/* 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.activiti.engine.impl.cmd;

import java.io.InputStream;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiObjectNotFoundException;
import org.activiti.engine.delegate.event.impl.ActivitiEventBuilder;
import org.activiti.engine.impl.db.DbSqlSession;
import org.activiti.engine.impl.identity.Authentication;
import org.activiti.engine.impl.interceptor.Command;
import org.activiti.engine.impl.interceptor.CommandContext;
import org.activiti.engine.impl.persistence.entity.AttachmentEntity;
import org.activiti.engine.impl.persistence.entity.ByteArrayEntity;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.persistence.entity.TaskEntity;
import org.activiti.engine.impl.util.IoUtil;
import org.activiti.engine.runtime.ProcessInstance;
import org.activiti.engine.task.Attachment;
import org.activiti.engine.task.Task;
import org.flowable.common.engine.api.delegate.event.FlowableEngineEventType;

/**
 * @author Tom Baeyens
 * @author Joram Barrez
 */
// Not Serializable
public class CreateAttachmentCmd implements Command<Attachment> {

    protected String attachmentType;
    protected String taskId;
    protected String processInstanceId;
    protected String attachmentName;
    protected String attachmentDescription;
    protected InputStream content;
    protected String url;

    public CreateAttachmentCmd(String attachmentType, String taskId, String processInstanceId, String attachmentName, String attachmentDescription, InputStream content, String url) {
        this.attachmentType = attachmentType;
        this.taskId = taskId;
        this.processInstanceId = processInstanceId;
        this.attachmentName = attachmentName;
        this.attachmentDescription = attachmentDescription;
        this.content = content;
        this.url = url;
    }

    @Override
    public Attachment execute(CommandContext commandContext) {

        verifyParameters(commandContext);

        AttachmentEntity attachment = new AttachmentEntity();
        attachment.setName(attachmentName);
        attachment.setDescription(attachmentDescription);
        attachment.setType(attachmentType);
        attachment.setTaskId(taskId);
        attachment.setProcessInstanceId(processInstanceId);
        attachment.setUrl(url);
        attachment.setUserId(Authentication.getAuthenticatedUserId());
        attachment.setTime(commandContext.getProcessEngineConfiguration().getClock().getCurrentTime());

        DbSqlSession dbSqlSession = commandContext.getDbSqlSession();
        dbSqlSession.insert(attachment);

        if (content != null) {
            byte[] bytes = IoUtil.readInputStream(content, attachmentName);
            ByteArrayEntity byteArray = ByteArrayEntity.createAndInsert(bytes);
            attachment.setContentId(byteArray.getId());
            attachment.setContent(byteArray);
        }

        commandContext.getHistoryManager()
                .createAttachmentComment(taskId, processInstanceId, attachmentName, true);

        if (commandContext.getProcessEngineConfiguration().getEventDispatcher().isEnabled()) {
            // Forced to fetch the process-instance to associate the right process definition
            String processDefinitionId = null;
            if (attachment.getProcessInstanceId() != null) {
                ExecutionEntity process = commandContext.getExecutionEntityManager().findExecutionById(processInstanceId);
                if (process != null) {
                    processDefinitionId = process.getProcessDefinitionId();
                }
            }

            commandContext.getProcessEngineConfiguration().getEventDispatcher().dispatchEvent(
                    ActivitiEventBuilder.createEntityEvent(FlowableEngineEventType.ENTITY_CREATED, attachment, processInstanceId, processInstanceId, processDefinitionId));
            commandContext.getProcessEngineConfiguration().getEventDispatcher().dispatchEvent(
                    ActivitiEventBuilder.createEntityEvent(FlowableEngineEventType.ENTITY_INITIALIZED, attachment, processInstanceId, processInstanceId, processDefinitionId));
        }

        return attachment;
    }

    private void verifyParameters(CommandContext commandContext) {
        if (taskId != null) {
            TaskEntity task = commandContext.getTaskEntityManager().findTaskById(taskId);

            if (task == null) {
                throw new ActivitiObjectNotFoundException("Cannot find task with id " + taskId, Task.class);
            }

            if (task.isSuspended()) {
                throw new ActivitiException("It is not allowed to add an attachment to a suspended task");
            }
        }

        if (processInstanceId != null) {
            ExecutionEntity execution = commandContext.getExecutionEntityManager().findExecutionById(processInstanceId);

            if (execution == null) {
                throw new ActivitiObjectNotFoundException("Process instance " + processInstanceId + " doesn't exist", ProcessInstance.class);
            }

            if (execution.isSuspended()) {
                throw new ActivitiException("It is not allowed to add an attachment to a suspended process instance");
            }
        }
    }

}