# places.ludic - four berths off the pier head and four bays at the trough. Nobody's boat waits in
# one: a player calls theirs into a place that is empty. A place is taken while a boat lies in it or
# a horse is tied at it, and frees itself the moment it is rowed or ridden away.
export function vehicles_dock_at(vehicles_st: mut VehiclesState, x: float, z: float, yaw: float) -> void {
  vehicles_st.ve_dock_x = x
  vehicles_st.ve_dock_z = z
  vehicles_st.ve_dock_yaw = yaw
  vehicles_st.ve_have_dock = true
}

export function vehicles_rail_at(vehicles_st: mut VehiclesState, x: float, z: float, yaw: float) -> void {
  vehicles_st.ve_rail_x = x
  vehicles_st.ve_rail_z = z
  vehicles_st.ve_rail_yaw = yaw
}

# which way the pier head faces, for the posts a game stands on it
export function vehicles_dock_yaw(vehicles_st: VehiclesState) -> float { return vehicles_st.ve_dock_yaw }

function ve_across(k: int) -> float { return -3.3 + float(k) * 2.2 }

# a berth: 90 cm off the pier head's outer edge, bow out; its post on the deck above it
export function vehicle_berth_x(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_dock_x - Math.sin(vehicles_st.ve_dock_yaw) * 7.25 + Math.cos(vehicles_st.ve_dock_yaw) * ve_across(k) }
export function vehicle_berth_z(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_dock_z - Math.cos(vehicles_st.ve_dock_yaw) * 7.25 - Math.sin(vehicles_st.ve_dock_yaw) * ve_across(k) }
export function vehicle_post_x(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_dock_x - Math.sin(vehicles_st.ve_dock_yaw) * 6.15 + Math.cos(vehicles_st.ve_dock_yaw) * ve_across(k) }
export function vehicle_post_z(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_dock_z - Math.cos(vehicles_st.ve_dock_yaw) * 6.15 - Math.sin(vehicles_st.ve_dock_yaw) * ve_across(k) }

# a bay: off the trough's long side, a trough's length apart - four horses at a feeding trough
# stand shoulder to shoulder along it
function ve_bay_across(k: int) -> float { return -1.44 + float(k) * 0.96 }
export function vehicle_bay_x(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_rail_x - Math.sin(vehicles_st.ve_rail_yaw) * 1.4 + Math.cos(vehicles_st.ve_rail_yaw) * ve_bay_across(k) }
export function vehicle_bay_z(vehicles_st: VehiclesState, k: int) -> float { return vehicles_st.ve_rail_z - Math.cos(vehicles_st.ve_rail_yaw) * 1.4 - Math.sin(vehicles_st.ve_rail_yaw) * ve_bay_across(k) }

export function vehicle_place_x(vehicles_st: VehiclesState, kind: int, k: int) -> float {
  if kind == VEHICLE_HORSE { return vehicle_bay_x(vehicles_st, k) }
  return vehicle_berth_x(vehicles_st, k)
}

export function vehicle_place_z(vehicles_st: VehiclesState, kind: int, k: int) -> float {
  if kind == VEHICLE_HORSE { return vehicle_bay_z(vehicles_st, k) }
  return vehicle_berth_z(vehicles_st, k)
}

# who is in place k: the boat lying in the berth or the horse tied in the bay, or null
export function vehicle_in_place(vehicles_st: VehiclesState, kind: int, k: int) -> Vehicle {
  let px = vehicle_place_x(vehicles_st, kind, k)
  let pz = vehicle_place_z(vehicles_st, kind, k)
  let l = ve_all(vehicles_st)
  for i in 0 .. len(l) {
    let v = l[i]
    if v.kind != kind or v.rider >= 0 { continue }
    # within half a place's spacing: the bays are 0.96 m apart, and a looser test put a horse in two
    var vx = v.x
    var vz = v.z
    var near = 1.2
    if kind == VEHICLE_HORSE {
      vx = v.home_x
      vz = v.home_z
      near = 0.2
    }
    if (vx - px) * (vx - px) + (vz - pz) * (vz - pz) < near { return v }
  }
  return null
}

# the first free place, or -1
export function vehicle_free_place(vehicles_st: VehiclesState, kind: int) -> int {
  for k in 0 .. VEHICLE_PLACES { if vehicle_in_place(vehicles_st, kind, k) == null { return k } }
  return -1
}

# this player's own is lying in one of the places
export function vehicle_mine_in_place(vehicles_st: VehiclesState, kind: int) -> bool {
  let mine = vehicle_find(vehicles_st, kind)
  if mine == null { return false }
  for k in 0 .. VEHICLE_PLACES {
    let h = vehicle_in_place(vehicles_st, kind, k)
    if h != null and h.nid == mine.nid { return true }
  }
  return false
}