/*
    * Licensed to The Apereo Foundation under one or more contributor license
    * agreements. See the NOTICE file distributed with this work for additional
    * information regarding copyright ownership.
    *
    *
    * The Apereo Foundation licenses this file to you 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://opensource.org/licenses/ecl2.txt
   *
   * 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.opencastproject.workflow.api;
  
  import java.util.Collections;
  import java.util.Date;
  import java.util.Map;
  import java.util.Objects;
  import java.util.Set;
  import java.util.TreeMap;
  
  import javax.persistence.Access;
  import javax.persistence.AccessType;
  import javax.persistence.CollectionTable;
  import javax.persistence.Column;
  import javax.persistence.ElementCollection;
  import javax.persistence.Entity;
  import javax.persistence.FetchType;
  import javax.persistence.GeneratedValue;
  import javax.persistence.Id;
  import javax.persistence.Index;
  import javax.persistence.JoinColumn;
  import javax.persistence.Lob;
  import javax.persistence.ManyToOne;
  import javax.persistence.MapKeyColumn;
  import javax.persistence.Table;
  import javax.persistence.Temporal;
  import javax.persistence.TemporalType;
  
  /**
   * A workflow operation belonging to a workflow instance.
   */
  @Entity(name = "WorkflowOperationInstance")
  @Access(AccessType.FIELD)
  @Table(name = "oc_workflow_operation", indexes = {
      @Index(name = "IX_oc_workflow_operation_workflow_id", columnList = ("workflow_id"))})
  public class WorkflowOperationInstance implements Configurable {
    public enum OperationState {
      INSTANTIATED, RUNNING, PAUSED, SUCCEEDED, FAILED, SKIPPED, RETRY
    }
  
    @Id
    @GeneratedValue
    @Column(name = "id")
    private Long id;
  
    @Column(name = "template")
    protected String template;
  
    @Column(name = "job")
    protected Long jobId;
  
    @Column(name = "state")
    protected OperationState state;
  
    @Column(name = "description")
    @Lob
    protected String description;
  
    @ElementCollection
    @CollectionTable(
            name = "oc_workflow_operation_configuration",
            joinColumns = @JoinColumn(name = "workflow_operation_id"),
            indexes = {
                  @Index(name = "IX_oc_workflow_operation_configuration_workflow_operation_id",
                      columnList = ("workflow_operation_id")),
            }
    )
    @MapKeyColumn(name = "configuration_key", nullable = false)
    @Lob
    @Column(name = "configuration_value")
    protected Map<String, String> configurations;
  
    @Column(name = "fail_on_error")
    protected boolean failOnError;
  
    @Column(name = "if_condition")
    @Lob
    protected String executeCondition;
  
   @Column(name = "exception_handler_workflow")
   protected String exceptionHandlingWorkflow;
 
   @Column(name = "abortable")
   protected Boolean abortable;
 
   @Column(name = "continuable")
   protected Boolean continuable;
 
   @Column(name = "started")
   @Temporal(TemporalType.TIMESTAMP)
   protected Date dateStarted;
 
   @Column(name = "completed")
   @Temporal(TemporalType.TIMESTAMP)
   protected Date dateCompleted;
 
   @Column(name = "time_in_queue")
   protected Long timeInQueue;
 
   @Column(name = "max_attempts")
   protected int maxAttempts;
 
   @Column(name = "failed_attempts")
   protected int failedAttempts;
 
   @Column(name = "execution_host")
   protected String executionHost;
 
   @Column(name = "retry_strategy", length = 128)
   protected RetryStrategy retryStrategy;
 
   @ManyToOne(fetch = FetchType.LAZY)
   @JoinColumn(name = "workflow_id", nullable = false)
   private WorkflowInstance instance;
 
   /**
    * No-arg constructor needed for JAXB serialization
    */
   public WorkflowOperationInstance() {
     this.maxAttempts = 1;
     this.retryStrategy = RetryStrategy.NONE;
   }
 
   /**
    * Builds a new workflow operation instance based on another workflow operation.
    *
    * @param def
    *          the workflow definition
    */
   public WorkflowOperationInstance(WorkflowOperationDefinition def) {
     this();
     setTemplate(def.getId());
     setState(OperationState.INSTANTIATED);
     setDescription(def.getDescription());
     setMaxAttempts(def.getMaxAttempts());
     setFailOnError(def.isFailWorkflowOnException());
     setExceptionHandlingWorkflow(def.getExceptionHandlingWorkflow());
     setExecutionCondition(def.getExecutionCondition());
     setRetryStrategy(def.getRetryStrategy());
     Set<String> defConfigs = def.getConfigurationKeys();
     this.configurations = new TreeMap<>();
     if (defConfigs != null) {
       for (String key : defConfigs) {
         configurations.put(key, def.getConfiguration(key));
       }
     }
 
     if ((retryStrategy == RetryStrategy.RETRY || retryStrategy == RetryStrategy.HOLD) && maxAttempts < 2) {
       maxAttempts = 2;
     }
   }
 
   /**
    * Constructs a new operation instance with the given id and initial state.
    *
    * @param id
    *          the operation id
    * @param state
    *          the state
    */
   public WorkflowOperationInstance(String id, OperationState state) {
     this();
     setTemplate(id);
     setState(state);
   }
 
   public WorkflowOperationInstance(
           String template,
           Long jobId,
           OperationState state,
           String description,
           Map<String, String> configurations,
           boolean failOnError,
           String executeCondition,
           String exceptionHandlingWorkflow,
           Boolean abortable,
           Boolean continuable,
           Date dateStarted,
           Date dateCompleted,
           Long timeInQueue,
           int maxAttempts,
           int failedAttempts,
           String executionHost,
           RetryStrategy retryStrategy) {
     this.template = template;
     this.jobId = jobId;
     this.state = state;
     this.description = description;
     this.configurations = configurations;
     this.failOnError = failOnError;
     this.executeCondition = executeCondition;
     this.exceptionHandlingWorkflow = exceptionHandlingWorkflow;
     this.abortable = abortable;
     this.continuable = continuable;
     this.dateStarted = dateStarted;
     this.dateCompleted = dateCompleted;
     this.timeInQueue = timeInQueue;
     this.maxAttempts = maxAttempts;
     this.failedAttempts = failedAttempts;
     this.executionHost = executionHost;
     this.retryStrategy = retryStrategy;
   }
 
   /**
    * Sets the template
    *
    * @param template
    *          the template
    */
   public void setTemplate(String template) {
     this.template = template;
   }
 
   /**
    * Gets the operation type.
    *
    * @return the operation type
    */
   public String getTemplate() {
     return template;
   }
 
   /**
    * Gets the unique identifier for this operation, or null.
    *
    * @return the identifier, or null if this operation has not yet run
    */
   public Long getId() {
     return jobId;
   }
 
   /**
    * Sets the unique identifier for this operation.
    *
    * @param jobId
    *          the identifier
    */
   public void setId(Long jobId) {
     this.jobId = jobId;
   }
 
   /**
    * Gets the operation description
    *
    * @return the description
    */
   public String getDescription() {
     return description;
   }
 
   /**
    * Set the operation description.
    *
    * @param description The new description
    */
   public void setDescription(String description) {
     this.description = description;
   }
 
   /**
    * The state of this operation.
    */
   public OperationState getState() {
     return state;
   }
 
   /**
    * Sets the state of this operation
    *
    * @param state
    *          the state to set
    */
   public void setState(OperationState state) {
     Date now = new Date();
     if (OperationState.RUNNING.equals(state)) {
       this.dateStarted = now;
     } else if (OperationState.FAILED.equals(state) || OperationState.SUCCEEDED.equals(state)) {
       this.dateCompleted = now;
     }
     this.state = state;
   }
 
   /**
    * Return configuration of this workflow operation as Map.
    * Guaranteed to be not null
    *
    * @return Configuration map
    */
   public Map<String, String> getConfigurations() {
     return configurations;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowInstance#getConfiguration(java.lang.String)
    */
   @Override
   public String getConfiguration(String key) {
     if (key == null || configurations == null) {
       return null;
     }
     return configurations.get(key);
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowInstance#removeConfiguration(java.lang.String)
    */
   @Override
   public void removeConfiguration(String key) {
     if (key == null || configurations == null) {
       return;
     }
     configurations.remove(key);
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowInstance#setConfiguration(java.lang.String, java.lang.String)
    */
   @Override
   public void setConfiguration(String key, String value) {
     if (key == null) {
       return;
     }
     if (configurations == null) {
       configurations = new TreeMap<>();
     }
 
     configurations.put(key, value);
   }
 
   /**
    * {@inheritDoc}
    *
    * @see org.opencastproject.workflow.api.WorkflowOperationInstance#getConfigurationKeys()
    */
   @Override
   public Set<String> getConfigurationKeys() {
     if (configurations == null) {
       return Collections.emptySet();
     }
     return configurations.keySet();
   }
 
   /** The workflow to run if an exception is thrown while this operation is running. */
   public String getExceptionHandlingWorkflow() {
     return exceptionHandlingWorkflow;
   }
 
   public void setExceptionHandlingWorkflow(String exceptionHandlingWorkflow) {
     this.exceptionHandlingWorkflow = exceptionHandlingWorkflow;
   }
 
   /**
    * If true, this workflow will be put into a failed (or failing, if getExceptionHandlingWorkflow() is not null) state
    * when exceptions are thrown during an operation.
    */
   public boolean isFailOnError() {
     return failOnError;
   }
 
   public void setFailOnError(boolean failOnError) {
     this.failOnError = failOnError;
   }
 
   /**
    * The timestamp this operation started. If the job was queued, this can be significantly later than the date created.
    */
   public Date getDateStarted() {
     return dateStarted;
   }
 
   /** The number of milliseconds this operation waited in a service queue */
   public Long getTimeInQueue() {
     return timeInQueue;
   }
 
   public void setTimeInQueue(long timeInQueue) {
     this.timeInQueue = timeInQueue;
   }
 
   /** The timestamp this operation completed */
   public Date getDateCompleted() {
     return dateCompleted;
   }
 
   /**
    * Returns either <code>null</code> or <code>true</code> to have the operation executed. Any other value is
    * interpreted as <code>false</code> and will skip the operation.
    * <p>
    * Usually, this will be a variable name such as <code>${foo}</code>, which will be replaced with its acutal value
    * once the workflow is executed.
    * <p>
    * If both <code>getExecuteCondition()</code> and <code>getSkipCondition</code> return a non-null value, the execute
    * condition takes precedence.
    *
    * @return the execution condition.
    */
   public String getExecutionCondition() {
     return executeCondition;
   }
 
   public void setExecutionCondition(String condition) {
     this.executeCondition = condition;
   }
 
   /**
    * Returns <code>true</code> if this operation can be continued by the user from an optional hold state. A return
    * value of <code>null</code> indicates that this operation instance does not have a hold state.
    *
    * @return <code>true</code> if this operation instance is continuable
    */
   public Boolean isContinuable() {
     return continuable;
   }
 
   /**
    * Defines whether this operation instance should be continuable from a hold state or whether it is resumed
    * automatically.
    *
    * @param continuable
    *          <code>true</code> to allow the user to resume the operation
    */
   public void setContinuable(Boolean continuable) {
     this.continuable = continuable;
   }
 
   /**
    * Returns <code>true</code> if this operation can be aborted by the user from an optional hold state. If a resumable
    * operation is aborted from its hold state, the workflow is put into
    * {@link org.opencastproject.workflow.api.WorkflowInstance.WorkflowState#STOPPED}. A return value of
    * <code>null</code> indicates that this operation instance does not have a hold state.
    *
    * @return <code>true</code> if this operation instance is abortable
    */
   public Boolean isAbortable() {
     return abortable;
   }
 
   /**
    * Defines whether this operation instance should be abortable from a hold state.
    *
    * @param abortable
    *          <code>true</code> to allow the user to cancel the operation
    */
   public void setAbortable(Boolean abortable) {
     this.abortable = abortable;
   }
 
   /**
    * Return the strategy to use in case of operation failure
    *
    * @return a strategy from {@link org.opencastproject.workflow.api.RetryStrategy}.
    */
   public RetryStrategy getRetryStrategy() {
     return retryStrategy;
   }
 
   private void setRetryStrategy(RetryStrategy retryStrategy) {
     this.retryStrategy = retryStrategy;
   }
 
   /**
    * Returns the number of attempts the workflow service will make to execute this operation.
    *
    * @return the maximum number of retries before failing
    */
   public int getMaxAttempts() {
     return maxAttempts;
   }
 
   /**
    * @param maxAttempts
    *          the maxAttempts to set
    * @throws IllegalArgumentException
    *           if maxAttempts is less than one.
    */
   private void setMaxAttempts(int maxAttempts) {
     if (maxAttempts < 1) {
       throw new IllegalArgumentException("maxAttempts must be >=1");
     }
     this.maxAttempts = maxAttempts;
   }
 
   /**
    * Returns the number of failed executions that have previously been attempted.
    *
    * @return the number of previous attempts
    */
   public int getFailedAttempts() {
     return failedAttempts;
   }
 
   public void setFailedAttempts(int failedAttempts) {
     this.failedAttempts = failedAttempts;
   }
 
   /**
    * Returns the current execution host
    *
    * @return the execution host
    */
   public String getExecutionHost() {
     return executionHost;
   }
 
   /**
    * Sets the current execution host
    *
    * @param executionHost
    *          the execution host
    */
   public void setExecutionHost(String executionHost) {
     this.executionHost = executionHost;
   }
 
   public WorkflowInstance getWorkflowInstance() {
     return instance;
   }
 
   public void setWorkflowInstance(WorkflowInstance instance) {
     this.instance = instance;
   }
 
   @Override
   public int hashCode() {
     return Long.valueOf(id).hashCode();
   }
 
   @Override
   public boolean equals(Object o) {
     if (this == o) {
       return true;
     }
     if (o instanceof WorkflowOperationInstance) {
       WorkflowOperationInstance other = (WorkflowOperationInstance) o;
       return other.getTemplate().equals(this.getTemplate()) && Objects.equals(other.id, this.id);
     }
     return false;
   }
 
   /**
    * {@inheritDoc}
    *
    * @see java.lang.Object#toString()
    */
   @Override
   public String toString() {
     return "operation:'" + template +  ", state:'" + this.state + "'";
   }
 }