#!/usr/bin/python3
from __future__ import print_function
import click
import pickle

def sort_profile_info(path, max_count=1000):

    profile_info = pickle.load(open(path, "rb"))

    # Classify unused rules. Some are "unused" because the have nullable
    # nonterminals and those show up as a different rule. Sothe rule
    # *is* used just not in the form where a nullable symbol hasn't been
    # nulled.

    # And in some cases this is intentional. Uncompyle6 creates such grammar
    # rules to ensure that positions of certain nonterminals in semantic
    # actions appear in the same place as similar grammar rules

    unused_rules = set() # just the grammar rules
    used_rules = []  # (count, grammar rule)
    for rule, count in profile_info.items():
        if count == 0:
            unused_rules.add(rule)
        else:
            used_rules.append((count, rule))

    for count, rule in used_rules:
        if rule.find("\\e_") > -1:
            canonic_rule = rule.replace("\\e_", "", 1000)
            if canonic_rule in unused_rules:
                unused_rules.remove(canonic_rule)
                pass
            pass
        pass

    unused_items = [(0, item) for item in sorted(unused_rules)]
    used_items = sorted(used_rules, reverse=False)
    return [item for item in unused_items + used_items
                if item[0] <= max_count]

DEFAULT_COVERAGE_FILE = "/tmp/spark-grammar.cover",
DEFAULT_COUNT = 100
@click.command()
@click.option('--path', type=str, default=DEFAULT_COVERAGE_FILE,
              help=("grammar coverage file (default %s)" % DEFAULT_COVERAGE_FILE))
@click.option('--max-count', type=int, default=DEFAULT_COUNT,
              help=("limit output to rules having no more than this many hits (default %d)" % DEFAULT_COUNT))
def run(path, max_count):
    """Print grammar reduce statistics for a series of spark-parser parses
    """
    for count, rule in sort_profile_info(path, max_count):
        print("%d: %s" % (count, rule))
        pass
    return

if __name__ == '__main__':
    run()