// See LICENSE for license details.

package firrtl

import scala.collection._
import scala.io.Source
import scala.sys.process.{BasicIO, ProcessLogger, stringSeqToProcess}
import scala.util.{Failure, Success, Try}
import scala.util.control.ControlThrowable
import java.io.{File, FileNotFoundException}

import net.jcazevedo.moultingyaml._
import logger.Logger
import Parser.{IgnoreInfo, InfoMode}
import annotations._
import firrtl.annotations.AnnotationYamlProtocol._
import firrtl.passes.{PassException, PassExceptions}
import firrtl.transforms._
import firrtl.Utils.throwInternalError


/**
  * The driver provides methods to access the firrtl compiler.
  * Invoke the compiler with either a FirrtlExecutionOption
  *
  * @example
  *          {{{
  *          val optionsManager = new ExecutionOptionsManager("firrtl")
  *          optionsManager.register(
  *              FirrtlExecutionOptionsKey ->
  *              new FirrtlExecutionOptions(topName = "Dummy", compilerName = "verilog"))
  *          firrtl.Driver.execute(optionsManager)
  *          }}}
  *  or a series of command line arguments
  * @example
  *          {{{
  *          firrtl.Driver.execute(Array("--top-name Dummy --compiler verilog".split(" +"))
  *          }}}
  * each approach has its own endearing aspects
  * @see firrtlTests/DriverSpec.scala in the test directory for a lot more examples
  * @see [[CompilerUtils.mergeTransforms]] to see how customTransformations are inserted
  */

object Driver {
  /** Print a warning message
    *
    * @param message error message
    */
  //scalastyle:off regex
  def dramaticWarning(message: String): Unit = {
    println(Console.YELLOW + "-"*78)
    println(s"Warning: $message")
    println("-"*78 + Console.RESET)
  }

  /**
    * print the message in red
    *
    * @param message error message
    */
  //scalastyle:off regex
  def dramaticError(message: String): Unit = {
    println(Console.RED + "-"*78)
    println(s"Error: $message")
    println("-"*78 + Console.RESET)
  }

  /** Load annotation file based on options
    * @param optionsManager use optionsManager config to load annotation file if it exists
    *                       update the firrtlOptions with new annotations if it does
    */
  @deprecated("Use side-effect free getAnnotation instead", "1.1")
  def loadAnnotations(optionsManager: ExecutionOptionsManager with HasFirrtlOptions): Unit = {
    val msg = "Driver.loadAnnotations is deprecated, use Driver.getAnnotations instead"
    Driver.dramaticWarning(msg)
    optionsManager.firrtlOptions = optionsManager.firrtlOptions.copy(
      annotations = Driver.getAnnotations(optionsManager).toList
    )
  }

  /** Get annotations from specified files and options
    *
    * @param optionsManager use optionsManager config to load annotation files
    * @return Annotations read from files
    */
  //scalastyle:off cyclomatic.complexity method.length
  def getAnnotations(
      optionsManager: ExecutionOptionsManager with HasFirrtlOptions
  ): Seq[Annotation] = {
    val firrtlConfig = optionsManager.firrtlOptions

    //noinspection ScalaDeprecation
    val oldAnnoFileName = firrtlConfig.getAnnotationFileName(optionsManager)
    val oldAnnoFile = new File(oldAnnoFileName).getCanonicalFile

    val (annoFiles, usingImplicitAnnoFile) = {
      val afs = firrtlConfig.annotationFileNames.map { x =>
        new File(x).getCanonicalFile
      }
      // Implicit anno file could be included explicitly, only include it and
      // warn if it's not also explicit
      val use = oldAnnoFile.exists && !afs.contains(oldAnnoFile)
      if (use) (oldAnnoFile +: afs, true) else (afs, false)
    }

    // Warnings to get people to change to drop old API
    if (firrtlConfig.annotationFileNameOverride.nonEmpty) {
      val msg = "annotationFileNameOverride is deprecated! " +
                "Use annotationFileNames"
      Driver.dramaticWarning(msg)
    } else if (usingImplicitAnnoFile) {
      val msg = "Implicit .anno file from top-name is deprecated!\n" +
             (" "*9) + "Use explicit -faf option or annotationFileNames"
      Driver.dramaticWarning(msg)
    }

    val loadedAnnos = annoFiles.flatMap { file =>
      if (!file.exists) {
        throw new AnnotationFileNotFoundException(file)
      }
      // Try new protocol first
      JsonProtocol.deserializeTry(file).recoverWith { case jsonException =>
        // Try old protocol if new one fails
        Try {
          val yaml = io.Source.fromFile(file).getLines().mkString("\n").parseYaml
          val result = yaml.convertTo[List[LegacyAnnotation]]
          val msg = s"$file is a YAML file!\n" +
                    (" "*9) + "YAML Annotation files are deprecated! Use JSON"
          Driver.dramaticWarning(msg)
          result
        }.orElse { // Propagate original JsonProtocol exception if YAML also fails
          Failure(jsonException)
        }
      }.get
    }

    val targetDirAnno = List(BlackBoxTargetDirAnno(optionsManager.targetDirName))

    // Output Annotations
    val outputAnnos = firrtlConfig.getEmitterAnnos(optionsManager)

    val globalAnnos = Seq(TargetDirAnnotation(optionsManager.targetDirName)) ++
      (if (firrtlConfig.dontCheckCombLoops) Seq(DontCheckCombLoopsAnnotation) else Seq()) ++
      (if (firrtlConfig.noDCE) Seq(NoDCEAnnotation) else Seq())

    val annos = targetDirAnno ++ outputAnnos ++ globalAnnos ++
                firrtlConfig.annotations ++ loadedAnnos
    LegacyAnnotation.convertLegacyAnnos(annos)
  }

  private sealed trait FileExtension
  private case object FirrtlFile extends FileExtension
  private case object ProtoBufFile extends FileExtension

  private def getFileExtension(filename: String): FileExtension =
    filename.drop(filename.lastIndexOf('.')) match {
      case ".pb" => ProtoBufFile
      case _ => FirrtlFile // Default to FIRRTL File
    }

  // Useful for handling erros in the options
  case class OptionsException(msg: String) extends Exception(msg)

  /** Get the Circuit from the compile options
    *
    * Handles the myriad of ways it can be specified
    */
  def getCircuit(optionsManager: ExecutionOptionsManager with HasFirrtlOptions): Try[ir.Circuit] = {
    val firrtlConfig = optionsManager.firrtlOptions
    Try {
      // Check that only one "override" is used
      val circuitSources = Map(
        "firrtlSource" -> firrtlConfig.firrtlSource.isDefined,
        "firrtlCircuit" -> firrtlConfig.firrtlCircuit.isDefined,
        "inputFileNameOverride" -> firrtlConfig.inputFileNameOverride.nonEmpty)
      if (circuitSources.values.count(x => x) > 1) {
        val msg = circuitSources.collect { case (s, true) => s }.mkString(" and ") +
          " are set, only 1 can be set at a time!"
        throw new OptionsException(msg)
      }
      firrtlConfig.firrtlCircuit.getOrElse {
        firrtlConfig.firrtlSource.map(x => Parser.parseString(x, firrtlConfig.infoMode)).getOrElse {
          if (optionsManager.topName.isEmpty && firrtlConfig.inputFileNameOverride.isEmpty) {
            val message = "either top-name or input-file-override must be set"
            throw new OptionsException(message)
          }
          if (
            optionsManager.topName.isEmpty &&
              firrtlConfig.inputFileNameOverride.nonEmpty &&
              firrtlConfig.outputFileNameOverride.isEmpty) {
            val message = "inputFileName set but neither top-name or output-file-override is set"
            throw new OptionsException(message)
          }
          val inputFileName = firrtlConfig.getInputFileName(optionsManager)
          try {
            // TODO What does InfoMode mean to ProtoBuf?
            getFileExtension(inputFileName) match {
              case ProtoBufFile => proto.FromProto.fromFile(inputFileName)
              case FirrtlFile => Parser.parseFile(inputFileName, firrtlConfig.infoMode)
            }
          }
          catch {
            case _: FileNotFoundException =>
              val message = s"Input file $inputFileName not found"
              throw new OptionsException(message)
          }
        }
      }
    }
  }

  /**
    * Run the firrtl compiler using the provided option
    *
    * @param optionsManager the desired flags to the compiler
    * @return a FirrtlExecutionResult indicating success or failure, provide access to emitted data on success
    *         for downstream tools as desired
    */
  //scalastyle:off cyclomatic.complexity method.length
  def execute(optionsManager: ExecutionOptionsManager with HasFirrtlOptions): FirrtlExecutionResult = {
    def firrtlConfig = optionsManager.firrtlOptions

    Logger.makeScope(optionsManager) {
      // Wrap compilation in a try/catch to present Scala MatchErrors in a more user-friendly format.
      val finalState = try {
        val circuit = getCircuit(optionsManager) match {
          case Success(c) => c
          case Failure(OptionsException(msg)) =>
            dramaticError(msg)
            return FirrtlExecutionFailure(msg)
          case Failure(e) => throw e
        }

        val annos = getAnnotations(optionsManager)

        // Does this need to be before calling compiler?
        optionsManager.makeTargetDir()

        firrtlConfig.compiler.compile(
          CircuitState(circuit, ChirrtlForm, annos),
          firrtlConfig.customTransforms
        )
      }
      catch {
        // Rethrow the exceptions which are expected or due to the runtime environment (out of memory, stack overflow)
        case p: ControlThrowable => throw p
        case p: PassException    => throw p
        case p: PassExceptions   => throw p
        case p: FIRRTLException  => throw p
        // Propagate exceptions from custom transforms
        case CustomTransformException(cause) => throw cause
        // Treat remaining exceptions as internal errors.
        case e: Exception => throwInternalError(exception = Some(e))
      }

      // Do emission
      // Note: Single emission target assumption is baked in here
      // Note: FirrtlExecutionSuccess emitted is only used if we're emitting the whole Circuit
      val emittedRes = firrtlConfig.getOutputConfig(optionsManager) match {
        case SingleFile(filename) =>
          val emitted = finalState.getEmittedCircuit
          val outputFile = new java.io.PrintWriter(filename)
          outputFile.write(emitted.value)
          outputFile.close()
          emitted.value
        case OneFilePerModule(dirName) =>
          val emittedModules = finalState.emittedComponents collect { case x: EmittedModule => x }
          if (emittedModules.isEmpty) throwInternalError() // There should be something
          emittedModules.foreach { module =>
            val filename = optionsManager.getBuildFileName(firrtlConfig.outputSuffix, s"$dirName/${module.name}")
            val outputFile = new java.io.PrintWriter(filename)
            outputFile.write(module.value)
            outputFile.close()
          }
          "" // Should we return something different here?
      }

      // If set, emit final annotations to a file
      optionsManager.firrtlOptions.outputAnnotationFileName match {
        case "" =>
        case file =>
          val filename = optionsManager.getBuildFileName("anno.json", file)
          val outputFile = new java.io.PrintWriter(filename)
          outputFile.write(JsonProtocol.serialize(finalState.annotations))
          outputFile.close()
      }

      FirrtlExecutionSuccess(firrtlConfig.compilerName, emittedRes, finalState)
    }
  }

  /**
    * this is a wrapper for execute that builds the options from a standard command line args,
    * for example, like strings passed to main()
    *
    * @param args  an Array of string s containing legal arguments
    * @return
    */
  def execute(args: Array[String]): FirrtlExecutionResult = {
    val optionsManager = new ExecutionOptionsManager("firrtl") with HasFirrtlOptions

    if(optionsManager.parse(args)) {
      execute(optionsManager) match {
        case success: FirrtlExecutionSuccess =>
          success
        case failure: FirrtlExecutionFailure =>
          optionsManager.showUsageAsError()
          failure
        case result =>
          throwInternalError(s"Error: Unknown Firrtl Execution result $result")
      }
    }
    else {
      FirrtlExecutionFailure("Could not parser command line options")
    }
  }

  def main(args: Array[String]): Unit = {
    execute(args)
  }
}

object FileUtils {
  /**
    * recursive create directory and all parents
    *
    * @param directoryName a directory string with one or more levels
    * @return
    */
  def makeDirectory(directoryName: String): Boolean = {
    val dirFile = new java.io.File(directoryName)
    if(dirFile.exists()) {
      if(dirFile.isDirectory) {
        true
      }
      else {
        false
      }
    }
    else {
      dirFile.mkdirs()
    }
  }

  /**
    * recursively delete all directories in a relative path
    * DO NOT DELETE absolute paths
    *
    * @param directoryPathName a directory hierarchy to delete
    */
  def deleteDirectoryHierarchy(directoryPathName: String): Boolean = {
    deleteDirectoryHierarchy(new File(directoryPathName))
  }
  /**
    * recursively delete all directories in a relative path
    * DO NOT DELETE absolute paths
    *
    * @param file: a directory hierarchy to delete
    */
  def deleteDirectoryHierarchy(file: File, atTop: Boolean = true): Boolean = {
    if(file.getPath.split("/").last.isEmpty ||
      file.getAbsolutePath == "/" ||
      file.getPath.startsWith("/")) {
      Driver.dramaticError(s"delete directory ${file.getPath} will not delete absolute paths")
      false
    }
    else {
      val result = {
        if(file.isDirectory) {
          file.listFiles().forall( f => deleteDirectoryHierarchy(f)) && file.delete()
        }
        else {
          file.delete()
        }
      }
      result
    }
  }

  /** Indicate if an external command (executable) is available (from the current PATH).
    *
    * @param cmd the command/executable plus any arguments to the command as a Seq().
    * @return true if ```cmd <args>``` returns a 0 exit status.
    */
  def isCommandAvailable(cmd: Seq[String]): Boolean = {
    // Eat any output.
    val sb = new StringBuffer
    val ioToDevNull = BasicIO(withIn = false, ProcessLogger(line => sb.append(line)))

    try {
      cmd.run(ioToDevNull).exitValue == 0
    } catch {
      case e: Throwable => false
    }
  }

  /** Indicate if an external command (executable) is available (from the current PATH).
    *
    * @param cmd the command/executable (without any arguments).
    * @return true if ```cmd``` returns a 0 exit status.
    */
  def isCommandAvailable(cmd:String): Boolean = {
    isCommandAvailable(Seq(cmd))
  }

  /** Flag indicating if vcs is available (for Verilog compilation and testing).
    * We used to use a bash command (`which ...`) to determine this, but this is problematic on Windows (issue #807).
    * Instead we try to run the executable itself (with innocuous arguments) and interpret any errors/exceptions
    *  as an indication that the executable is unavailable.
    */
  lazy val isVCSAvailable: Boolean = isCommandAvailable(Seq("vcs",  "-platform"))
}