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/*
* Copyright 2017 47 Degrees, LLC. <http://www.47deg.com>
*
* 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 freestyle.cassandra.sample
import java.util.UUID
import cats.instances.future._
import com.datastax.driver.core.{BoundStatement, PreparedStatement, Session}
import freestyle._
import freestyle.implicits._
import freestyle.cassandra.implicits._
import freestyle.cassandra.api.ClusterAPI
import freestyle.cassandra.codecs._
import freestyle.asyncCatsEffect.implicits._
import freestyle.cassandra.sample.Implicits._
import freestyle.cassandra.sample.Model._
import freestyle.loggingJVM.implicits._
import monix.eval.Task
import monix.execution.Scheduler
import scala.concurrent.Await
import scala.concurrent.duration.Duration
object LowLevelApi extends App {
import Modules.CassandraApp
def connect[F[_]](implicit clusterAPI: ClusterAPI[F]): FreeS[F, Session] =
clusterAPI.connectKeyspace("demodb")
def program[F[_]](implicit app: CassandraApp[F]): FreeS[F, User] = {
import app._
import app.queryModule._
val newUser = User(UUID.randomUUID(), "Username")
def bindValues(st: PreparedStatement)(
implicit c1: ByteBufferCodec[UUID],
c2: ByteBufferCodec[String]): FreeS[F, BoundStatement] =
List(
statementAPI.setValueByName(_: BoundStatement, "id", newUser.id, c1),
statementAPI.setValueByName(_: BoundStatement, "name", newUser.name, c2))
.foldLeft[FreeS[F, BoundStatement]](statementAPI.bind(st)) { (freeS, func) =>
freeS.flatMap(boundSt => func(boundSt))
}
for {
_ <- log.debug("# Preparing insert query")
preparedStatement <- sessionAPI.prepare("INSERT INTO users (id, name) VALUES (?, ?)")
_ <- log.debug("# Binding values")
boundStatement <- bindValues(preparedStatement)
_ <- log.debug(s"# Executing insert query with id ${newUser.id}")
_ <- sessionAPI.executeStatement(boundStatement)
_ <- log.debug("# Selecting previous inserted item")
user <- sessionAPI.executeWithMap(
s"SELECT id, name FROM users WHERE id = ?",
Map("id" -> newUser.id)) map { rs =>
val row = rs.one()
User(row.getUUID(0), row.getString(1))
}
_ <- log.debug(s"# Fetched item $user")
_ <- log.debug(s"# Closing connection")
_ <- sessionAPI.close
} yield user
}
def close[F[_]](implicit clusterAPI: ClusterAPI[F]): FreeS[F, Unit] = clusterAPI.close
implicit val executionContext: Scheduler = Scheduler.Implicits.global
val beforeTask: Task[Session] = connect[ClusterAPI.Op].interpret[Task]
implicit val session: Session = Await.result(beforeTask.runAsync, Duration.Inf)
val task: Task[User] = program[CassandraApp.Op].interpret[Task]
Await.result(task.runAsync, Duration.Inf)
val afterTask: Task[Unit] = close[ClusterAPI.Op].interpret[Task]
Await.result(afterTask.runAsync, Duration.Inf)
}