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*/

package firrtl

import scala.io.Source
import scala.collection.mutable
import Annotations._

import Utils._
import Parser.{InfoMode, IgnoreInfo, UseInfo, GenInfo, AppendInfo}

object Driver {
  /**
   * Implements the default Firrtl compilers and an inlining pass.
   *
   * Arguments specify the compiler, input file, output file, and
   * optionally the module/instances to inline.
   */
  def main(args: Array[String]) = {
    val usage = """
Usage: firrtl -i <input_file> -o <output_file> -X <compiler> [options] 
       sbt "run-main firrtl.Driver -i <input_file> -o <output_file> -X <compiler> [options]"

Required Arguments:
  -i <filename>         Specify the input *.fir file
  -o <filename>         Specify the output file
  -X <compiler>         Specify the target compiler
                        Currently supported: high low verilog

Optional Arguments:
  --info-mode <mode>             Specify Info Mode
                                 Supported modes: ignore, use, gen, append
  --inferRW <circuit>            Enable readwrite port inference for the target circuit
  --inline <module>|<instance>   Inline a module (e.g. "MyModule") or instance (e.g. "MyModule.myinstance")

  --replSeqMem -c:<circuit>:-i<filename>:-o<filename> 
  *** Replace sequential memories with blackboxes + configuration file
  *** Input configuration file optional
  *** Note: sub-arguments to --replSeqMem should be delimited by : and not white space!
  
  [--help|-h]                    Print usage string
"""

    def handleInlineOption(value: String): Annotation =
      value.split('.') match {
        case Array(circuit) =>
          passes.InlineAnnotation(CircuitName(circuit), TransID(0))
        case Array(circuit, module) =>
          passes.InlineAnnotation(ModuleName(module, CircuitName(circuit)), TransID(0))
        case Array(circuit, module, inst) =>
          passes.InlineAnnotation((ComponentName(inst,ModuleName(module,CircuitName(circuit)))), TransID(0))
        case _ => throw new Exception(s"Bad inline instance/module name: $value" + usage)
      }

    def handleInferRWOption(value: String) = 
      passes.InferReadWriteAnnotation(value, TransID(-1))

    def handleReplSeqMem(value: String) = 
      passes.ReplSeqMemAnnotation(value, TransID(-2))

    run(args: Array[String],
      Map( "high" -> new HighFirrtlCompiler(),
        "low" -> new LowFirrtlCompiler(),
        "verilog" -> new VerilogCompiler()),
      Map("--inline" -> handleInlineOption _,
          "--inferRW" -> handleInferRWOption _,
          "--replSeqMem" -> handleReplSeqMem _),
      usage
    )
  }


  // Compiles circuit. First parses a circuit from an input file,
  //  executes all compiler passes, and writes result to an output
  //  file.
  def compile(
      input: String, 
      output: String, 
      compiler: Compiler, 
      infoMode: InfoMode = IgnoreInfo,
      annotations: AnnotationMap = new AnnotationMap(Seq.empty)) = {
    val parsedInput = Parser.parse(Source.fromFile(input).getLines, infoMode)
    val outputBuffer = new java.io.CharArrayWriter
    compiler.compile(parsedInput, annotations, outputBuffer)

    val outputFile = new java.io.PrintWriter(output)
    outputFile.write(outputBuffer.toString)
    outputFile.close()
  }

  /**
   * Runs a Firrtl compiler.
   *
   * @param args list of commandline arguments
   * @param compilers mapping a compiler name to a compiler
   * @param customOptions mapping a custom option name to a function that returns an annotation
   * @param usage describes the commandline API
   */
  def run(args: Array[String], compilers: Map[String,Compiler], customOptions: Map[String, String=>Annotation], usage: String) = {
    /**
     * Keys commandline values specified by user in OptionMap
     */
    sealed trait CompilerOption
    case object InputFileName extends CompilerOption
    case object OutputFileName extends CompilerOption
    case object CompilerName extends CompilerOption
    case object AnnotationOption extends CompilerOption
    case object InfoModeOption extends CompilerOption
    /**
     * Maps compiler option to user-specified value
     */
    type OptionMap = Map[CompilerOption, String]

    /**
     * Populated by custom annotations returned from corresponding function
     * held in customOptions
     */
    val annotations = mutable.ArrayBuffer[Annotation]()
    def nextOption(map: OptionMap, list: List[String]): OptionMap = {
      list match {
        case Nil => map
        case "-i" :: value :: tail =>
          nextOption(map + (InputFileName -> value), tail)
        case "-o" :: value :: tail =>
          nextOption(map + (OutputFileName -> value), tail)
        case "-X" :: value :: tail =>
          nextOption(map + (CompilerName -> value), tail)
        case "--info-mode" :: value :: tail =>
          nextOption(map + (InfoModeOption -> value), tail)
        case flag :: value :: tail if(customOptions.contains(flag)) =>
          annotations += customOptions(flag)(value)
          nextOption(map, tail)
        case ("-h" | "--help") :: tail => { println(usage); sys.exit(0) }
        case option :: tail =>
          throw new Exception("Unknown option " + option + usage)
      }
    }

    val arglist = args.toList
    val options = nextOption(Map[CompilerOption, String](), arglist)

    // Get input circuit/output filenames
    val input = options.getOrElse(InputFileName, throw new Exception("No input file provided!" + usage))
    val output = options.getOrElse(OutputFileName, throw new Exception("No output file provided!" + usage))

    val infoMode = options.get(InfoModeOption) match {
      case (Some("use") | None) => UseInfo
      case Some("ignore") => IgnoreInfo
      case Some("gen") => GenInfo(input)
      case Some("append") => AppendInfo(input)
      case Some(other) => throw new Exception("Unknown info mode option: " + other + usage)
    }

    // Execute selected compiler - error if not recognized compiler
    options.get(CompilerName) match {
      case Some(name) =>
        compilers.get(name) match {
          case Some(compiler) => compile(input, output, compiler, infoMode, new AnnotationMap(annotations.toSeq))
          case None => throw new Exception("Unknown compiler option: " + name + usage)
        }
      case None => throw new Exception("No specified compiler option." + usage)
    }
  }
}