/**
 * Copyright 2005-2015 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.kew.routelog.web;

import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;
import org.kuali.rice.kew.actionrequest.ActionRequestValue;
import org.kuali.rice.kew.actionrequest.service.ActionRequestService;
import org.kuali.rice.kew.actiontaken.ActionTakenValue;
import org.kuali.rice.kew.api.KewApiServiceLocator;
import org.kuali.rice.kew.api.WorkflowRuntimeException;
import org.kuali.rice.kew.api.action.ActionRequest;
import org.kuali.rice.kew.api.action.ActionRequestStatus;
import org.kuali.rice.kew.api.action.RoutingReportCriteria;
import org.kuali.rice.kew.api.document.DocumentDetail;
import org.kuali.rice.kew.api.document.node.RouteNodeInstanceState;
import org.kuali.rice.kew.api.exception.InvalidActionTakenException;
import org.kuali.rice.kew.doctype.SecuritySession;
import org.kuali.rice.kew.doctype.service.DocumentSecurityService;
import org.kuali.rice.kew.dto.DTOConverter.RouteNodeInstanceLoader;
import org.kuali.rice.kew.engine.node.Branch;
import org.kuali.rice.kew.engine.node.NodeState;
import org.kuali.rice.kew.engine.node.RouteNode;
import org.kuali.rice.kew.engine.node.RouteNodeInstance;
import org.kuali.rice.kew.engine.node.service.RouteNodeService;
import org.kuali.rice.kew.routeheader.DocumentRouteHeaderValue;
import org.kuali.rice.kew.service.KEWServiceLocator;
import org.kuali.rice.kew.util.Utilities;
import org.kuali.rice.kew.web.KewKualiAction;
import org.kuali.rice.krad.UserSession;
import org.kuali.rice.krad.util.GlobalVariables;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;


/**
 * A Struts Action used to display the routelog.
 *
 * @author Kuali Rice Team (rice.collab@kuali.org)
 */
public class RouteLogAction extends KewKualiAction {

    private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(RouteLogAction.class);
    private static Comparator<ActionRequestValue> ROUTE_LOG_ACTION_REQUEST_SORTER = new Utilities.RouteLogActionRequestSorter();
    
    @Override
        public ActionForward execute(ActionMapping mapping, ActionForm form, HttpServletRequest request, HttpServletResponse response) throws Exception {

        RouteLogForm rlForm = (RouteLogForm) form;
        String documentId = null;
        if (! org.apache.commons.lang.StringUtils.isEmpty(rlForm.getDocumentId())) {
                documentId = rlForm.getDocumentId();
        } else if (! org.apache.commons.lang.StringUtils.isEmpty(rlForm.getDocId())) {
                documentId =rlForm.getDocId();
        } else {
                throw new WorkflowRuntimeException("No paramater provided to fetch document");
        }

        DocumentRouteHeaderValue routeHeader = KEWServiceLocator.getRouteHeaderService().getRouteHeader(documentId);

        DocumentSecurityService security = KEWServiceLocator.getDocumentSecurityService();
        if (!security.routeLogAuthorized(getUserSession().getPrincipalId(), routeHeader, new SecuritySession(GlobalVariables.getUserSession().getPrincipalId()))) {
          return mapping.findForward("NotAuthorized");
        }
        
        fixActionRequestsPositions(routeHeader);
        populateRouteLogFormActionRequests(rlForm, routeHeader);

        rlForm.setLookFuture(routeHeader.getDocumentType().getLookIntoFuturePolicy().getPolicyValue().booleanValue());

        if (rlForm.isShowFuture()) {
            try {
                populateRouteLogFutureRequests(rlForm, routeHeader);
            } catch (Exception e) {
                String errorMsg = "Unable to determine Future Action Requests";
                LOG.info(errorMsg,e);
                rlForm.setShowFutureError(errorMsg);
            }
        }
        request.setAttribute("routeHeader", routeHeader);
        
                // check whether action message logging should be enabled, user must
                // have KIM permission for doc type 
        boolean isAuthorizedToAddRouteLogMessage = KEWServiceLocator.getDocumentTypePermissionService()
                                .canAddRouteLogMessage(GlobalVariables.getUserSession().getPrincipalId(), routeHeader);
                if (isAuthorizedToAddRouteLogMessage) {
                        rlForm.setEnableLogAction(true);
                } else {
                        rlForm.setEnableLogAction(false);
                }
        
        return super.execute(mapping, rlForm, request, response);
    }

    @SuppressWarnings("unchecked")
        public void populateRouteLogFormActionRequests(RouteLogForm rlForm, DocumentRouteHeaderValue routeHeader) {
        List<ActionRequestValue> rootRequests = getActionRequestService().getRootRequests(routeHeader.getActionRequests());
        Collections.sort(rootRequests, ROUTE_LOG_ACTION_REQUEST_SORTER);
        rootRequests = switchActionRequestPositionsIfPrimaryDelegatesPresent(rootRequests);
        int arCount = 0;
        for ( ActionRequestValue actionRequest : rootRequests ) {
            if (actionRequest.isPending()) {
                arCount++;

                if (ActionRequestStatus.INITIALIZED.getCode().equals(actionRequest.getStatus())) {
                    actionRequest.setDisplayStatus("PENDING");
                } else if (ActionRequestStatus.ACTIVATED.getCode().equals(actionRequest.getStatus())) {
                    actionRequest.setDisplayStatus("IN ACTION LIST");
                }
            }
        }
        rlForm.setRootRequests(rootRequests);
        rlForm.setPendingActionRequestCount(arCount);
    }

    @SuppressWarnings("unchecked")
        private ActionRequestValue switchActionRequestPositionIfPrimaryDelegatePresent( ActionRequestValue actionRequest ) {
        
        /**
         * KULRICE-4756 - The main goal here is to fix the regression of what happened in Rice 1.0.2 with the display
         * of primary delegate requests.  The delegate is displayed at the top-most level correctly on action requests
         * that are "rooted" at a "role" request.
         * 
         * If they are rooted at a principal or group request, then the display of the primary delegator at the top-most
         * level does not happen (instead it shows the delegator and you have to expand the request to see the primary
         * delegate).
         * 
         * Ultimately, the KAI group and Rice BA need to come up with a specification for how the Route Log should
         * display delegate information.  For now, will fix this so that in the non "role" case, it will put the
         * primary delegate as the outermost request *except* in the case where there is more than one primary delegate.
         */
        
        if (!actionRequest.isRoleRequest()) {
                List<ActionRequestValue> primaryDelegateRequests = actionRequest.getPrimaryDelegateRequests();
                // only display primary delegate request at top if there is only *one* primary delegate request
                if ( primaryDelegateRequests.size() != 1) {
                        return actionRequest;
                }
                ActionRequestValue primaryDelegateRequest = primaryDelegateRequests.get(0);
                actionRequest.getChildrenRequests().remove(primaryDelegateRequest);
                primaryDelegateRequest.setChildrenRequests(actionRequest.getChildrenRequests());
                primaryDelegateRequest.setParentActionRequest(actionRequest.getParentActionRequest());

                actionRequest.setChildrenRequests( new ArrayList<ActionRequestValue>(0) );
                actionRequest.setParentActionRequest(primaryDelegateRequest);

                primaryDelegateRequest.getChildrenRequests().add(0, actionRequest);
                
                for (ActionRequestValue delegateRequest : primaryDelegateRequest.getChildrenRequests()) {
                        delegateRequest.setParentActionRequest(primaryDelegateRequest);
                }
                
                return primaryDelegateRequest;
        }
        
        return actionRequest;
    }

    private List<ActionRequestValue> switchActionRequestPositionsIfPrimaryDelegatesPresent( Collection<ActionRequestValue> actionRequests ) {
        List<ActionRequestValue> results = new ArrayList<ActionRequestValue>( actionRequests.size() );
        for ( ActionRequestValue actionRequest : actionRequests ) {
                        results.add( switchActionRequestPositionIfPrimaryDelegatePresent(actionRequest) );
        }
        return results;
    }
    
    @SuppressWarnings("unchecked")
    private void fixActionRequestsPositions(DocumentRouteHeaderValue routeHeader) {
        for (ActionTakenValue actionTaken : routeHeader.getActionsTaken()) {
            Collections.sort((List<ActionRequestValue>) actionTaken.getActionRequests(), ROUTE_LOG_ACTION_REQUEST_SORTER);
            actionTaken.setActionRequests( actionTaken.getActionRequests() );
        }
    }
    
    /**
     * executes a simulation of the future routing, and sets the futureRootRequests and futureActionRequestCount
     * properties on the provided RouteLogForm.
     * 
     * @param rlForm the RouteLogForm --used in a write-only fashion.
     * @param document the DocumentRouteHeaderValue for the document whose future routing is being simulated.
     * @throws Exception
     */
    public void populateRouteLogFutureRequests(RouteLogForm rlForm, DocumentRouteHeaderValue document) throws Exception {

        RoutingReportCriteria reportCriteria = RoutingReportCriteria.Builder.createByDocumentId(document.getDocumentId()).build();
        String applicationId = document.getDocumentType().getApplicationId();

        // gather the IDs for action requests that predate the simulation
                Set<String> preexistingActionRequestIds = getActionRequestIds(document);
        
                // run the simulation
        DocumentDetail documentDetail = KewApiServiceLocator.getWorkflowDocumentActionsService(applicationId).executeSimulation(reportCriteria);

        // fabricate our ActionRequestValueS from the results
        List<ActionRequestValue> futureActionRequests = 
                reconstituteActionRequestValues(documentDetail, preexistingActionRequestIds);

        Collections.sort(futureActionRequests, ROUTE_LOG_ACTION_REQUEST_SORTER);
        
        futureActionRequests = switchActionRequestPositionsIfPrimaryDelegatesPresent(futureActionRequests);
        
        int pendingActionRequestCount = 0;
        for (ActionRequestValue actionRequest: futureActionRequests) {
            if (actionRequest.isPending()) {
                pendingActionRequestCount++;

                if (ActionRequestStatus.INITIALIZED.getCode().equals(actionRequest.getStatus())) {
                    actionRequest.setDisplayStatus("PENDING");
                } else if (ActionRequestStatus.ACTIVATED.getCode().equals(actionRequest.getStatus())) {
                    actionRequest.setDisplayStatus("IN ACTION LIST");
                }
            }
        }

        rlForm.setFutureRootRequests(futureActionRequests);
        rlForm.setFutureActionRequestCount(pendingActionRequestCount);
    }


        /**
         * This utility method returns a Set of LongS containing the IDs for the ActionRequestValueS associated with 
         * this DocumentRouteHeaderValue. 
         */
        @SuppressWarnings("unchecked")
        private Set<String> getActionRequestIds(DocumentRouteHeaderValue document) {
                Set<String> actionRequestIds = new HashSet<String>();

                List<ActionRequestValue> actionRequests = 
                        KEWServiceLocator.getActionRequestService().findAllActionRequestsByDocumentId(document.getDocumentId());
                
                if (actionRequests != null) {
                        for (ActionRequestValue actionRequest : actionRequests) {
                                if (actionRequest.getActionRequestId() != null) {
                                        actionRequestIds.add(actionRequest.getActionRequestId());
                                }
                        }
                }
                return actionRequestIds;
        }

        /**
         * This method creates ActionRequestValue objects from the DocumentDetailDTO output from
         * 
         * @param documentDetail contains the DTOs from which the ActionRequestValues are reconstituted
         * @param preexistingActionRequestIds this is a Set of ActionRequest IDs that will not be reconstituted
         * @return the ActionRequestValueS that have been created
         */
        private List<ActionRequestValue> reconstituteActionRequestValues(DocumentDetail documentDetail,
                        Set<String> preexistingActionRequestIds) {

        RouteNodeInstanceFabricator routeNodeInstanceFabricator = 
                new RouteNodeInstanceFabricator(KEWServiceLocator.getRouteNodeService());

        if (documentDetail.getRouteNodeInstances() != null && !documentDetail.getRouteNodeInstances().isEmpty()) {
                for (org.kuali.rice.kew.api.document.node.RouteNodeInstance routeNodeInstanceVO : documentDetail.getRouteNodeInstances()) {
                        routeNodeInstanceFabricator.importRouteNodeInstanceDTO(routeNodeInstanceVO);
                }
                }
        
        List<ActionRequest> actionRequestVOs = documentDetail.getActionRequests();
        List<ActionRequestValue> futureActionRequests = new ArrayList<ActionRequestValue>();
        if (actionRequestVOs != null) {
                        for (ActionRequest actionRequestVO : actionRequestVOs) {
                                if (actionRequestVO != null) {
                                        if (!preexistingActionRequestIds.contains(actionRequestVO.getId())) {
                                                ActionRequestValue converted = ActionRequestValue.from(actionRequestVO,
                                routeNodeInstanceFabricator);
                                                futureActionRequests.add(converted);
                                        }
                                }
                        }
                }
                return futureActionRequests;
        }
    
    private ActionRequestService getActionRequestService() {
        return (ActionRequestService) KEWServiceLocator.getService(KEWServiceLocator.ACTION_REQUEST_SRV);
    }
    
    private UserSession getUserSession() {
        return GlobalVariables.getUserSession();
    }
    
    /**
     * Creates dummy RouteNodeInstances based on imported data from RouteNodeInstanceDTOs.
     * It is then able to vend those RouteNodeInstanceS back by their IDs.
     * 
     * @author Kuali Rice Team (rice.collab@kuali.org)
     *
     */
    private static class RouteNodeInstanceFabricator implements RouteNodeInstanceLoader {

        private Map<String,Branch> branches = new HashMap<String, Branch>();
        private Map<String, RouteNodeInstance> routeNodeInstances =
                new HashMap<String, RouteNodeInstance>();
        private Map<String,RouteNode> routeNodes = new HashMap<String, RouteNode>();
        private Map<String,NodeState> nodeStates = new HashMap<String, NodeState>();

        private RouteNodeService routeNodeService;
        
        /**
                 * This constructs a FutureRouteNodeInstanceFabricator, which will generate bogus
                 * RouteNodeInstances for SimulationEngine results
                 * 
                 */
                public RouteNodeInstanceFabricator(RouteNodeService routeNodeService) {
                        this.routeNodeService = routeNodeService;
                }

                /**
                 * 
                 * This method looks at the given RouteNodeInstanceDTO and imports it (and all it's ancestors)
                 * as dummy RouteNodeInstanceS
                 * 
                 * @param nodeInstanceDTO
                 */
                public void importRouteNodeInstanceDTO(org.kuali.rice.kew.api.document.node.RouteNodeInstance nodeInstanceDTO) {
                        _importRouteNodeInstanceDTO(nodeInstanceDTO);
                }
                
                /**
                 * helper method for {@link #importRouteNodeInstanceDTO(org.kuali.rice.kew.api.document.node.RouteNodeInstance)} which does all
                 * the work.  The public method just wraps this one but hides the returned RouteNodeInstance,
                 * which is used for the recursive call to populate the nextNodeInstanceS inside our 
                 * RouteNodeInstanceS.
                 * 
                 * @param nodeInstanceDTO
                 * @return
                 */
        private RouteNodeInstance _importRouteNodeInstanceDTO(org.kuali.rice.kew.api.document.node.RouteNodeInstance nodeInstanceDTO) {
                if (nodeInstanceDTO == null) {
                        return null;
                }
                RouteNodeInstance nodeInstance = new RouteNodeInstance();
                nodeInstance.setActive(nodeInstanceDTO.isActive());

                nodeInstance.setComplete(nodeInstanceDTO.isComplete());
                nodeInstance.setDocumentId(nodeInstanceDTO.getDocumentId());
                nodeInstance.setInitial(nodeInstanceDTO.isInitial());

                Branch branch = getBranch(nodeInstanceDTO.getBranchId());
                nodeInstance.setBranch(branch);

                if (nodeInstanceDTO.getRouteNodeId() != null) {
                        RouteNode routeNode = routeNodeService.findRouteNodeById(nodeInstanceDTO.getRouteNodeId());

                        if (routeNode == null) {
                                routeNode = getRouteNode(nodeInstanceDTO.getRouteNodeId());
                                routeNode.setNodeType(nodeInstanceDTO.getName());
                        }

                        nodeInstance.setRouteNode(routeNode);

                        if (routeNode.getBranch() != null) {
                                branch.setName(routeNode.getBranch().getName());
                        } 
                }

                RouteNodeInstance process = getRouteNodeInstance(nodeInstanceDTO.getProcessId());
                nodeInstance.setProcess(process);

                nodeInstance.setRouteNodeInstanceId(nodeInstanceDTO.getId());

                List<NodeState> nodeState = new ArrayList<NodeState>();
                if (nodeInstanceDTO.getState() != null) {
                                for (RouteNodeInstanceState stateDTO : nodeInstanceDTO.getState()) {
                                        NodeState state = getNodeState(stateDTO.getId());
                                        if (state != null) {
                                                state.setKey(stateDTO.getKey());
                                                state.setValue(stateDTO.getValue());
                                                state.setStateId(stateDTO.getId());
                                                state.setNodeInstance(nodeInstance);
                                                nodeState.add(state);
                                        }
                                }
                        }
                nodeInstance.setState(nodeState);

                List<RouteNodeInstance> nextNodeInstances = new ArrayList<RouteNodeInstance>();


                for (org.kuali.rice.kew.api.document.node.RouteNodeInstance nextNodeInstanceVO : nodeInstanceDTO.getNextNodeInstances()) {
                        // recurse to populate nextNodeInstances
                        nextNodeInstances.add(_importRouteNodeInstanceDTO(nextNodeInstanceVO));
                }
            nodeInstance.setNextNodeInstances(nextNodeInstances);

                routeNodeInstances.put(nodeInstance.getRouteNodeInstanceId(), nodeInstance);
                return nodeInstance;
        }
        
                /**
                 * This method returns a dummy RouteNodeInstance for the given ID, or null if it hasn't
                 * imported from a RouteNodeInstanceDTO with that ID
                 * 
                 * @see org.kuali.rice.kew.dto.DTOConverter.RouteNodeInstanceLoader#load(String)
                 */
                @Override
                public RouteNodeInstance load(String routeNodeInstanceID) {
                        return routeNodeInstances.get(routeNodeInstanceID);
                }


        /**
         * This method creates bogus BranchES as needed
         * 
         * @param branchId
         * @return
         */
        private Branch getBranch(String branchId) {
                Branch result = null;

                if (branchId != null) {
                        // if branch doesn't exist, create it
                        if (!branches.containsKey(branchId)) {
                                result = new Branch();
                                result.setBranchId(branchId);
                                branches.put(branchId, result);
                        } else {
                                result = branches.get(branchId);
                        }
                }
                return result;
        }

        /**
         * This method creates bogus RouteNodeS as needed
         * 
         * @param routeNodeId
         * @return
         */
        private RouteNode getRouteNode(String routeNodeId) {
                RouteNode result = null;

                if (routeNodeId != null) {
                        // if RouteNode doesn't exist, create it
                        if (!routeNodes.containsKey(routeNodeId)) {
                                result = new RouteNode();
                                result.setRouteNodeId(routeNodeId);
                                routeNodes.put(routeNodeId, result);
                        } else {
                                result = routeNodes.get(routeNodeId);
                        }
                }
                return result;
        }

        /**
         * This method creates bogus RouteNodeInstanceS as needed
         * 
         * @param routeNodeInstanceId
         * @return
         */
        public RouteNodeInstance getRouteNodeInstance(String routeNodeInstanceId) {
                RouteNodeInstance result = null;

                if (routeNodeInstanceId != null) {
                        // if RouteNodeInstance doesn't exist, create it
                        if (!routeNodeInstances.containsKey(routeNodeInstanceId)) {
                    result = new RouteNodeInstance();
                                result.setRouteNodeInstanceId(routeNodeInstanceId);
                                routeNodeInstances.put(routeNodeInstanceId, result);
                        } else {
                                result = routeNodeInstances.get(routeNodeInstanceId);
                        }
                }
                return result;
        }

        /**
         * This method creates bogus NodeStateS as needed
         * 
         * @param nodeStateId
         * @return
         */
        private NodeState getNodeState(String nodeStateId) {
                NodeState result = null;

                if (nodeStateId != null) {
                        // if NodeState doesn't exist, create it
                        if (!nodeStates.containsKey(nodeStateId)) {
                                result = new NodeState();
                                result.setNodeStateId(nodeStateId);
                                nodeStates.put(nodeStateId, result);
                        } else {
                                result = nodeStates.get(nodeStateId);
                        }
                }
                return result;
        }

    } // end inner class FutureRouteNodeInstanceFabricator

    /**
     * Logs a new message to the route log for the current document, then refreshes the action taken list to display
     * back the new message in the route log tab. User must have permission to log a message for the doc type and the
     * request must be coming from the route log tab display (not the route log page).
     */
        public ActionForward logActionMessageInRouteLog(ActionMapping mapping, ActionForm form, HttpServletRequest request,
                        HttpServletResponse response) throws Exception {
                RouteLogForm routeLogForm = (RouteLogForm) form;

                String documentId = null;
                if (!org.apache.commons.lang.StringUtils.isEmpty(routeLogForm.getDocumentId())) {
                        documentId = routeLogForm.getDocumentId();
                } else if (!org.apache.commons.lang.StringUtils.isEmpty(routeLogForm.getDocId())) {
                        documentId = routeLogForm.getDocId();
                } else {
                        throw new WorkflowRuntimeException("No paramater provided to fetch document");
                }
                
                DocumentRouteHeaderValue routeHeader = KEWServiceLocator.getRouteHeaderService().getRouteHeader(documentId);
                
                // check user has permission to add a route log message
                boolean isAuthorizedToAddRouteLogMessage = KEWServiceLocator.getDocumentTypePermissionService()
                                .canAddRouteLogMessage(GlobalVariables.getUserSession().getPrincipalId(), routeHeader);

                if (!isAuthorizedToAddRouteLogMessage) {
                        throw new InvalidActionTakenException("Principal with name '"
                                        + GlobalVariables.getUserSession().getPrincipalName()
                                        + "' is not authorized to add route log messages for documents of type '"
                                        + routeHeader.getDocumentType().getName());
                }

                LOG.info("Logging new action message for user " + GlobalVariables.getUserSession().getPrincipalName()
                                + ", route header " + routeHeader);
                KEWServiceLocator.getWorkflowDocumentService().logDocumentAction(
                                GlobalVariables.getUserSession().getPrincipalId(), routeHeader,
                                routeLogForm.getNewRouteLogActionMessage());

                routeLogForm.setNewRouteLogActionMessage("");

                // retrieve routeHeader again to pull new action taken
                routeHeader = KEWServiceLocator.getRouteHeaderService().getRouteHeader(documentId, true);
                fixActionRequestsPositions(routeHeader);
                request.setAttribute("routeHeader", routeHeader);

                return mapping.findForward(getDefaultMapping());
        }
    
}