# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
# All Rights Reserved. See LICENSE file for details.

from shlex import split
from re import search

from tfw.decorators.lazy_property import lazy_property


class CommandsEqual:
    def __init__(self, command_1, command_2, fuzzyness=1, must_begin_similarly=True, must_contain_patterns=None):
        self.command_1 = split(command_1)
        self.command_2 = split(command_2)
        self.fuzzyness = fuzzyness
        self.must_begin_similarly = must_begin_similarly
        self.must_contain_patterns = must_contain_patterns

    def __bool__(self):
        if self.must_begin_similarly and not self.beginnings_are_equal:
            return False

        if self.must_contain_patterns is not None and not self.commands_contain_necessary_parts:
            return False

        return self.similarity >= self.fuzzyness

    @lazy_property
    def beginnings_are_equal(self):
        return self.command_1[0] == self.command_2[0]

    @lazy_property
    def commands_contain_necessary_parts(self):
        return all((
            self.contains_neccessary_parts(self.command_1),
            self.contains_neccessary_parts(self.command_2)
        ))

    def contains_neccessary_parts(self, command):
        command = ' '.join(command)
        for pattern in self.must_contain_patterns:
            if not search(pattern, command):
                return False
        return True

    @lazy_property
    def similarity(self):
        parts_1 = set(self.command_1)
        parts_2 = set(self.command_2)

        difference = parts_1 - parts_2
        deviance = len(difference) / len(max(parts_1, parts_2))
        return 1 - deviance