs.getString("NAME"));
            application.setType(rs.getString("TYPE"));

            if (rs.getBytes("APP_PROPERTIES") != null) {
                byte[] appProperties = rs.getBytes("APP_PROPERTIES");
                bais = new ByteArrayInputStream(appProperties);

                ois = new ObjectInputStream(bais);
                properties = (Properties) ois.readObject();
                application.setAppProperties(properties);
            }
            application.setCategory(rs.getString("CATEGORY"));
            application.setImageUrl(rs.getString("IMAGE_URL"));
            application.setLocationUrl(rs.getString("LOCATION_URL"));
            application.setPlatform(rs.getString("PLATFORM"));
            application.setVersion(rs.getString("VERSION"));
            application.setMemoryUsage(rs.getInt("MEMORY_USAGE"));
            application.setActive(rs.getBoolean("IS_ACTIVE"));
            application.setApplicationIdentifier(rs.getString("APP_IDENTIFIER"));

        } catch (IOException e) {
            throw new DeviceManagementDAOException("IO error occurred fetch at app properties", e);
        } catch (ClassNotFoundException e) {
            throw new DeviceManagementDAOException("Class not found error occurred fetch at app properties", e);
        } catch (SQLException e) {
            throw new DeviceManagementDAOException("SQL error occurred fetch at application", e);
        }

        return application;
    }

}
