import os.path
import re
from datetime import datetime, timedelta
from gentoolkit.package import Package
from dateutil.parser import parse

from django.db.models import Q

from gentoolkit.errors import GentoolkitFatalError

from djeuscan.processing import FakeLogger
from djeuscan.models import Version


def get_version_date(version, date_limit):
    """
    Returns the datetime when the version was added to Portage,
    if less than date_limit
    """
    changelog_path = os.path.join(
        os.path.dirname(version.ebuild_path),
        "ChangeLog"
    )
    if not os.path.exists(changelog_path):
        return

    with open(changelog_path) as changelog:
        for line in changelog:
            match = re.match(
                r"^\*([^\(]+) \((\d\d \w\w\w \d\d\d\d)\)\s*$", line
            )
            if match:
                version_date = parse(match.group(2)).date()
                if version_date < date_limit:
                    return version_date


def stabilization_candidates(days_to_candidate=30, logger=None):
    """
    Collect stabilization candidates
    """

    if logger is None:
        logger = FakeLogger()

    date_diff = (datetime.utcnow() - timedelta(days=days_to_candidate))
    date_limit = date_diff.date()

    logger.info("Collecting stabilization candidates - date_limit=%s",
                str(date_limit))

    # Set all versions to not be stabilization_candidates
    #Version.objects.update(stabilization_candidate=False)

    # For every version check if it's unstable.
    # If it is then check if can be a stabilization candidate
    versions = Version.objects.filter(overlay='gentoo').filter(
        Q(vtype='release') | Q(vtype='p'))
    for version in versions:
        pkg = Package(version.cpv())
        try:
            keywords = pkg.environment("KEYWORDS").split()
        except GentoolkitFatalError:
            logger.warning("Error while processing %s!", version)
            continue
        if all([x.startswith("~") for x in keywords]):
            version_date = get_version_date(version, date_limit)
            if version_date:
                logger.info('+ [s] %s @ %s', version, version_date)
                # XXX: What should we save? A flag and the date?Just the date?
                version.stabilization_candidate = version_date
                version.save()

    logger.info("Finished collecting stabilization candidates")