package mtmc.os.shell.builtins

import mtmc.emulator.MonTanaMiniComputer
import mtmc.os.exec.Executable.Companion.load
import mtmc.os.fs.FileSystem
import mtmc.os.fs.Path
import mtmc.os.shell.ShellCommand
import mtmc.tokenizer.MTMCTokenizer

class LoadCommand : ShellCommand() {
  @Throws(Exception::class)
  override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
    val fs = computer.fileSystem
    val program = tokens.collapseTokensAsString()
    require(!(program == null || program.isBlank())) { "missing or required argument 'src'" }
    val srcPath: Path = getDiskPath(program, fs)

    val exec = load(srcPath)
    computer.load(exec!!.code, exec.data, exec.graphics, exec.debugInfo)
    val source = tokens.source

    // set up an argument if given
    if (tokens.more()) {
      val firstArgToken = tokens.consume()
      val startChar: Int = firstArgToken.start
      val arg = source.substring(startChar)
      val strippedArg = arg.trim()
      if (!strippedArg.isEmpty()) {
        computer.setArg(strippedArg)
      }
    }
  }

  override val help: String
    get() = """
                load <exec>
                    - exec : path to an executable file
                    """.trimIndent()

  companion object {
    fun getDiskPath(pathString: String, fs: FileSystem): Path {
      val path = Path.of("disk" + fs.resolve(pathString))
      return path.toAbsolutePath()
    }
  }
}