# coding=utf-8
# Copyright 2015 Pants project contributors (see CONTRIBUTORS.md).
# Licensed under the Apache License, Version 2.0 (see LICENSE).

from __future__ import absolute_import, division, print_function, unicode_literals

import io
import os
import re


class FileExcluder(object):
    def __init__(self, excludes_path, log):
        self.excludes = {}
        if excludes_path:
            if not os.path.exists(excludes_path):
                raise ValueError("Excludes file does not exist: {0}".format(excludes_path))
            with io.open(excludes_path, "r") as fh:
                for line in fh.readlines():
                    if line and not line.startswith("#") and "::" in line:
                        pattern, plugins = line.strip().split("::", 2)
                        style_plugins = plugins.split()

                        self.excludes[pattern] = {
                            "regex": re.compile(pattern),
                            "plugins": style_plugins,
                        }
                        log.debug("Exclude pattern: {pattern}".format(pattern=pattern))
        else:
            log.debug("No excludes file specified. All python sources will be checked.")

    def should_include(self, source_filename, plugin):
        for exclude_rule in self.excludes.values():
            if exclude_rule["regex"].match(source_filename) and (
                (exclude_rule["plugins"] == [".*"]) or (plugin in exclude_rule["plugins"])
            ):
                return False
        return True