@(messages: Seq[parsing.Message])

@messageCrcs() = @{
  for (i <- 0 to 255) yield {
    val crc = messages.find(_.id == i).map(_.checksum).getOrElse(0)
    crc.toString
  }
}

package org.mavlink

case class Packet(
  seq: Byte,
  systemId: Byte,
  componentId: Byte,
  messageId: Byte,
  payload: Seq[Byte]
) {

  lazy val crc = {
    var c = new Crc()
    c = c.accumulate(payload.length.toByte)
    c = c.accumulate(seq)
    c = c.accumulate(systemId)
    c = c.accumulate(componentId)
    c = c.accumulate(messageId)
    for (p <- payload) {
      c = c.accumulate(p)
    }
    c = c.accumulate(Packet.extraCrc(messageId))
    c
  }

  def toSeq: Seq[Byte] = Seq(
    Packet.Stx,
    payload.length.toByte,
    seq,
    systemId,
    componentId,
    messageId
  ) ++ payload ++ Seq(
    crc.lsb,
    crc.msb
  )

}

object Packet {

  final val Stx: Byte = (0xfe).toByte
  final val MaxPayloadLength: Int = @messages.map(_.fields.map(_.tpe.width).sum).max

  final val ExtraCrcs: Seq[Byte] = @messageCrcs().mkString("Array[Byte](", ", ", ")")
  
  def extraCrc(id: Byte) = ExtraCrcs(id & 0xff)

  final val Empty = Packet(0, 0, 0, -1, Array(0: Byte))

}