from django.db.transaction import commit_on_success
from django.utils import timezone

from djeuscan.models import Package, Herd, Maintainer, Version, HerdLog, \
    MaintainerLog, CategoryLog, WorldLog, Category, Overlay
from djeuscan import charts
from djeuscan.processing import FakeLogger

from distutils.version import StrictVersion, LooseVersion


def _compare_versions(version1, version2):
    try:
        return cmp(StrictVersion(version1), StrictVersion(version2))
    # in case of abnormal version number, fall back to LooseVersion
    except ValueError:
        return cmp(LooseVersion(version1), LooseVersion(version2))


def _add_safe(storage, key):
    if key not in storage:
        storage[key] = 1
    else:
        storage[key] += 1


def _add_last_ver(storage, version):
    key = version['package_id']
    if key not in storage:
        storage[key] = version
        return
    if version['version'].startswith('9999'):
        return
    if _compare_versions(storage[key]['version'],
                        version['version']) < 0:
        storage[key] = version


@commit_on_success
def update_counters(fast=False, nolog=False, logger=None):
    logger = logger or FakeLogger()

    now = timezone.now()

    categories = {}
    herds = {}
    maintainers = {}

    wlog = None

    # Populate Category and Overlay
    for cat in Package.objects.values('category').distinct():
        obj, created = Category.objects.get_or_create(name=cat["category"])
        if created:
            logger.info("+ [c] %s", cat["category"])

    for overlay in Version.objects.values('overlay').distinct():
        if not overlay["overlay"]:
            continue
        obj, created = Overlay.objects.get_or_create(name=overlay["overlay"])
        if created:
            logger.info("+ [o] %s", overlay["overlay"])

    if not nolog:
        wlog = WorldLog()
        wlog.datetime = now

        for cat in Package.objects.values('category').distinct():
            clog = CategoryLog()
            clog.datetime = now
            clog.category = cat['category']
            categories[clog.category] = clog

        for herd in Herd.objects.all():
            hlog = HerdLog()
            hlog.datetime = now
            hlog.herd = herd
            herds[herd.id] = hlog

        for maintainer in Maintainer.objects.all():
            mlog = MaintainerLog()
            mlog.datetime = now
            mlog.maintainer = maintainer
            maintainers[maintainer.id] = mlog

    package_queryset = Package.objects.all()

    n_versions = {}
    n_packaged = {}
    n_overlay = {}

    last_versions_gentoo = {}
    last_versions_overlay = {}
    last_versions_upstream = {}

    if not fast:
        attrs = ['id', 'version', 'overlay', 'packaged', 'package_id']
        for version in Version.objects.all().values(*attrs):
            overlay, packaged = version['overlay'], version['packaged']
            package_id = version['package_id']

            _add_safe(n_versions, package_id)

            if not packaged:
                _add_last_ver(last_versions_upstream, version)
                continue
            if overlay == 'gentoo':
                _add_safe(n_packaged, package_id)
                _add_last_ver(last_versions_gentoo, version)
            else:
                _add_safe(n_overlay, package_id)
                _add_last_ver(last_versions_overlay, version)

    for package in package_queryset.select_related('herds', 'maintainers'):
        if not fast:
            package.n_versions = n_versions.get(package.id, 0)
            package.n_packaged = n_packaged.get(package.id, 0)
            package.n_overlay = n_overlay.get(package.id, 0)

            default = {'id': None}
            package.last_version_gentoo_id = last_versions_gentoo.get(
                package.id, default
            )['id']
            package.last_version_overlay_id = last_versions_overlay.get(
                package.id, default
            )['id']
            package.last_version_upstream_id = last_versions_upstream.get(
                package.id, default
            )['id']

            package.save()

        n_packages_gentoo = int(package.n_packaged == package.n_versions)
        n_packages_overlay = int(package.n_overlay and package.n_packaged \
                                 + package.n_overlay == package.n_versions)
        n_packages_outdated = int(package.n_packaged + package.n_overlay \
                                  < package.n_versions)

        def update_row(storage, key):
            storage[key].n_packages_gentoo += n_packages_gentoo
            storage[key].n_packages_overlay += n_packages_overlay
            storage[key].n_packages_outdated += n_packages_outdated

            storage[key].n_versions_gentoo += package.n_packaged
            storage[key].n_versions_overlay += package.n_overlay
            storage[key].n_versions_upstream += package.n_versions - \
                                                package.n_packaged - \
                                                package.n_overlay

        def update_log(storage, qs):
            for row in qs:
                update_row(storage, row['id'])

        if not nolog:
            update_log(herds, package.herds.all().values('id'))
            update_log(maintainers, package.maintainers.all().values('id'))
            update_row(categories, package.category)

            wlog.n_packages_gentoo += n_packages_gentoo
            wlog.n_packages_overlay += n_packages_overlay
            wlog.n_packages_outdated += n_packages_outdated

            wlog.n_versions_gentoo += package.n_packaged
            wlog.n_versions_overlay += package.n_overlay
            wlog.n_versions_upstream += package.n_versions - \
                                        package.n_packaged - \
                                        package.n_overlay

    if nolog:
        return

    for clog in categories.values():
        logger.info('+ [cl] %s', clog)
        charts.rrd_update('category-%s' % clog.category, now, clog)
        clog.save()

    for hlog in herds.values():
        logger.info('+ [hl] %s', hlog)
        charts.rrd_update('herd-%d' % hlog.herd.id, now, hlog)
        hlog.save()

    for mlog in maintainers.values():
        logger.info('+ [ml] %s', mlog)
        charts.rrd_update('maintainer-%d' % mlog.maintainer.id, now, mlog)
        mlog.save()

    charts.rrd_update('world', now, wlog)
    wlog.save()