def handle_build_action(self, civ, action):
"""Handle incoming build actions and update game state."""
if self._civs[civ].id != action.unit._civ_id:
return ([], ServerError(4))
building_type = action.building_type
tile = self.validate_tile(action.unit.position)
unit = self.validate_unit(civ, action.unit)
bld_id = database_API.Building.insert(self._session,
self._civs[civ]._id,
True, Building.get_type
(building_type),
tile.x, tile.y, tile.z)
self._civs[civ].build_structure(unit,
building_type,
bld_id)
return ([tile], bld_id)
