MPI closestLocationInRange function

function closestLocationInRange(position, parent, range, exclude)
  local locations = util.map(celestial.children(parent), function(p) return {"coordinate", p} end)
  local objectOrbits = {}

  if compare(celestial.currentSystem(), coordinateSystem(parent)) then
    -- current system, use all current objects even temporary
    for _,uuid in pairs(celestial.systemObjects()) do
      local orbit = celestial.objectOrbit(uuid)
      if orbit then
        objectOrbits[uuid] = orbit
        table.insert(locations, {"object", uuid})
      end
    end
  elseif parent.planet == 0 then
    -- another system, use permanent mapped objects
    for uuid,object in pairs(player.mappedObjects(parent)) do
      if celestial.objectTypeConfig(object.typeName).permanent then
        objectOrbits[uuid] = object.orbit
        table.insert(locations, {"object", uuid})
      end
    end
  end
  -- include parent if it's a planet
  if parent.planet > 0 then
    table.insert(locations, {"coordinate", parent})
  end

  locations = util.filter(locations, function(location)
    --if location[1] == "coordinate" then
      --local parameters = celestial.planetParameters(location[2])
      --if parameters and parameters.worldType == "Asteroids" then
        --return false
      --end
    --end
    return true
  end)

  local distance = function(location, first)
    local second
    if location[1] == "coordinate" then
      second = celestial.planetPosition(location[2])
    elseif location[1] == "object" then
      second = celestial.orbitPosition(objectOrbits[location[2]])
    end

    return vec2.mag(vec2.sub(first, second))
  end
  locations = util.filter(locations, function(s)
      return distance(s, position) < range and not compare(s, exclude)
    end)
  table.sort(locations, function(a, b)
      return distance(a, position) < distance(b, position)
    end)
  return locations[1]
end