/*

  * Copyright 2007-2008 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.kns.service.impl;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.Iterator;

 import java.util.List;

 import java.util.Map;

 import java.util.Set;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.core.util.RiceConstants;

 import org.kuali.rice.kim.bo.Person;

 import org.kuali.rice.kim.service.IdentityManagementService;

 import org.kuali.rice.kim.service.KIMServiceLocator;

 import org.kuali.rice.kim.service.PersonService;

 import org.kuali.rice.kim.util.KimConstants.PermissionNames;

 import org.kuali.rice.kns.authorization.AuthorizationConstants;

 import org.kuali.rice.kns.document.Document;

 import org.kuali.rice.kns.document.authorization.PessimisticLock;

 import org.kuali.rice.kns.exception.AuthorizationException;

 import org.kuali.rice.kns.exception.PessimisticLockingException;

 import org.kuali.rice.kns.service.BusinessObjectService;

 import org.kuali.rice.kns.service.DataDictionaryService;

 import org.kuali.rice.kns.service.KNSServiceLocator;

 import org.kuali.rice.kns.service.PessimisticLockService;

 import org.kuali.rice.kns.util.GlobalVariables;

 import org.kuali.rice.kns.util.KNSConstants;

 import org.kuali.rice.kns.util.KNSPropertyConstants;

 import org.kuali.rice.kns.util.ObjectUtils;

 import org.springframework.transaction.annotation.Transactional;

 /**

  * This is a service implementation for pessimistic locking

  *

  * @author Kuali Rice Team (rice.collab@kuali.org)

  *

  */

 @Transactional

 public class PessimisticLockServiceImpl implements PessimisticLockService {

     private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(PessimisticLockServiceImpl.class);

     private PersonService<Person> personService;

     private BusinessObjectService businessObjectService;

     private DataDictionaryService dataDictionaryService;

     private IdentityManagementService identityManagementService;

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#delete(java.lang.String)

      */

     public void delete(String id) {

         if (StringUtils.isBlank(id)) {

             throw new IllegalArgumentException("An invalid blank id was passed to delete a Pessimistic Lock.");

         }

         Map<String,Object> primaryKeys = new HashMap<String,Object>();

         primaryKeys.put(KNSPropertyConstants.ID, Long.valueOf(id));

         PessimisticLock lock = (PessimisticLock) getBusinessObjectService().findByPrimaryKey(PessimisticLock.class, primaryKeys);

         if (ObjectUtils.isNull(lock)) {

             throw new IllegalArgumentException("Pessimistic Lock with id " + id + " cannot be found in the database.");

         }

         Person user = GlobalVariables.getUserSession().getPerson();

         if ( (!lock.isOwnedByUser(user)) && (!isPessimisticLockAdminUser(user)) ) {

             throw new AuthorizationException(user.getName(),"delete", "Pessimistick Lock (id " + id + ")");

         }

         delete(lock);

     }

     private void delete(PessimisticLock lock) {

             if ( LOG.isDebugEnabled() ) {

                     LOG.debug("Deleting lock: " + lock);

             }

         getBusinessObjectService().delete(lock);

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#generateNewLock(String)

      */

     public PessimisticLock generateNewLock(String documentNumber) {

         return generateNewLock(documentNumber, GlobalVariables.getUserSession().getPerson());

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#generateNewLock(java.lang.String)

      */

     public PessimisticLock generateNewLock(String documentNumber, String lockDescriptor) {

         return generateNewLock(documentNumber, lockDescriptor, GlobalVariables.getUserSession().getPerson());

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#generateNewLock(java.lang.String, org.kuali.rice.kim.bo.Person)

      */

     public PessimisticLock generateNewLock(String documentNumber, Person user) {

         return generateNewLock(documentNumber, PessimisticLock.DEFAULT_LOCK_DESCRIPTOR, user);

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#generateNewLock(java.lang.String, java.lang.String, org.kuali.rice.kim.bo.Person)

      */

     public PessimisticLock generateNewLock(String documentNumber, String lockDescriptor, Person user) {

         PessimisticLock lock = new PessimisticLock(documentNumber, lockDescriptor, user);

         save(lock);

         if ( LOG.isDebugEnabled() ) {

                 LOG.debug("Generated new lock: " + lock);

         }

         return lock;

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#getPessimisticLocksForDocument(java.lang.String)

      */

     @SuppressWarnings("unchecked")

     public List<PessimisticLock> getPessimisticLocksForDocument(String documentNumber) {

         Map fieldValues = new HashMap();

         fieldValues.put(KNSPropertyConstants.DOCUMENT_NUMBER, documentNumber);

         return (List<PessimisticLock>) getBusinessObjectService().findMatching(PessimisticLock.class, fieldValues);

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#isPessimisticLockAdminUser(org.kuali.rice.kim.bo.Person)

      */

     public boolean isPessimisticLockAdminUser(Person user) {

             return getIdentityManagementService().isAuthorized( user.getPrincipalId(), KNSConstants.KNS_NAMESPACE, PermissionNames.ADMIN_PESSIMISTIC_LOCKING, null, null );

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#releaseAllLocksForUser(java.util.List, org.kuali.rice.kim.bo.Person)

      */

     public void releaseAllLocksForUser(List<PessimisticLock> locks, Person user) {

         for (Iterator<PessimisticLock> iterator = locks.iterator(); iterator.hasNext();) {

             PessimisticLock lock = (PessimisticLock) iterator.next();

             if (lock.isOwnedByUser(user)) {

                 delete(lock);

             }

         }

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#releaseAllLocksForUser(java.util.List, org.kuali.rice.kim.bo.Person, java.lang.String)

      */

     public void releaseAllLocksForUser(List<PessimisticLock> locks, Person user, String lockDescriptor) {

         for (Iterator<PessimisticLock> iterator = locks.iterator(); iterator.hasNext();) {

             PessimisticLock lock = (PessimisticLock) iterator.next();

             if ( (lock.isOwnedByUser(user)) && (lockDescriptor.equals(lock.getLockDescriptor())) ) {

                 delete(lock);

             }

         }

     }

     /**

      * @see org.kuali.rice.kns.service.PessimisticLockService#save(org.kuali.rice.kns.document.authorization.PessimisticLock)

      */

     public void save(PessimisticLock lock) {

             if ( LOG.isDebugEnabled() ) {

                     LOG.debug("Saving lock: " + lock);

             }

         getBusinessObjectService().save(lock);

     }

     public BusinessObjectService getBusinessObjectService() {

         return this.businessObjectService;

     }

     public void setBusinessObjectService(BusinessObjectService businessObjectService) {

         this.businessObjectService = businessObjectService;

     }

     /**

      * @param document

      * @param user

      * @return Set of actions are permitted the given user on the given document

      */

     public Set getDocumentActions(Document document, Person user, Set<String> documentActions){

             if(documentActions.contains(KNSConstants.KUALI_ACTION_CAN_CANCEL) && !hasPreRouteEditAuthorization(document, user) ){

                     documentActions.remove(KNSConstants.KUALI_ACTION_CAN_CANCEL);

             }

             if(documentActions.contains(KNSConstants.KUALI_ACTION_CAN_SAVE)  && !hasPreRouteEditAuthorization(document, user)){

                     documentActions.remove(KNSConstants.KUALI_ACTION_CAN_SAVE);

             }

         if(documentActions.contains(KNSConstants.KUALI_ACTION_CAN_ROUTE) && !hasPreRouteEditAuthorization(document, user)){

                 documentActions.remove(KNSConstants.KUALI_ACTION_CAN_ROUTE);

         }

         if (documentActions.contains(KNSConstants.KUALI_ACTION_CAN_BLANKET_APPROVE) && !hasPreRouteEditAuthorization(document, user)){

                 documentActions.remove(KNSConstants.KUALI_ACTION_CAN_BLANKET_APPROVE);

         }

             return documentActions;

     }

     /**

      * This method checks to see that the given user has a lock on the document and return true if one is found.

      *

      * @param document - document to check

      * @param user - current user

      * @return true if the document is using Pessimistic Locking, the user has initiate authorization (see

      *         {@link #hasInitiateAuthorization(Document, Person)}), and the document has a lock owned by the given

      *         user. If the document is not using Pessimistic Locking the value returned will be that returned by

      *         {@link #hasInitiateAuthorization(Document, Person)}.

      */

     protected boolean hasPreRouteEditAuthorization(Document document, Person user) {

             if (document.getPessimisticLocks().isEmpty()) {

                     return true;

             }

             for (Iterator iterator = document.getPessimisticLocks().iterator(); iterator.hasNext();) {

                     PessimisticLock lock = (PessimisticLock) iterator.next();

                     if (lock.isOwnedByUser(user)) {

                             return true;

             }

         }

         return false;

     }

     protected boolean usesPessimisticLocking(Document document) {

         return getDataDictionaryService().getDataDictionary().getDocumentEntry(document.getClass().getName()).getUsePessimisticLocking();

     }

     /**

      * This method creates a new {@link PessimisticLock} when Workflow processing requires one

      *

      * @param document - the document to create the lock against and add the lock to

      * @see org.kuali.rice.kns.document.authorization.DocumentAuthorizer#establishWorkflowPessimisticLocking(org.kuali.rice.kns.document.Document)

      */

     public void establishWorkflowPessimisticLocking(Document document) {

         PessimisticLock lock = createNewPessimisticLock(document, new HashMap(), getWorkflowPessimisticLockOwnerUser());

         document.addPessimisticLock(lock);

     }

     /**

      * This method releases locks created via the {@link #establishWorkflowPessimisticLocking(Document)} method for the given document

      *

      * @param document - document to release locks from

      * @see org.kuali.rice.kns.document.authorization.DocumentAuthorizer#releaseWorkflowPessimisticLocking(org.kuali.rice.kns.document.Document)

      */

     public void releaseWorkflowPessimisticLocking(Document document) {

         releaseAllLocksForUser(document.getPessimisticLocks(), getWorkflowPessimisticLockOwnerUser());

         document.refreshPessimisticLocks();

     }

     /**

      * This method identifies the user that should be used to create and clear {@link PessimisticLock} objects required by

      * Workflow.<br>

      * <br>

      * The default is the Kuali system user defined by {@link RiceConstants#SYSTEM_USER}. This method can be overriden by

      * implementing documents if another user is needed.

      *

      * @return a valid {@link Person} object

      */

     protected Person getWorkflowPessimisticLockOwnerUser() {

         String networkId = KNSConstants.SYSTEM_USER;

         return getPersonService().getPersonByPrincipalName(networkId);

     }

     /**

      * This implementation will check the given document, editMode map, and user object to verify Pessimistic Locking. If the

      * given edit mode map contains an 'entry type' edit mode then the system will check the locks already in existence on

      * the document. If a valid lock for the given user is found the system will return the given edit mode map. If a valid

      * lock is found but is owned by another user the edit mode map returned will have any 'entry type' edit modes removed. If the

      * given document has no locks and the edit mode map passed in has at least one 'entry type' mode then a new

      * {@link PessimisticLock} object will be created and set on the document for the given user.<br>

      * <br>

      * NOTE: This method is only called if the document uses pessimistic locking as described in the data dictionary file.

      *

      * @see org.kuali.rice.kns.document.authorization.DocumentAuthorizer#establishLocks(org.kuali.rice.kns.document.Document,

      *      java.util.Map, org.kuali.rice.kim.bo.Person)

      */

     public Map establishLocks(Document document, Map editMode, Person user) {

         Map editModeMap = new HashMap();

         // givenUserLockDescriptors is a list of lock descriptors currently held on the document by the given user

         List<String> givenUserLockDescriptors = new ArrayList<String>();

         // lockDescriptorUsers is a map with lock descriptors as keys and users other than the given user who hold a lock of each descriptor

         Map<String,Set<Person>> lockDescriptorUsers = new HashMap<String,Set<Person>>();

         // build the givenUserLockDescriptors set and the lockDescriptorUsers map

         for (PessimisticLock lock : document.getPessimisticLocks()) {

             if (lock.isOwnedByUser(user)) {

                 // lock is owned by given user

                 givenUserLockDescriptors.add(lock.getLockDescriptor());

             } else {

                 // lock is not owned by the given user

                 if (!lockDescriptorUsers.containsKey(lock.getLockDescriptor())) {

                     lockDescriptorUsers.put(lock.getLockDescriptor(), new HashSet<Person>());

                 }

                 ((Set<Person>) lockDescriptorUsers.get(lock.getLockDescriptor())).add(lock.getOwnedByUser());

             }

         }

         // verify that no locks held by current user exist for any other user

         for (String givenUserLockDescriptor : givenUserLockDescriptors) {

             if ( (lockDescriptorUsers.containsKey(givenUserLockDescriptor)) && (lockDescriptorUsers.get(givenUserLockDescriptor).size() > 0) ) {

                 Set<Person> users = lockDescriptorUsers.get(givenUserLockDescriptor);

                 if ( (users.size() != 1) || (!getWorkflowPessimisticLockOwnerUser().getPrincipalId().equals(users.iterator().next().getPrincipalId())) ) {

                     String descriptorText = (document.useCustomLockDescriptors()) ? " using lock descriptor '" + givenUserLockDescriptor + "'" : "";

                     String errorMsg = "Found an invalid lock status on document number " + document.getDocumentNumber() + "with current user and other user both having locks" + descriptorText + " concurrently";

                     LOG.debug(errorMsg);

                     throw new PessimisticLockingException(errorMsg);

                 }

             }

         }

         // check to see if the given user has any locks in the system at all

         if (givenUserLockDescriptors.isEmpty()) {

             // given user has no locks... check for other user locks

             if (lockDescriptorUsers.isEmpty()) {

                 // no other user has any locks... set up locks for given user if user has edit privileges

                 if (isLockRequiredByUser(document, editMode, user)) {

                     document.addPessimisticLock(createNewPessimisticLock(document, editMode, user));

                 }

                 editModeMap.putAll(editMode);

             } else {

                 // at least one other user has at least one other lock... adjust edit mode for read only

                 if (document.useCustomLockDescriptors()) {

                     // check to see if the custom lock descriptor is already in use

                     String customLockDescriptor = document.getCustomLockDescriptor(user);

                     if (lockDescriptorUsers.containsKey(customLockDescriptor)) {

                         // at least one other user has this descriptor locked... remove editable edit modes

                         editModeMap = getEditModeWithEditableModesRemoved(editMode);

                     } else {

                         // no other user has a lock with this descriptor

                         if (isLockRequiredByUser(document, editMode, user)) {

                             document.addPessimisticLock(createNewPessimisticLock(document, editMode, user));

                         }

                         editModeMap.putAll(editMode);

                     }

                 } else {

                     editModeMap = getEditModeWithEditableModesRemoved(editMode);

                 }

             }

         } else {

             // given user already has at least one lock descriptor

             if (document.useCustomLockDescriptors()) {

                 // get the custom lock descriptor and check to see if if the given user has a lock with that descriptor

                 String customLockDescriptor = document.getCustomLockDescriptor(user);

                 if (givenUserLockDescriptors.contains(customLockDescriptor)) {

                     // user already has lock that is required

                     editModeMap.putAll(editMode);

                 } else {

                     // user does not have lock for descriptor required

                     if (lockDescriptorUsers.containsKey(customLockDescriptor)) {

                         // another user has the lock descriptor that the given user requires... disallow lock and alter edit modes to have read only

                         editModeMap = getEditModeWithEditableModesRemoved(editMode);

                     } else {

                         // no other user has a lock with this descriptor... check if this user needs a lock

                         if (isLockRequiredByUser(document, editMode, user)) {

                             document.addPessimisticLock(createNewPessimisticLock(document, editMode, user));

                         }

                         editModeMap.putAll(editMode);

                     }

                 }

             } else {

                 // user already has lock and no descriptors are being used... use the existing edit modes

                 editModeMap.putAll(editMode);

             }

         }

         return editModeMap;

     }

     /**

      * This method is used to check if the given parameters warrant a new lock to be created for the given user. This method

      * utilizes the {@link #isEntryEditMode(java.util.Map.Entry)} method.

      *

      * @param document -

      *            document to verify lock creation against

      * @param editMode -

      *            edit modes list to check for 'entry type' edit modes

      * @param user -

      *            user the lock will be 'owned' by

      * @return true if the given edit mode map has at least one 'entry type' edit mode... false otherwise

      */

     protected boolean isLockRequiredByUser(Document document, Map editMode, Person user) {

         // check for entry edit mode

         for (Iterator iterator = editMode.entrySet().iterator(); iterator.hasNext();) {

             Map.Entry entry = (Map.Entry) iterator.next();

             if (isEntryEditMode(entry)) {

                 return true;

             }

         }

         return false;

     }

    /**

      * This method is used to remove edit modes from the given map that allow the user to edit data on the document. This

      * method utilizes the {@link #isEntryEditMode(java.util.Map.Entry)} method to identify if an edit mode is defined as an

      * 'entry type' edit mode. It also uses the {@link #getEntryEditModeReplacementMode(java.util.Map.Entry)} method to replace

      * any 'entry type' edit modes it finds.

      *

      * @param currentEditMode -

      *            current set of edit modes the user has assigned to them

      * @return an adjusted edit mode map where 'entry type' edit modes have been removed or replaced using the

      *         {@link #getEntryEditModeReplacementMode()} method

      */

     protected Map getEditModeWithEditableModesRemoved(Map currentEditMode) {

         Map editModeMap = new HashMap();

         for (Iterator iterator = currentEditMode.entrySet().iterator(); iterator.hasNext();) {

             Map.Entry entry = (Map.Entry) iterator.next();

             if (isEntryEditMode(entry)) {

                 editModeMap.putAll(getEntryEditModeReplacementMode(entry));

             } else {

                 editModeMap.put(entry.getKey(), entry.getValue());

             }

         }

         return editModeMap;

     }

     /**

      * This method is used to check if the given {@link Map.Entry} is an 'entry type' edit mode and that the value is set to

      * signify that this user has that edit mode available to them

      *

      * @param entry -

      *            the {@link Map.Entry} object that contains an edit mode such as the ones returned but

      *            {@link #getEditMode(Document, Person)}

      * @return true if the given entry has a key signifying an 'entry type' edit mode and the value is equal to

      *         {@link #EDIT_MODE_DEFAULT_TRUE_VALUE}... false if not

      */

     protected boolean isEntryEditMode(Map.Entry entry) {

             // check for FULL_ENTRY edit mode set to default true value

             if (AuthorizationConstants.EditMode.FULL_ENTRY.equals(entry.getKey())) {

                     String fullEntryEditModeValue = (String)entry.getValue();           

                     return ( StringUtils.equalsIgnoreCase(KNSConstants.KUALI_DEFAULT_TRUE_VALUE, fullEntryEditModeValue) );             

             }

             return false;

     }

     /**

      * This method is used to return values needed to replace the given 'entry type' edit mode {@link Map.Entry} with one that will not allow the user to enter data on the document

      *

      * @param entry - the current 'entry type' edit mode to replace

      * @return a Map of edit modes that will be used to replace this edit mode (represented by the given entry parameter)

      */

     protected Map getEntryEditModeReplacementMode(Map.Entry entry) {

         Map editMode = new HashMap();

         editMode.put(AuthorizationConstants.EditMode.VIEW_ONLY, KNSConstants.KUALI_DEFAULT_TRUE_VALUE);

         return editMode;

     }

     /**

      * This method creates a new {@link PessimisticLock} object using the given document and user. If the document's

      * useCustomLockDescriptors() method returns true then the new lock will also have a custom lock descriptor

      * value set to the return value of the document's getCustomLockDescriptor(Person) method.

      *

      * @param document -

      *            document to place the lock on

      * @param editMode -

      *            current edit modes for given user

      * @param user -

      *            user who will 'own' the new lock object

      * @return the newly created lock object

      */

     protected PessimisticLock createNewPessimisticLock(Document document, Map editMode, Person user) {

         if (document.useCustomLockDescriptors()) {

             return generateNewLock(document.getDocumentNumber(), document.getCustomLockDescriptor(user), user);

         } else {

             return generateNewLock(document.getDocumentNumber(), user);

         }

     }

     public PersonService getPersonService() {

         if ( personService == null ) {

             personService = KIMServiceLocator.getPersonService();

         }

         return personService;

     }

         public DataDictionaryService getDataDictionaryService() {

         if ( dataDictionaryService == null ) {

                 dataDictionaryService = KNSServiceLocator.getDataDictionaryService();

         }

                 return dataDictionaryService;

         }

         public IdentityManagementService getIdentityManagementService() {

         if ( identityManagementService == null ) {

                 identityManagementService = KIMServiceLocator.getIdentityManagementService();

         }

                 return identityManagementService;

         }

 }