/*
 *   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.mobile.android.impl;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.wso2.carbon.device.mgt.common.Device;
import org.wso2.carbon.device.mgt.common.DeviceIdentifier;
import org.wso2.carbon.device.mgt.common.DeviceManagementConstants;
import org.wso2.carbon.device.mgt.common.DeviceManagementException;
import org.wso2.carbon.device.mgt.common.DeviceManager;
import org.wso2.carbon.device.mgt.common.EnrolmentInfo;
import org.wso2.carbon.device.mgt.common.FeatureManager;
import org.wso2.carbon.device.mgt.common.configuration.mgt.PlatformConfiguration;
import org.wso2.carbon.device.mgt.common.license.mgt.License;
import org.wso2.carbon.device.mgt.common.license.mgt.LicenseManagementException;
import org.wso2.carbon.device.mgt.common.license.mgt.LicenseManager;
import org.wso2.carbon.device.mgt.extensions.license.mgt.registry.RegistryBasedLicenseManager;
import org.wso2.carbon.device.mgt.mobile.android.impl.dao.AbstractMobileDeviceManagementDAOFactory;
import org.wso2.carbon.device.mgt.mobile.android.impl.dao.AndroidDAOFactory;
import org.wso2.carbon.device.mgt.mobile.android.impl.dao.MobileDeviceManagementDAOException;
import org.wso2.carbon.device.mgt.mobile.android.impl.dao.impl.AndroidDeviceMgtPluginException;
import org.wso2.carbon.device.mgt.mobile.android.impl.dto.MobileDevice;
import org.wso2.carbon.device.mgt.mobile.android.impl.util.AndroidPluginConstants;
import org.wso2.carbon.device.mgt.mobile.android.impl.util.AndroidPluginUtils;
import org.wso2.carbon.device.mgt.mobile.android.impl.util.MobileDeviceManagementUtil;
import org.wso2.carbon.registry.api.RegistryException;
import org.wso2.carbon.registry.api.Resource;

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;
import javax.xml.bind.Unmarshaller;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamException;
import javax.xml.stream.XMLStreamReader;
import java.io.StringReader;
import java.io.StringWriter;
import java.nio.charset.Charset;
import java.util.ArrayList;
import java.util.List;

public class AndroidDeviceManager implements DeviceManager {

    private AbstractMobileDeviceManagementDAOFactory daoFactory;
    private static final Log log = LogFactory.getLog(AndroidDeviceManagementService.class);
    private FeatureManager featureManager = new AndroidFeatureManager();
    private LicenseManager licenseManager;

    public AndroidDeviceManager() {
        this.daoFactory = new AndroidDAOFactory();
        this.licenseManager = new RegistryBasedLicenseManager();
        License defaultLicense;

        try {
            if (licenseManager.getLicense(AndroidDeviceManagementService.DEVICE_TYPE_ANDROID,
                    AndroidPluginConstants.MobilePluginConstants.LANGUAGE_CODE_ENGLISH_US) ==
                    null) {
                defaultLicense = AndroidPluginUtils.getDefaultLicense();
                licenseManager.addLicense(AndroidDeviceManagementService.DEVICE_TYPE_ANDROID, defaultLicense);
            }
            featureManager.addSupportedFeaturesToDB();
        } catch (LicenseManagementException e) {
            log.error("Error occurred while adding default license for Android devices", e);
        } catch (DeviceManagementException e) {
            log.error("Error occurred while adding supported device features for Android platform", e);
        }
    }

    @Override
    public FeatureManager getFeatureManager() {
        return featureManager;
    }

    @Override
    public boolean saveConfiguration(PlatformConfiguration tenantConfiguration)
            throws DeviceManagementException {
        boolean status;
        try {
            if (log.isDebugEnabled()) {
                log.debug("Persisting android configurations in Registry");
            }
            String resourcePath = MobileDeviceManagementUtil.getPlatformConfigPath(
                    DeviceManagementConstants.
                            MobileDeviceTypes.MOBILE_DEVICE_TYPE_ANDROID);
            StringWriter writer = new StringWriter();
            JAXBContext context = JAXBContext.newInstance(PlatformConfiguration.class);
            Marshaller marshaller = context.createMarshaller();
            marshaller.marshal(tenantConfiguration, writer);

            Resource resource = MobileDeviceManagementUtil.getConfigurationRegistry().newResource();
            resource.setContent(writer.toString());
            resource.setMediaType(AndroidPluginConstants.MobilePluginConstants.MEDIA_TYPE_XML);
            MobileDeviceManagementUtil.putRegistryResource(resourcePath, resource);
            status = true;
        } catch (AndroidDeviceMgtPluginException e) {
            throw new DeviceManagementException(
                    "Error occurred while retrieving the Registry instance : " + e.getMessage(), e);
        } catch (RegistryException e) {
            throw new DeviceManagementException(
                    "Error occurred while persisting the Registry resource of Android Configuration : " + e.getMessage(), e);
        } catch (JAXBException e) {
            throw new DeviceManagementException(
                    "Error occurred while parsing the Android configuration : " + e.getMessage(), e);
        }
        return status;
    }

    @Override
    public PlatformConfiguration getConfiguration() throws DeviceManagementException {
        Resource resource;
        try {
            String androidRegPath =
                    MobileDeviceManagementUtil.getPlatformConfigPath(DeviceManagementConstants.
                            MobileDeviceTypes.MOBILE_DEVICE_TYPE_ANDROID);
            resource = MobileDeviceManagementUtil.getRegistryResource(androidRegPath);
            if (resource != null) {
                XMLInputFactory factory = XMLInputFactory.newInstance();
                factory.setProperty(XMLInputFactory.IS_SUPPORTING_EXTERNAL_ENTITIES, false);
                factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
                XMLStreamReader reader = factory.createXMLStreamReader(
                        new StringReader(new String((byte[]) resource.getContent(), Charset.
                                forName(AndroidPluginConstants.MobilePluginConstants.CHARSET_UTF8))));
                JAXBContext context = JAXBContext.newInstance(PlatformConfiguration.class);
                Unmarshaller unmarshaller = context.createUnmarshaller();
                return (PlatformConfiguration) unmarshaller.unmarshal(reader);
            }
            return null;
        } catch (AndroidDeviceMgtPluginException e) {
            throw new DeviceManagementException(
                    "Error occurred while retrieving the Registry instance : " + e.getMessage(), e);
        } catch (JAXBException | XMLStreamException e) {
            throw new DeviceManagementException(
                    "Error occurred while parsing the Android configuration : " + e.getMessage(), e);
        } catch (RegistryException e) {
            throw new DeviceManagementException(
                    "Error occurred while retrieving the Registry resource of Android Configuration : " + e.getMessage(), e);
        }
    }

    @Override
    public boolean enrollDevice(Device device) throws DeviceManagementException {
        boolean status = false;
        boolean isEnrolled = this.isEnrolled(
                new DeviceIdentifier(device.getDeviceIdentifier(), device.getType()));

        try {
            if (log.isDebugEnabled()) {
                log.debug("Enrolling a new Android device : " + device.getDeviceIdentifier());
            }

            if (isEnrolled) {
                this.modifyEnrollment(device);
            } else {
                MobileDevice mobileDevice = MobileDeviceManagementUtil.convertToMobileDevice(device);
                AndroidDAOFactory.beginTransaction();
                status = daoFactory.getMobileDeviceDAO().addMobileDevice(mobileDevice);
                AndroidDAOFactory.commitTransaction();
            }
        } catch (MobileDeviceManagementDAOException e) {
            try {
                AndroidDAOFactory.rollbackTransaction();
            } catch (MobileDeviceManagementDAOException mobileDAOEx) {
                String msg = "Error occurred while roll back the device enrol transaction :" +
                        device.toString();
                log.warn(msg, mobileDAOEx);
            }
            String msg =
                    "Error while enrolling the Android device : " + device.getDeviceIdentifier();
            throw new DeviceManagementException(msg, e);
        }
        return status;
    }

    @Override
    public boolean modifyEnrollment(Device device) throws DeviceManagementException {
        boolean status;
        MobileDevice mobileDevice = MobileDeviceManagementUtil.convertToMobileDevice(device);
        try {
            if (log.isDebugEnabled()) {
                log.debug("Modifying the Android device enrollment data");
            }
            AndroidDAOFactory.beginTransaction();
            status = daoFactory.getMobileDeviceDAO().updateMobileDevice(mobileDevice);
            AndroidDAOFactory.commitTransaction();
        } catch (MobileDeviceManagementDAOException e) {
            try {
                AndroidDAOFactory.rollbackTransaction();
            } catch (MobileDeviceManagementDAOException mobileDAOEx) {
                String msg = "Error occurred while roll back the update device transaction :" +
                        device.toString();
                log.warn(msg, mobileDAOEx);
            }
            String msg = "Error while updating the enrollment of the Android device : " +
                    device.getDeviceIdentifier();
            throw new DeviceManagementException(msg, e);
        }
        return status;
    }

    @Override
    public boolean disenrollDevice(DeviceIdentifier deviceId) throws DeviceManagementException {
        //Here we don't have anything specific to do. Hence returning.
        return true;
    }

    @Override
    public boolean isEnrolled(DeviceIdentifier deviceId) throws DeviceManagementException {
        boolean isEnrolled = false;
        try {
            if (log.isDebugEnabled()) {
                log.debug("Checking the enrollment of Android device : " + deviceId.getId());
            }
            MobileDevice mobileDevice =
                    daoFactory.getMobileDeviceDAO().getMobileDevice(deviceId.getId());
            if (mobileDevice != null) {
                isEnrolled = true;
            }
        } catch (MobileDeviceManagementDAOException e) {
            String msg = "Error while checking the enrollment status of Android device : " +
                    deviceId.getId();
            throw new DeviceManagementException(msg, e);
        }
        return isEnrolled;
    }

    @Override
    public boolean isActive(DeviceIdentifier deviceId) throws DeviceManagementException {
        return true;
    }

    @Override
    public boolean setActive(DeviceIdentifier deviceId, boolean status)
            throws DeviceManagementException {
        return true;
    }

    @Override
    public Device getDevice(DeviceIdentifier deviceId) throws DeviceManagementException {
        Device device;
        try {
            if (log.isDebugEnabled()) {
                log.debug("Getting the details of Android device : '" + deviceId.getId() + "'");
            }
            MobileDevice mobileDevice = daoFactory.getMobileDeviceDAO().
                    getMobileDevice(deviceId.getId());
            device = MobileDeviceManagementUtil.convertToDevice(mobileDevice);
        } catch (MobileDeviceManagementDAOException e) {
            throw new DeviceManagementException(
                    "Error occurred while fetching the Android device: '" +
                            deviceId.getId() + "'", e);
        }
        return device;
    }

    @Override
    public boolean updateDeviceProperties(DeviceIdentifier deviceIdentifier, List<Device.Property> list) throws DeviceManagementException {
        return false;
    }

    @Override
    public boolean setOwnership(DeviceIdentifier deviceId, String ownershipType)
            throws DeviceManagementException {
        return true;
    }

    @Override
    public boolean isClaimable(DeviceIdentifier deviceIdentifier) throws DeviceManagementException {
        return false;
    }

    @Override
    public boolean setStatus(DeviceIdentifier deviceIdentifier, String currentUser,
                             EnrolmentInfo.Status status) throws DeviceManagementException {
        return false;
    }

    @Override
    public License getLicense(String languageCode) throws LicenseManagementException {
        return licenseManager.
                getLicense(AndroidDeviceManagementService.DEVICE_TYPE_ANDROID, languageCode);
    }

    @Override
    public void addLicense(License license) throws LicenseManagementException {
        licenseManager.addLicense(AndroidDeviceManagementService.DEVICE_TYPE_ANDROID, license);
    }

    @Override
    public boolean requireDeviceAuthorization() {
        return true;
    }

    @Override
    public boolean updateDeviceInfo(DeviceIdentifier deviceIdentifier, Device device)
            throws DeviceManagementException {
        boolean status;
        Device existingDevice = this.getDevice(deviceIdentifier);
        // This object holds the current persisted device object
        MobileDevice existingMobileDevice =
                MobileDeviceManagementUtil.convertToMobileDevice(existingDevice);

        // This object holds the newly received device object from response
        MobileDevice mobileDevice = MobileDeviceManagementUtil.convertToMobileDevice(device);

        // Updating current object features using newer ones
        existingMobileDevice.setLatitude(mobileDevice.getLatitude());
        existingMobileDevice.setLongitude(mobileDevice.getLongitude());
        existingMobileDevice.setDeviceProperties(mobileDevice.getDeviceProperties());

        try {
            if (log.isDebugEnabled()) {
                log.debug(
                        "updating the details of Android device : " + device.getDeviceIdentifier());
            }
            AndroidDAOFactory.beginTransaction();
            status = daoFactory.getMobileDeviceDAO().updateMobileDevice(existingMobileDevice);
            AndroidDAOFactory.commitTransaction();
        } catch (MobileDeviceManagementDAOException e) {
            try {
                AndroidDAOFactory.rollbackTransaction();
            } catch (MobileDeviceManagementDAOException e1) {
                log.warn("Error occurred while roll back the update device info transaction : '" +
                        device.toString() + "'", e1);
            }
            throw new DeviceManagementException(
                    "Error occurred while updating the Android device: '" +
                            device.getDeviceIdentifier() + "'", e);
        }
        return status;
    }

    @Override
    public List<Device> getAllDevices() throws DeviceManagementException {
        List<Device> devices = null;
        try {
            if (log.isDebugEnabled()) {
                log.debug("Fetching the details of all Android devices");
            }
            List<MobileDevice> mobileDevices =
                    daoFactory.getMobileDeviceDAO().getAllMobileDevices();
            if (mobileDevices != null) {
                devices = new ArrayList<>(mobileDevices.size());
                for (MobileDevice mobileDevice : mobileDevices) {
                    devices.add(MobileDeviceManagementUtil.convertToDevice(mobileDevice));
                }
            }
        } catch (MobileDeviceManagementDAOException e) {
            throw new DeviceManagementException("Error occurred while fetching all Android devices",
                    e);
        }
        return devices;
    }

}
