# mount.ludic - getting on, and getting off onto a spot the rider's own safe-spot rule found: the
# same one answer a seat and a stand-up use, so a landing is never inside a boulder or on a bank
# the body cannot climb off
# this machine's player onto v; false when it is somebody else's, taken, or a hungry horse
export function vehicle_mount(vehicles_st: mut VehiclesState, v: Vehicle) -> bool {
  if v == null or v.owner != 0 or v.rider >= 0 or vehicles_st.ve_cur != null { return false }
  if v.kind == VEHICLE_HORSE and v.food < vehicle_spec(vehicles_st, v.kind).hay_min {
    ve_say(vehicles_st, VEHICLE_HUNGRY, v, v.food)
    return false
  }
  vehicles_st.ve_cur = v
  v.rider = 0
  VehicleRider.board(v.x, v.z, v.yaw)
  ve_say(vehicles_st, VEHICLE_MOUNTED, v, 0.0)
  return true
}

# Off, onto the nearest spot a body could stand and walk off: from a boat a wade of up to its spec's
# off_depth, from a horse off_side out by its right flank. False (and said) when a boat is too far out.
export function vehicle_dismount(vehicles_st: mut VehiclesState) -> bool {
  let v = vehicles_st.ve_cur
  if v == null { return false }
  let sp = vehicle_spec(vehicles_st, v.kind)
  if v.kind == VEHICLE_BOAT {
    if not VehicleRider.safe_spot(v.x, v.z, VehicleWorld.water(v.x, v.z), sp.off_depth) {
      ve_say(vehicles_st, VEHICLE_NO_LANDING, v, 0.0)
      return false
    }
    VehicleRider.step_off(VehicleRider.safe_x(), VehicleRider.safe_z())
    ve_moor(v)
  } else {
    let wx = v.x + Math.cos(v.yaw) * sp.off_side
    let wz = v.z - Math.sin(v.yaw) * sp.off_side
    if VehicleRider.safe_spot(wx, wz, VehicleWorld.ground(v.x, v.z), 0.0) {
      VehicleRider.step_off(VehicleRider.safe_x(), VehicleRider.safe_z())
    } else { VehicleRider.step_off(v.x, v.z) }
    v.home_x = v.x
    v.home_z = v.z
  }
  vehicles_st.ve_cur = null
  v.rider = -1
  v.speed = 0.0
  ve_say(vehicles_st, VEHICLE_DISMOUNTED, v, 0.0)
  return true
}

# off whatever this player is on, wherever it is (a load, a collapse, a map change)
export function vehicle_drop(vehicles_st: mut VehiclesState) -> void {
  if vehicles_st.ve_cur != null {
    vehicles_st.ve_cur.rider = -1
    vehicles_st.ve_cur.speed = 0.0
    if vehicles_st.ve_cur.kind == VEHICLE_BOAT { ve_moor(vehicles_st.ve_cur) }
  }
  vehicles_st.ve_cur = null
}