/* NOTE: Adapted from ScalaJSPartest.scala in
 * https://github.com/scala-js/scala-js/
 * TODO make partest configurable */

package dotty.partest

import scala.reflect.io.AbstractFile
import scala.tools.partest._
import scala.tools.partest.nest._
import scala.util.matching.Regex
import tools.nsc.io.{ File => NSCFile }
import java.io.{ File, PrintStream, FileOutputStream, PrintWriter, FileWriter }
import java.net.URLClassLoader

/** Runs dotty partest from the Console, discovering test sources in
  * DPConfig.testRoot that have been generated automatically by
  * DPPrepJUnitRunner. Use `sbt partest` to run. If additional jars are
  * required by some run tests, add them to partestDeps in the sbt Build.scala.
  */
object DPConsoleRunner {
  def main(args: Array[String]): Unit = {
    // unfortunately sbt runTask passes args as single string
    // extra jars for run tests are passed with -dottyJars <count> <jar1> <jar2> ...
    val jarFinder = """-dottyJars (\d*) (.*)""".r
    val (jarList, otherArgs) = args.toList.partition(jarFinder.findFirstIn(_).isDefined)
    val (extraJars, moreArgs) = jarList match {
      case Nil => sys.error("Error: DPConsoleRunner needs \"-dottyJars <jarCount> <jars>*\".")
      case jarFinder(nr, jarString) :: Nil =>
        val jars = jarString.split(" ").toList
        val count = nr.toInt
        if (jars.length < count)
          sys.error("Error: DPConsoleRunner found wrong number of dottyJars: " + jars + ", expected: " + nr)
        else (jars.take(count), jars.drop(count))
      case list => sys.error("Error: DPConsoleRunner found several -dottyJars options: " + list)
    }
    new DPConsoleRunner((otherArgs ::: moreArgs) mkString (" "), extraJars).runPartest
  }
}

// console runner has a suite runner which creates a test runner for each test
class DPConsoleRunner(args: String, extraJars: List[String]) extends ConsoleRunner(args) {

  override val suiteRunner = new DPSuiteRunner (
    testSourcePath = optSourcePath getOrElse DPConfig.testRoot,
    fileManager = new DottyFileManager(extraJars),
    updateCheck = optUpdateCheck,
    failed = optFailed,
    consoleArgs = args)

  override def run = {}
  def runPartest = super.run
}

class DottyFileManager(extraJars: List[String]) extends FileManager(Nil) {
  lazy val extraJarList = extraJars.map(NSCFile(_))
  override lazy val libraryUnderTest  = Path(extraJars.find(_.contains("scala-library")).getOrElse(""))
  override lazy val reflectUnderTest  = Path(extraJars.find(_.contains("scala-reflect")).getOrElse(""))
  override lazy val compilerUnderTest = Path(extraJars.find(_.contains("dotty")).getOrElse(""))
}

class DPSuiteRunner(testSourcePath: String, // relative path, like "files", or "pending"
  fileManager: DottyFileManager,
  updateCheck: Boolean,
  failed: Boolean,
  consoleArgs: String,
  javaCmdPath: String = PartestDefaults.javaCmd,
  javacCmdPath: String = PartestDefaults.javacCmd,
  scalacExtraArgs: Seq[String] = Seq.empty)
extends SuiteRunner(testSourcePath, fileManager, updateCheck, failed, javaCmdPath, javacCmdPath, scalacExtraArgs) {

  if (!DPConfig.runTestsInParallel)
    sys.props("partest.threads") = "1"

  sys.props("partest.root") = "."

  // override to provide Dotty banner
  override def banner: String = {
    s"""|Welcome to Partest for Dotty! Partest version: ${Properties.versionNumberString}
        |Compiler under test: dotty.tools.dotc.Bench or dotty.tools.dotc.Main
        |Generated test sources: ${PathSettings.srcDir}${File.separator}
        |Test directories: ${DPConfig.testDirs.toList.mkString(", ")}
        |Debugging: failed tests have compiler output in test-kind.clog, run output in test-kind.log, class files in test-kind.obj
        |Parallel: ${DPConfig.runTestsInParallel}
        |Options: (use partest --help for usage information) ${consoleArgs}
    """.stripMargin
  }

  // override for DPTestRunner and redirecting compilation output to test.clog
  override def runTest(testFile: File): TestState = {
    val runner = new DPTestRunner(testFile, this)

    val state =
      try {
        runner.run match {
          // Append compiler output to transcript if compilation failed,
          // printed with --verbose option
          case TestState.Fail(f, r@"compilation failed", transcript) =>
            TestState.Fail(f, r, transcript ++ runner.cLogFile.fileLines.dropWhile(_ == ""))
          case res => res
        }
      } catch {
        case t: Throwable => throw new RuntimeException(s"Error running $testFile", t)
      }
    reportTest(state)
    runner.cleanup()

    onFinishTest(testFile, state)
  }

  // override NestUI.reportTest because --show-diff doesn't work. The diff used
  // seems to add each line to transcript separately, whereas NestUI assumes
  // that the diff string was added as one entry in the transcript
  def reportTest(state: TestState) = {
    import NestUI._
    import NestUI.color._

    if (isTerse && state.isOk) {
      NestUI.reportTest(state)
    } else {
      echo(statusLine(state))
      if (!state.isOk && isDiffy) {
        val differ = bold(red("% ")) + "diff "
        state.transcript.dropWhile(s => !(s startsWith differ)) foreach (echo(_))
        // state.transcript find (_ startsWith differ) foreach (echo(_)) // original
      }
    }
  }
}

class DPTestRunner(testFile: File, suiteRunner: DPSuiteRunner) extends nest.Runner(testFile, suiteRunner) {
  val cLogFile = SFile(logFile).changeExtension("clog")

  // override to provide DottyCompiler
  override def newCompiler = new dotty.partest.DPDirectCompiler(this)

  // override to provide default dotty flags from file in directory
  override def flagsForCompilation(sources: List[File]): List[String] = {
    val specificFlags = super.flagsForCompilation(sources)
    if (specificFlags.isEmpty) defaultFlags
    else specificFlags
  }
  val defaultFlags = {
    val defaultFile = parentFile.listFiles.toList.find(_.getName == "__defaultFlags.flags")
    defaultFile.map({ file =>
      SFile(file).safeSlurp.map({ content => words(content).filter(_.nonEmpty) }).getOrElse(Nil)
    }).getOrElse(Nil)
  }

  // override to add the check for nr of compilation errors if there's a
  // target.nerr file
  override def runNegTest() = runInContext {
    import TestState.{ Crash, Fail }
    import scala.reflect.internal.FatalError

    sealed abstract class NegTestState
    // Don't get confused, the neg test passes when compilation fails for at
    // least one round (optionally checking the number of compiler errors and
    // compiler console output)
    case class CompFailed() extends NegTestState
    // the neg test fails when all rounds return either of these:
    case class CompFailedButWrongNErr(expected: String, found: String) extends NegTestState
    case class CompFailedButWrongDiff() extends NegTestState
    case class CompSucceeded() extends NegTestState

    def nerrIsOk(reason: String) = {
      val nerrFinder = """compilation failed with (\d+) errors""".r
      reason match {
        case nerrFinder(found) =>
          SFile(FileOps(testFile) changeExtension "nerr").safeSlurp match {
            case Some(exp) if (exp != found) => CompFailedButWrongNErr(exp, found)
            case _ => CompFailed
          }
        case _ => CompFailed
      }
    }

    // we keep the partest semantics where only one round needs to fail
    // compilation, not all
    val compFailingRounds = compilationRounds(testFile).map({round =>
      val ok = round.isOk
      setLastState(if (ok) genPass else genFail("compilation failed"))
      (round.result, ok)
    }).filter({ case (_, ok) => !ok })

    val failureStates = compFailingRounds.map({ case (result, _) => result match {
      // or, OK, we'll let you crash the compiler with a FatalError if you supply a check file
      case Crash(_, t, _) if !checkFile.canRead || !t.isInstanceOf[FatalError] => CompSucceeded
      case Fail(_, reason, _) => if (diffIsOk) nerrIsOk(reason) else CompFailedButWrongDiff
      case _ => if (diffIsOk) CompFailed else CompFailedButWrongDiff
    }})

    if (failureStates.exists({ case CompFailed => true; case _ => false })) {
      true
    } else {
      val existsNerr = failureStates.exists({
        case CompFailedButWrongNErr(exp, found) => nextTestActionFailing(s"wrong number of compilation errors, expected: $exp, found: $found"); true
        case _ => false
      })
      if (existsNerr) {
        false
      } else {
        val existsDiff = failureStates.exists({
          case CompFailedButWrongDiff() => nextTestActionFailing(s"output differs"); true
          case _ => false
        })
        if (existsDiff) {
          false
        } else {
          nextTestActionFailing("expected compilation failure")
        }
      }
    }
  }

  // override to change check file updating to original file, not generated
  override def diffIsOk: Boolean = {
    // always normalize the log first
    normalizeLog()
    val diff = currentDiff
    // if diff is not empty, is update needed?
    val updating: Option[Boolean] = (
      if (diff == "") None
      else Some(suiteRunner.updateCheck)
    )
    pushTranscript(s"diff $logFile $checkFile")
    nextTestAction(updating) {
      case Some(true) =>
        val origCheck = SFile(checkFile.changeExtension("checksrc").fileLines(1))
        NestUI.echo("Updating original checkfile " + origCheck)
        origCheck writeAll file2String(logFile)
        genUpdated()
      case Some(false) =>
        // Get a word-highlighted diff from git if we can find it
        val bestDiff = if (updating.isEmpty) "" else {
          if (checkFile.canRead)
            gitDiff(logFile, checkFile) getOrElse {
              s"diff $logFile $checkFile\n$diff"
            }
          else diff
        }
        pushTranscript(bestDiff)
        genFail("output differs")
      case None        => genPass()  // redundant default case
    } getOrElse true
  }

  // override because Dotty currently doesn't handle separate compilation well,
  // so we ignore groups (tests suffixed with _1 and _2)
  override def groupedFiles(sources: List[File]): List[List[File]] = {
    val grouped = sources groupBy (_.group)
    val flatGroup = List(grouped.keys.toList.sorted.map({ k => grouped(k) sortBy (_.getName) }).flatten)
    try { // try/catch because of bug in partest that throws exception
      if (flatGroup != super.groupedFiles(sources))
        throw new java.lang.UnsupportedOperationException()
    } catch {
      case e: java.lang.UnsupportedOperationException =>
        val genlogFWriter = new FileWriter(DPConfig.genLog.jfile, true)
        val genlogWriter = new PrintWriter(genlogFWriter, true)
        genlogWriter.println("Warning: Overriding compilation groups for tests: " + sources)
        genlogWriter.close
        genlogFWriter.close
    }
    flatGroup
  }

  // override to avoid separate compilation of scala and java sources
  override def mixedCompileGroup(allFiles: List[File]): List[CompileRound] = List(OnlyDotty(allFiles))
  case class OnlyDotty(fs: List[File]) extends CompileRound {
    def description = s"dotc $fsString"
    lazy val result = { pushTranscript(description) ; attemptCompile(fs) }
  }

  // override to add dotty and scala jars to classpath
  override def extraClasspath = suiteRunner.fileManager.asInstanceOf[DottyFileManager].extraJarList ::: super.extraClasspath

  // override to keep class files if failed and delete clog if ok
  override def cleanup = if (lastState.isOk) {
    logFile.delete
    cLogFile.delete
    Directory(outDir).deleteRecursively
  }
}