/*
 * Copyright 2017 Red Hat, Inc. and/or its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package org.jbpm.services.task.impl;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.drools.mvel.MVELSafeHelper;
import org.jbpm.services.task.commands.TaskCommand;
import org.jbpm.services.task.commands.TaskContext;
import org.jbpm.services.task.events.TaskEventSupport;
import org.jbpm.services.task.internals.lifecycle.LifeCycleManager;
import org.jbpm.services.task.utils.ClassUtil;
import org.jbpm.services.task.utils.ContentMarshallerHelper;
import org.kie.api.command.Command;
import org.kie.api.runtime.Environment;
import org.kie.api.task.model.Content;
import org.kie.api.task.model.I18NText;
import org.kie.api.task.model.OrganizationalEntity;
import org.kie.api.task.model.Status;
import org.kie.api.task.model.Task;
import org.kie.api.task.model.TaskSummary;
import org.kie.api.task.model.User;
import org.kie.internal.task.api.ContentMarshallerContext;
import org.kie.internal.task.api.TaskInstanceService;
import org.kie.internal.task.api.TaskModelProvider;
import org.kie.internal.task.api.TaskPersistenceContext;
import org.kie.internal.task.api.model.ContentData;
import org.kie.internal.task.api.model.FaultData;
import org.kie.internal.task.api.model.InternalContent;
import org.kie.internal.task.api.model.InternalI18NText;
import org.kie.internal.task.api.model.InternalPeopleAssignments;
import org.kie.internal.task.api.model.InternalTask;
import org.kie.internal.task.api.model.InternalTaskData;
import org.kie.internal.task.api.model.Operation;
import org.kie.internal.task.api.model.SubTasksStrategy;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 *
 */
public class TaskInstanceServiceImpl implements TaskInstanceService {
    
    private static final Logger logger = LoggerFactory.getLogger(TaskInstanceServiceImpl.class);
    
    protected static final Pattern PARAMETER_MATCHER = Pattern.compile("\\$\\{([\\S&&[^\\}]]+)\\}", Pattern.DOTALL);
    
    private LifeCycleManager lifeCycleManager;
    
    private org.kie.internal.task.api.TaskContext context;
   
    private TaskPersistenceContext persistenceContext;    
    private TaskEventSupport taskEventSupport;
    private Environment environment;

    public TaskInstanceServiceImpl() {
    }

    public TaskInstanceServiceImpl(org.kie.internal.task.api.TaskContext context, TaskPersistenceContext persistenceContext,
    		LifeCycleManager lifeCycleManager, TaskEventSupport taskEventSupport,
    		Environment environment) {
    	this.context = context;
    	this.persistenceContext = persistenceContext;
    	this.lifeCycleManager = lifeCycleManager;
    	this.taskEventSupport = taskEventSupport;
    	this.environment = environment;
    }

    public void setLifeCycleManager(LifeCycleManager lifeCycleManager) {
        this.lifeCycleManager = lifeCycleManager;
    }

    public void setTaskEventSupport(TaskEventSupport taskEventSupport) {
        this.taskEventSupport = taskEventSupport;
    }

    
    public void setPersistenceContext(TaskPersistenceContext persistenceContext) {
        this.persistenceContext = persistenceContext;
    }

   
    public long addTask(Task task, Map<String, Object> params) {    	
    	taskEventSupport.fireBeforeTaskAdded(task, context);
    	
    	persistenceContext.persistTask(task);
    	
    	resolveTaskDetailsForTaskProperties(task);    	
    	
    	if (params != null) {
    	    taskEventSupport.fireBeforeTaskInputVariablesChanged(task, context, Collections.emptyMap());
    	    resolveTaskDetails(params, task);
    	    
    	    ContentData contentData = ContentMarshallerHelper.marshal(task, params, TaskContentRegistry.get().getMarshallerContext(task).getEnvironment());
			Content content = TaskModelProvider.getFactory().newContent();
			((InternalContent) content).setContent(contentData.getContent());
			persistenceContext.persistContent(content);
			persistenceContext.setDocumentToTask(content, contentData, task);
			
			taskEventSupport.fireAfterTaskInputVariablesChanged(task, context, params);
		}

		
		taskEventSupport.fireAfterTaskAdded(task, context);
		return task.getId();
    }

    public long addTask(Task task, ContentData contentData) {
    	taskEventSupport.fireBeforeTaskAdded(task, context);  
    	
    	persistenceContext.persistTask(task);
    	
    	resolveTaskDetailsForTaskProperties(task);
        
    	if (contentData != null) {
            Content content = TaskModelProvider.getFactory().newContent();
            ((InternalContent) content).setContent(contentData.getContent());
            persistenceContext.persistContent(content);
            persistenceContext.setDocumentToTask(content, contentData, task);
        }
        
        
        taskEventSupport.fireAfterTaskAdded(task, context);
        return task.getId();
    }

    public void activate(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Activate, taskId, userId, null, null, toGroups(null));
    }

    public void claim(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Claim, taskId, userId, null, null, toGroups(null));
    }

    public void claim(long taskId, String userId, List<String> groupIds) {
    	lifeCycleManager.taskOperation(Operation.Claim, taskId, userId, null, null, groupIds);
    }

    public void claimNextAvailable(String userId) {
        List<Status> status = new ArrayList<Status>();
        status.add(Status.Ready);
        List<TaskSummary> queryTasks = persistenceContext.queryWithParametersInTransaction("TasksAssignedAsPotentialOwnerByStatus", 
                persistenceContext.addParametersToMap("userId", userId, "status", status),
                ClassUtil.<List<TaskSummary>>castClass(List.class));;
        if (queryTasks.size() > 0) {
            lifeCycleManager.taskOperation(Operation.Claim, queryTasks.get(0).getId(), userId, null, null, toGroups(null));
        } else {
        	logger.info("No task available to assign for user {}", userId);
        }
    }

    public void claimNextAvailable(String userId, List<String> groupIds) {
        List<Status> status = new ArrayList<Status>();
        status.add(Status.Ready);
        List<TaskSummary> queryTasks = persistenceContext.queryWithParametersInTransaction("TasksAssignedAsPotentialOwnerByStatusByGroup", 
                persistenceContext.addParametersToMap("userId", userId, "status", status, "groupIds", groupIds),
                ClassUtil.<List<TaskSummary>>castClass(List.class));;
        if (queryTasks.size() > 0) {
            lifeCycleManager.taskOperation(Operation.Claim, queryTasks.get(0).getId(), userId, null, null, groupIds);
        } else {
            logger.info("No task available to assign for user {} and groups {}", userId, groupIds);
        }
    }

    public void complete(long taskId, String userId, Map<String, Object> data) {
        lifeCycleManager.taskOperation(Operation.Complete, taskId, userId, null, data, toGroups(null));
    }

    public void delegate(long taskId, String userId, String targetUserId) {
        lifeCycleManager.taskOperation(Operation.Delegate, taskId, userId, targetUserId, null, toGroups(null));
    }

    public void deleteFault(long taskId, String userId) {
    	Task task = persistenceContext.findTask(taskId);
    	
    	long contentId = task.getTaskData().getFaultContentId();
        Content content = persistenceContext.findContent(contentId);
        FaultData data = TaskModelProvider.getFactory().newFaultData();
        persistenceContext.removeContent(content);
        
        persistenceContext.setFaultToTask(null, data, task);
    }

    public void deleteOutput(long taskId, String userId) {
    	Task task = persistenceContext.findTask(taskId);
    	
    	long contentId = task.getTaskData().getOutputContentId();
        Content content = persistenceContext.findContent(contentId);
        
        Map<String, Object> initialContent = new HashMap<>();
        ContentMarshallerContext context = TaskContentRegistry.get().getMarshallerContext(task);
        Object unmarshalledObject = ContentMarshallerHelper.unmarshall(content.getContent(), context.getEnvironment(), context.getClassloader());
        if(unmarshalledObject != null && unmarshalledObject instanceof Map){
            // set initial content before updating with this params
            initialContent.putAll((Map<String, Object>)unmarshalledObject);
        }
        taskEventSupport.fireBeforeTaskOutputVariablesChanged(task, this.context, initialContent);
        
        ContentData data = TaskModelProvider.getFactory().newContentData();
        persistenceContext.removeContent(content);
        persistenceContext.setOutputToTask(null, data, task);
        taskEventSupport.fireAfterTaskOutputVariablesChanged(task, this.context, null);
    }

    public void exit(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Exit, taskId, userId, null, null, toGroups(null));
    }

    public void fail(long taskId, String userId, Map<String, Object> faultData) {
        lifeCycleManager.taskOperation(Operation.Fail, taskId, userId, null, faultData, toGroups(null));
    }

    public void forward(long taskId, String userId, String targetEntityId) {
        lifeCycleManager.taskOperation(Operation.Forward, taskId, userId, targetEntityId, null, toGroups(null));
    }

    public void release(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Release, taskId, userId, null, null, toGroups(null));
    }

    public void remove(long taskId, String userId) {
    	Task task = persistenceContext.findTask(taskId);
    	User user = persistenceContext.findUser(userId);
    	if (((InternalPeopleAssignments)task.getPeopleAssignments()).getRecipients().contains(user)) {
    		((InternalPeopleAssignments)task.getPeopleAssignments()).getRecipients().remove(user);
		} else {
			throw new RuntimeException("Couldn't remove user " + userId + " since it isn't a notification recipient");
		}
    }

    public void resume(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Resume, taskId, userId, null, null, toGroups(null));
    }

    public void setFault(long taskId, String userId, FaultData fault) {
    	Task task = persistenceContext.findTask(taskId);
    	
    	Content content = TaskModelProvider.getFactory().newContent();
		((InternalContent) content).setContent(fault.getContent());
		persistenceContext.persistContent(content);
		persistenceContext.setFaultToTask(content, fault, task);
    }

    public void setOutput(long taskId, String userId, Object outputContentData) {
    	Task task = persistenceContext.findTask(taskId);
    	
    	ContentData contentData = ContentMarshallerHelper.marshal(task, outputContentData, environment);
		Content content = TaskModelProvider.getFactory().newContent();
		((InternalContent) content).setContent(contentData.getContent());
		persistenceContext.persistContent(content);
		persistenceContext.setOutputToTask(content, contentData, task);
    }

    public void setPriority(long taskId, int priority) {
        Task task = persistenceContext.findTask(taskId);
        
        taskEventSupport.fireBeforeTaskUpdated(task, context);
        
        ((InternalTask) task).setPriority(priority);
        
        taskEventSupport.fireAfterTaskUpdated(task, context);
    }

    public void setTaskNames(long taskId, List<I18NText> inputTaskNames) {
        Task task = persistenceContext.findTask(taskId);
        
        taskEventSupport.fireBeforeTaskUpdated(task, context);
       
        List<I18NText> taskNames = new ArrayList<I18NText>(inputTaskNames.size());
        for( I18NText inputText : inputTaskNames ) { 
            I18NText text = TaskModelProvider.getFactory().newI18NText();
            ((InternalI18NText) text).setLanguage(inputText.getLanguage()); 
            ((InternalI18NText) text).setText(inputText.getText());
            taskNames.add(text);
        }
        ((InternalTask) task).setNames(taskNames);
        ((InternalTask) task).setName(taskNames.get(0).getText());
        
        taskEventSupport.fireAfterTaskUpdated(task, context);
    }

    public void skip(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Skip, taskId, userId, null, null, toGroups(null));
    }

    public void start(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Start, taskId, userId, null, null, toGroups(null));
    }

    public void stop(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Stop, taskId, userId, null, null, toGroups(null));
    }

    public void suspend(long taskId, String userId) {
        lifeCycleManager.taskOperation(Operation.Suspend, taskId, userId, null, null, toGroups(null));
    }

    public void nominate(long taskId, String userId, List<OrganizationalEntity> potentialOwners) {      
        lifeCycleManager.taskOperation(Operation.Nominate, taskId, userId, null, null, toGroups(null), 
        		potentialOwners.toArray(new OrganizationalEntity[potentialOwners.size()]));
    }

    public void setSubTaskStrategy(long taskId, SubTasksStrategy strategy) {
        Task task = persistenceContext.findTask(taskId);
        ((InternalTask) task).setSubTaskStrategy(strategy);
    }

    public void setExpirationDate(long taskId, Date date) {
        Task task = persistenceContext.findTask(taskId);
        
        taskEventSupport.fireBeforeTaskUpdated(task, context);
        
        ((InternalTaskData) task.getTaskData()).setExpirationTime(date);
        
        taskEventSupport.fireAfterTaskUpdated(task, context);
    }

    public void setDescriptions(long taskId, List<I18NText> inputDescriptions) {
        Task task = persistenceContext.findTask(taskId);
        
        taskEventSupport.fireBeforeTaskUpdated(task, context);
       
        List<I18NText> descriptions = new ArrayList<I18NText>(inputDescriptions.size());
        for( I18NText inputText : inputDescriptions ) { 
            I18NText text = TaskModelProvider.getFactory().newI18NText();
            ((InternalI18NText) text).setLanguage(inputText.getLanguage()); 
            ((InternalI18NText) text).setText(inputText.getText());
            descriptions.add(text);
        }
        ((InternalTask) task).setDescriptions(descriptions);
        ((InternalTask) task).setDescription(descriptions.get(0).getText());
        
        taskEventSupport.fireAfterTaskUpdated(task, context);
    }

    public void setSkipable(long taskId, boolean skipable) {
        Task task = persistenceContext.findTask(taskId);
        ((InternalTaskData) task.getTaskData()).setSkipable(skipable);
    }

    public int getPriority(long taskId) {
        Task task = persistenceContext.findTask(taskId);
        return task.getPriority();
    }

    public Date getExpirationDate(long taskId) {
        Task task = persistenceContext.findTask(taskId);
        return task.getTaskData().getExpirationTime();
    }

    public List<I18NText> getDescriptions(long taskId) {
        Task task = persistenceContext.findTask(taskId);
        return (List<I18NText>) task.getDescriptions();
    }

    public boolean isSkipable(long taskId) {
        Task task = persistenceContext.findTask(taskId);
        return task.getTaskData().isSkipable();
    }

    public SubTasksStrategy getSubTaskStrategy(long taskId) {
        Task task = persistenceContext.findTask(taskId);
        return ((InternalTask) task).getSubTaskStrategy();
    }
    
    @SuppressWarnings({ "unchecked", "rawtypes" })
	public <T> T execute(Command<T> command) {
        return (T) ((TaskCommand) command).execute( new TaskContext() );
    }

    @Override
    public void setName(long taskId, String name) {
        Task task = persistenceContext.findTask(taskId);
        ((InternalTask) task).setName(name);
    }

    @Override
    public void setDescription(long taskId, String description) {
        Task task = persistenceContext.findTask(taskId);
        ((InternalTask) task).setDescription(description);
    }

    @Override
    public void setSubject(long taskId, String subject) {
        Task task = persistenceContext.findTask(taskId);
        ((InternalTask) task).setSubject(subject);
    }
   
    @Override
    public long addOutputContentFromUser( long taskId, String userId, Map<String, Object> params ) {
        // check permissions
        this.lifeCycleManager.taskOperation(Operation.Modify, taskId, userId, null, null, toGroups(null));
        return new TaskContentServiceImpl(context, this.persistenceContext, taskEventSupport).addOutputContent(taskId, params);
    }

    @Override
    public Content getContentByIdForUser( long contentId, String userId ) {
        long taskId = persistenceContext.findTaskIdByContentId(contentId);
        // check permissions
        this.lifeCycleManager.taskOperation(Operation.View, taskId, userId, null, null, toGroups(null));
        return this.persistenceContext.findContent(contentId);
    }
    
    @Override
    public Map<String, Object> getContentMapForUser( Long taskId, String userId ) {
        // check permissions
        this.lifeCycleManager.taskOperation(Operation.View, taskId, userId, null, null, toGroups(null));
        Task task = this.persistenceContext.findTask(taskId);
        if( task.getTaskData() != null && task.getTaskData().getOutputContentId() != null ) { 
            Content content = this.persistenceContext.findContent(task.getTaskData().getOutputContentId());
            ContentMarshallerContext mContext = TaskContentRegistry.get().getMarshallerContext(task);
            Object outputContent = ContentMarshallerHelper.unmarshall(content.getContent(), mContext.getEnvironment(), mContext.getClassloader());
            if( outputContent instanceof Map ) { 
               return (Map<String, Object>) outputContent;
            } else { 
                throw new IllegalStateException("Output content for task " + taskId + " is not a Map<String, Object>!");
            }
        }
        return null;
    }
    
    @SuppressWarnings("unchecked")
	protected List<String> toGroups(List<String> groups) {
    	if (groups == null) {
    		return (List<String>) context.get("local:groups");
    	}
    	
    	return groups;
    }
    
    protected Map<String, Object> resolveTaskDetails(Map<String, Object> parameters, Task task) {
        for (Map.Entry<String, Object> entry: parameters.entrySet()) {
            if (entry.getValue() != null && entry.getValue() instanceof String) {
                String s = (String) entry.getValue();
                Map<String, String> replacements = new HashMap<String, String>();
                Matcher matcher = PARAMETER_MATCHER.matcher(s);
                while (matcher.find()) {
                    String paramName = matcher.group(1);
                    if (replacements.get(paramName) == null) {
               
                        try {
                            Object variableValue = MVELSafeHelper.getEvaluator().eval(paramName, new TaskResolverFactory(task));
                            String variableValueString = variableValue == null ? "" : variableValue.toString();
                            replacements.put(paramName, variableValueString);
                        } catch (Throwable t) {
    
                            logger.error("Continuing without setting parameter.");
                        }
                    }
                    
                }
                for (Map.Entry<String, String> replacement: replacements.entrySet()) {
                    s = s.replace("${" + replacement.getKey() + "}", replacement.getValue());
                }
                parameters.put(entry.getKey(), s);
            }
        }
        return parameters;
    }
    
    protected void resolveTaskDetailsForTaskProperties(Task task) {
        Map<String, Object> parameters = new HashMap<String, Object>();
        parameters.put("name", task.getName());
        parameters.put("description", task.getDescription());
        parameters.put("subject", task.getSubject());
        parameters.put("formName", ((InternalTask)task).getFormName());
        
        Map<String, Object> replacements = resolveTaskDetails(parameters, task);
        ((InternalTask)task).setName((String) replacements.get("name"));
        ((InternalTask)task).setDescription((String) replacements.get("description"));
        ((InternalTask)task).setSubject((String) replacements.get("subject"));
        ((InternalTask)task).setFormName((String) replacements.get("formName"));
    }

    @Override
    public void fireEvent(Operation operation, long taskId) {
        fireEvent(operation, context.getPersistenceContext().findTask(taskId));
    }

    @Override
    public void fireEvent(Operation operation, Task task) {
        switch (operation) {
            case Activate:
                this.taskEventSupport.fireBeforeTaskActivated(task, context);
                this.taskEventSupport.fireAfterTaskActivated(task, context);
                break;
            default:
                break;
        }
    }

}
