ExplainSpec.scala

/*
 * Copyright 2014–2016 SlamData Inc.
 *
 * 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 quasar.fs

import quasar.Predef._
import quasar.Variables
import quasar.contrib.pathy.AFile
import quasar.main.FilesystemQueries
import quasar.sql.{Query, fixParser}

import pathy.Path._
import scalaz._
import scalaz.syntax.functor._
import scalaz.syntax.show._

class ExplainSpec
  extends FileSystemTest[FileSystem](
    FileSystemTest.externalFsUT.map(_.map(ut => ut.contramapF(chroot.fileSystem[FileSystem](ut.testDir)))))
  with quasar.sql.CompilerHelpers {

  import FileSystemTest.oneDoc

  val fsq    = new FilesystemQueries[FileSystem]
  val write  = WriteFile.Ops[FileSystem]
  val manage = ManageFile.Ops[FileSystem]

  val dataFile: AFile = rootDir </> dir("explain") </> file("data")
  val dataStr: String = posixCodec.printPath(dataFile)

  def explainQuery(sql: String, fs: FileSystemUT[FileSystem]) =
    s"QUERY: $sql" >> {
      val parsedQuery =
        fixParser.parse(Query(sql))
          .valueOr(err => throw new RuntimeException(err.shows))

      val result =
        fsq.explainQuery(parsedQuery, Variables.empty, rootDir)
          .run.run.run

      fs.testInterpM(result).map { case (phases, disj) =>
        disj match {
          case \/-(-\/(err)) => ko(err.shows).toResult
          case -\/(err)      => ko(err.shows).toResult
          case \/-(\/-(_))   => pending("\n" + phases.map(_.shows).mkString("\n\n"))
        }
      }.unsafePerformSync
    }

  fileSystemShould { fs =>
    step(runT(fs.setupInterpM)(write.saveThese(dataFile, oneDoc).void).runVoid)

    "Explain Queries" should {

      //explainQuery(s"select * from `$dataStr`", fs)

      //explainQuery(s"select * from `$dataStr` limit 10", fs)

      //explainQuery(s"select city, pop from `$dataStr` limit 10", fs)

      //explainQuery(s"select city, loc[0] from `$dataStr`", fs)

      //explainQuery(s"select count(*) from `$dataStr` limit 11", fs)

      explainQuery(s"select sum(pop) from `$dataStr`", fs)

      //explainQuery(s"select avg(pop) from `$dataStr` group by state", fs)

      //explainQuery(s"select count(*) from `$dataStr` where pop > 1000", fs)

      //explainQuery(s"select count(*) from `$dataStr` where pop < 1000 and length(city) < 8", fs)

      //explainQuery(s"select length(loc) from `$dataStr`", fs)

      //explainQuery(s"""select city, pop, date_part("dow", TO_TIMESTAMP(pop)) as test_ts from `$dataStr` where city = "SPRINGFIELD" offset 50 limit 10""", fs)
    }

    step(runT(fs.setupInterpM)(manage.delete(dataFile)).runVoid)
  }
}