# Tools to optimize the handling of moves by the {hotpath} heuristic.
# Last edited on 2021-05-22 10:16:39 by jstolfi

import move_hp_IMP
import move; from move import Move
import path; from path import Path
import block; from block import Block
import move_parms
import path
import pyx

# These prcedures are meant to accelerate the {hotpath} heuristic by
# using additional attributes of {Move} objects: either "static"
# attributes, that are set only once during pre-processing of the input
# data set, and "dynamic" atributes that are modified during the
# heuristic.
#
# These attributes are NOT defined automatically by the functions in the
# {move} module. Their values must be initialized by
# {preprocess_input_data} and {initialize_state} at the start of the
# procedure, and updated as needed by the {set_*} procedures below.

# STATIC HOTPATH-RELATED ATTRIBUTES

def preprocess_input_data(BCS):
  # Sets all static {hotpath}-related static attributes of moves given the list 
  # {BCS} of input {block.Block} objects.
  #
  # This procedure runs in time proportional to {nmv}, the sum of the move counts
  # of all choices of all blocks of {BCS}.
  move_hp_IMP.preprocess_input_data(BCS)

def input_paths(omv):
  # Given a non-jump oriented move {omv}, returns a list {L} of all pairs {(oph,imv)}
  # where {oph} is a choice of a block of {BCS}, and {path.elem(oph,imv)} is {omv} or
  # its reverse.
  #
  # Note that the same {Move} object often occurs in several choices of the same
  # block, and each choice will appear in a separate element of {L}.
  # However, a move must not occur twice in the same path, or in two
  # difference blocks.
  #
  # The procedure returns {None} if {omv} is not a trace, or if neither
  # it nor its reverse occur in any of he input blocks {BCS}. It runs in
  # {O(1)} time since it uses information stored in the {Move} object by
  # {preprocess}.
  return move_hp_IMP.input_paths(omv)
  
def clear_input_data(BCS):
  # Clears all the fields that were set by {set_input_data} so that the 
  # {hotpath} heuristic can be run again on a differen input data set.
  move_hp_IMP.clear_input_data(BCS)

# DYNAMIC HOTPATH-RELATED ATTRIBUTES

def initialize_state(BCS):
  # Sets all dynamic {hotath}-related move attributes to their proper
  # state at the beginning of its execution.
  
  # There are no dynamic {hotpath}-related {Move} attributes in this version,
  # so this procedure is currently a no-op, proveided for documentaton purposes.
  move_hp_IMP.initialize_state(BCS)