"""
This file contains all the HAL-related functions.

TODO:
    * Add functions to homogeneize interface with arXiv one.
"""
import re

from libbmc import tools


# TODO: This is too restrictive
REGEX = re.compile(r"((hal-\d{8})((, version (\d+))|v(\d+))?)")


def is_valid(hal_id):
    """
    Check that a given HAL id is a valid one.

    :param hal_id: The HAL id to be checked.
    :returns: Boolean indicating whether the HAL id is valid or not.

    >>> is_valid("hal-01258754, version 1")
    True

    >>> is_valid("hal-01258754")
    True

    >>> is_valid("hal-01258754v2")
    True

    >>> is_valid("foobar")
    False
    """
    match = REGEX.match(hal_id)
    return (match is not None) and (match.group(0) == hal_id)


def extract_from_text(text):
    """
    Extract HAL ids from a text.

    :param text: The text to extract HAL ids from.
    :returns: A list of matching HAL ids.

    >>> sorted(extract_from_text("hal-01258754 hal-01258754v2 foobar"))
    ['hal-01258754', 'hal-01258754v2']
    """
    return tools.remove_duplicates([i[0]
                                    for i in REGEX.findall(text) if i != ''])