/**

  * Copyright 2010 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.osedu.org/licenses/ECL-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.kuali.student.lum.program.client.requirements;

 import java.util.*;

 import org.kuali.student.common.assembly.data.Data;

 import org.kuali.student.common.ui.client.application.KSAsyncCallback;

 import org.kuali.student.common.ui.client.mvc.*;

 import org.kuali.student.core.statement.dto.StatementTreeViewInfo;

 import org.kuali.student.core.statement.dto.StatementTypeInfo;

 import org.kuali.student.core.statement.ui.client.widgets.rules.RulesUtil;

 import org.kuali.student.lum.program.client.ProgramConstants;

 import org.kuali.student.lum.program.client.events.StoreRequirementIDsEvent;

 import org.kuali.student.lum.program.client.events.StoreSpecRequirementIDsEvent;

 import org.kuali.student.lum.program.client.rpc.MajorDisciplineRpcService;

 import org.kuali.student.lum.program.client.rpc.MajorDisciplineRpcServiceAsync;

 import org.kuali.student.lum.program.client.rpc.StatementRpcService;

 import org.kuali.student.lum.program.client.rpc.StatementRpcServiceAsync;

 import org.kuali.student.lum.program.dto.ProgramRequirementInfo;

 import com.google.gwt.core.client.GWT;

 import com.google.gwt.event.shared.HandlerManager;

 import com.google.gwt.user.client.Window;

 public class ProgramRequirementsDataModel {

     private final MajorDisciplineRpcServiceAsync programRemoteService = GWT.create(MajorDisciplineRpcService.class);

     private StatementRpcServiceAsync statementRpcServiceAsync = GWT.create(StatementRpcService.class);

     private Model model = null;

     private HandlerManager eventBus;

     //keeping track of rules and rule state

     public enum requirementState {STORED, ADDED, EDITED, DELETED;}

     private Map<Integer, ProgramRequirementInfo> progReqInfos = new LinkedHashMap<Integer, ProgramRequirementInfo>();

     private Map<Integer, ProgramRequirementInfo> origProgReqInfos = new LinkedHashMap<Integer, ProgramRequirementInfo>();

     private Map<Integer, requirementState> progReqState = new HashMap<Integer, requirementState>();

     private Map<Integer, requirementState> origProgReqState = new HashMap<Integer, requirementState>();

     private List<StatementTypeInfo> stmtTypes = new ArrayList<StatementTypeInfo>();

     private boolean isInitialized = false;

     private static Integer progReqIDs = 111111;

     public ProgramRequirementsDataModel(HandlerManager eventBus) {

         this.eventBus = eventBus;

     }

     //find out whether we need to reset rules based on whether we have a new program ID or not

     public void setupRules(Controller parentController, String modelId, final Callback<Boolean> onReadyCallback) {

         parentController.requestModel(modelId, new ModelRequestCallback() {

             @Override

             public void onRequestFail(Throwable cause) {

                 GWT.log("Unable to retrieve program model for program summary view", cause);

                 onReadyCallback.exec(false);

             }

             @Override

             public void onModelReady(Model modelIn) {

                 //TODO how can we reliably know that we need to reload rules (or not)

                 //String programId = (model == null ? null : (String)((DataModel)model).getRoot().get("id"));

                 //String modelProgramId = ((DataModel)modelIn).getRoot().get(ProgramConstants.ID);

                 //if ((modelProgramId == null) || (!modelProgramId.equals(programId))) {

                     resetRules();

                 //}

                 model = modelIn;

                 onReadyCallback.exec(true);

             }

         });

     }

     private void resetRules() {

         progReqInfos = new LinkedHashMap<Integer, ProgramRequirementInfo>();

         origProgReqInfos = new LinkedHashMap<Integer, ProgramRequirementInfo>();

         progReqState = new HashMap<Integer, requirementState>();

         origProgReqState = new HashMap<Integer, requirementState>();

         stmtTypes = new ArrayList<StatementTypeInfo>();

         model = null;

         isInitialized = false;

     }

     //retrieve rules based on IDs stored in this program

     public void retrieveProgramRequirements(Controller parentController, String modelId, final Callback<Boolean> onReadyCallback) {

         setupRules(parentController, modelId, new Callback<Boolean>() {

             @Override

             public void exec(Boolean result) {

                 Data program = ((DataModel)model).getRoot().get(ProgramConstants.PROGRAM_REQUIREMENTS);

                 Iterator<Data.Property> realPropertyIterator = program.realPropertyIterator();

                 ArrayList<String> programRequirementIds = new ArrayList<String>();

                 while(realPropertyIterator.hasNext()) {

                     programRequirementIds.add((String)realPropertyIterator.next().getValue());

                 }

                 retrieveStatementTypes(programRequirementIds, onReadyCallback);

             }

         });               

     }

     private void retrieveStatementTypes(final List<String> programRequirementIds, final Callback<Boolean> onReadyCallback) {

         //retrieve available program requirement types

         statementRpcServiceAsync.getStatementTypesForStatementType("kuali.statement.type.program", new KSAsyncCallback<List<StatementTypeInfo>>() {

             @Override

             public void handleFailure(Throwable caught) {

                     Window.alert(caught.getMessage());

                     GWT.log("getStatementTypes failed", caught);

                 onReadyCallback.exec(false);

             }

             @Override

             public void onSuccess(List<StatementTypeInfo> stmtInfoTypes) {

                 //store the statement types

                 for (StatementTypeInfo stmtInfoType : stmtInfoTypes) {

                     stmtTypes.add(stmtInfoType);

                 }

                 //now retrieve the actual rules

                 retrieveRules(programRequirementIds, onReadyCallback);

             }

         });

     }

     private void retrieveRules(List<String> programRequirementIds, final Callback<Boolean> onReadyCallback) {

         //true if no program requirements exist yet

         if ((programRequirementIds == null) || programRequirementIds.isEmpty()) {

             isInitialized = true;

             onReadyCallback.exec(true);

             return;

         }

         programRemoteService.getProgramRequirements(programRequirementIds, new KSAsyncCallback<List<ProgramRequirementInfo>>() {

             @Override

             public void handleFailure(Throwable caught) {

                 Window.alert(caught.getMessage());

                 GWT.log("getProgramRequirement failed", caught);

                 onReadyCallback.exec(false);

             }

             @Override

             public void onSuccess(List<ProgramRequirementInfo> programReqInfos) {

                 //update rules list with new program requirements

                 origProgReqInfos.clear();

                 origProgReqState.clear();

                 progReqInfos.clear();

                 progReqState.clear();

                 for (ProgramRequirementInfo programReqInfo : programReqInfos) {

                     if (getStmtTypeInfo(programReqInfo.getStatement().getType()) == null) {

                         Window.alert("Did not find corresponding statement type for program requirement of type: " + programReqInfo.getStatement().getType());

                         GWT.log("Did not find corresponding statement type for program requirement of type: " + programReqInfo.getStatement().getType(), null);

                     }

                     setRuleState(programReqInfo);

                     origProgReqInfos.put(progReqIDs, cloneProgReq(programReqInfo));

                     origProgReqState.put(progReqIDs, requirementState.STORED);

                     progReqInfos.put(progReqIDs, programReqInfo);

                     progReqState.put(progReqIDs++, requirementState.STORED);

                 }

                 isInitialized = true;

                 onReadyCallback.exec(true);

             }

         });     

     }

     public ProgramRequirementInfo updateRules(StatementTreeViewInfo newSubRule, Integer internalProgReqID, boolean isNewRule) {

         ProgramRequirementInfo affectedRule = progReqInfos.get(internalProgReqID);

         if (affectedRule == null) {

             Window.alert("Cannot find program requirement with a statement that has id: '" + newSubRule.getId() + "'");

             GWT.log("Cannot find program requirement with a statement that has id: '" + newSubRule.getId() + "'", null);

             return null;

         }

         if (progReqState.get(internalProgReqID) == ProgramRequirementsDataModel.requirementState.STORED) {

             progReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.EDITED);

         }

         //if we don't have top level req. components wrapped in statement, do so before we add another statement

         StatementTreeViewInfo affectedTopTree = affectedRule.getStatement();

         if ((affectedTopTree.getReqComponents() != null) && !affectedTopTree.getReqComponents().isEmpty()) {

             StatementTreeViewInfo stmtTree = new StatementTreeViewInfo();

             stmtTree.setId(ProgramRequirementsSummaryView.generateStatementTreeId());

             stmtTree.setType( affectedRule.getStatement().getType());

             stmtTree.setReqComponents(affectedTopTree.getReqComponents());

             List<StatementTreeViewInfo> stmtList = new ArrayList<StatementTreeViewInfo>();

             stmtList.add(stmtTree);

             affectedTopTree.setStatements(stmtList);

         }

         //now update the actual rule

         List<StatementTreeViewInfo> affectedSubRules = affectedTopTree.getStatements();

         if (isNewRule) {

             affectedSubRules.add(newSubRule);

         } else {

             //update rule

             if (affectedSubRules == null || affectedSubRules.isEmpty()) {

                 affectedRule.setStatement(newSubRule);

             } else { //replace the related stored subrule with a new version

                 for (StatementTreeViewInfo subRule : affectedSubRules) {

                     if (subRule.getId().equals(newSubRule.getId())) {

                         int treeIx = affectedSubRules.indexOf(subRule);

                         //only update if the rule is not empty

                         if (!isEmptyRule(newSubRule)) {

                             affectedSubRules.add(treeIx, newSubRule);

                         }

                         affectedSubRules.remove(subRule);

                         break;

                     }

                 }

             }

         }

         return affectedRule;

     }

     public void updateProgramEntities(final Callback<List<ProgramRequirementInfo>> callback) {

         final List<String> referencedProgReqIds = new ArrayList<String>();

         programRemoteService.storeProgramRequirements(progReqState, progReqInfos, new KSAsyncCallback<Map<Integer, ProgramRequirementInfo>>() {

             @Override

             public void handleFailure(Throwable caught) {

                 Window.alert(caught.getMessage());

                 GWT.log("storeProgramRequirements failed", caught);

             }

             @Override

             public void onSuccess(Map<Integer, ProgramRequirementInfo> storedRules) {

                 for (Integer internalProgReqID : storedRules.keySet()) {

                     ProgramRequirementInfo storedRule = storedRules.get(internalProgReqID);

                     switch (progReqState.get(internalProgReqID)) {

                         case STORED:

                             //rule was not changed so continue

                             referencedProgReqIds.add(progReqInfos.get(internalProgReqID).getId());

                             break;

                         case ADDED:

                             referencedProgReqIds.add(storedRule.getId());

                             progReqInfos.put(internalProgReqID, storedRule);

                             origProgReqInfos.put(internalProgReqID, cloneProgReq(storedRule));

                             origProgReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.STORED);

                             progReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.STORED);

                             break;

                         case EDITED:

                             referencedProgReqIds.add(storedRule.getId());

                             progReqInfos.put(internalProgReqID, storedRule);

                             origProgReqInfos.put(internalProgReqID, cloneProgReq(storedRule));

                             origProgReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.STORED);

                             progReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.STORED);

                             break;

                         case DELETED:

                             progReqInfos.remove(internalProgReqID);

                             origProgReqInfos.remove(internalProgReqID);

                             origProgReqState.remove(internalProgReqID);                            

                             progReqState.remove(internalProgReqID);

                             break;

                         default:

                             break;

                     }

                 }

                 saveRequirementIds(referencedProgReqIds, storedRules, callback);

             }

         });        

     }

     private void saveRequirementIds(final List<String> referencedProgReqIds, final Map<Integer, ProgramRequirementInfo> storedRules, final Callback<List<ProgramRequirementInfo>> callback) {

         String programId = ((DataModel)model).getRoot().get("id");

         String programType = ((DataModel)model).getRoot().get("type");

         //for some reason, credential program has type stored in 'credentialProgramType'

         if (programType == null) {

             programType = ((DataModel)model).getRoot().get("credentialProgramType");    

         }

         //specializations will be handled differently from Major

         if (programType.equals(ProgramConstants.VARIATION_TYPE_KEY)) {

             eventBus.fireEvent(new StoreSpecRequirementIDsEvent(programId, programType, referencedProgReqIds));

         } else {

             eventBus.fireEvent(new StoreRequirementIDsEvent(programId, programType, referencedProgReqIds));

         }

         callback.exec(new ArrayList(storedRules.values()));  //update display widgets

     }

     public List<ProgramRequirementInfo> getProgReqInfo(String stmtTypeId) {

         List<ProgramRequirementInfo> rules = new ArrayList<ProgramRequirementInfo>();

         for(ProgramRequirementInfo progReqInfo : progReqInfos.values()) {

             if (progReqInfo.getStatement().getType().equals(stmtTypeId)) {

                 rules.add(progReqInfo);

             }

         }

         return rules;

     }

     public Integer getInternalProgReqID(ProgramRequirementInfo progReqInfo) {

         for(Integer key : progReqInfos.keySet()) {

             if (progReqInfos.get(key) == progReqInfo) {

                 return key;

             }

         }

         Window.alert("Problem retrieving key for program requirement: " + progReqInfo.getId());

         GWT.log("Problem retrieving key for program requirement: " + progReqInfo.getId(), null);        

         return null;

     }

     public StatementTypeInfo getStmtTypeInfo(String stmtTypeId) {

         for (StatementTypeInfo stmtInfo : stmtTypes) {

             if (stmtInfo.getId().equals(stmtTypeId)) {

                 return stmtInfo;

             }

         }

         Window.alert("Did not find StatementTypeInfo based on type: " + stmtTypeId);

         GWT.log("Did not find StatementTypeInfo based on type: " + stmtTypeId);

         return null;

     }

     public void deleteRule(Integer internalProgReqID) {

         if (progReqState.get(internalProgReqID) == ProgramRequirementsDataModel.requirementState.ADDED) {

             //user added a rule, didn't save it and now wants to delete it

             progReqState.remove(internalProgReqID);

             progReqInfos.remove(internalProgReqID);

         } else {

             markRuleAsDeleted(internalProgReqID);

         }

     }

     public void addRule(ProgramRequirementInfo programReqInfo) { 

             setRuleState(programReqInfo);

         progReqInfos.put(progReqIDs, programReqInfo);

         progReqState.put(progReqIDs++, requirementState.ADDED);

     }

     public void updateRule(Integer internalProgReqID, ProgramRequirementInfo programReqInfo) {

             setRuleState(programReqInfo);            

         progReqInfos.put(internalProgReqID, programReqInfo);

         markRuleAsEdited(internalProgReqID);

     }

     /**

      * Set the state of the program requirement to state of the program.

      * 

      * @param programReqInfo

      */

     protected void setRuleState(ProgramRequirementInfo programReqInfo) {

         if (model != null) {

             String programState = ((DataModel) model).get(ProgramConstants.STATE);

             programReqInfo.setState(programState);

         }

     }

     public void markRuleAsDeleted(Integer internalProgReqID) {

         if ((progReqState.get(internalProgReqID) == ProgramRequirementsDataModel.requirementState.STORED) ||

             (progReqState.get(internalProgReqID) == ProgramRequirementsDataModel.requirementState.EDITED)) {

             progReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.DELETED);

         }

     }

     public void markRuleAsEdited(Integer internalProgReqID) {

         if (progReqState.get(internalProgReqID) == ProgramRequirementsDataModel.requirementState.STORED) {

             progReqState.put(internalProgReqID, ProgramRequirementsDataModel.requirementState.EDITED);

         }

     }

     public String getStmtTypeName(String stmtTypeId) {

         String name = getStmtTypeInfo(stmtTypeId).getName();

         return (name == null ? "" : name);

     }

     public boolean isRuleExists(String stmtTypeId) {

         boolean showNoRuleText = true;

         for(ProgramRequirementInfo ruleInfo : progReqInfos.values()) {

             if ((ruleInfo.getStatement().getType().equals(stmtTypeId)) && (progReqState.get(getInternalProgReqID(ruleInfo)) != ProgramRequirementsDataModel.requirementState.DELETED)) {

                 showNoRuleText = false;

             }

         }

         return showNoRuleText;

     }

     public boolean isDirty() {

         if (progReqState.size() != origProgReqState.size()) {

             return true;

         }

         for(Integer key : progReqState.keySet()) {

             if (!progReqState.get(key).equals(origProgReqState.get(key))) {

                 return true;

             }

         }

         /*

         for(Integer key : progReqInfos.keySet()) {

             if (!progReqInfos.get(key).equals(origProgReqInfos.get(key))) {

                 return true;

             }

         } */

         return false;

     }

     public void revertRuleChanges() {

         progReqInfos = new HashMap<Integer, ProgramRequirementInfo>();

         progReqState = new HashMap<Integer, requirementState>();

         for(Integer key : origProgReqInfos.keySet()) {

             progReqInfos.put(key, cloneProgReq(origProgReqInfos.get(key)));

             progReqState.put(key, origProgReqState.get(key));

         }

     }

     public ProgramRequirementInfo getProgReqByInternalId(Integer internalProgReqID) {

         return progReqInfos.get(internalProgReqID);

     }

     public boolean isEmptyRule(StatementTreeViewInfo tree) {

         return (tree.getStatements() == null || tree.getStatements().isEmpty() && (tree.getReqComponents() == null || tree.getReqComponents().isEmpty()));

     }  

     public boolean isInitialized() {

         return isInitialized;

     }

     public void setInitialized(boolean initialized) {

         isInitialized = initialized;

     }

     public List<StatementTypeInfo> getStmtTypes() {

         return stmtTypes;

     }

     private ProgramRequirementInfo cloneProgReq(ProgramRequirementInfo inProgReqInfo) {

         ProgramRequirementInfo clonedProgReqInfo = null;

         if (inProgReqInfo != null) {

             clonedProgReqInfo = new ProgramRequirementInfo();

             clonedProgReqInfo.setId(inProgReqInfo.getId());

             clonedProgReqInfo.setShortTitle(inProgReqInfo.getShortTitle());

             clonedProgReqInfo.setLongTitle(inProgReqInfo.getLongTitle());

             clonedProgReqInfo.setDescr(inProgReqInfo.getDescr());

             clonedProgReqInfo.setMinCredits(inProgReqInfo.getMinCredits());

             clonedProgReqInfo.setMaxCredits(inProgReqInfo.getMaxCredits());

             clonedProgReqInfo.setState(inProgReqInfo.getState());

             clonedProgReqInfo.setType(inProgReqInfo.getType());

             clonedProgReqInfo.setStatement(RulesUtil.clone(inProgReqInfo.getStatement()));

             //TODO clonedProgReqInfo.setAttributes();

             //TODO clonedProgReqInfo.setLearningObjectives();

             //TODO clonedProgReqInfo.setMetaInfo();

         }

         return clonedProgReqInfo;

     }  

 }