Add parsing of command line options

.scalafmt.conf

@@ -1,2 +1,14 @@
-version = "3.7.3"
+version = 3.7.3
+
 runner.dialect = scala3
+
+preset = IntelliJ
+align.preset = more
+maxColumn = 120
+docstrings.style = Asterisk
+docstrings.blankFirstLine = yes
+docstrings.wrap = no
+importSelectors = singleLine
+newlines.source = keep
+
+rewrite.scala3.convertToNewSyntax = yes

build.sbt

@@ -5,12 +5,24 @@ enablePlugins(ScalaNativePlugin)
 // set to Debug for compilation details (Info is default)
 logLevel := Level.Info
 
+libraryDependencies ++= Seq(
+  "com.github.scopt" %%% "scopt" % "4.1.0"
+)
+
+Compile/run/mainClass := Some("ij_plugins.imagej_launcher.Main")
+
 // import to add Scala Native options
 import scala.scalanative.build._
 
+
 // defaults set with common options shown
 nativeConfig ~= { c =>
-  c.withLTO(LTO.none) // thin
+  c.withLTO(LTO.none)     // thin
     .withMode(Mode.debug) // releaseFast
-    .withGC(GC.immix) // commix
+    .withGC(GC.immix)     // commix
 }
+
+//// Enable verbose reporting during compilation
+//nativeConfig ~= { c =>
+//  c.withCompileOptions(c.compileOptions ++ Seq("-v"))
+//}

project/build.properties

@@ -1 +1 @@
-sbt.version = 1.8.2
+sbt.version = 1.8.3

project/plugins.sbt

@@ -1 +1 @@
-addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.10")
+addSbtPlugin("org.scala-native" % "sbt-scala-native" % "0.4.12")

src/main/scala/Main.scala

@@ -1,4 +0,0 @@
-object Main {
-  def main(args: Array[String]): Unit =
-    println("Hello, world!")
-}

src/main/scala/ij_plugins/imagej_launcher/ErrorCode.scala

@@ -0,0 +1,17 @@
+/*
+ * Copyright (c) 2000-2023 Jarek Sacha. All Rights Reserved.
+ * Author's e-mail: jpsacha at gmail.com
+ */
+package ij_plugins.imagej_launcher
+
+import scala.collection.immutable
+
+enum ErrorCode(val value: Int, val message: String):
+  case OK                          extends ErrorCode(0, "OK")
+  case InvalidCommandLineArguments extends ErrorCode(-10, "Invalid command line arguments")
+  case GeneralError                extends ErrorCode(-100, "General error")
+  case UnhandledNonFatalError      extends ErrorCode(-200, "Unhandled non-fatal error")
+  case UnhandledFatalError         extends ErrorCode(-300, "Unhandled fatal error")
+  case NotImplemented              extends ErrorCode(-400, "Functionality not implemented")
+
+  override def toString: String = s"$message [exit code: $value]"

src/main/scala/ij_plugins/imagej_launcher/Launcher.scala

@@ -0,0 +1,14 @@
+/*
+ * Copyright (c) 2000-2023 Jarek Sacha. All Rights Reserved.
+ * Author's e-mail: jpsacha at gmail.com
+ */
+
+package ij_plugins.imagej_launcher
+
+import ij_plugins.imagej_launcher.Main.Config
+
+class Launcher(logger: Logger) {
+  def run(config: Config): ErrorCode = {
+    ErrorCode.NotImplemented
+  }
+}

src/main/scala/ij_plugins/imagej_launcher/Logger.scala

@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2000-2023 Jarek Sacha. All Rights Reserved.
+ * Author's e-mail: jpsacha at gmail.com
+ */
+
+package ij_plugins.imagej_launcher
+
+import ij_plugins.imagej_launcher.Logger.Level
+
+class Logger {
+
+  var level: Level = Level.Info
+
+  def debug(msg: String): Unit = pprint(Level.Debug, msg)
+  def info(msg: String): Unit  = pprint(Level.Info, msg)
+  def error(msg: String): Unit = pprint(Level.Error, msg)
+
+  private def pprint(l: Level, message: String): Unit =
+    if l.level <= level.level then println(s"${l.name}: $message")
+}
+
+object Logger:
+  enum Level(val level: Int, val name: String):
+    case Off extends Level(0, "OFF")
+    case Error extends Level(200, "ERROR")
+    case Info extends Level(400, "INFO")
+    case Debug extends Level(500, "DEBUG")
+    case All extends Level(Int.MaxValue, "DEBUG")

src/main/scala/ij_plugins/imagej_launcher/Main.scala

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2000-2023 Jarek Sacha. All Rights Reserved.
+ * Author's e-mail: jpsacha at gmail.com
+ */
+
+package ij_plugins.imagej_launcher
+
+import ij_plugins.imagej_launcher.ErrorCode
+import scopt.{DefaultOEffectSetup, OParser}
+
+import java.io.File
+
+object Main {
+  private val logger  = new Logger()
+  private val AppName = "ijp-imagej-launcher"
+  //  private val AppVersion = s"${Version.version} [${Version.buildTimeStr}]"
+  private val AppVersion     = s"0.1.0"
+  private val VersionMessage = s"v.$AppVersion"
+  private val AppDescription =
+    """Native launcher for ImageJ2
+      |""".stripMargin
+
+  case class Config(
+    logLevel: Logger.Level = Logger.Level.Error,
+    dryRun: Boolean = false,
+    javaHome: Option[File] = None
+  )
+
+  def main(args: Array[String]): Unit =
+    setupLogger(Logger.Level.All)
+
+    val ret: ErrorCode =
+      parseCommandLine(args) match
+        case Some(config) =>
+          setupLogger(config.logLevel)
+          runLauncher(config)
+        case None =>
+          // arguments are bad
+          ErrorCode.InvalidCommandLineArguments
+
+    val msg = s"${ret.message} [exit code: ${ret.value}]"
+    if ret == ErrorCode.OK then
+      logger.info(msg)
+    else
+      logger.error(msg)
+
+//    System.exit(ret.value)
+  end main
+
+  private def parseCommandLine(args: Array[String]): Option[Config] =
+    val builder = OParser.builder[Config]
+    val parser1 = {
+      import builder.*
+      OParser.sequence(
+        programName(AppName),
+        head(AppName, VersionMessage),
+        note(AppDescription),
+        //
+        help('h', "help").text("prints this usage text"),
+        //
+        version("version").text("prints version"),
+        //
+        opt[Unit]("dry-run")
+          .action((_, c) => c.copy(dryRun = true))
+          .text("show the command line, but do not run anything"),
+        //
+        opt[Unit]("info")
+          .action((_, c) => c.copy(logLevel = Logger.Level.Info))
+          .text("informational output"),
+        //
+        opt[Unit]("debug")
+          .action((_, c) => c.copy(logLevel = Logger.Level.Debug))
+          .text("verbose output"),
+        //
+        opt[File]("java-home")
+          .valueName("<path>")
+          .action((path, c) => c.copy(javaHome = Option(path)))
+          .text("specify JAVA_HOME explicitly"),
+        //
+        opt[Unit]("print-java-home")
+          .action((_, c) => c.copy(dryRun = true))
+          .text("print ImageJ's idea of JAVA_HOME")
+      )
+    }
+
+    OParser.parse(parser1, args, Config())
+  end parseCommandLine
+
+  private def setupLogger(logLevel: Logger.Level): Unit = logger.level = logLevel
+
+  private def runLauncher(config: Config): ErrorCode = new Launcher(logger).run(config)
+}