/*
 * Copyright 2014 JBoss by Red Hat.
 *
 * 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.
 */

package org.jbpm.services.api;

import java.util.Collection;
import java.util.List;
import java.util.Map;

import org.kie.api.command.Command;
import org.kie.api.runtime.manager.Context;
import org.kie.api.runtime.process.ProcessInstance;
import org.kie.api.runtime.process.WorkItem;

public interface ProcessService {
	
	/**
	 * Starts a process with no variables
	 * 
	 * @param deploymentId deployment information for the process's kjar
	 * @param processId The process's identifier 
	 * @return process instance identifier
	 * @throws RuntimeException in case of encountered errors
	 * @throws DeploymentNotFoundException in case deployment with given deployment id does not exist or is not active
	 */
	Long startProcess(String deploymentId, String processId);

	/**
	 * Starts a process with no variables
	 * 
	 * @param deploymentId deployment information for the process's kjar
	 * @param processId The process's identifier 
	 * @param params process variables
	 * @return process instance identifier
	 * @throws RuntimeException in case of encountered errors
	 * @throws DeploymentNotFoundException in case deployment with given deployment id does not exist or is not active
	 */
    Long startProcess(String deploymentId, String processId, Map<String, Object> params);

    /**
	 * Aborts the specified process
	 * 
	 * @param processInstanceId process instance's unique identifier
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void abortProcessInstance(Long processInstanceId);
    
    /**
	 * Aborts all specified processes
	 * 
	 * @param processInstanceIds list of process instance unique identifiers
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void abortProcessInstances(List<Long> processInstanceIds);

    /**
	 * Signal an event to a single process instance
	 * 
	 * @param processInstanceId the process instance's unique identifier
	 * @param signalName the signal's id in the process
	 * @param event the event object to be passed in with the event
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void signalProcessInstance(Long processInstanceId, String signalName, Object event);
    
    /**
	 * Signal an event to given list of process instances
	 * 
	 * @param processInstanceIds list of process instance unique identifiers
	 * @param signalName the signal's id in the process
	 * @param event the event object to be passed in with the event
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void signalProcessInstances(List<Long> processInstanceIds, String signalName, Object event);
    
    /**
	 * Returns process instance information. Will return null if no
	 * active process with that id is found
	 * 
	 * @param processInstanceId The process instance's unique identifier
	 * @return Process instance information
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 */
    ProcessInstance getProcessInstance(Long processInstanceId);

    /**
	 * Sets a process variable.
	 * @param processInstanceId The process instance's unique identifier.
	 * @param variableName The variable name to set.
	 * @param variable The variable value.
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void setProcessVariable(Long processInstanceId, String variableId, Object value);
    
    /**
	 * Sets process variables.
	 * @param processInstanceId The process instance's unique identifier.
	 * @param variables map of process variables (key - variable name, value - variable value)
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	 */
    void setProcessVariables(Long processInstanceId, Map<String, Object> variables);
    
    /**
	 * Gets a process instance's variable.
	 * @param processInstanceId the process instance's unique identifier.
	 * @param variableName the variable name to get from the process.
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	*/
    Object getProcessInstanceVariable(Long processInstanceId, String variableName);

	/**
	 * Gets a process instance's variable values.
	 * @param processInstanceId The process instance's unique identifier.
	 * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
	*/
	Map<String, Object> getProcessInstanceVariables(Long processInstanceId);

	/**
	 * Returns all signals available in current state of given process instance
	 * @param processInstanceId process instance id
	 * @return list of available signals or empty list if no signals are available
	 */
    Collection<String> getAvailableSignals(Long processInstanceId);
    
	/**
	 * Completes the specified WorkItem with the given results
	 * 
	 * @param id workItem id
	 * @param results results of the workItem
	 * @throws DeploymentNotFoundException in case deployment unit was not found
     * @throws WorkItemNotFoundException in case work item with given id was not found
	 */
    void completeWorkItem(Long id, Map<String, Object> results);

    /**
     * Abort the specified workItem
     * 
     * @param id workItem id
     * @throws DeploymentNotFoundException in case deployment unit was not found
     * @throws WorkItemNotFoundException in case work item with given id was not found
     */
    void abortWorkItem(Long id);
    
    /**
     * Returns the specified workItem
     * 
     * @param id workItem id
     * @return The specified workItem
     * @throws DeploymentNotFoundException in case deployment unit was not found
     * @throws WorkItemNotFoundException in case work item with given id was not found
     */
    WorkItem getWorkItem(Long id);

    /**
     * Returns active work items by process instance id.
     * 
     * @param processInstanceId process instance id
     * @return The list of active workItems for the process instance
     * @throws DeploymentNotFoundException in case deployment unit was not found
	 * @throws ProcessInstanceNotFoundException in case process instance with given id was not found
     */
    List<WorkItem> getWorkItemByProcessInstance(Long processInstanceId);
    
    
    /**
     * Executes provided command on the underlying command executor (usually KieSession)
     * @param deploymentId deployment information for the process's kjar
     * @param command actual command for execution
     * @return results of command execution
     * @throws DeploymentNotFoundException in case deployment with given deployment id does not exist 
     * or is not active for restricted commands (e.g. start process)
     */
    public <T> T execute(String deploymentId, Command<T> command);
    
    /**
     * Executes provided command on the underlying command executor (usually KieSession)
     * @param deploymentId deployment information for the process's kjar
     * @param context context implementation to be used to get runtime engine
     * @param command actual command for execution
     * @return results of command execution
     * @throws DeploymentNotFoundException in case deployment with given deployment id does not exist 
     * or is not active for restricted commands (e.g. start process)
     */
    public <T> T execute(String deploymentId, Context<?> context, Command<T> command);

}
