/**
    * Copyright 2005-2013 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.krms.impl.repository;
  
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.CoreApiServiceLocator;
  import org.kuali.rice.core.api.criteria.CriteriaLookupService;
  import org.kuali.rice.core.api.criteria.GenericQueryResults;
  import org.kuali.rice.core.api.criteria.Predicate;
  import org.kuali.rice.core.api.criteria.QueryByCriteria;
  import org.kuali.rice.core.api.exception.RiceIllegalArgumentException;
  import org.kuali.rice.core.api.exception.RiceIllegalStateException;
  import org.kuali.rice.core.api.mo.ModelObjectUtils;
  import org.kuali.rice.core.impl.services.CoreImplServiceLocator;
  import org.kuali.rice.coreservice.api.CoreServiceApiServiceLocator;
  import org.kuali.rice.coreservice.framework.CoreFrameworkServiceLocator;
  import org.kuali.rice.kns.service.KNSServiceLocator;
  import org.kuali.rice.krad.service.BusinessObjectService;
  import org.kuali.rice.krad.service.KRADServiceLocator;
  import org.kuali.rice.krad.service.SequenceAccessorService;
  import org.kuali.rice.krms.api.repository.agenda.AgendaDefinition;
  import org.kuali.rice.krms.api.repository.agenda.AgendaItemDefinition;
  import org.kuali.rice.krms.api.repository.type.KrmsAttributeDefinition;
  import org.kuali.rice.krms.impl.util.KrmsImplConstants.PropertyNames;
  import org.springframework.util.CollectionUtils;
  
  import static org.kuali.rice.core.api.criteria.PredicateFactory.in;
  
  /**
   * Implementation of the interface for accessing KRMS repository Agenda related
   * business objects. 
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   *
   */
  public final class AgendaBoServiceImpl implements AgendaBoService {
  
      // TODO: deal with active flag
  
      private BusinessObjectService businessObjectService;
      private CriteriaLookupService criteriaLookupService;
      private KrmsAttributeDefinitionService attributeDefinitionService;
      private SequenceAccessorService sequenceAccessorService;
  
      // used for converting lists of BOs to model objects
      private static final ModelObjectUtils.Transformer<AgendaItemBo, AgendaItemDefinition> toAgendaItemDefinition =
              new ModelObjectUtils.Transformer<AgendaItemBo, AgendaItemDefinition>() {
                  public AgendaItemDefinition transform(AgendaItemBo input) {
                      return AgendaItemBo.to(input);
                  };
              };
  
      // used for converting lists of BOs to model objects
      private static final ModelObjectUtils.Transformer<AgendaBo, AgendaDefinition> toAgendaDefinition =
              new ModelObjectUtils.Transformer<AgendaBo, AgendaDefinition>() {
                  public AgendaDefinition transform(AgendaBo input) {
                      return AgendaBo.to(input);
                  };
              };
  
  
      /**
       * This overridden method creates a KRMS Agenda in the repository
       */
      @Override
      public AgendaDefinition createAgenda(AgendaDefinition agenda) {
          if (agenda == null){
              throw new RiceIllegalArgumentException("agenda is null");
          }
          final String nameKey = agenda.getName();
          final String contextId = agenda.getContextId();
          final AgendaDefinition existing = getAgendaByNameAndContextId(nameKey, contextId);
          if (existing != null){
              throw new IllegalStateException("the agenda to create already exists: " + agenda);
          }
  
         AgendaBo agendaBo = from(agenda);
         businessObjectService.save(agendaBo);
         return to(agendaBo);
     }
 
     /**
      * This overridden method updates an existing Agenda in the repository
      */
     @Override
     public void updateAgenda(AgendaDefinition agenda) {
         if (agenda == null){
             throw new RiceIllegalArgumentException("agenda is null");
         }
 
         // must already exist to be able to update
         final String agendaIdKey = agenda.getId();
         final AgendaBo existing = businessObjectService.findBySinglePrimaryKey(AgendaBo.class, agendaIdKey);
         if (existing == null) {
             throw new IllegalStateException("the agenda does not exist: " + agenda);
         }
         final AgendaDefinition toUpdate;
         if (existing.getId().equals(agenda.getId())) {
             toUpdate = agenda;
         } else {
             // if passed in id does not match existing id, correct it
             final AgendaDefinition.Builder builder = AgendaDefinition.Builder.create(agenda);
             builder.setId(existing.getId());
             toUpdate = builder.build();
         }
 
         // copy all updateable fields to bo
         AgendaBo boToUpdate = from(toUpdate);
 
         // delete any old, existing attributes
         Map<String,String> fields = new HashMap<String,String>(1);
         fields.put(PropertyNames.Agenda.AGENDA_ID, toUpdate.getId());
         businessObjectService.deleteMatching(AgendaAttributeBo.class, fields);
 
         // update new agenda and create new attributes
         businessObjectService.save(boToUpdate);
     }
 
     @Override
     public void deleteAgenda(String agendaId) {
         if (agendaId == null){ throw new RiceIllegalArgumentException("agendaId is null"); }
         final AgendaDefinition existing = getAgendaByAgendaId(agendaId);
         if (existing == null){ throw new IllegalStateException("the Agenda to delete does not exists: " + agendaId);}
         businessObjectService.delete(from(existing));
     }
 
     /**
      * This overridden method retrieves an Agenda from the repository
      */
     @Override
     public AgendaDefinition getAgendaByAgendaId(String agendaId) {
         if (StringUtils.isBlank(agendaId)){
             throw new RiceIllegalArgumentException("agenda id is null");
         }
         AgendaBo bo = businessObjectService.findBySinglePrimaryKey(AgendaBo.class, agendaId);
         return to(bo);
     }
 
     /**
      * This overridden method retrieves an agenda from the repository
      */
     @Override
     public AgendaDefinition getAgendaByNameAndContextId(String name, String contextId) {
         if (StringUtils.isBlank(name)) {
             throw new RiceIllegalArgumentException("name is blank");
         }
         if (StringUtils.isBlank(contextId)) {
             throw new RiceIllegalArgumentException("contextId is blank");
         }
 
         final Map<String, Object> map = new HashMap<String, Object>();
         map.put("name", name);
         map.put("contextId", contextId);
 
         AgendaBo myAgenda = businessObjectService.findByPrimaryKey(AgendaBo.class, Collections.unmodifiableMap(map));
         return to(myAgenda);
     }
 
     /**
      * This overridden method retrieves a set of agendas from the repository
      */
     @Override
     public List<AgendaDefinition> getAgendasByContextId(String contextId) {
         if (StringUtils.isBlank(contextId)){
             throw new RiceIllegalArgumentException("context ID is null or blank");
         }
         final Map<String, Object> map = new HashMap<String, Object>();
         map.put("contextId", contextId);
         List<AgendaBo> bos = (List<AgendaBo>) businessObjectService.findMatching(AgendaBo.class, map);
         return convertAgendaBosToImmutables(bos);
     }
 
     /**
      * This overridden method creates a new Agenda in the repository
      */
     @Override
     public AgendaItemDefinition createAgendaItem(AgendaItemDefinition agendaItem) {
         if (agendaItem == null){
             throw new RiceIllegalArgumentException("agendaItem is null");
         }
         if (agendaItem.getId() != null){
             final AgendaDefinition existing = getAgendaByAgendaId(agendaItem.getId());
             if (existing != null){
                 throw new IllegalStateException("the agendaItem to create already exists: " + agendaItem);
             }
         }
 
         AgendaItemBo bo = AgendaItemBo.from(agendaItem);
         businessObjectService.save(bo);
         return AgendaItemBo.to(bo);
     }
 
     /**
      * This overridden method updates an existing Agenda in the repository
      */
     @Override
     public void updateAgendaItem(AgendaItemDefinition agendaItem) {
         if (agendaItem == null){
             throw new RiceIllegalArgumentException("agendaItem is null");
         }
         final String agendaItemIdKey = agendaItem.getId();
         final AgendaItemDefinition existing = getAgendaItemById(agendaItemIdKey);
         if (existing == null) {
             throw new IllegalStateException("the agenda item does not exist: " + agendaItem);
         }
         final AgendaItemDefinition toUpdate;
         if (existing.getId().equals(agendaItem.getId())) {
             toUpdate = agendaItem;
         } else {
             final AgendaItemDefinition.Builder builder = AgendaItemDefinition.Builder.create(agendaItem);
             builder.setId(existing.getId());
             toUpdate = builder.build();
         }
 
         businessObjectService.save(AgendaItemBo.from(toUpdate));
     }
 
     /**
      * This overridden method adds a new AgendaItemDefinition to the repository
      */
     @Override
     public void addAgendaItem(AgendaItemDefinition agendaItem, String parentId, Boolean position) {
         if (agendaItem == null){
             throw new RiceIllegalArgumentException("agendaItem is null");
         }
         AgendaItemDefinition parent = null;
         if (parentId != null){
             parent = getAgendaItemById(parentId);
             if (parent == null){
                 throw new IllegalStateException("parent agendaItem does not exist in repository. parentId = " + parentId);
             }
         }
         // create new AgendaItemDefinition
         final AgendaItemDefinition toCreate;
         if (agendaItem.getId() == null) {
             SequenceAccessorService sas = getSequenceAccessorService();
             final AgendaItemDefinition.Builder builder = AgendaItemDefinition.Builder.create(agendaItem);
             final String newId =sas.getNextAvailableSequenceNumber(
                     "KRMS_AGENDA_ITM_S", AgendaItemBo.class).toString();
             builder.setId(newId);
             toCreate = builder.build();
         } else {
             toCreate = agendaItem;
         }
         createAgendaItem(toCreate);
 
         // link it to it's parent (for whenTrue/whenFalse, sibling for always
         if (parentId != null) {
             final AgendaItemDefinition.Builder builder = AgendaItemDefinition.Builder.create(parent);
             if (position == null){
                 builder.setAlwaysId( toCreate.getId() );
             } else if (position.booleanValue()){
                 builder.setWhenTrueId( toCreate.getId() );
             } else if (!position.booleanValue()){
                 builder.setWhenFalseId( toCreate.getId() );
             }
             final AgendaItemDefinition parentToUpdate = builder.build();
             updateAgendaItem( parentToUpdate );
         }
     }
 
     /**
      * This overridden method retrieves an AgendaItemDefinition from the repository
      */
     @Override
     public AgendaItemDefinition getAgendaItemById(String id) {
         if (StringUtils.isBlank(id)){
             throw new RiceIllegalArgumentException("agenda item id is null or blank");
         }
         AgendaItemBo bo = businessObjectService.findBySinglePrimaryKey(AgendaItemBo.class, id);
         return AgendaItemBo.to(bo);
     }
 
     @Override
     public List<AgendaItemDefinition> getAgendaItemsByAgendaId(String agendaId) {
         if (StringUtils.isBlank(agendaId)){
             throw new RiceIllegalArgumentException("agenda id is null or null");
         }
         List<AgendaItemDefinition> results = null;
 
         Collection<AgendaItemBo> bos = businessObjectService.findMatching(AgendaItemBo.class, Collections.singletonMap("agendaId", agendaId));
 
         if (CollectionUtils.isEmpty(bos)) {
             results = Collections.emptyList();
         } else {
             results = Collections.unmodifiableList(ModelObjectUtils.transform(bos, toAgendaItemDefinition));
         }
 
         return results;
     }
 
     @Override
     public List<AgendaDefinition> getAgendasByType(String typeId) throws RiceIllegalArgumentException {
         if (StringUtils.isBlank(typeId)){
             throw new RiceIllegalArgumentException("type ID is null or blank");
         }
         final Map<String, Object> map = new HashMap<String, Object>();
         map.put("typeId", typeId);
         List<AgendaBo> bos = (List<AgendaBo>) businessObjectService.findMatching(AgendaBo.class, map);
         return convertAgendaBosToImmutables(bos);
     }
 
     @Override
     public List<AgendaDefinition> getAgendasByTypeAndContext(String typeId,
             String contextId) throws RiceIllegalArgumentException {
         if (StringUtils.isBlank(typeId)){
             throw new RiceIllegalArgumentException("type ID is null or blank");
         }
         if (StringUtils.isBlank(contextId)){
             throw new RiceIllegalArgumentException("context ID is null or blank");
         }
         final Map<String, Object> map = new HashMap<String, Object>();
         map.put("typeId", typeId);
         map.put("contextId", contextId);
         Collection<AgendaBo> bos = businessObjectService.findMatching(AgendaBo.class, map);
         return convertAgendaBosToImmutables(bos);
     }
 
     @Override
     public List<AgendaItemDefinition> getAgendaItemsByType(String typeId) throws RiceIllegalArgumentException {
         return findAgendaItemsForAgendas(getAgendasByType(typeId));
     }
 
     @Override
     public List<AgendaItemDefinition> getAgendaItemsByContext(String contextId) throws RiceIllegalArgumentException {
         return findAgendaItemsForAgendas(getAgendasByContextId(contextId));
     }
 
     @Override
     public List<AgendaItemDefinition> getAgendaItemsByTypeAndContext(String typeId,
             String contextId) throws RiceIllegalArgumentException {
         return findAgendaItemsForAgendas(getAgendasByTypeAndContext(typeId, contextId));
     }
 
     @Override
     public void deleteAgendaItem(String agendaItemId) throws RiceIllegalArgumentException {
         if (StringUtils.isBlank(agendaItemId)) {
             throw new RiceIllegalArgumentException("agendaItemId must not be blank or null");
         }
 
         businessObjectService.deleteMatching(AgendaItemBo.class, Collections.singletonMap("id", agendaItemId));
     }
 
     private List<AgendaItemDefinition> findAgendaItemsForAgendas(List<AgendaDefinition> agendaDefinitions) {
         List<AgendaItemDefinition> results = null;
 
         if (!CollectionUtils.isEmpty(agendaDefinitions)) {
             List<AgendaItemBo> boResults = new ArrayList<AgendaItemBo>(agendaDefinitions.size());
 
             List<String> agendaIds = new ArrayList<String>(20);
             for (AgendaDefinition agendaDefinition : agendaDefinitions) {
                 agendaIds.add(agendaDefinition.getId());
 
                 if (agendaIds.size() == 20) {
                     // fetch batch
 
                     Predicate predicate = in("agendaId", agendaIds.toArray());
                     QueryByCriteria criteria = QueryByCriteria.Builder.fromPredicates(predicate);
                     GenericQueryResults<AgendaItemBo> batch = criteriaLookupService.lookup(AgendaItemBo.class, criteria);
 
                     boResults.addAll(batch.getResults());
 
                     // reset agendaIds
                     agendaIds.clear();
                 }
             }
 
             if (agendaIds.size() > 0) {
                 Predicate predicate = in("agendaId", agendaIds.toArray());
                 QueryByCriteria criteria = QueryByCriteria.Builder.fromPredicates(predicate);
                 GenericQueryResults<AgendaItemBo> batch = criteriaLookupService.lookup(AgendaItemBo.class, criteria);
 
                 boResults.addAll(batch.getResults());
             }
 
             results = Collections.unmodifiableList(ModelObjectUtils.transform(boResults, toAgendaItemDefinition));
         } else {
             results = Collections.emptyList();
         }
 
         return results;
     }
 
     public CriteriaLookupService getCriteriaLookupService() {
         if (criteriaLookupService == null) {
             criteriaLookupService = KrmsRepositoryServiceLocator.getCriteriaLookupService();
         }
         return criteriaLookupService;
     }
 
     public void setCriteriaLookupService(CriteriaLookupService criteriaLookupService) {
         this.criteriaLookupService = criteriaLookupService;
     }
 
     /**
      * Sets the businessObjectService attribute value.
      *
      * @param businessObjectService The businessObjectService to set.
      */
     public void setBusinessObjectService(final BusinessObjectService businessObjectService) {
         this.businessObjectService = businessObjectService;
     }
 
     protected BusinessObjectService getBusinessObjectService() {
         if ( businessObjectService == null ) {
             businessObjectService = KNSServiceLocator.getBusinessObjectService();
         }
         return businessObjectService;
     }
 
     /**
      * Sets the sequenceAccessorService attribute value.
      *
      * @param sequenceAccessorService The sequenceAccessorService to set.
      */
     public void setSequenceAccessorService(final SequenceAccessorService sequenceAccessorService) {
         this.sequenceAccessorService = sequenceAccessorService;
     }
 
     protected SequenceAccessorService getSequenceAccessorService() {
         if ( sequenceAccessorService == null ) {
             sequenceAccessorService = KRADServiceLocator.getSequenceAccessorService();
         }
         return sequenceAccessorService;
     }
 
     protected KrmsAttributeDefinitionService getAttributeDefinitionService() {
         if (attributeDefinitionService == null) {
             attributeDefinitionService = KrmsRepositoryServiceLocator.getKrmsAttributeDefinitionService();
         }
         return attributeDefinitionService;
     }
 
     public void setAttributeDefinitionService(KrmsAttributeDefinitionService attributeDefinitionService) {
         this.attributeDefinitionService = attributeDefinitionService;
     }
 
     /**
      * Converts a Set<AgendaBo> to an Unmodifiable Set<Agenda>
      *
      * @param agendaBos a mutable Set<AgendaBo> to made completely immutable.
      * @return An unmodifiable Set<Agenda>
      */
     public List<AgendaDefinition> convertAgendaBosToImmutables(final Collection<AgendaBo> agendaBos) {
         if (CollectionUtils.isEmpty(agendaBos)) {
             return Collections.emptyList();
         }
         return Collections.unmodifiableList(ModelObjectUtils.transform(agendaBos, toAgendaDefinition));
     }
 
     /**
      * Converts a mutable bo to it's immutable counterpart
      * @param bo the mutable business object
      * @return the immutable object
      */
     @Override
     public AgendaDefinition to(AgendaBo bo) {
         if (bo == null) { return null; }
         return org.kuali.rice.krms.api.repository.agenda.AgendaDefinition.Builder.create(bo).build();
     }
 
 
     /**
      * Converts a immutable object to it's mutable bo counterpart
      * @param im immutable object
      * @return the mutable bo
      */
     @Override
     public AgendaBo from(AgendaDefinition im) {
         if (im == null) { return null; }
 
         AgendaBo bo = new AgendaBo();
         bo.setId(im.getId());
         bo.setName( im.getName() );
         bo.setTypeId( im.getTypeId() );
         bo.setContextId( im.getContextId() );
         bo.setFirstItemId( im.getFirstItemId() );
         bo.setVersionNumber( im.getVersionNumber() );
         bo.setActive(im.isActive());
         Set<AgendaAttributeBo> attributes = buildAgendaAttributeBo(im);
 
         bo.setAttributeBos(attributes);
 
         return bo;
     }
 
     private Set<AgendaAttributeBo> buildAgendaAttributeBo(AgendaDefinition im) {
         Set<AgendaAttributeBo> attributes = new HashSet<AgendaAttributeBo>();
 
         // build a map from attribute name to definition
         Map<String, KrmsAttributeDefinition> attributeDefinitionMap = new HashMap<String, KrmsAttributeDefinition>();
 
         List<KrmsAttributeDefinition> attributeDefinitions =
                 getAttributeDefinitionService().findAttributeDefinitionsByType(im.getTypeId());
 
         for (KrmsAttributeDefinition attributeDefinition : attributeDefinitions) {
             attributeDefinitionMap.put(attributeDefinition.getName(), attributeDefinition);
         }
 
         // for each entry, build an AgendaAttributeBo and add it to the set
         for (Entry<String,String> entry  : im.getAttributes().entrySet()){
             KrmsAttributeDefinition attrDef = attributeDefinitionMap.get(entry.getKey());
 
             if (attrDef != null) {
                 AgendaAttributeBo attributeBo = new AgendaAttributeBo();
                 attributeBo.setAgendaId( im.getId() );
                 attributeBo.setAttributeDefinitionId(attrDef.getId());
                 attributeBo.setValue(entry.getValue());
                 attributeBo.setAttributeDefinition(KrmsAttributeDefinitionBo.from(attrDef));
                 attributes.add( attributeBo );
             } else {
                 throw new RiceIllegalStateException("there is no attribute definition with the name '" +
                         entry.getKey() + "' that is valid for the agenda type with id = '" + im.getTypeId() +"'");
             }
         }
         return attributes;
     }
 
 }