Prototype protobuf generator for scala-cli

protobuf-generator-scala-cli.scala

//> using scala "2.13"
//> using dep "com.thesamet.scalapb::scalapbc:0.11.13"

import scalapb.ScalaPBC

class ProtobufGenerator {
  def metadataJson: String =
    s"""{
       |  "name" : "Protobuf generator",
       |  "version" : "1.0.0",
       |  "supportedExtensions" : ["proto"],
       |  "isReferentiallyTransparent" : true
       |}""".stripMargin

  def generate(inputLocation: String, outputLocation: String): Unit = {
    ScalaPBC.main(Array(s"--scala_out=${outputLocation}", inputLocation))
  }
}

object Main {
  def main(args: Array[String]) = {
    val generator = new ProtobufGenerator()

    args.toList match {
      case "generate" :: output :: inputs if inputs.nonEmpty =>
        inputs.foreach { input =>
          println(s"Running protobuf generation from [$input] to [$output]")
          generator.generate(input, output)
        }
      case "generator-metadata" :: "protobuf" :: Nil =>
        println("Protobuf generator metadata:")
        println(generator.metadataJson)
      case _ =>
        println("Expected usages")
        println("scala-cli . -- generate <output directory> <input file>*")
        println("scala-cli . -- generator-metadata protobuf")
        System.exit(1)
    }
  }
}