package mtmc.os.shell.builtins

import mtmc.emulator.MonTanaMiniComputer
import mtmc.emulator.Register
import mtmc.os.shell.ShellCommand
import mtmc.tokenizer.MTMCToken
import mtmc.tokenizer.MTMCTokenizer

class SetCommand : ShellCommand() {
  @Throws(Exception::class)
  public override fun exec(tokens: MTMCTokenizer, computer: MonTanaMiniComputer) {
    val memLocation = tokens.matchAndConsume(
      MTMCToken.TokenType.INTEGER,
      MTMCToken.TokenType.HEX,
      MTMCToken.TokenType.BINARY
    )
    if (memLocation == null) {
      val register = tokens.matchAndConsume(MTMCToken.TokenType.IDENTIFIER)
      if (register == null) usageException()
      val value = tokens.matchAndConsume(
        MTMCToken.TokenType.INTEGER,
        MTMCToken.TokenType.HEX,
        MTMCToken.TokenType.BINARY
      )
      if (value == null) usageException()
      val reg = Register.toInteger(register!!.stringValue)
      if (reg >= 0) {
        computer.setRegisterValue(reg, value!!.intValue())
      } else {
        throw IllegalArgumentException("Bad register: " + register.stringValue)
      }
    } else {
      val value = tokens.matchAndConsume(
        MTMCToken.TokenType.INTEGER,
        MTMCToken.TokenType.HEX,
        MTMCToken.TokenType.BINARY,
        MTMCToken.TokenType.STRING
      )
      if (value == null) usageException()
      if (value?.type === MTMCToken.TokenType.INTEGER || value?.type === MTMCToken.TokenType.BINARY || value?.type === MTMCToken.TokenType.HEX) {
        computer.writeWordToMemory(memLocation.intValue(), value.intValue())
      } else {
        computer.writeStringToMemory(
          memLocation.intValue(),
          value!!.stringValue.encodeToByteArray()
        )
      }
    }
  }

  override val help: String
    get() = """
                set <loc> <value>- sets a memory location value
                     loc:   a register name or memory location
                     value: an integer, hex or binary value, or, for memory locations, a quoted string
                     """.trimIndent()
}