/**
 * Copyright (C) 2009 Scalable Solutions.
 */

package se.scalablesolutions.akka.kernel.state

import java.io.{File, Flushable, Closeable}

import kernel.util.Logging
import serialization.{Serializer, Serializable, SerializationProtocol}

import org.apache.cassandra.config.DatabaseDescriptor
import org.apache.cassandra.service._

//import org.apache.thrift.server.TThreadPoolServer
import org.apache.thrift.TProcessorFactory
import org.apache.thrift.transport._
import org.apache.thrift._
import org.apache.thrift.transport._
import org.apache.thrift.protocol._

/**
 * NOTE: requires command line options:
 * <br/>
 *   <code>-Dcassandra -Dstorage-config=config/ -Dpidfile=akka.pid</code>
 * <p/>
 * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
 */
object CassandraStorage extends Logging {
  val TABLE_NAME = "akka"
  val MAP_COLUMN_FAMILY = "map"
  val VECTOR_COLUMN_FAMILY = "vector"
  val REF_COLUMN_FAMILY = "ref:item"

  val IS_ASCENDING = true

  import kernel.Kernel.config

  val CASSANDRA_SERVER_HOSTNAME = config.getString("akka.storage.cassandra.hostname", "localhost")
  val CASSANDRA_SERVER_PORT = config.getInt("akka.storage.cassandra.port", 9160)
  val BLOCKING_CALL = if (config.getBool("akka.storage.cassandra.blocking", true)) 0
                      else 1 

  @volatile private[this] var isRunning = false
  private[this] val protocol: Protocol = {
    config.getString("akka.storage.cassandra.storage-format", "binary") match {
      case "binary" => Protocol.Binary
      case "json" => Protocol.JSON
      case "simple-json" => Protocol.SimpleJSON
      case unknown => throw new UnsupportedOperationException("Unknown storage serialization protocol [" + unknown + "]")
    }
  }

  
  private[this] var sessions: Option[CassandraSessionPool[_]] = None

  def start = synchronized {
    if (!isRunning) {
      try {
        sessions = Some(new CassandraSessionPool(StackPool(SocketProvider(CASSANDRA_SERVER_HOSTNAME, CASSANDRA_SERVER_PORT)), protocol))
        log.info("Cassandra persistent storage has started up successfully");
      } catch {
        case e =>
          log.error("Could not start up Cassandra persistent storage")
          throw e
      }
      isRunning
    }
  }
 
  def stop = synchronized {
    if (isRunning && sessions.isDefined) sessions.get.close
  }
 
  //implicit def strToBytes(s: String) = s.getBytes("UTF-8")

/*
  def insertRefStorageFor(name: String, element: AnyRef) = sessions.withSession { session => {
    val user_id = "1"
    session ++| ("users", user_id, "base_attributes:name", "Lord Foo Bar", false)
    session ++| ("users", user_id, "base_attributes:age", "24", false)
    for( i <- session / ("users", user_id, "base_attributes", None, None).toList) println(i)
  }}
*/
  // ===============================================================
  // For Ref
  // ===============================================================

  def insertRefStorageFor(name: String, element: String) = if (sessions.isDefined) {
    sessions.get.withSession {
      _ ++| (
        TABLE_NAME,
        name,
        REF_COLUMN_FAMILY,
        element,
        System.currentTimeMillis,
        BLOCKING_CALL)
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getRefStorageFor(name: String): Option[String] = if (sessions.isDefined) {
    try {
      val column = sessions.get.withSession { _ | (TABLE_NAME, name, REF_COLUMN_FAMILY) }
      Some(column.value)
    } catch {
      case e =>
        e.printStackTrace
        None 
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  // ===============================================================
  // For Vector
  // ===============================================================

  def insertVectorStorageEntryFor(name: String, element: String) = if (sessions.isDefined) {
    sessions.get.withSession {
      _ ++| (
        TABLE_NAME,
        name,
        VECTOR_COLUMN_FAMILY + ":" + getVectorStorageSizeFor(name),
        element,
        System.currentTimeMillis,
        BLOCKING_CALL)
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getVectorStorageEntryFor(name: String, index: Int): String = if (sessions.isDefined) {
    try {
      val column = sessions.get.withSession { _ | (TABLE_NAME, name, VECTOR_COLUMN_FAMILY + ":" + index) }
      column.value
    } catch {
      case e =>
        e.printStackTrace
        throw new NoSuchElementException(e.getMessage)
    }  
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getVectorStorageRangeFor(name: String, start: Int, count: Int): List[String] = if (sessions.isDefined) {
    sessions.get.withSession { _ / (TABLE_NAME, name, VECTOR_COLUMN_FAMILY, IS_ASCENDING, count) }.map(_.value) 
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getVectorStorageSizeFor(name: String): Int = if (sessions.isDefined) {
    sessions.get.withSession { _ |# (TABLE_NAME, name, VECTOR_COLUMN_FAMILY) }
  } else throw new IllegalStateException("CassandraStorage is not started")

  // ===============================================================
  // For Map
  // ===============================================================

  def insertMapStorageEntryFor(name: String, key: String, value: String) = if (sessions.isDefined) {
    sessions.get.withSession {
      _ ++| (
        TABLE_NAME, 
        name,
        MAP_COLUMN_FAMILY + ":" + key,
        value,
        System.currentTimeMillis,
        BLOCKING_CALL)
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def insertMapStorageEntriesFor(name: String, entries: List[Tuple2[String, String]]) = if (sessions.isDefined) {
    import java.util.{Map, HashMap, List, ArrayList}
    val columns: Map[String, List[column_t]] = new HashMap
    for (entry <- entries) {
      val cls: List[column_t] = new ArrayList
      cls.add(new column_t(entry._1, entry._2, System.currentTimeMillis))
      columns.put(MAP_COLUMN_FAMILY, cls)
    }
    sessions.get.withSession {
      _ ++| (
        new batch_mutation_t(
          TABLE_NAME, 
          name,
          columns),
        BLOCKING_CALL)
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getMapStorageEntryFor(name: String, key: String): Option[String] = if (sessions.isDefined) {
    try {
      val column = sessions.get.withSession { _ | (TABLE_NAME, name, MAP_COLUMN_FAMILY + ":" + key) }
      Some(column.value)
    } catch {
      case e =>
        e.printStackTrace
        None
    }
  } else throw new IllegalStateException("CassandraStorage is not started")

  /*
  def getMapStorageFor(name: String): List[Tuple2[String, String]]  = if (sessions.isDefined) {
    val columns = server.get_columns_since(TABLE_NAME, name, MAP_COLUMN_FAMILY, -1)
      .toArray.toList.asInstanceOf[List[org.apache.cassandra.service.column_t]]
    for {
      column <- columns
      col = (column.columnName, column.value)
    } yield col
  } else throw new IllegalStateException("CassandraStorage is not started")
  */

  def getMapStorageSizeFor(name: String): Int = if (sessions.isDefined) {
    sessions.get.withSession { _ |# (TABLE_NAME, name, MAP_COLUMN_FAMILY) }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def removeMapStorageFor(name: String) = if (sessions.isDefined) {
    sessions.get.withSession { _ -- (TABLE_NAME, name, MAP_COLUMN_FAMILY, System.currentTimeMillis, BLOCKING_CALL) }
  } else throw new IllegalStateException("CassandraStorage is not started")

  def getMapStorageRangeFor(name: String, start: Int, count: Int): List[Tuple2[String, String]] = if (sessions.isDefined) {
    sessions.get.withSession { _ / (TABLE_NAME, name, MAP_COLUMN_FAMILY, IS_ASCENDING, count) }.toArray.toList.asInstanceOf[List[Tuple2[String, String]]]
  } else throw new IllegalStateException("CassandraStorage is not started")
}

trait CassandraSession extends Closeable with Flushable {
  import scala.collection.jcl.Conversions._
  import org.scala_tools.javautils.Imports._

  private implicit def null2Option[T](t: T): Option[T] = if(t != null) Some(t) else None

  protected val client: Cassandra.Client

  val obtainedAt: Long
    
  def /(tableName: String, key: String, columnParent: String, start: Option[Int],end: Option[Int]): List[column_t] =
    client.get_slice(tableName, key, columnParent, start.getOrElse(-1),end.getOrElse(-1)).toList
  
  def /(tableName: String, key: String, columnParent: String, colNames: List[String]): List[column_t] = 
    client.get_slice_by_names(tableName, key, columnParent, colNames.asJava ).toList

  def |(tableName: String, key: String, colPath: String): Option[column_t] =
    client.get_column(tableName, key, colPath)
  
  def |#(tableName: String, key: String, columnParent: String): Int =
    client.get_column_count(tableName, key, columnParent)
  
  def ++|(tableName: String, key: String, columnPath: String, cellData: Array[Byte], timestamp: Long, block: Int) =
    client.insert(tableName, key, columnPath, cellData,timestamp,block)
  
  def ++|(tableName: String, key: String, columnPath: String, cellData: Array[Byte], block: Int) =
    client.insert(tableName,key,columnPath,cellData,obtainedAt,block)
  
  def ++|(batch: batch_mutation_t, block: Int) =
    client.batch_insert(batch, block)
  
  def --(tableName: String, key: String, columnPathOrParent: String, timestamp: Long, block: Int) =
    client.remove(tableName, key, columnPathOrParent, timestamp, block)
  
  def --(tableName: String, key: String, columnPathOrParent: String, block: Int) =
    client.remove(tableName, key, columnPathOrParent, obtainedAt, block)
  
  def /@(tableName: String, key: String, columnParent: String, timestamp: Long): List[column_t] =
    client.get_columns_since(tableName, key, columnParent, timestamp).toList
  
  def /^(tableName: String, key: String, columnFamily: String, start: Option[Int], end: Option[Int], count: Int ): List[superColumn_t] =
    client.get_slice_super(tableName, key,columnFamily, start.getOrElse(-1), end.getOrElse(-1)).toList //TODO upgrade thrift interface to support count

  def /^(tableName: String, key: String, columnFamily: String, superColNames: List[String]): List[superColumn_t] =
    client.get_slice_super_by_names(tableName, key, columnFamily, superColNames.asJava).toList

  def |^(tableName: String, key: String, superColumnPath: String): Option[superColumn_t] =
    client.get_superColumn(tableName,key,superColumnPath)

  def ++|^ (batch: batch_mutation_super_t, block: Int) =
    client.batch_insert_superColumn(batch, block)

  def keys(tableName: String, startsWith: String, stopsAt: String, maxResults: Option[Int]): List[String] =
    client.get_key_range(tableName, startsWith, stopsAt, maxResults.getOrElse(-1)).toList
  
  def property(name: String): String = client.getStringProperty(name)
  def properties(name: String): List[String] = client.getStringListProperty(name).toList
  def describeTable(tableName: String) = client.describeTable(tableName)
  
  def ?(query: String) = client.executeQuery(query)
}

class CassandraSessionPool[T <: TTransport](transportPool: Pool[T], inputProtocol: Protocol, outputProtocol: Protocol) extends Closeable {
  def this(transportPool: Pool[T], ioProtocol: Protocol) = this(transportPool,ioProtocol,ioProtocol)
    
  def newSession: CassandraSession = {
    val t = transportPool.borrowObject
    val c = new Cassandra.Client(inputProtocol(t),outputProtocol(t))
    new CassandraSession {
      val client = c
      val obtainedAt = System.currentTimeMillis
      def flush = t.flush
      def close = transportPool.returnObject(t)
    }
  }

  def withSession[R](body: CassandraSession => R) = {
    val session = newSession
    try {
      val result = body(session)
      session.flush
      result
    } finally {
      session.close
    }
  }
  
  def close = transportPool.close
}

sealed abstract class Protocol(val factory: TProtocolFactory) {
  def apply(transport: TTransport) = factory.getProtocol(transport)
}

object Protocol {
  object Binary extends Protocol(new TBinaryProtocol.Factory)
  object SimpleJSON extends Protocol(new TSimpleJSONProtocol.Factory)
  object JSON extends Protocol(new TJSONProtocol.Factory)
}

/**
 * NOTE: requires command line options:
 * <br/>
 *   <code>-Dcassandra -Dstorage-config=config/ -Dpidfile=akka.pid</code>
 * <p/>
 * @author <a href="http://jonasboner.com">Jonas Bon&#233;r</a>
 *
object EmbeddedCassandraStorage extends Logging {
  val TABLE_NAME = "akka"
  val MAP_COLUMN_FAMILY = "map"
  val VECTOR_COLUMN_FAMILY = "vector"
  val REF_COLUMN_FAMILY = "ref:item"

  val IS_ASCENDING = true

  val RUN_THRIFT_SERVICE = kernel.Kernel.config.getBool("akka.storage.cassandra.thrift-server.service", false)
  val BLOCKING_CALL = {
     if (kernel.Kernel.config.getBool("akka.storage.cassandra.blocking", true)) 0
     else 1 
  }

  @volatile private[this] var isRunning = false
  private[this] val serializer: Serializer = {
    kernel.Kernel.config.getString("akka.storage.cassandra.storage-format", "java") match {
      case "scala-json" => Serializer.ScalaJSON
      case "java-json" =>  Serializer.JavaJSON
      case "protobuf" =>   Serializer.Protobuf
      case "java" =>       Serializer.Java
      case "sbinary" =>    throw new UnsupportedOperationException("SBinary serialization protocol is not yet supported for storage")
      case "avro" =>       throw new UnsupportedOperationException("Avro serialization protocol is not yet supported for storage")
      case unknown =>      throw new UnsupportedOperationException("Unknown storage serialization protocol [" + unknown + "]")
    }
  }
 
  // TODO: is this server thread-safe or needed to be wrapped up in an actor?
  private[this] val server = classOf[CassandraServer].newInstance.asInstanceOf[CassandraServer]

  private[this] var thriftServer: CassandraThriftServer = _
  
  def start = synchronized {
    if (!isRunning) {
      try {
        server.start
        log.info("Cassandra persistent storage has started up successfully");
      } catch {
        case e =>
          log.error("Could not start up Cassandra persistent storage")
          throw e
      }
      if (RUN_THRIFT_SERVICE) {
        thriftServer = new CassandraThriftServer(server)
        thriftServer.start
      }
      isRunning
    }
  }

  def stop = if (isRunning) {
    //server.storageService.shutdown
    if (RUN_THRIFT_SERVICE) thriftServer.stop
  }

  // ===============================================================
  // For Ref
  // ===============================================================

  def insertRefStorageFor(name: String, element: AnyRef) = {
    server.insert(
      TABLE_NAME,
      name,
      REF_COLUMN_FAMILY,
      element,
      System.currentTimeMillis,
      BLOCKING_CALL)
  }

  def getRefStorageFor(name: String): Option[AnyRef] = {
    try {
      val column = server.get_column(TABLE_NAME, name, REF_COLUMN_FAMILY)
      Some(serializer.in(column.value, None))
    } catch {
      case e =>
        e.printStackTrace
        None 
    }
  }

  // ===============================================================
  // For Vector
  // ===============================================================

  def insertVectorStorageEntryFor(name: String, element: AnyRef) = {
    server.insert(
      TABLE_NAME,
      name,
      VECTOR_COLUMN_FAMILY + ":" + getVectorStorageSizeFor(name),
      element,
      System.currentTimeMillis,
      BLOCKING_CALL)
  }

  def getVectorStorageEntryFor(name: String, index: Int): AnyRef = {                                                                                
    try {
      val column = server.get_column(TABLE_NAME, name, VECTOR_COLUMN_FAMILY + ":" + index)
      serializer.in(column.value, None)
    } catch {
      case e =>
        e.printStackTrace
        throw new Predef.NoSuchElementException(e.getMessage)
    }  
  }

  def getVectorStorageRangeFor(name: String, start: Int, count: Int): List[AnyRef]  =
    server.get_slice(TABLE_NAME, name, VECTOR_COLUMN_FAMILY, IS_ASCENDING, count)
      .toArray.toList.asInstanceOf[List[Tuple2[String, AnyRef]]].map(tuple => tuple._2)

  def getVectorStorageSizeFor(name: String): Int =
    server.get_column_count(TABLE_NAME, name, VECTOR_COLUMN_FAMILY)

  // ===============================================================
  // For Map
  // ===============================================================

  def insertMapStorageEntryFor(name: String, key: String, value: AnyRef) = {
    server.insert(
      TABLE_NAME, 
      name,
      MAP_COLUMN_FAMILY + ":" + key,
      serializer.out(value),
      System.currentTimeMillis,
      BLOCKING_CALL)
  }

  def insertMapStorageEntriesFor(name: String, entries: List[Tuple2[String, AnyRef]]) = {
    import java.util.{Map, HashMap, List, ArrayList}
    val columns: Map[String, List[column_t]] = new HashMap
    for (entry <- entries) {
      val cls: List[column_t] = new ArrayList
      cls.add(new column_t(entry._1, serializer.out(entry._2), System.currentTimeMillis))
      columns.put(MAP_COLUMN_FAMILY, cls)
    }
    server.batch_insert(new batch_mutation_t(
      TABLE_NAME, 
      name,
      columns),
      BLOCKING_CALL)
  }

  def getMapStorageEntryFor(name: String, key: AnyRef): Option[AnyRef] = {
    try {
      val column = server.get_column(TABLE_NAME, name, MAP_COLUMN_FAMILY + ":" + key)
      Some(serializer.in(column.value, None))
    } catch {
      case e =>
        e.printStackTrace
        None
    }
  }

  def getMapStorageFor(name: String): List[Tuple2[String, AnyRef]]  = {
    val columns = server.get_columns_since(TABLE_NAME, name, MAP_COLUMN_FAMILY, -1)
      .toArray.toList.asInstanceOf[List[org.apache.cassandra.service.column_t]]
    for {
      column <- columns
      col = (column.columnName, serializer.in(column.value, None))
    } yield col
  }
  
  def getMapStorageSizeFor(name: String): Int =
    server.get_column_count(TABLE_NAME, name, MAP_COLUMN_FAMILY)

  def removeMapStorageFor(name: String) =
    server.remove(TABLE_NAME, name, MAP_COLUMN_FAMILY, System.currentTimeMillis, BLOCKING_CALL)

  def getMapStorageRangeFor(name: String, start: Int, count: Int): List[Tuple2[String, AnyRef]] = {
    server.get_slice(TABLE_NAME, name, MAP_COLUMN_FAMILY, IS_ASCENDING, count)
            .toArray.toList.asInstanceOf[List[Tuple2[String, AnyRef]]]
  }
}


class CassandraThriftServer(server: CassandraServer) extends Logging {
  case object Start
  case object Stop

  private[this] val serverEngine: TThreadPoolServer = try {
    val pidFile = kernel.Kernel.config.getString("akka.storage.cassandra.thrift-server.pidfile", "akka.pid")
    if (pidFile != null) new File(pidFile).deleteOnExit();
    val listenPort = DatabaseDescriptor.getThriftPort

    val processor = new Cassandra.Processor(server)
    val tServerSocket = new TServerSocket(listenPort)
    val tProtocolFactory = new TBinaryProtocol.Factory

    val options = new TThreadPoolServer.Options
    options.minWorkerThreads = 64
    new TThreadPoolServer(new TProcessorFactory(processor),
      tServerSocket,
      new TTransportFactory,
      new TTransportFactory,
      tProtocolFactory,
      tProtocolFactory,
      options)
  } catch {
    case e =>
      log.error("Could not start up Cassandra thrift service")
      throw e
  }

  import scala.actors.Actor._
  private[this] val serverDaemon = actor {
    receive {
     case Start =>
        serverEngine.serve
        log.info("Cassandra thrift service has starting up successfully")
     case Stop =>
        log.info("Cassandra thrift service is shutting down...")
        serverEngine.stop
    }
  }

  def start = serverDaemon ! Start
  def stop = serverDaemon ! Stop
}
*/