MySQLClusterState

package com.klout.api.models

import com.klout.playful2.sugar.config

/**
* A status for a MySQL node
*/
sealed trait MySQLNodeStatus

/**
* MySQL is up!
*/
case object MySQLUp extends MySQLNodeStatus

/**
* MySQL is down! Ops!
*/
case object MySQLDown extends MySQLNodeStatus

/**
* MySQL is up but f'ed up!
*/
case object MySQLDegraded extends MySQLNodeStatus

/**
* This is the class used to identify the current state of the MySQL cluster used through Akka
*
* @author Felipe Oliveira [@_felipera]
*/
case class MySQLClusterState(nodes: Map[String, MySQLNodeStatus], overrideNodes: Option[List[String]]) {

   /**
    * Define a new state taking in consideration this update
    */
   def withNodeUpdate(db: String, status: MySQLNodeStatus): MySQLClusterState = {
       this copy (nodes = nodes ++ Map(db -> status))
   }

   /**
    * Define a new state taking in consideration an update to the list of override nodes
    */
   def withOverrideNodes(overrideNodes: Option[String]): MySQLClusterState = overrideNodes match {
       case Some(value) => this copy (overrideNodes = Option(value.split(",").toList))
       case _           => this copy (overrideNodes = None)
   }

   /**
    * Get a list of healthy MySQL nodes
    */
   def getHealthyNodes: List[String] = nodes.filter(_._2 == MySQLUp).keys.toList

   /**
    * Get Current State
    */
   def currentState: Map[String, Any] = {
       val list = nodes map { node =>
           (node._1, node._2.toString)
       }
       Map("nodes" -> list, "overrideNodes" -> overrideNodes.getOrElse(List()))
   }

}

/**
* Companion for the cluster state class defined above
*
* @author Felipe Oliveira [@_felipera]
*/
object MySQLClusterState {

   /**
    * Return the list of all possible MySQL nodes in the cluster
    */
   lazy val allNodes: List[String] = (config string "slave.dbs" !) split "," toList

}