/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.apache.openwhisk.core.entity

import java.time.Instant

import spray.json.DefaultJsonProtocol
import org.apache.openwhisk.core.database.DocumentFactory
import spray.json._

/**
 * WhiskTriggerPut is a restricted WhiskTrigger view that eschews properties
 * that are auto-assigned or derived from URI: namespace and name.
 */
case class WhiskTriggerPut(parameters: Option[Parameters] = None,
                           limits: Option[TriggerLimits] = None,
                           version: Option[SemVer] = None,
                           publish: Option[Boolean] = None,
                           annotations: Option[Parameters] = None)

/**
 * Representation of a rule to be stored inside a trigger. Contains all
 * information needed to be able to determine if and which action is to
 * be fired.
 *
 * @param action the fully qualified name of the action to be fired
 * @param status status of the rule
 */
case class ReducedRule(action: FullyQualifiedEntityName, status: Status)

/**
 * A WhiskTrigger provides an abstraction of the meta-data
 * for a whisk trigger.
 *
 * The WhiskTrigger object is used as a helper to adapt objects between
 * the schema used by the database and the WhiskTrigger abstraction.
 *
 * @param namespace the namespace for the trigger
 * @param name the name of the trigger
 * @param parameters the set of parameters to bind to the trigger environment
 * @param limits the limits to impose on the trigger
 * @param version the semantic version
 * @param publish true to share the action or false otherwise
 * @param annotations the set of annotations to attribute to the trigger
 * @param rules the map of the rules that are associated with this trigger. Key is the rulename and value is the ReducedRule
 * @param updated the timestamp when the trigger is updated
 * @throws IllegalArgumentException if any argument is undefined
 */
@throws[IllegalArgumentException]
case class WhiskTrigger(namespace: EntityPath,
                        override val name: EntityName,
                        parameters: Parameters = Parameters(),
                        limits: TriggerLimits = TriggerLimits(),
                        version: SemVer = SemVer(),
                        publish: Boolean = false,
                        annotations: Parameters = Parameters(),
                        rules: Option[Map[FullyQualifiedEntityName, ReducedRule]] = None,
                        override val updated: Instant = WhiskEntity.currentMillis())
    extends WhiskEntity(name, "trigger") {

  require(limits != null, "limits undefined")

  def toJson = WhiskTrigger.serdes.write(this).asJsObject

  def withoutRules = copy(rules = None).revision[WhiskTrigger](rev)

  /**
   * Inserts the rulename, its status and the action to be fired into the trigger.
   *
   * @param rulename The fully qualified name of the rule, that will be fired by this trigger.
   * @param rule The rule, that will be fired by this trigger. It's from type ReducedRule. This type
   * contains the fully qualified name of the action to be fired by the rule and the status of the rule.
   */
  def addRule(rulename: FullyQualifiedEntityName, rule: ReducedRule) = {
    val entry = rulename -> rule
    val links = rules getOrElse Map.empty[FullyQualifiedEntityName, ReducedRule]
    copy(rules = Some(links + entry)).revision[WhiskTrigger](docinfo.rev)
  }

  /**
   * Removes the rule from the trigger.
   *
   * @param rule The fully qualified name of the rule, that should be removed from the
   * trigger. After removing the rule, it won't be fired anymore by this trigger.
   */
  def removeRule(rule: FullyQualifiedEntityName) = {
    copy(rules = rules.map(_ - rule)).revision[WhiskTrigger](docinfo.rev)
  }
}

object ReducedRule extends DefaultJsonProtocol {
  private implicit val fqnSerdes = FullyQualifiedEntityName.serdes
  implicit val serdes = jsonFormat2(ReducedRule.apply)
}

object WhiskTrigger
    extends DocumentFactory[WhiskTrigger]
    with WhiskEntityQueries[WhiskTrigger]
    with DefaultJsonProtocol {
  import WhiskActivation.instantSerdes

  override val collectionName = "triggers"

  private implicit val fqnSerdesAsDocId = FullyQualifiedEntityName.serdesAsDocId
  override implicit val serdes = jsonFormat9(WhiskTrigger.apply)

  override val cacheEnabled = true
}

object WhiskTriggerPut extends DefaultJsonProtocol {
  implicit val serdes = jsonFormat5(WhiskTriggerPut.apply)
}